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Meder M, Jelley H, Kocolas I, Al-Hamad D. Hypotonia and Poor Weight Gain in a 4-month-old Girl. Pediatr Rev 2024; 45:354-357. [PMID: 38821897 DOI: 10.1542/pir.2021-005379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 10/28/2022] [Accepted: 11/08/2022] [Indexed: 06/02/2024]
Affiliation(s)
- Michelle Meder
- University of Utah, Salt Lake City, UT
- Primary Children's Hospital, Salt Lake City, UT
| | - Hannah Jelley
- University of Utah, Salt Lake City, UT
- Primary Children's Hospital, Salt Lake City, UT
| | - Irene Kocolas
- University of Utah, Salt Lake City, UT
- Primary Children's Hospital, Salt Lake City, UT
| | - Dania Al-Hamad
- University of Utah, Salt Lake City, UT
- Primary Children's Hospital, Salt Lake City, UT
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Alsarraf F, Ali DS, Almonaei K, Al-Alwani H, Khan AA, Brandi ML. Hypophosphatasia: presentation and response to asfotase alfa. Osteoporos Int 2024; 35:717-725. [PMID: 37993691 DOI: 10.1007/s00198-023-06943-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Accepted: 10/04/2023] [Indexed: 11/24/2023]
Abstract
Hypophosphatasia (HPP) is a rare bone disease with limited scientific evidence on the tolerability and safety of its novel treatment, Asfotase Alfa (AA). We report 7 HPP patients' heterogenous presentations and the significant improvement in various clinical outcomes attained with AA shedding light on this highly effective and safe therapy. INTRODUCTION Hypophosphatasia (HPP) is a rare inherited metabolic bone disorder characterized by a deficiency in the tissue non-specific alkaline phosphatase (TNSALP) due to loss of function mutation in the ALPL gene. HPP is associated with impaired skeletal mineralization due to elevations in inorganic pyrophosphate and altered phosphate : pyrophosphate ratio. Asfotase alfa (AA) "enzyme replacement" was approved for treatment of HPP in 2015. We present 7 patients with HPP, 5 with pediatric-onset, and 2 with adult-onset, who have been treated with AA and describe the efficacy and safety in these patients. METHODS 7 patients (4 females, 3 males) aged 19-68 years with HPP were included in this study. Diagnosis of HPP was confirmed by DNA analysis. AA was administered in doses of 6mg/kg/week with a mean follow-up of 6 months (SD= 5). RESULTS Subjective improvement in muscle strength, muscle pain, walking ability, and walking distance with a reduction in the use of gait aids was seen "with AA in HPP patients." Muscle strength and pain improved by up to 70% from baseline as quantified subjectively by patients. Walking distance improved by up to 100%. Patients also reported improved cognition, mood, and energy levels, with up to 90% improvement in mood and 75% improvement in energy levels. 4 out of 6 patients first noted clinical signs of improvement after 3 months of being on therapy. 1 out of the 7 patients sustained a toe fracture 10 months from being on AA. AA was well-tolerated with injection site reactions being the most reported adverse effect. CONCLUSION HPP treatment with AA in individuals with both pediatric and adult-onset forms resulted in significant subjective improvement in musculoskeletal and cognitive manifestations in addition to patients' quality of life. The drug was well tolerated in 6 patients. 1 patient discontinued therapy because of minor adverse effects with myalgias.
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Affiliation(s)
- F Alsarraf
- Division of Endocrinology and Metabolism, McMaster University, Hamilton, Ontario, Canada.
| | - D S Ali
- Division of Endocrinology and Metabolism, McMaster University, Hamilton, Ontario, Canada
| | - K Almonaei
- Department of Endocrinology and Diabetes, Diabetes Treatment Center, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - H Al-Alwani
- Department of Medicine, University of Jeddah, Jeddah, Saudi Arabia
| | - A A Khan
- Division of Endocrinology and Metabolism, McMaster University, Hamilton, Ontario, Canada
| | - M L Brandi
- F.I.R.M.O. Italian Foundation for the Research on Bone Diseases, Florence, Italy
- Donatello Bone Clinic, Villa Donatello Hospital, Florence, Italy
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Zervou Z, Plooij R, van Velsen EFS, Timmermans RGM, Demirdas S, Zillikens MC. Impressive clinical improvement and disappearance of neuropathic pain in an adult patient with hypophosphatasia treated with asfotase alfa. Eur J Med Genet 2024; 68:104915. [PMID: 38325645 DOI: 10.1016/j.ejmg.2024.104915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 01/16/2024] [Accepted: 01/28/2024] [Indexed: 02/09/2024]
Abstract
Hypophosphatasia (HPP) is a rare disorder, resulting from loss-of-function variants of the ALPL gene encoding non-tissue specific alkaline phosphatase (TNSALP). Presentation varies largely, with increased severity usually occurring with earlier disease onset. Here we describe the clinical improvement of a 57-year-old woman with childhood onset HPP, after initiating treatment with asfotase alfa (Strensiq®). This was started because of the rapid and progressive radiological deterioration of bone structure after placement of nails in both upper legs for spontaneous atypical femur fracture (AFF) - like fractures. Initiation of treatment, not only resulted in stabilization of bone structure on X-rays, but within a few weeks there was a dramatic reduction of burning pain sensations in the lower legs, attributed in retrospect to neuropathic pain, and also almost complete disappearance of headaches. Additionally, unhealed metatarsal fractures finally healed after almost 10 years. Drug efficacy was further evaluated through -quality of life questionnaires and multiple tests conducted by the physiotherapist, and showed clear improvements. Within 3 months after starting asfotase alfa, the patient was able to carry out her daily tasks indoors without relying on a walker and even started electric bike rides for 20 km/day. In conclusion, treatment with asfotase alfa, halted rapid radiological bone deterioration after bilateral intramedullary femoral pen placement and strongly increased quality of life, marked by rapid disappearance of neuropathic pain, reduction in headaches and musculoskeletal pains, and enhanced muscle strength and mobility. The quick and almost complete disappearance of neuropathic pain and headache suggests a relation with disturbed levels of metabolites in HPP.
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Affiliation(s)
- Zografia Zervou
- Erasmus MC Bone Center, Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Roel Plooij
- Erasmus MC, Department of Rehabilitation Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Evert F S van Velsen
- Erasmus MC Bone Center, Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Remco G M Timmermans
- Erasmus MC, Department of Rehabilitation Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Serwet Demirdas
- Department of Clinical Genetics, Sophia Children's Hospital, Erasmus Medical Centre, Erasmus University, Rotterdam, the Netherlands
| | - M Carola Zillikens
- Erasmus MC Bone Center, Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands.
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Whyte MP, Zhang F, Mack KE, Wenkert D, Gottesman GS, Ericson KL, Cole JT, Coburn SP. Pyridoxine challenge reflects pediatric hypophosphatasia severity and thereby examines tissue-nonspecific alkaline phosphatase's role in vitamin B 6 metabolism. Bone 2024; 181:117033. [PMID: 38307176 DOI: 10.1016/j.bone.2024.117033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 12/28/2023] [Accepted: 01/30/2024] [Indexed: 02/04/2024]
Abstract
Alkaline phosphatase (ALP) is detected in most human tissues. However, ALP activity is routinely assayed using high concentrations of artificial colorimetric substrates in phosphate-free laboratory buffers at lethal pH. Hypophosphatasia (HPP) is the inborn-error-of-metabolism caused by loss-of-function mutation(s) of the ALPL gene that encodes the ALP isoenzyme expressed in bone, liver, kidney, and elsewhere and is therefore designated "tissue-nonspecific" ALP (TNSALP). Consequently, HPP harbors clues concerning the biological function of this phosphohydrolase that is anchored onto the surface of cells. The biochemical signature of HPP features low serum ALP activity (hypophosphatasemia) together with elevated plasma levels of three natural substrates of TNSALP: i) phosphoethanolamine (PEA), a component of the linkage apparatus that binds ALPs and other proteins to the plasma membrane surface; ii) inorganic pyrophosphate (PPi), an inhibitor of bone and tooth mineralization; and iii) pyridoxal 5'-phosphate (PLP), the principal circulating vitameric form of vitamin B6 (B6). Autosomal dominant and autosomal recessive inheritance involving several hundred ALPL mutations underlies the remarkably broad-ranging expressivity of HPP featuring tooth loss often with muscle weakness and rickets or osteomalacia. Thus, HPP associates the "bone" isoform of TNSALP with biomineralization, whereas the physiological role of the "liver", "kidney", and other isoforms of TNSALP remains uncertain. Herein, to examine HPP's broad-ranging severity and the function of TNSALP, we administered an oral challenge of pyridoxine (PN) hydrochloride to 116 children with HPP. We assayed both pre- and post-challenge serum ALP activity and plasma levels of PLP, the B6 degradation product pyridoxic acid (PA), and the B6 vitamer pyridoxal (PL) that can enter cells. Responses were validated by PN challenge of 14 healthy adults and 19 children with metabolic bone diseases other than HPP. HPP severity was assessed using our HPP clinical nosology and patient height Z-scores. PN challenge of all study groups did not alter serum ALP activity in our clinical laboratory. In HPP, both the post-challenge PLP level and the PLP increment correlated (Ps < 0.0001) with the clinical nosology and height Z-scores (Rs = +0.6009 and + 0.4886, and Rs = -0.4846 and - 0.5002, respectively). In contrast, the plasma levels and increments of PA and PL from the PN challenge became less pronounced with HPP severity. We discuss how our findings suggest extraskeletal TNSALP primarily conditioned the PN challenge responses, and explain why they caution against overzealous B6 supplementation of HPP.
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Affiliation(s)
- Michael P Whyte
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children-St Louis, St. Louis, MO 63110, USA; Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, MO 63110, USA.
| | - Fan Zhang
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children-St Louis, St. Louis, MO 63110, USA.
| | - Karen E Mack
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children-St Louis, St. Louis, MO 63110, USA
| | - Deborah Wenkert
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children-St Louis, St. Louis, MO 63110, USA.
| | - Gary S Gottesman
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children-St Louis, St. Louis, MO 63110, USA; Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, MO 63110, USA.
| | - Karen L Ericson
- Department of Chemistry and Biochemistry, Purdue University Fort Wayne, Fort Wayne, IN 46805, USA.
| | - Jeffrey T Cole
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children-St Louis, St. Louis, MO 63110, USA.
| | - Stephen P Coburn
- Department of Chemistry and Biochemistry, Purdue University Fort Wayne, Fort Wayne, IN 46805, USA.
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Galetaki DM, Merchant N, Dauber A. Novel therapies for growth disorders. Eur J Pediatr 2024; 183:1121-1128. [PMID: 37831302 DOI: 10.1007/s00431-023-05239-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/21/2023] [Accepted: 09/22/2023] [Indexed: 10/14/2023]
Abstract
As we continue to understand more about the complex mechanism of growth, a plethora of novel therapies have recently been developed that aim to address barriers and optimize efficacy. This review aims to explore these novel therapies and provide a succinct review based on the latest clinical studies in order to introduce clinicians to therapies that will soon constitute the future in the field of short stature. Conclusion: The review focuses on long-acting growth hormone formulations, a novel growth hormone oral secretagogue, novel treatments for children with achondroplasia, and targeted therapies for rare forms of skeletal dysplasias. What is Known: • Recombinant human growth hormone has been the mainstay of treatment for children with short stature for years. • Such therapy is not always effective based on the underlying diagnosis (e.g achondroplasia, Turner syndrome). Compliance with daily injections is challenging and can directly affect efficacy. What is New: • Recent development of long-acting growth hormone regimens and oral secretagogues can overcome some of these barriers, however several limitations need to be taken into consideration. • Newer therapies for achondroplasia, and other rare forms of skeletal dysplasias introduce us to a new era of targeted therapies for children with short stature. Clinicians ought to be aware of pitfalls and caveats before introducing these novel therapies to every day practice.
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Affiliation(s)
- Despoina M Galetaki
- Division of Endocrinology, Children's National Hospital, Washington, DC, USA
| | - Nadia Merchant
- Division of Endocrinology, Children's National Hospital, Washington, DC, USA
- Department of Pediatrics, George Washington School of Medicine, Washington, DC, USA
| | - Andrew Dauber
- Division of Endocrinology, Children's National Hospital, Washington, DC, USA.
- Department of Pediatrics, George Washington School of Medicine, Washington, DC, USA.
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Baroncelli GI, Carlucci G, Freri E, Giuca MR, Guarnieri V, Navarra G, Toschi B, Mora S. The diagnosis of hypophosphatasia in children as a multidisciplinary effort: an expert opinion. J Endocrinol Invest 2024; 47:739-747. [PMID: 37752373 PMCID: PMC10904512 DOI: 10.1007/s40618-023-02199-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 09/12/2023] [Indexed: 09/28/2023]
Abstract
Hypophosphatasia (HPP) is a rare genetic disorder in which pathogenic variants of the ALPL gene lead to a marked decrease of tissue non-specific alkaline phosphatase (TNSALP) activity. Although HPP is a systemic disorder, its clinical manifestations are more evident on bones, teeth, muscle and central nervous system. The clinical spectrum ranges from severe forms with extreme skeletal deformities, respiratory impairment, seizures, to very mild forms with onset in late adulthood and few clinical signs. The diagnosis can be suspected by measurement of TNSALP activity, but the insufficient awareness among health professionals and the lack of official guidelines are responsible for delayed diagnosis in children with HPP. The purpose of the current document is to provide an expert opinion directed at optimizing the diagnostic pathway of pediatric HPP. From April to December 2022, a multidisciplinary working group of 6 experts including two pediatric endocrinologists, a pediatric neurologist, a pediatric odontologist, a clinical geneticist, and a molecular biologist gathered in a series of periodic meetings to discuss the main issues related to the diagnosis of HPP in children and formalize an Expert Opinion statement. The experts agreed on a diagnostic trail that begins with the recognition of specific clinical signs, leading to biochemical analyses of TNSALP activity and vitamin B6 serum concentration. Very important are the neurological and dental manifestation of the disease that should be thoroughly investigated. The evaluation of TNSALP activity must consider sex and age variability and low activity must be persistent. Repeated blood measurements are thus necessary. The molecular analysis is then mandatory to confirm the diagnosis and for genetic counseling.
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Affiliation(s)
- G I Baroncelli
- Pediatric and Adolescent Endocrinology, Division of Pediatrics, Department of Obstetrics, Gynecology and Pediatrics, University Hospital, Pisa, Italy
| | - G Carlucci
- OPT S.P.A., Soluzioni Per Il Mondo Healthcare, Milan, Italy
| | - E Freri
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - M R Giuca
- Unit of Pediatric Dentistry, Department of Surgical Medical Molecular Pathology and Critical Area, Dental and Oral Surgery Clinic, University of Pisa, Pisa, Italy
| | - V Guarnieri
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, Foggia, Italy
| | - G Navarra
- OPT S.P.A., Soluzioni Per Il Mondo Healthcare, Milan, Italy
| | - B Toschi
- Section of Medical Genetics, Department of Medical and Oncological Area, University Hospital, Pisa, Italy
| | - S Mora
- Laboratory of Pediatric Endocrinology, Department of Pediatrics, IRCCS San Raffaele Hospital, Milan, Italy.
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7
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Raimann A, Misof BM, Fratzl P, Fratzl-Zelman N. Bone Material Properties in Bone Diseases Affecting Children. Curr Osteoporos Rep 2023; 21:787-805. [PMID: 37897675 DOI: 10.1007/s11914-023-00822-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/12/2023] [Indexed: 10/30/2023]
Abstract
PURPOSE OF REVIEW Metabolic and genetic bone disorders affect not only bone mass but often also the bone material, including degree of mineralization, matrix organization, and lacunar porosity. The quality of juvenile bone is moreover highly influenced by skeletal growth. This review aims to provide a compact summary of the present knowledge on the complex interplay between bone modeling and remodeling during skeletal growth and to alert the reader to the complexity of bone tissue characteristics in children with bone disorders. RECENT FINDINGS We describe cellular events together with the characteristics of the different tissues and organic matrix organization (cartilage, woven and lamellar bone) occurring during linear growth. Subsequently, we present typical alterations thereof in disorders leading to over-mineralized bone matrix compared to those associated with low or normal mineral content based on bone biopsy studies. Growth spurts or growth retardation might amplify or mask disease-related alterations in bone material, which makes the interpretation of bone tissue findings in children complex and challenging.
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Affiliation(s)
- Adalbert Raimann
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Pulmonology, Allergology and Endocrinology, Medical University of Vienna, Vienna, Austria
- Vienna Bone and Growth Center, Vienna, Austria
| | - Barbara M Misof
- Vienna Bone and Growth Center, Vienna, Austria
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Center Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | - Peter Fratzl
- Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, Research Campus Golm, Potsdam, Germany
| | - Nadja Fratzl-Zelman
- Vienna Bone and Growth Center, Vienna, Austria.
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Center Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria.
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Hidaka N, Murata H, Tachikawa K, Osaki K, Sekiyama T, Kinoshita Y, Kato H, Hoshino Y, Kimura S, Sunouchi T, Watanabe S, Nangaku M, Makita N, Michigami T, Ito N. The Effect of Asfotase Alfa on Plasma and Urine Pyrophosphate Levels and Pseudofractures in a Patient With Adult-Onset Hypophosphatasia. JBMR Plus 2023; 7:e10842. [PMID: 38130758 PMCID: PMC10731098 DOI: 10.1002/jbm4.10842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/07/2023] [Accepted: 10/25/2023] [Indexed: 12/23/2023] Open
Abstract
Hypophosphatasia (HPP) is an inherited disease caused by variants of the ALPL gene encoding tissue-nonspecific alkaline phosphatase. Adult-onset HPP (adult HPP), known as a mild form of HPP, develops symptoms involving osteomalacia after the age of 18 years. Asfotase alfa (AA) is a modulated recombinant human alkaline phosphatase (ALP) that has been established as a first-line therapy for severe forms of HPP, such as perinatal and infantile forms. We described a 64-year-old female who presented with pseudofractures in bilateral femur diaphyses and impaired mobility. Low serum ALP activity and a high concentration of urine phosphoethanolamine indicated the diagnosis of HPP, which was confirmed by the identification of a homozygous variant in the ALPL gene (c.319G > A; p.Val107Ile). An in vitro transfection experiment to measure the ALP activity of this novel variant protein was performed, resulting in 40% of the residual enzymatic activity compared with the wild type. AA was initiated to facilitate the union of pseudofracture and to improve mobility. After 6 months, radiographic images revealed the disappearance of fracture lines, and improvement of ambulatory ability was confirmed by the 6-minute walk test (525 to 606 m). The EQ-5D-5L index was also improved (0.757 to 0.895). Within a follow-up period, the levels of urine pyrophosphate corrected by urine creatinine (uPPi/Cre) declined in parallel with the level of plasma PPi (plasma PPi: 6.34 to 1.04 μM, uPPi/Cre: 226.8 to 75.4 nmol/mg). The beneficial effect of AA on pseudofracture healing in adult HPP was presented, although the application of AA should be restricted to patients exhibiting relatively severe manifestations. In addition, a novel pathogenic variant of the ALPL gene was identified with the supportive result of functional analysis. Furthermore, when monitoring patients with HPP treated with AA, uPPi/Cre might be a convenient substitute for plasma PPi, which requires immediate filtration after blood sampling. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Naoko Hidaka
- Division of Nephrology and EndocrinologyThe University of Tokyo HospitalTokyoJapan
- Osteoporosis CenterThe University of Tokyo HospitalTokyoJapan
| | - Hiroaki Murata
- Department of Orthopaedic Surgery, Panasonic Health Insurance OrganizationMatsushita Memorial HospitalOsakaJapan
| | - Kanako Tachikawa
- Department of Bone and Mineral Research, Research InstituteOsaka Women's and Children's HospitalOsakaJapan
| | - Keiichi Osaki
- Department of Rehabilitation, Panasonic Health Insurance OrganizationMatsushita Memorial HospitalOsakaJapan
| | - Takashi Sekiyama
- Department of Rehabilitation, Panasonic Health Insurance OrganizationMatsushita Memorial HospitalOsakaJapan
| | - Yuka Kinoshita
- Division of Nephrology and EndocrinologyThe University of Tokyo HospitalTokyoJapan
- Osteoporosis CenterThe University of Tokyo HospitalTokyoJapan
| | - Hajime Kato
- Division of Nephrology and EndocrinologyThe University of Tokyo HospitalTokyoJapan
- Osteoporosis CenterThe University of Tokyo HospitalTokyoJapan
| | - Yoshitomo Hoshino
- Division of Nephrology and EndocrinologyThe University of Tokyo HospitalTokyoJapan
- Osteoporosis CenterThe University of Tokyo HospitalTokyoJapan
| | - Soichiro Kimura
- Division of Nephrology and EndocrinologyThe University of Tokyo HospitalTokyoJapan
- Osteoporosis CenterThe University of Tokyo HospitalTokyoJapan
| | - Takashi Sunouchi
- Division of Nephrology and EndocrinologyThe University of Tokyo HospitalTokyoJapan
- Osteoporosis CenterThe University of Tokyo HospitalTokyoJapan
| | - So Watanabe
- Osteoporosis CenterThe University of Tokyo HospitalTokyoJapan
- Department of Geriatric Medicine, Graduate School of MedicineThe University of TokyoTokyoJapan
| | - Masaomi Nangaku
- Division of Nephrology and EndocrinologyThe University of Tokyo HospitalTokyoJapan
| | - Noriko Makita
- Division of Nephrology and EndocrinologyThe University of Tokyo HospitalTokyoJapan
- Osteoporosis CenterThe University of Tokyo HospitalTokyoJapan
| | - Toshimi Michigami
- Department of Bone and Mineral Research, Research InstituteOsaka Women's and Children's HospitalOsakaJapan
| | - Nobuaki Ito
- Division of Nephrology and EndocrinologyThe University of Tokyo HospitalTokyoJapan
- Osteoporosis CenterThe University of Tokyo HospitalTokyoJapan
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Fratzl-Zelman N, Linglart A, Bin K, Rauch F, Blouin S, Coutant R, Donzeau A. Combination of osteogenesis imperfecta and hypophosphatasia in three children with multiple fractures, low bone mass and severe osteomalacia, a challenge for therapeutic management. Eur J Med Genet 2023; 66:104856. [PMID: 37758163 DOI: 10.1016/j.ejmg.2023.104856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 09/05/2023] [Accepted: 09/24/2023] [Indexed: 10/03/2023]
Abstract
Osteogenesis imperfecta (OI) and hypophosphatasia (HPP) are rare skeletal disorders caused by mutations in the genes encoding collagen type I (COL1A, COL1A2) and tissue-non-specific isoenzyme of alkaline phosphatase (ALPL), respectively. Both conditions result in skeletal deformities and bone fragility although bone tissue abnormalities differ considerably. Children with OI have low bone mass and hypermineralized matrix, whereas HPP children develop rickets and osteomalacia. We report a family, father and three children, affected with growth retardation, low bone mass and recurrent fractures. None of them had rickets, blue sclera or dentinogenesis imperfecta. ALP serum levels were low and genetics revealed in the four probands heterozygous pathogenic mutations in COL1A2 c.838G > A (p.Gly280Ser) and in ALPL c.1333T > C (p.Ser445Pro). After multidisciplinary meeting, a diagnostic transiliac bone biopsy was indicated for each sibling for therapeutic decision. Bone histology and histomorphometry, as compared to reference values of children with OI type I as well as, to a control pediatric patient harboring the same COL1A2 mutation, revealed similarly decreased trabecular bone volume, increased osteocyte lacunae, but additionally severe osteomalacia. Quantitative backscattered electron imaging demonstrated that bone matrix mineralization was not as decreased as expected for osteomalacia. In summary, we observed within each biopsy samples classical features of OI and classical features of HPP. The apparent nearly normal bone mineralization density distribution results presumably from divergent effects of OI and HPP on matrix mineralization. A combination therapy was initiated with ALP enzyme-replacement and one month later with bisphosphonates. The ongoing treatment led to improved skeletal growth, increased BMD and markedly reduced fracture incidence.
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Affiliation(s)
- Nadja Fratzl-Zelman
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Med. Department Hanusch Hospital, Vienna, Austria; Vienna Bone and Growth Center, Vienna, Austria.
| | - Agnès Linglart
- AP-HP, Paris Saclay University, INSERM, Reference Center for Rare Diseases of the Calcium and Phosphate Metabolism, Platform of Expertise for Rare Diseases, OSCAR Filière, EndoERN and BOND ERN Center, Endocrinology and Diabetes for Children, Bicêtre Paris Saclay Hospital, France
| | - Kim Bin
- Pediatric Orthopedic Surgery Angers University Hospital, Angers, France
| | - Frank Rauch
- Shriners Hospital for Children, Canada, Montreal, QC, Canada
| | - Stéphane Blouin
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Med. Department Hanusch Hospital, Vienna, Austria; Vienna Bone and Growth Center, Vienna, Austria
| | - Régis Coutant
- AP-HP, Paris Saclay University, INSERM, Reference Center for Rare Diseases of the Calcium and Phosphate Metabolism, Platform of Expertise for Rare Diseases, OSCAR Filière, EndoERN and BOND ERN Center, Endocrinology and Diabetes for Children, Bicêtre Paris Saclay Hospital, France; Department of Pediatric Endocrinology and Diabetology, Competence Center for Rare Diseases of the Calcium and Phosphate Metabolism, Angers University Hospital, Angers, France
| | - Aurélie Donzeau
- Department of Pediatric Endocrinology and Diabetology, Competence Center for Rare Diseases of the Calcium and Phosphate Metabolism, Angers University Hospital, Angers, France
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10
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Kim EN, Leung KL, Wong A, McGregor J, Skolnick GB, Patel KB, Gosman AA. Management of Craniosynostosis in Lethal Perinatal Hypophosphatasia. J Craniofac Surg 2023; 34:2422-2425. [PMID: 37610006 DOI: 10.1097/scs.0000000000009641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 06/11/2023] [Indexed: 08/24/2023] Open
Abstract
Although perinatal lethal hypophosphatasia (HPP) was once a disease with a universally poor prognosis, it has now become a rare but treatable condition with the advent of enzyme replacement therapy with asfotase alfa. As a result, a greater population of patients with perinatal HPP are presenting with abnormal head shape and craniosynostosis. The authors present here 3 cases of perinatal lethal HPP, 1 treated with traditional open cranial vault remodeling and 2 treated utilizing distraction osteogenesis techniques. All patients demonstrated outcomes comparable to those previously reported with traditional observation or open cranial vault repair. Thorough consideration and discussion between the surgical team and patient's family is needed to determine a treatment plan that best addresses the goals of patient and family in light of recent advances in medical treatment in this rare patient population in which surgical interventions were previously nearly impossible. This article further supports the safety and efficacy of surgical intervention and explores the utility of distraction osteogenesis to address craniosynostosis in this patient population.
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Affiliation(s)
- Erinn N Kim
- Division of Plastic Surgery, University of California San Diego, San Diego, CA
| | - Karen L Leung
- Division of Plastic Surgery, University of California San Diego, San Diego, CA
| | - Alvin Wong
- Division of Plastic Surgery, Virginia Commonwealth University, Richmond, VA
| | - Jyoti McGregor
- Section of Plastic Surgery, University of Mannitoba, Winnipeg, MB, Canada
| | - Gary B Skolnick
- Division of Plastic Surgery, Washington University, St. Louis, MO
| | - Kamlesh B Patel
- Division of Plastic Surgery, Washington University, St. Louis, MO
| | - Amanda A Gosman
- Division of Plastic Surgery, University of California San Diego, San Diego, CA
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11
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Nair SC, Al-Dahmani KM. The Development of a Clinical Research Model Complementing Medical Residency and the Assessment of Research Productivity. Cureus 2023; 15:e48684. [PMID: 38090409 PMCID: PMC10714375 DOI: 10.7759/cureus.48684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2023] [Indexed: 01/24/2024] Open
Abstract
BACKGROUND AND OBJECTIVE Despite modern healthcare infrastructure, there is a paucity of information about the clinical research framework supporting healthcare in the United Arab Emirates (UAE). Therefore, this study aimed to assess research performance productivity, and the clinical research framework, complementing medical residency, at the nation's hub for clinical research. METHODS A cross-sectional retrospective review of records from the research database of the institution was conducted to assess productivity, and framework development, and data analyzed. RESULTS The migration of global healthcare providers, and the pharmaceutical industry offices, the adoption of the International Conference on Harmonization (ICH) guidelines, and electronic medical records established a research culture. Following the development of the governance framework, a total of 1,328 research projects were submitted to the ethics committee until 2023. Approximately 63% of the total studies were of minimal risk, followed by industry-sponsored clinical trials (4.9%, 58/1,163), and prospective interventional studies (3.5%, 39/1,163). Almost half (48.3%, 28/58) of the total industry-sponsored clinical trials were phase II and phase III. The number of peer-reviewed indexed publications, a measure of research productivity, indicated that the periods between 2011 and 2015, 2016 and 2020, and 2021 and 2023 witnessed a 3.8-, 9.3-, and 7.9-fold increase compared to the baseline period (1995-2005). The implementation of the Focus on International Research Strategy, Teaching, Evaluation, and Mentoring (FIRSTEM) strategy, to accommodate mandatory research activity requirements for residents by the physician licensing boards, observed substantial increases in output. The number of international peer-reviewed indexed publications/resident projects doubled from 10.8% (2010-2015) to 24% (2016-2020) and reached 40.1% in 2023. CONCLUSION This is the first research governance model established in the UAE, a country with an increasing prevalence of diabetes, and cardiovascular and genetic diseases. The model indicates that the medical trainees differentiate the best research evidence in making decisions about the clinical care of patients. The study outcomes may potentially be useful for other countries in developing a clinical research framework.
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Affiliation(s)
- Satish C Nair
- Medical Research, Johns Hopkins Medicine International, Tawam Hospital, Al Ain, ARE
| | - Khaled M Al-Dahmani
- Diabetes and Endocrinology, Johns Hopkins Medicine International, Tawam Hospital, Al Ain, ARE
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Seefried L, Genest F, Petryk A, Veith M. Effects of asfotase alfa in adults with pediatric-onset hypophosphatasia over 24 months of treatment. Bone 2023; 175:116856. [PMID: 37481150 DOI: 10.1016/j.bone.2023.116856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 06/30/2023] [Accepted: 07/19/2023] [Indexed: 07/24/2023]
Abstract
BACKGROUND Hypophosphatasia (HPP) is a rare, heritable metabolic disorder caused by deficient activity of tissue-nonspecific alkaline phosphatase (TNSALP). Asfotase alfa (AA) is a human recombinant TNSALP that promotes bone mineralization and is approved to treat eligible patients with HPP. METHODS This prospective single-center observational study evaluated AA in adults with pediatric-onset HPP over 2 years of treatment (ClinicalTrials.govNCT03418389). Primary outcomes evaluated physical function; secondary outcomes assessed quality of life (QoL) and pain. RESULTS The study included 17 females and 5 males (mean age: 48.7 years). Median distance walked in the 6-Minute Walk Test increased significantly from baseline to 12 months (P = 0.034) and results were sustained. Median Timed Up and Go test time significantly decreased from baseline at 12 (P = 0.003) and 24 months (P = 0.005), as did the median chair rise time test at 12 (P = 0.003) and 24 months (P < 0.002). The change from baseline in usual gait speed was significant at 12 (P = 0.003) and 24 months (P = 0.015). Mean dominant and nondominant hand grip strength improved at 24 months (P = 0.029 and P = 0.019, respectively). Median Short Form 36 Physical Component Summary scores significantly improved from baseline at 12 (P = 0.012) and 24 (P = 0.005) months, and median Lower Extremity Functional Scale scores improved from baseline at 12 (P = 0.001) and 24 (P = 0.002) months. No significant change was noted in pain level at these timepoints. While injection site reactions occurred in 86.4 % of the participants, there were no severe side effects or safety findings. CONCLUSIONS Adults with pediatric-onset HPP treated with AA experienced marked improvement in functional and QoL outcomes that were observed as early as within 3 months of initial treatment and were sustained over 24 months.
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Affiliation(s)
- Lothar Seefried
- Osteology Department, Julius-Maximilians-Universität Würzburg, Würzburg, Germany.
| | - Franca Genest
- Osteology Department, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Anna Petryk
- Department of Global Medical Affairs, Alexion, AstraZeneca Rare Disease, Boston, MA, USA
| | - Marina Veith
- Osteology Department, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
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Pontán F, Hauta-Alus H, Valkama S, Rosendahl J, Enlund-Cerullo M, Andersson S, Mäkitie O, Holmlund-Suila E. Alkaline Phosphatase and Hyperphosphatasemia in Vitamin D Trial in Healthy Infants and Toddlers. J Clin Endocrinol Metab 2023; 108:e1082-e1091. [PMID: 37061810 DOI: 10.1210/clinem/dgad208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/16/2023] [Accepted: 04/12/2023] [Indexed: 04/17/2023]
Abstract
CONTEXT Childhood hyperphosphatasemia is usually transient and may be associated with infections. It remains less well known how hyperphosphatasemia is related to growth and bone mineralization. OBJECTIVE We explored alkaline phosphatase (ALP) concentrations and prevalence of hyperphosphatasemia, and their association with vitamin D, growth, infections, and bone parameters in healthy children. METHODS The study was a secondary analysis of a vitamin D intervention trial. Participants received vitamin D3 10 or 30 µg daily from age 2 weeks to 2 years. Children with data on ALP at 12 and/or 24 months (n = 813, girls 51.9%) were included. Anthropometrics and bone parameters were measured at 12 and 24 months. Infections were recorded prospectively by the parents. RESULTS Boys had higher ALP than girls at 12 months (median [IQR] 287 [241-345] U/L vs 266 [218-341] U/L; P = .02). At 24 months concentrations were lower than at 12 months (240 [202-284]; P < .001) but without sex difference. The prevalence of hyperphosphatasemia (ALP > 1000 U/L) at 12 months was 5.3% and at 24 months 0.6%. Body size, growth rate, and bone mineral content associated positively with ALP, while vitamin D intervention had no effect. Infants with hyperphosphatasemia were smaller than infants with ALP ≤ 1000 U/L. Hyperphosphatasemia was not associated with previous infections. CONCLUSION Approximately 5% of infants had hyperphosphatasemia at 12 months, but <1% at 24 months. ALP concentrations and hyperphosphatasemia were associated with sex, anthropometry, and bone mineralization. Infections did not contribute to hyperphosphatasemia.
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Affiliation(s)
- Freja Pontán
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland
| | - Helena Hauta-Alus
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
- Population Health Unit, Finnish Institute for Health and Welfare (THL), 00300 Helsinki, Finland
- Clinical Medicine Research Unit, Medical Research Center Oulu, Oulu University Hospital and University of Oulu, 90014 Oulu, Finland
| | - Saara Valkama
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
| | - Jenni Rosendahl
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
| | - Maria Enlund-Cerullo
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
- Institute of Genetics, Folkhälsan Research Center, 00290 Helsinki, Finland
| | - Sture Andersson
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland
| | - Outi Mäkitie
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
- Institute of Genetics, Folkhälsan Research Center, 00290 Helsinki, Finland
- Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 77 Stockholm, Sweden
- Department of Clinical Genetics, Karolinska University Hospital, 171 77 Stockholm, Sweden
| | - Elisa Holmlund-Suila
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
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Yu Y, Rong K, Yao D, Zhang Q, Cao X, Rao B, Xia Y, Lu Y, Shen Y, Yao Y, Xu H, Ma P, Cao Y, Qin A. The structural pathology for hypophosphatasia caused by malfunctional tissue non-specific alkaline phosphatase. Nat Commun 2023; 14:4048. [PMID: 37422472 PMCID: PMC10329691 DOI: 10.1038/s41467-023-39833-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 06/30/2023] [Indexed: 07/10/2023] Open
Abstract
Hypophosphatasia (HPP) is a metabolic bone disease that manifests as developmental abnormalities in bone and dental tissues. HPP patients exhibit hypo-mineralization and osteopenia due to the deficiency or malfunction of tissue non-specific alkaline phosphatase (TNAP), which catalyzes the hydrolysis of phosphate-containing molecules outside the cells, promoting the deposition of hydroxyapatite in the extracellular matrix. Despite the identification of hundreds of pathogenic TNAP mutations, the detailed molecular pathology of HPP remains unclear. Here, to address this issue, we determine the crystal structures of human TNAP at near-atomic resolution and map the major pathogenic mutations onto the structure. Our study reveals an unexpected octameric architecture for TNAP, which is generated by the tetramerization of dimeric TNAPs, potentially stabilizing the TNAPs in the extracellular environments. Moreover, we use cryo-electron microscopy to demonstrate that the TNAP agonist antibody (JTALP001) forms a stable complex with TNAP by binding to the octameric interface. The administration of JTALP001 enhances osteoblast mineralization and promoted recombinant TNAP-rescued mineralization in TNAP knockout osteoblasts. Our findings elucidate the structural pathology of HPP and highlight the therapeutic potential of the TNAP agonist antibody for osteoblast-associated bone disorders.
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Affiliation(s)
- Yating Yu
- Department of Orthopedics, Shanghai Key Laboratory of Orthopedics Implant, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
- Institute of Precision Medicine, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 115 Jinzun Road, Shanghai, 200125, China
| | - Kewei Rong
- Department of Orthopedics, Shanghai Key Laboratory of Orthopedics Implant, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
| | - Deqiang Yao
- State Key Laboratory of Oncogenes and Related Genes, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Qing Zhang
- Department of Orthopedics, Shanghai Key Laboratory of Orthopedics Implant, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
- Institute of Precision Medicine, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 115 Jinzun Road, Shanghai, 200125, China
| | - Xiankun Cao
- Department of Orthopedics, Shanghai Key Laboratory of Orthopedics Implant, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
| | - Bing Rao
- Department of Orthopedics, Shanghai Key Laboratory of Orthopedics Implant, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
- Institute of Precision Medicine, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 115 Jinzun Road, Shanghai, 200125, China
| | - Ying Xia
- Institute of Precision Medicine, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 115 Jinzun Road, Shanghai, 200125, China
| | - Yi Lu
- Institute of Precision Medicine, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 115 Jinzun Road, Shanghai, 200125, China
| | - Yafeng Shen
- Institute of Precision Medicine, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 115 Jinzun Road, Shanghai, 200125, China
| | - Ying Yao
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, 201210, China
| | - Hongtao Xu
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, 201210, China
| | - Peixiang Ma
- Department of Orthopedics, Shanghai Key Laboratory of Orthopedics Implant, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China.
| | - Yu Cao
- Department of Orthopedics, Shanghai Key Laboratory of Orthopedics Implant, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China.
- Institute of Precision Medicine, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 115 Jinzun Road, Shanghai, 200125, China.
| | - An Qin
- Department of Orthopedics, Shanghai Key Laboratory of Orthopedics Implant, the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China.
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15
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Reis FS, Lazaretti-Castro M. Hypophosphatasia: from birth to adulthood. ARCHIVES OF ENDOCRINOLOGY AND METABOLISM 2023; 67:e000626. [PMID: 37249457 PMCID: PMC10665056 DOI: 10.20945/2359-3997000000626] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 12/12/2022] [Indexed: 05/31/2023]
Abstract
Hypophosphatasia (HPP) is an inherited disease caused by a low activity of tissue-nonspecific alkaline phosphatase, a hydrolase that removes phosphate groups from many molecules. Decreased alkaline phosphatase activity leads to the accumulation of three main metabolites, i.e., pyridoxal 5´-phosphate (PLP), inorganic pyrophosphate (PPi), and phosphoethanolamine. Impairment in PLP dephosphorylation induces seizures, while PPi accumulation inhibits bone mineralization. Clinically, HPP has a wide spectrum of presentations, ranging from neonatal death to an apparent lack of symptoms. This disease is classified into six subtypes according to the age at onset of first signs or symptoms. The clinical manifestations of the disease include rickets-like bone changes, bone demineralization, fragility fractures, reduced muscular strength, chest deformity, pulmonary hypoplasia, nephrolithiasis, nephrocalcinosis, and chondrocalcinosis. Treatment of HPP consists of enzyme replacement therapy. Before this therapy was approved, treatment was palliative and associated with high morbidity and mortality. Asfotase alfa has changed the prognosis of the disease by reducing bone deformity and improving bone mineralization, lung function, and muscle weakness, among other benefits. In adults, teriparatide and anti-sclerostin antibody have been used off-label in selected cases, demonstrating benefit in accelerating fracture healing and in concomitant treatment of osteoporosis. This review summarizes the main aspects of HPP and identifies the particularities of the disease in adult patients.
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Affiliation(s)
- Fernanda Salles Reis
- Departamento de Medicina, Disciplina de Endocrinologia, Universidade Federal de São Paulo (Unifesp), São Paulo, Brasil
| | - Marise Lazaretti-Castro
- Departamento de Medicina, Disciplina de Endocrinologia, Universidade Federal de São Paulo (Unifesp), São Paulo, Brasil,
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16
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Smart G, Jensen ED, Poirier BF, Sethi S. The impact of enzyme replacement therapy on the oral health manifestations of hypophosphatasia among children: a scoping review. Eur Arch Paediatr Dent 2023:10.1007/s40368-023-00796-0. [PMID: 37036643 DOI: 10.1007/s40368-023-00796-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 03/22/2023] [Indexed: 04/11/2023]
Abstract
PURPOSE A scoping review to describe the use of enzyme replacement therapy (ERT) in the form of asfotase alfa to decrease the severity of oral manifestations in children with hypophosphatasia (HPP). METHODS Six databases were searched using keywords and index terms related to "hypophosphatasia," "children," and "enzyme replacement therapy." Duplicates were removed and two independent reviewers screened the titles and abstracts to identify articles for full-text review. Extracted data was summarised narratively. RESULTS The systematic search identified 3548 articles, with 171 suitable for full-text review and a final 22 that met inclusion criteria. Enzyme replacement therapy generally resulted in a reduction in the presence and severity of oral manifestations of HPP. However, numerous studies failed to report specific details regarding the nature of oral health outcomes and there were reported cases of further loss of primary teeth. CONCLUSIONS The available evidence suggests that that ERT in the form of asfotase alfa for HPP in infants and young children leads to improved oral health outcomes. It is recommended that the outcomes are improved with earlier initiation of ERT. Further, well-designed clinical research is required to assess oral health improvements and decreased morbidity associated with the early loss of teeth.
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Affiliation(s)
- G Smart
- Department of Paediatric Dentistry, Women's and Children's Hospital, 72 King William Road, North Adelaide, SA, 5006, Australia.
| | - E D Jensen
- Department of Paediatric Dentistry, Women's and Children's Hospital, 72 King William Road, North Adelaide, SA, 5006, Australia
- Adelaide Dental School, The University of Adelaide, Adelaide, SA, Australia
| | - B F Poirier
- Adelaide Dental School, The University of Adelaide, Adelaide, SA, Australia
| | - S Sethi
- Adelaide Dental School, The University of Adelaide, Adelaide, SA, Australia
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17
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Riancho JA. Diagnostic Approach to Patients with Low Serum Alkaline Phosphatase. Calcif Tissue Int 2023; 112:289-296. [PMID: 36348061 DOI: 10.1007/s00223-022-01039-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 10/26/2022] [Indexed: 11/09/2022]
Abstract
Increased serum levels of alkaline phosphatase (ALP) are widely recognized as a biochemical marker of many disorders affecting the liver or bone. However, the approach for patients with low ALP phosphatase is not well-established. Low serum ALP is an epiphenomenon of many severe acute injuries and diseases. Persistently low serum ALP may be secondary to drug therapy (including antiresorptives) or a variety of acquired disorders, such as malnutrition, vitamin and mineral deficiencies, endocrine disorders, etc. Hypophosphatasia, due to pathogenic variants of the ALPL gene, which encodes tissue non-specific ALP, is the most common genetic cause of low serum ALP. Marked bone hypomineralization is frequent in severe pediatric-onset cases. However, adult forms of hypophosphatasia usually present with milder manifestations, such as skeletal pain, chondrocalcinosis, calcific periarthritis, dental problems, and stress fractures. The diagnostic approach to these patients is discussed. Measuring several ALP substrates, such as pyrophosphate, pyridoxal phosphate, or phosphoethanolamine, may help to establish enzyme deficiency. Gene analysis showing a pathogenic variant in ALPL may confirm the diagnosis. However, a substantial proportion of patients show normal results after sequencing ALPL exons. It is still unknown if those patients carry unidentified mutations in regulatory regions of ALPL, epigenetic changes, or abnormalities in other genes.
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Affiliation(s)
- Jose A Riancho
- Departamento de Medicina y Psiquiatría, Universidad de Cantabria, Servicio de Medicina Interna, Hospital UM Valdecilla-IDIVAL, Av Valdecilla sn, 39008, Santander, Spain.
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18
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Wölfel EM, von Kroge S, Matthies L, Koehne T, Petz K, Beikler T, Schmid-Herrmann CU, Kahl-Nieke B, Tsiakas K, Santer R, Muschol NM, Herrmann J, Busse B, Amling M, Rolvien T, Jandl NM, Barvencik F. Effects of Infantile Hypophosphatasia on Human Dental Tissue. Calcif Tissue Int 2023; 112:308-319. [PMID: 36414794 PMCID: PMC9968273 DOI: 10.1007/s00223-022-01041-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 11/02/2022] [Indexed: 11/23/2022]
Abstract
Hypophosphatasia (HPP) is an inherited, systemic disorder, caused by loss-of-function variants of the ALPL gene encoding the enzyme tissue non-specific alkaline phosphatase (TNSALP). HPP is characterized by low serum TNSALP concentrations associated with defective bone mineralization and increased fracture risk. Dental manifestations have been reported as the exclusive feature (odontohypophosphatasia) and in combination with skeletal complications. Enzyme replacement therapy (asfotase alfa) has been shown to improve respiratory insufficiency and skeletal complications in HPP patients, while its effects on dental status have been understudied to date. In this study, quantitative backscattered electron imaging (qBEI) and histological analysis were performed on teeth from two patients with infantile HPP before and during asfotase alfa treatment and compared to matched healthy control teeth. qBEI and histological methods revealed varying mineralization patterns in cementum and dentin with lower mineralization in HPP. Furthermore, a significantly higher repair cementum thickness was observed in HPP compared to control teeth. Comparison before and during treatment showed minor improvements in mineralization and histological parameters in the patient when normalized to matched control teeth. HPP induces heterogeneous effects on mineralization and morphology of the dental status. Short treatment with asfotase alfa slightly affects mineralization in cementum and dentin. Despite HPP being a rare disease, its mild form occurs at higher prevalence. This study is of high clinical relevance as it expands our knowledge of HPP and dental involvement. Furthermore, it contributes to the understanding of dental tissue treatment, which has hardly been studied so far.
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Affiliation(s)
- Eva Maria Wölfel
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany
- Interdisciplinary Competence Center for Interface Research (ICCIR), Lottestr. 55A, Hamburg, Germany
| | - Simon von Kroge
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany
| | - Levi Matthies
- Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Till Koehne
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany
- Department of Orthodontics, Center for Dental and Oral Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Karin Petz
- Department of Periodontics, Preventive and Restorative Dentistry, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Thomas Beikler
- Department of Periodontics, Preventive and Restorative Dentistry, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Carmen Ulrike Schmid-Herrmann
- Department of Orthodontics, Center for Dental and Oral Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Bärbel Kahl-Nieke
- Department of Orthodontics, Center for Dental and Oral Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Konstantinos Tsiakas
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - René Santer
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Nicole Maria Muschol
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Jochen Herrmann
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, Section of Pediatric Radiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Björn Busse
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany
- Interdisciplinary Competence Center for Interface Research (ICCIR), Lottestr. 55A, Hamburg, Germany
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany
| | - Tim Rolvien
- Division of Orthopaedics, Department of Trauma and Orthopaedic Surgery, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Nico Maximilian Jandl
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany
- Division of Orthopaedics, Department of Trauma and Orthopaedic Surgery, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Florian Barvencik
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany.
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Kim I, Noh ES, Kim MS, Jang JH, Jeon TY, Choi HW, Cho SY. Six-year clinical outcomes of enzyme replacement therapy for perinatal lethal and infantile hypophosphatasia in Korea: Two case reports. Medicine (Baltimore) 2023; 102:e32800. [PMID: 36820543 PMCID: PMC9907957 DOI: 10.1097/md.0000000000032800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
INTRODUCTION Hypophosphatasia (HPP) is a genetic disease caused by loss-of-function mutations in ALPL, which encodes tissue-nonspecific alkaline phosphatase (ALP). Early diagnosis and treatment of perinatal and infantile HPP are important because of their high mortality rates. Enzyme replacement therapy (ERT) using human recombinant tissue-nonspecific ALP asfotase alfa was introduced in Korea in 2016. We report the first experience of ERT over 6 years for perinatal lethal and infantile HPP in Korea. PATIENT CONCERNS The first patient was a 6-week-old Korean boy with a failure to thrive. The second patient was an 8-day-old Korean-Uzbek body with generalized tonic-clonic seizure with cyanosis. DIAGNOSES HPP was suspected in both patients because of the very low level of ALP activity and rachitic findings on radiographs, and the disease was confirmed by Sanger sequencing of the ALPL gene. INTERVENTION The first patient with infantile HPP started ERT at 21 months of age and the second patient with perinatal HPP started ERT at 30 days of age. Both patients received asfotase alfa (2 mg/kg 3 times per week subcutaneously, adjusted to 3 mg/kg 3 times per week if required) for 6 years. OUTCOMES After 6 years of ERT, radiographic findings and growth standard deviation scores improved in both patients. The second patient showed no evidence of rickets after 3 years of ERT. Mechanical respiratory support and supplemental oxygen were not required after 4.5 years of treatment in the first patient and at 2 months after treatment in the second patient. CONCLUSION Among the 2 patients, the patient who started ERT early had a much better prognosis despite a more severe initial clinical presentation. Our results suggest that early diagnosis and prompt treatment play an important role in improving long-term prognosis and avoiding morbidity and premature mortality in patients with perinatal and infantile HPP.
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Affiliation(s)
- Insung Kim
- Department of Public Health Administration, Asan City Health Center, Asan, Korea
| | - Eu-Seon Noh
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Min-Sun Kim
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Ja-Hyun Jang
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Tae Yeon Jeon
- Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hae Won Choi
- Department of Orthodontics, The Institute of Oral Health Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Sung Yoon Cho
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
- * Correspondence: Sung Yoon Cho, Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 06351, Korea (e-mail: )
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Ross J, Bowden MR, Yu C, Diaz-Thomas A. Transition of young adults with metabolic bone diseases to adult care. Front Endocrinol (Lausanne) 2023; 14:1137976. [PMID: 37008909 PMCID: PMC10064010 DOI: 10.3389/fendo.2023.1137976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 03/06/2023] [Indexed: 03/19/2023] Open
Abstract
As more accurate diagnostic tools and targeted therapies become increasingly available for pediatric metabolic bone diseases, affected children have a better prognosis and significantly longer lifespan. With this potential for fulfilling lives as adults comes the need for dedicated transition and intentional care of these patients as adults. Much work has gone into improving the transitions of medically fragile children into adulthood, encompassing endocrinologic conditions like type 1 diabetes mellitus and congenital adrenal hyperplasia. However, there are gaps in the literature regarding similar guidance concerning metabolic bone conditions. This article intends to provide a brief review of research and guidelines for transitions of care more generally, followed by a more detailed treatment of bone disorders specifically. Considerations for such transitions include final adult height, fertility, fetal risk, heritability, and access to appropriately identified specialists. A nutrient-dense diet, optimal mobility, and adequate vitamin D stores are protective factors for these conditions. Primary bone disorders include hypophosphatasia, X-linked hypophosphatemic rickets, and osteogenesis imperfecta. Metabolic bone disease can also develop secondarily as a sequela of such diverse exposures as hypogonadism, a history of eating disorder, and cancer treatment. This article synthesizes research by experts of these specific disorders to describe what is known in this field of transition medicine for metabolic bone diseases as well as unanswered questions. The long-term objective is to develop and implement strategies for successful transitions for all patients affected by these various conditions.
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Affiliation(s)
- Jordan Ross
- Division of Pediatric Endocrinology, University of Tennessee Health Science Center, Memphis, TN, United States
- *Correspondence: Jordan Ross,
| | - Michelle R. Bowden
- Division of General Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States
- Le Bonheur Children’s Hospital, Memphis, TN, United States
| | - Christine Yu
- Endocrinology Division, St. Jude Children’s Research Hospital, Memphis, TN, United States
| | - Alicia Diaz-Thomas
- Division of Pediatric Endocrinology, University of Tennessee Health Science Center, Memphis, TN, United States
- Le Bonheur Children’s Hospital, Memphis, TN, United States
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21
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Osteomalacia Is Not a Single Disease. Int J Mol Sci 2022; 23:ijms232314896. [PMID: 36499221 PMCID: PMC9740398 DOI: 10.3390/ijms232314896] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 11/18/2022] [Accepted: 11/23/2022] [Indexed: 11/29/2022] Open
Abstract
Among bone-material qualities, mineralization is pivotal in conferring stiffness and toughness to the bone. Osteomalacia, a disease ensuing from inadequate mineralization of the skeleton, is caused by different processes leading to decreased available mineral (calcium and/or phosphate) or enzymatic alterations. Vitamin D deficiency, which remains the major cause of altered mineralization leading to inadequate intestinal calcium and phosphate absorption, may be also associated with other conditions primarily responsible for abnormal mineralization. Given the reality of widespread vitamin D inadequacy, a full biochemical assessment of mineral metabolism is always necessary to rule out or confirm other conditions. Both too-high or too-low serum alkaline phosphatase (ALP) levels are important for diagnosis. Osteomalacic syndrome is reversible, at least in part, by specific treatment. Osteomalacia and bone mineralization themselves constitute largely unexplored fields of research. The true prevalence of the different forms of osteomalacia and the recovery after proper therapy have yet to be determined in the real world. Although non-invasive techniques to assess bone mineralization are not available in clinical practice, the systematic assessment of bone quality could help in refining the diagnosis and guiding the treatment. This review summarizes what is known of osteomalacia recent therapeutic developments and highlights the future issues of research in this field.
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22
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Koh AJ, Nam HK, Michalski MN, Do J, McCauley LK, Hatch NE. Anabolic actions of parathyroid hormone in a hypophosphatasia mouse model. Osteoporos Int 2022; 33:2423-2433. [PMID: 35871207 PMCID: PMC9568459 DOI: 10.1007/s00198-022-06496-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 07/07/2022] [Indexed: 11/17/2022]
Abstract
UNLABELLED Hypophosphatasia, the rare heritable disorder caused by TNAP enzyme mutations, presents wide-ranging severity of bone hypomineralization and skeletal abnormalities. Intermittent PTH (1-34) increased long bone volume in Alpl-/- mice but did not alter the skull phenotype. PTH may have therapeutic value for adults with TNAP deficiency-associated osteoporosis. INTRODUCTION Hypophosphatasia is the rare heritable disorder caused by mutations in the tissue non-specific alkaline phosphatase (TNAP) enzyme leading to TNAP deficiency. Individuals with hypophosphatasia commonly present with bone hypomineralization and skeletal abnormalities. The purpose of this study was to determine the impact of intermittent PTH on the skeletal phenotype of TNAP-deficient Alpl-/- mice. METHODS Alpl-/- and Alpl+/+ (wild-type; WT) littermate mice were administered PTH (1-34) (50 µg/kg) or vehicle control from days 4 to 12 and skeletal analyses were performed including gross measurements, micro-CT, histomorphometry, and serum biochemistry. RESULTS Alpl-/- mice were smaller with shorter tibial length and skull length compared to WT mice. Tibial BV/TV was reduced in Alpl-/- mice and daily PTH (1-34) injections significantly increased BV/TV and BMD but not TMD in both WT and Alpl-/- tibiae. Trabecular spacing was not different between genotypes and was decreased by PTH in both genotypes. Serum P1NP was unchanged while TRAcP5b was significantly lower in Alpl-/- vs. WT mice, with no PTH effect, and no differences in osteoclast numbers. Skull height and width were increased in Alpl-/- vs. WT mice, and PTH increased skull width in WT but not Alpl-/- mice. Frontal skull bones in Alpl-/- mice had decreased BV/TV, BMD, and calvarial thickness vs. WT with no significant PTH effects. Lengths of cranial base bones (basioccipital, basisphenoid, presphenoid) and lengths of synchondroses (growth plates) between the cranial base bones, plus bone of the basioccipitus, were assessed. All parameters were reduced (except lengths of synchondroses, which were increased) in Alpl-/- vs. WT mice with no PTH effect. CONCLUSION PTH increased long bone volume in the Alpl-/- mice but did not alter the skull phenotype. These data suggest that PTH can have long bone anabolic activity in the absence of TNAP, and that PTH may have therapeutic value for individuals with hypophosphatasia-associated osteoporosis.
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Affiliation(s)
- Amy J Koh
- Department of Periodontology and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - Hwa Kyung Nam
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - Megan N Michalski
- Department of Cell Biology, Van Andel Institute, Grand Rapids, MI, USA
| | - Justin Do
- Department of Periodontology and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - Laurie K McCauley
- Department of Periodontology and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA.
- Department of Pathology, School of Medicine, University of Michigan, Ann Arbor, MI, USA.
| | - Nan E Hatch
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, MI, USA.
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Okawa R, Nakano K. Dental manifestation and management of hypophosphatasia. JAPANESE DENTAL SCIENCE REVIEW 2022; 58:208-216. [PMID: 35814738 PMCID: PMC9260292 DOI: 10.1016/j.jdsr.2022.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 06/22/2022] [Accepted: 06/26/2022] [Indexed: 11/24/2022] Open
Abstract
Hypophosphatasia is an inherited metabolic disorder characterized by defective mineralization of bones and teeth with a wide variety of manifestations, ranging from stillbirth to dental symptoms alone. Recently, the prognosis of severe hypophosphatasia patients has been greatly improved by the introduction of enzyme replacement therapy. The typical dental manifestation is early exfoliation of primary teeth due to disturbed cementum formation, so dentures are recommended to ensure that important oral functions are acquired. Some studies have shown that enzyme replacement therapy improves dental mineralization, resulting in the stabilization of periodontal tissues and better growth of tooth roots. A nationwide Japanese survey revealed the common genetic and dental manifestations of patients with mild hypophosphatasia, which markedly differ from those of the severe forms. There may be many undiagnosed mild patients, so dentists should contribute to the early diagnosis by screening possible cases based on the typical finding of early exfoliation of primary teeth. Early diagnosis is important for patients to receive early intervention in both medical and dental fields. The establishment of fundamental dental therapy to solve the dental problems is still underway and is eagerly anticipated.
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24
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Roumpou A, Yavropoulou MP, Chronopoulos E, Kassi E. Novel Therapeutic Agents for Rare Diseases of Calcium and Phosphate Metabolism. Horm Metab Res 2022; 54:645-657. [PMID: 36049757 DOI: 10.1055/a-1917-0519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The last decade has been revolutionary regarding the management of rare bone diseases caused by impaired calcium and phosphate metabolism. Elucidation of the underlying genetic basis and pathophysiologic alterations has been the determinant factor for the development of new, disease-specific treatment agents. The phosphaturic hormone Fibroblast Growth Factor 23 (FGF23) possesses a critical role in the pathogenesis of various hypophosphatemic disorders. Among them, the genetic disorder of X-linked hypophosphatemia and the acquired syndrome of tumor-induced osteomalacia, although very rare, have attracted the scientific community's attention towards designing an FGF23-inhibitor as a potential specific therapy. The monoclonal antibody burosumab was approved for the treatment of children and adult patients with X-linked hypophosphatemia and recently for tumor-induced osteomalacia patients, demonstrating benefits regarding their symptoms, biochemical profile and bone mineralization status. Asfotase alfa is a hydroxyapatite-targeted recombinant alkaline phosphatase, an enzymatic replacement therapy, substituting the defective activity of tissue non-specific alkaline phosphatase, in patients suffering from hypophosphatasia. Promising data regarding its favorable effect on survival rate, bone quality, fracture healing, muscle strength, mobility, respiratory function, and general quality of life have led to the approval of the drug for the treatment of childhood-onset hypophosphatasia. Given the high costs of treatment for both agents and their limited clinical use until now, more data are needed to define patients' characteristics that make them ideal candidates for therapy. Long-term safety issues also need to be clarified.
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Affiliation(s)
- Afroditi Roumpou
- Division of Endocrinology, Metabolism and Diabetes, First Department of Pediatrics, "Aghia Sofia" Children's Hospital, National and Kapodistrian University of Athens School of Medicine, Athens, Greece
- Laboratory for Research of the Musculoskeletal System, National and Kapodistrian University of Athens School of Medicine, Athens, Greece
| | - Maria P Yavropoulou
- Centre of Expertise for Rare Endocrine Diseases, C.E.R.E.D. Disorders of Calcium & Phosphate Metabolism, First Department of Propaedeutic and Internal Medicine, Laiko Hospital, National and Kapodistrian University of Athens School of Medicine, Athens, Greece
| | - Efstathios Chronopoulos
- Laboratory for Research of the Musculoskeletal System, National and Kapodistrian University of Athens School of Medicine, Athens, Greece
| | - Eva Kassi
- Laboratory for Research of the Musculoskeletal System, National and Kapodistrian University of Athens School of Medicine, Athens, Greece
- Centre of Expertise for Rare Endocrine Diseases, C.E.R.E.D. Disorders of Calcium & Phosphate Metabolism, First Department of Propaedeutic and Internal Medicine, Laiko Hospital, National and Kapodistrian University of Athens School of Medicine, Athens, Greece
- Department of Biological Chemistry, National and Kapodistrian University of Athens, Athens, Greece
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25
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Collins MT, Marcucci G, Anders HJ, Beltrami G, Cauley JA, Ebeling PR, Kumar R, Linglart A, Sangiorgi L, Towler DA, Weston R, Whyte MP, Brandi ML, Clarke B, Thakker RV. Skeletal and extraskeletal disorders of biomineralization. Nat Rev Endocrinol 2022; 18:473-489. [PMID: 35578027 DOI: 10.1038/s41574-022-00682-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/13/2022] [Indexed: 12/15/2022]
Abstract
The physiological process of biomineralization is complex and deviation from it leads to a variety of diseases. Progress in the past 10 years has enhanced understanding of the genetic, molecular and cellular pathophysiology underlying these disorders; sometimes, this knowledge has both facilitated restoration of health and clarified the very nature of biomineralization as it occurs in humans. In this Review, we consider the principal regulators of mineralization and crystallization, and how dysregulation of these processes can lead to human disease. The knowledge acquired to date and gaps still to be filled are highlighted. The disorders of mineralization discussed comprise a broad spectrum of conditions that encompass bone disorders associated with alterations of mineral quantity and quality, as well as disorders of extraskeletal mineralization (hyperphosphataemic familial tumoural calcinosis). Included are disorders of alkaline phosphatase (hypophosphatasia) and phosphate homeostasis (X-linked hypophosphataemic rickets, fluorosis, rickets and osteomalacia). Furthermore, crystallopathies are covered as well as arterial and renal calcification. This Review discusses the current knowledge of biomineralization derived from basic and clinical research and points to future studies that will lead to new therapeutic approaches for biomineralization disorders.
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Affiliation(s)
- Michael T Collins
- Skeletal Disorders and Mineral Homeostasis Section, National Institute of Dental and Craniofacial Research, NIH, Bethesda, MD, USA.
| | - Gemma Marcucci
- Bone Metabolic Diseases Unit, Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Florence, Italy
| | - Hans-Joachim Anders
- Department of Medicine IV, Hospital of the University of Munich, Ludwig-Maximilians University, Munich, Germany
| | - Giovanni Beltrami
- Department Paediatric Orthopedic Oncology, Careggi and Meyer Children Hospital, Florence, Italy
| | - Jane A Cauley
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Peter R Ebeling
- Department of Medicine, School of Clinical Sciences, Monash University, Melbourne, Australia
| | - Rajiv Kumar
- Departments of Medicine, Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA
| | - Agnès Linglart
- APHP, Endocrinologie et diabète de l'enfant, Paris, France
| | - Luca Sangiorgi
- Medical Genetics and Skeletal Rare Diseases, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Dwight A Towler
- University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Ria Weston
- Cardiovascular Research Group, Manchester Metropolitan University, Manchester, UK
| | - Michael P Whyte
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children-St Louis, St Louis, MO, USA
- Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, MO, USA
| | | | - Bart Clarke
- Mayo Clinic Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Rochester, MN, USA
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
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Lin Z, Zhao D, Lin J, Ni A, Lin J. Statistical methods of indirect comparison with real-world data for survival endpoint under non-proportional hazards. J Biopharm Stat 2022; 32:582-599. [PMID: 35675418 DOI: 10.1080/10543406.2022.2080696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In clinical studies that utilize real-world data, time-to-event outcomes are often germane to scientific questions of interest. Two main obstacles are the presence of non-proportional hazards and confounding bias. Existing methods that could adjust for NPH or confounding bias, but no previous work delineated the complexity of simultaneous adjustments for both. In this paper, a propensity score stratified MaxCombo and weighted Cox model is proposed. This model can adjust for confounding bias and NPH and can be pre-specified when NPH pattern is unknown in advance. The method has robust performance as demonstrated in simulation studies and in a case study.
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Affiliation(s)
- Zihan Lin
- Division of Biostatistics, College of Public Health, the Ohio State University, Columbus, Ohio, USA
| | - Dan Zhao
- Biometrics Department, Servier Pharmaceuticals, Boston, Massachusetts, USA
| | - Junjing Lin
- Statistical and Quantitative Sciences, Takeda Pharmaceuticals, Cambridge, Massachusetts, USA
| | - Ai Ni
- Division of Biostatistics, College of Public Health, the Ohio State University, Columbus, Ohio, USA
| | - Jianchang Lin
- Statistical and Quantitative Sciences, Takeda Pharmaceuticals, Cambridge, Massachusetts, USA
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27
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Kato H, Hidaka N, Koga M, Kinoshita Y, Makita N, Nangaku M, Ito N. Radiological evaluation of pseudofracture after the administration of asfotase alfa in an adult with benign prenatal hypophosphatasia: A case report. Bone Rep 2022; 16:101163. [PMID: 35024386 PMCID: PMC8728307 DOI: 10.1016/j.bonr.2021.101163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 12/24/2021] [Accepted: 12/27/2021] [Indexed: 11/28/2022] Open
Abstract
Hypophosphatasia (HPP) is a congenital disorder with decreased activity of tissue-nonspecific alkaline phosphatase. Asfotase alfa is the only treatment approved for HPP and improves the impairment of bone mineralization. Although several previous studies have reported the efficacy of asfotase alfa to treat fractures and pseudofractures in patients with HPP, there are only a few reports with a detailed description of the healing process. In this case report, we present an 18-year-old female patient with benign prenatal HPP who received asfotase alfa to treat her pseudofracture. At the age of 17, a pseudofracture developed in her left tibia after repetitive gymnastic exercise for months. Following observation over a year, she was referred to our department. X-ray images indicated a narrow radiolucent band in the mid-diaphysis of her left tibia, and bone scintigraphy showed nuclide accumulation in the same region. Replacement therapy with asfotase alfa was started, resulting in pain relief in two months, and the disappearance of nuclide accumulation on bone scintigraphy and union of the pseudofracture on X-ray after two years. This is the first case report describing the detailed pseudofracture healing process in a patient with benign prenatal HPP initiating asfotase alfa.
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Affiliation(s)
- Hajime Kato
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Japan
| | - Naoko Hidaka
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Japan
| | - Minae Koga
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Japan
| | - Yuka Kinoshita
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Japan
| | - Noriko Makita
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Japan
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Japan
| | - Nobuaki Ito
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Japan
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28
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Imaging patterns in pediatric hypophosphatasia. Pediatr Radiol 2022; 52:998-1006. [PMID: 34854966 DOI: 10.1007/s00247-021-05232-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 08/23/2021] [Accepted: 10/20/2021] [Indexed: 10/19/2022]
Abstract
Hypophosphatasia is a rare genetic disorder of calcium and phosphate metabolism due to ALPL gene mutations, which leads to abnormal mineralization of the bones and teeth. Hypophosphatasia is characterized by low serum alkaline phosphatase activity and a number of clinical signs, including failure to thrive, bone pain and dental issues. The diagnosis is suspected based on clinical, laboratory and imaging findings and confirmed by genetic testing. Diagnosis in children is often delayed due to a lack of disease awareness, despite specific imaging findings that are a cornerstone of the diagnosis. The recent approval of enzyme replacement therapy (bone-targeted recombinant tissue nonspecific alkaline phosphatase) has given imaging an important role in monitoring treatment efficacy. The aim of this pictorial essay is to review the imaging features of hypophosphatasia at diagnosis and during follow-up, including whole-body magnetic resonance imaging patterns.
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29
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Nam HK, Emmanouil E, Hatch NE. Deletion of the Pyrophosphate Generating Enzyme ENPP1 Rescues Craniofacial Abnormalities in the TNAP−/− Mouse Model of Hypophosphatasia and Reveals FGF23 as a Marker of Phenotype Severity. FRONTIERS IN DENTAL MEDICINE 2022; 3. [PMID: 35909501 PMCID: PMC9336114 DOI: 10.3389/fdmed.2022.846962] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Hypophosphatasia is a rare heritable metabolic disorder caused by deficient Tissue Non-specific Alkaline Phosphatase (TNAP) enzyme activity. A principal function of TNAP is to hydrolyze the tissue mineralization inhibitor pyrophosphate. ENPP1 (Ectonucleotide Pyrophosphatase/Phosphodiesterase 1) is a primary enzymatic generator of pyrophosphate and prior results showed that elimination of ENPP1 rescued bone hypomineralization of skull, vertebral and long bones to different extents in TNAP null mice. Current TNAP enzyme replacement therapy alleviates skeletal, motor and cognitive defects but does not eliminate craniosynostosis in pediatric hypophosphatasia patients. To further understand mechanisms underlying craniosynostosis development in hypophosphatasia, here we sought to determine if craniofacial abnormalities including craniosynostosis and skull shape defects would be alleviated in TNAP null mice by genetic ablation of ENPP1. Results show that homozygous deletion of ENPP1 significantly diminishes the incidence of craniosynostosis and that skull shape abnormalities are rescued by hemi- or homozygous deletion of ENPP1 in TNAP null mice. Skull and long bone hypomineralization were also alleviated in TNAP−/−/ENPP1−/− compared to TNAP−/−/ENPP1+/+ mice, though loss of ENPP1 in combination with TNAP had different effects than loss of only TNAP on long bone trabeculae. Investigation of a relatively large cohort of mice revealed that the skeletal phenotypes of TNAP null mice were markedly variable. Because FGF23 circulating levels are known to be increased in ENPP1 null mice and because FGF23 influences bone, we measured serum intact FGF23 levels in the TNAP null mice and found that a subset of TNAP−/−/ENPP1+/+ mice exhibited markedly high serum FGF23. Serum FGF23 levels also correlated to mouse body measurements, the incidence of craniosynostosis, skull shape abnormalities and skull bone density and volume fraction. Together, our results demonstrate that balanced expression of TNAP and ENPP1 enzymes are essential for microstructure and mineralization of both skull and long bones, and for preventing craniosynostosis. The results also show that FGF23 rises in the TNAP−/− model of murine lethal hypophosphatasia. Future studies are required to determine if the rise in FGF23 is a cause, consequence, or marker of disease phenotype severity.
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Krishnan N, Dunbar N. Management of perinatal HPP during critical illness/ECMO. J Pediatr Endocrinol Metab 2022; 35:115-119. [PMID: 34582635 DOI: 10.1515/jpem-2021-0187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 09/06/2021] [Indexed: 11/15/2022]
Abstract
OBJECTIVES With the advent of asfotase alfa, the enzyme replacement therapy (ERT) approved for hypophosphatasia (HPP), health care providers need to navigate management of ERT during critical illness. CASE PRESENTATION We present the case of a young girl, treated with ERT for severe perinatal HPP, who had cardiorespiratory arrest in the setting of influenza A. Her life-saving treatment involving extra corporeal membrane oxygenation (ECMO) required a two-week interruption of ERT leading to persistent hypercalcemia and hyperphosphatemia. A three year old female presented with respiratory distress and blood tinged secretions. She was influenza A positive with bilateral opacities on chest X-ray (CXR). Worsening respiratory distress and bradycardic arrest required intubation, CPR and venoarterial ECMO cannulation. She remained on ECMO for 10 days with anticoagulation restrictions requiring her thrice-weekly subcutaneous ERT to be held. Hypercalcemia (12.3 mg/dL) and hyperphosphatemia (7.6 mg/dL) developed two weeks after restarting ERT and resolved six weeks later. CONCLUSIONS We highlight that the obligatory cessation of ERT while on ECMO led to the loss of functional TNSALP with a profound decrease in bone mineralization leading to excess circulating calcium and phosphorus. In cases where it is necessary to interrupt ERT, we advise close monitoring of calcium and phosphorous levels.
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Affiliation(s)
- Neetu Krishnan
- Department of Pediatric Endocrinology, University of Connecticut, Farmington, CT, USA
| | - Nancy Dunbar
- Department of Pediatric Endocrinology, Connecticut Children's, Farmington, CT, USA
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31
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Verminderte Mineralisation des Knochens: Rachitis und Osteomalazie. Monatsschr Kinderheilkd 2022. [DOI: 10.1007/s00112-021-01392-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
ZusammenfassungDie Mineralisation der Wachstumsfuge und des Knochens benötigt suffiziente Mengen an Kalzium und Phosphat, um ein adäquates Körperwachstum und eine adäquate Knochenstärke zu gewährleisten. Bei Mangelzuständen nehmen Härte und Stärke des Knochens ab (Osteomalazie), mit typischen Veränderungen an der Wachstumsfuge (Rachitis). Die vermeidbaren Komplikationen einer erworbenen Rachitis können lebensbedrohlich sein und sind auch deshalb ein global wichtiges Public-Health-Thema. Typische klinische Zeichen, Laborparameter und radiologische Veränderungen sollten zur unverzüglichen Diagnose führen. Erbliche und erworbene Formen der Rachitis wie X‑chromosomale Hypophosphatämie oder Hypophosphatasie werden, wie oftmals bei seltenen Erkrankungen, spät diagnostiziert. Diagnose, Therapie und Management von Rachitiden sollten durch tertiäre kinderosteologische Spezialisten erfolgen, die in internationalen „Rare-diseases“-Netzwerken arbeiten und in enger Kooperation mit Selbsthilfegruppen stehen.
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Evaluation of alveolar bone hypomineralization in pediatric hypophosphatasia using orthopantomography. Sci Rep 2022; 12:1211. [PMID: 35075203 PMCID: PMC8786966 DOI: 10.1038/s41598-022-05171-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 01/07/2022] [Indexed: 12/15/2022] Open
Abstract
Hypophosphatasia (HPP) is a metabolic disease characterized by impaired bone mineralization and early exfoliation of primary teeth. This study was performed to develop a method for quantitatively evaluating alveolar bone hypomineralization using orthopantomographic images. Alveolar bone density was defined according to the pixel values and corrected by brightness shown by an indicator applied to the orthopantomographic device. Images of 200 healthy subjects (aged 2-15 years) were classified into five age groups. The corrected pixel values were significantly lower in the younger group than in those aged 14-15 years (2-4, 5-7, and 8-10 years versus 14-15 years: P < 0.0001, 11-13 years versus 14-15 years: P < 0.01). Orthopantomographic images of 17 patients with HPP were evaluated. The corrected pixel values of three-fourths of the patients with odonto type HPP were lower than the mean values of the healthy group. One-third of patients treated with enzyme replacement therapy showed higher corrected pixel values than the healthy group. Our results suggest that odonto type HPP without skeletal problems is occasionally accompanied by hypomineralization of alveolar bone and that alveolar bone hypomineralization in patients with severe HPP is possibly improved by enzyme replacement therapy.
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Whyte MP, Zhang F, Wenkert D, Mack KE, Bijanki VN, Ericson KL, Coburn SP. Hypophosphatasia: Vitamin B 6 status of affected children and adults. Bone 2022; 154:116204. [PMID: 34547524 DOI: 10.1016/j.bone.2021.116204] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 09/09/2021] [Accepted: 09/14/2021] [Indexed: 12/20/2022]
Abstract
Hypophosphatasia (HPP) is the heritable dento-osseous disease caused by loss-of-function mutation(s) of the gene ALPL that encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). TNSALP is a cell-surface homodimeric phosphomonoester phosphohydrolase expressed in healthy people especially in the skeleton, liver, kidneys, and developing teeth. In HPP, diminished TNSALP activity leads to extracellular accumulation of its natural substrates including inorganic pyrophosphate (PPi), an inhibitor of mineralization, and pyridoxal 5'-phosphate (PLP), the principal circulating form of vitamin B6 (B6). Autosomal dominant and autosomal recessive inheritance involving >450 usually missense defects scattered throughout ALPL largely explains the remarkably broad-ranging severity of this inborn-error-of-metabolism. In 1985 when we identified elevated plasma PLP as a biochemical hallmark of HPP, all 14 investigated affected children and adults had markedly increased PLP levels. However, pyridoxal (PL), the dephosphorylated form of PLP that enters cells to cofactor many enzymatic reactions, was not low but often inexplicably elevated. Levels of pyridoxic acid (PA), the B6 degradation product quantified to assess B6 sufficiency, were unremarkable. Canonical signs or symptoms of B6 deficiency or toxicity were absent. B6-dependent seizures in infants with life-threatening HPP were later explained by their profound deficiency of TNSALP activity blocking PLP dephosphorylation to PL and diminishing gamma-aminobutyric acid synthesis in the brain. Now, there is speculation that altered B6 metabolism causes further clinical complications in HPP. Herein, we assessed the plasma PL and PA levels accompanying previously reported elevated plasma PLP concentrations in 150 children and adolescents with HPP. Their mean (SD) plasma PL level was nearly double the mean for our healthy pediatric controls: 66.7 (59.0) nM versus 37.1 (22.2) nM (P < 0.0001), respectively. Their PA levels were broader than our pediatric control range, but their mean value was normal; 40.2 (25.1) nM versus 39.3 (9.9) nM (P = 0.7793), respectively. In contrast, adults with HPP often had plasma PL and PA levels suggestive of dietary B6 insufficiency. We discuss why the B6 levels of our pediatric patients with HPP would not cause B6 toxicity or deficiency, whereas in affected adults dietary B6 insufficiency can develop.
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Affiliation(s)
- Michael P Whyte
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children - St. Louis, St. Louis, MO 63110, USA; Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, MO 63110, USA.
| | - Fan Zhang
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children - St. Louis, St. Louis, MO 63110, USA.
| | - Deborah Wenkert
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children - St. Louis, St. Louis, MO 63110, USA.
| | - Karen E Mack
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children - St. Louis, St. Louis, MO 63110, USA.
| | - Vinieth N Bijanki
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children - St. Louis, St. Louis, MO 63110, USA.
| | - Karen L Ericson
- Department of Chemistry, Purdue University Fort Wayne, Fort Wayne, IN 46805, USA.
| | - Stephen P Coburn
- Department of Chemistry, Purdue University Fort Wayne, Fort Wayne, IN 46805, USA.
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Thrailkill KM, Kalaitzoglou E, Fowlkes JL. Emerging therapies for the treatment of rare pediatric bone disorders. Front Pediatr 2022; 10:1012816. [PMID: 36304528 PMCID: PMC9592743 DOI: 10.3389/fped.2022.1012816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 09/09/2022] [Indexed: 11/24/2022] Open
Abstract
In recent years, new therapies for the treatment of rare pediatric bone disorders have emerged, guided by an increasing understanding of the genetic and molecular etiology of these diseases. Herein, we review three such disorders, impacted by debilitating deficits in bone mineralization or cartilage ossification, as well as the novel disease-modifying drugs that are now available to treat these conditions. Specifically, we discuss asfotase alfa, burosumab-twza, and vosoritide, for the treatment of hypophosphatasia, X-linked hypophosphatemia and achondroplasia, respectively. For each skeletal disorder, an overview of the clinical phenotype and natural history of disease is provided, along with a discussion of the clinical pharmacology, mechanism of action and FDA indication for the relevant medication. In each case, a brief review of clinical trial data supporting drug development for each medication is provided. Additionally, guidance as to drug dosing and long-term monitoring of adverse events and pediatric efficacy is presented, to aid the clinician seeking to utilize these novel therapies in their practice, or to become familiar with the healthcare expectations for children receiving these medications through specialized multidisciplinary clinics. The availability of these targeted therapies now significantly augments treatment options for conditions in which past therapy has relied upon less specific, symptomatic medical and orthopedic care.
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Affiliation(s)
- Kathryn M Thrailkill
- Department of Pediatrics, University of Kentucky Barnstable Brown Diabetes Center, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Evangelia Kalaitzoglou
- Department of Pediatrics, University of Kentucky Barnstable Brown Diabetes Center, University of Kentucky College of Medicine, Lexington, KY, United States
| | - John L Fowlkes
- Department of Pediatrics, University of Kentucky Barnstable Brown Diabetes Center, University of Kentucky College of Medicine, Lexington, KY, United States
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Seefried L, Rak D, Petryk A, Genest F. Bone turnover and mineral metabolism in adult patients with hypophosphatasia treated with asfotase alfa. Osteoporos Int 2021; 32:2505-2513. [PMID: 34215909 PMCID: PMC8608777 DOI: 10.1007/s00198-021-06025-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 05/31/2021] [Indexed: 11/04/2022]
Abstract
UNLABELLED There is limited understanding of how asfotase alfa affects mineral metabolism and bone turnover in adults with pediatric-onset hypophosphatasia. This study showed that adults with hypophosphatasia treated with asfotase alfa experienced significant changes in biochemical markers of bone and mineral metabolism, possibly reflecting enhanced bone remodeling of previously osteomalacic bone. INTRODUCTION Hypophosphatasia (HPP), due to a tissue nonspecific alkaline phosphatase (TNSALP) deficiency, can cause impaired bone mineralization and turnover. Although HPP may be treated with asfotase alfa, an enzyme replacement therapy, limited data are available on how treatment with asfotase alfa affects mineral metabolism and bone turnover in adults with HPP. METHODS ALP substrates, bone turnover and mineral metabolism markers, and bone mineral density (BMD) data from EmPATHY, a single-center, observational study of adults (≥ 18 years) with pediatric-onset HPP treated with asfotase alfa (NCT03418389), were collected during routine clinical care and analyzed from baseline through 24 months of treatment. RESULTS Data from 21 patients showed significantly increased ALP activity and reduced urine phosphoethanolamine (PEA)/creatinine (Cr) ratios after baseline through 24 months of asfotase alfa treatment. There were significant transient increases in parathyroid hormone 1-84 (PTH), osteocalcin, and procollagen type 1 N-propeptide (P1NP) levels at 3 and 6 months and in tartrate-resistant acid phosphatase 5b (TRAP5b) levels at 3 months, with a significant decrease in N-terminal telopeptide of type 1 collagen (NTX) levels at 24 months. Lumbar spine BMD T scores continuously increased during treatment. CONCLUSION Significant changes in bone turnover and mineral metabolism markers after asfotase alfa treatment suggest that treatment-mediated mineralization may enable remodeling and bone turnover on previously unmineralized surfaces. Urine PEA/Cr ratios may be a useful parameter in monitoring treatment during routine care.
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Affiliation(s)
- L Seefried
- Orthopedic Clinic König-Ludwig-Haus, Julius-Maximilians-Universität Würzburg, Brettreichstr. 11, 97070, Würzburg, Germany.
| | - D Rak
- Orthopedic Clinic König-Ludwig-Haus, Julius-Maximilians-Universität Würzburg, Brettreichstr. 11, 97070, Würzburg, Germany
| | - A Petryk
- Alexion Pharmaceuticals, Inc., Boston, MA, USA
| | - F Genest
- Orthopedic Clinic König-Ludwig-Haus, Julius-Maximilians-Universität Würzburg, Brettreichstr. 11, 97070, Würzburg, Germany
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Abstract
Hypophosphatasia (HPP) is an inherited metabolic disease caused by loss-of-function mutations in the tissue non-specific alkaline phosphatase (TNAP) gene. Reduced activity of TNAP leads to the accumulation of its substrates, mainly inorganic pyrophosphate and pyridoxal-5′-phosphate, metabolic aberrations that largely explain the musculoskeletal and systemic features of the disease. More than 400 ALPL mutations, mostly missense, are reported to date, transmitted by either autosomal dominant or recessive mode. Severe disease is rare, with incidence ranging from 1:100,000 to 1:300,000 live births, while the estimated prevalence of the less severe adult form is estimated to be between 1:3100 to 1:508, in different countries in Europe. Presentation largely varies, ranging from death in utero to asymptomatic adults. In infants and children, clinical features include skeletal, respiratory and neurologic complications, while recurrent, poorly healing fractures, muscle weakness and arthropathy are common in adults. Persistently low serum alkaline phosphatase is the cardinal biochemical feature of the disease. Management requires a dedicated multidisciplinary team. In mild cases, treatment is usually symptomatic. Severe cases, with life-threating or debilitating complications, can be successfully treated with enzyme replacement therapy with asfotase alfa.
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Hoover-Fong J. Current state of the art in treatment of Mendelian disease: Skeletal dysplasias. Am J Med Genet A 2021; 185:3359-3368. [PMID: 34487414 DOI: 10.1002/ajmg.a.62468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 12/23/2022]
Abstract
The current state of the art in treatment of Mendelian disease, specifically skeletal dysplasias, benefits tremendously from Dr. Victor McKusick's early delineation and standardization of the nomenclature surrounding these conditions. Through close observation and careful description of each dysplasia to flesh out the nosologic backbone of the genetic skeletal disorders, individuals with the same diagnosis were identified and grouped together for genetic interrogation. These efforts have resulted in the identification of the genetic etiology of nearly all recognized skeletal disorders. This, in turn, is leading to disease-specific treatment for many of the skeletal dysplasias in this new era of precision medicine. Furthermore, Dr. McKusick's natural history descriptions of many genetic skeletal disorders helped to establish the baseline disease state against which the effect of new treatment is compared.
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Affiliation(s)
- Julie Hoover-Fong
- Greenberg Center for Skeletal Dysplasias, Department of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland, USA
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Kinoshita Y, Mohamed FF, Amadeu de Oliveira F, Narisawa S, Miyake K, Foster BL, Millán JL. Gene Therapy Using Adeno-Associated Virus Serotype 8 Encoding TNAP-D 10 Improves the Skeletal and Dentoalveolar Phenotypes in Alpl -/- Mice. J Bone Miner Res 2021; 36:1835-1849. [PMID: 34076297 PMCID: PMC8446309 DOI: 10.1002/jbmr.4382] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/25/2021] [Accepted: 05/28/2021] [Indexed: 12/26/2022]
Abstract
Hypophosphatasia (HPP) is caused by loss-of-function mutations in the ALPL gene that encodes tissue-nonspecific alkaline phosphatase (TNAP), whose deficiency results in the accumulation of extracellular inorganic pyrophosphate (PPi ), a potent mineralization inhibitor. Skeletal and dental hypomineralization characterizes HPP, with disease severity varying from life-threatening perinatal or infantile forms to milder forms that manifest in adulthood or only affect the dentition. Enzyme replacement therapy (ERT) using mineral-targeted recombinant TNAP (Strensiq/asfotase alfa) markedly improves the life span, skeletal phenotype, motor function, and quality of life of patients with HPP, though limitations of ERT include frequent injections due to a short elimination half-life of 2.28 days and injection site reactions. We tested the efficacy of a single intramuscular administration of adeno-associated virus 8 (AAV8) encoding TNAP-D10 to increase the life span and improve the skeletal and dentoalveolar phenotypes in TNAP knockout (Alpl-/- ) mice, a murine model for severe infantile HPP. Alpl-/- mice received 3 × 1011 vector genomes/body of AAV8-TNAP-D10 within 5 days postnatal (dpn). AAV8-TNAP-D10 elevated serum ALP activity and suppressed plasma PPi . Treatment extended life span of Alpl-/- mice, and no ectopic calcifications were observed in the kidneys, aorta, coronary arteries, or brain in the 70 dpn observational window. Treated Alpl-/- mice did not show signs of rickets, including bowing of long bones, enlargement of epiphyses, or fractures. Bone microstructure of treated Alpl-/- mice was similar to wild type, with a few persistent small cortical and trabecular defects. Histology showed no measurable osteoid accumulation but reduced bone volume fraction in treated Alpl-/- mice versus controls. Treated Alpl-/- mice featured normal molar and incisor dentoalveolar tissues, with the exceptions of slightly reduced molar enamel and alveolar bone density. Histology showed the presence of cementum and normal periodontal ligament attachment. These results support gene therapy as a promising alternative to ERT for the treatment of HPP. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Yuka Kinoshita
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Fatma F Mohamed
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - Flavia Amadeu de Oliveira
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Sonoko Narisawa
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Koichi Miyake
- Department of Biochemistry and Molecular Biology, Nippon Medical School, Tokyo, Japan
| | - Brian L Foster
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - José Luis Millán
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
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Okawa R, Kokomoto K, Nakano K. Dental effects of enzyme replacement therapy in case of childhood-type hypophosphatasia. BMC Oral Health 2021; 21:323. [PMID: 34176466 PMCID: PMC8237502 DOI: 10.1186/s12903-021-01673-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 06/11/2021] [Indexed: 12/02/2022] Open
Abstract
Background Hypophosphatasia (HPP), a skeletal disease characterized by hypomineralization of bone and teeth, is caused by an ALPL gene mutation that leads to low activity of the tissue non-specific alkaline phosphatase enzyme. Although enzyme replacement therapy (ERT) was recently introduced for affected patients, no known studies have been reported regarding its dental effects related to permanent teeth and jaw bones. In the present study, we examined the dental effects of ERT in a case of childhood-type hypophosphatasia, including panoramic radiography findings used to estimate the dental age of permanent teeth and mandibular bone density. Furthermore, the effects of that therapy on the periodontal condition of the patient were evaluated by comparing periodontal pocket depth before and after initiation. Case presentation An 11-year-1-month-old boy was referred to our clinic for consultation regarding oral management. Two primary incisors had spontaneously exfoliated at 1 year 8 months old and he had been diagnosed with childhood-type HPP at the age of 2 years 2 months. Obvious symptoms were localized in the dental region at the time of diagnosis, though later extended to other parts of the body such as bone pain. ERT was started at 11 years 7 months of age, after which bone pain disappeared, and motor functions and activities of daily living improved. We estimated dental age based on tooth development stage. The age gap between chronological and dental ages was expanded before treatment, and then showed a constant decrease after ERT initiation and finally disappeared. The index for mandibular bone density (mandibular cortical width / length from mesial buccal cusp to apex of first molar) was increased after ERT initiation. Furthermore, the periodontal condition for all teeth except those exfoliated was stable after starting therapy. Conclusions ERT resulted in improved tooth and mandibular bone mineralization, with notably good effects on teeth under formation. Acceleration of mineralization of roots associated with erupting teeth leads to stabilization of the periodontal condition. We concluded that ERT contributed to the improved dental condition seen in this patient. Supplementary Information The online version contains supplementary material available at 10.1186/s12903-021-01673-2.
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Affiliation(s)
- Rena Okawa
- Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, 1-8 Yamada-oka, Suita, Osaka, 565-0871, Japan.
| | - Kazuma Kokomoto
- Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, 1-8 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Kazuhiko Nakano
- Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, 1-8 Yamada-oka, Suita, Osaka, 565-0871, Japan
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Pan WJ, Pradhan R, Pelto R, Seefried L. Pharmacokinetics of Asfotase Alfa in Adult Patients With Pediatric-Onset Hypophosphatasia. J Clin Pharmacol 2021; 61:1334-1343. [PMID: 33822385 PMCID: PMC8518624 DOI: 10.1002/jcph.1870] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 04/01/2021] [Indexed: 11/24/2022]
Abstract
Hypophosphatasia is a rare metabolic disease resulting from variant(s) in the gene‐encoding tissue‐nonspecific isozyme of alkaline phosphatase. In this 13‐week, phase 2a, multicenter, randomized, open‐label, dose‐response study (ClinicalTrials.gov: NCT02797821), the pharmacokinetics of asfotase alfa, an enzyme replacement therapy approved for the treatment of hypophosphatasia, was assessed in adult patients with pediatric‐onset hypophosphatasia. In total, 27 adults were randomly assigned 1:1:1 to a single subcutaneous dose of asfotase alfa (0.5, 2.0, or 3.0 mg/kg) during week 1. From week 3 to week 9, patients received 0.5, 2.0, or 3.0 mg/kg subcutaneously 3 times per week (equivalent to 1.5, 6.0, or 9.0 mg/kg/wk, respectively). Noncompartmental analysis revealed exposure (maximum concentration in the dosing interval and area under the concentration‐time curve from time 0 to infinity) to asfotase alfa increased between single‐ and multiple‐dose administration and with increasing doses; however, extensive interindividual variability was observed in the concentration‐time profiles within each dose cohort. Median terminal elimination half‐life was ≈5 days following multiple‐dose administration, with steady state achieved by approximately day 29. Dose‐normalized exposure data indicated that asfotase alfa activity was approximately dose‐proportional within the studied dose range. Additionally, dose‐normalized exposure was comparable across body mass index categories of <25, ≥25 to <30, and ≥30 kg/m2, indicating that asfotase alfa dosing bioavailability was consistent in these patients, including those who were obese. These data, together with previously published pharmacodynamic results in this study population, support the use of asfotase alfa at the recommended dose of 6 mg/kg/wk in adults with pediatric‐onset hypophosphatasia.
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Affiliation(s)
- Wei-Jian Pan
- Alexion Pharmaceuticals, Inc., Boston, Massachusetts, USA
| | | | - Ryan Pelto
- Alexion Pharmaceuticals, Inc., Boston, Massachusetts, USA
| | - Lothar Seefried
- Orthopedic Department, University of Würzburg, Würzburg, Bavaria, Germany
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Marchetti M, Faggiano S, Mozzarelli A. Enzyme Replacement Therapy for Genetic Disorders Associated with Enzyme Deficiency. Curr Med Chem 2021; 29:489-525. [PMID: 34042028 DOI: 10.2174/0929867328666210526144654] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/23/2021] [Accepted: 03/17/2021] [Indexed: 11/22/2022]
Abstract
Mutations in human genes might lead to loss of functional proteins, causing diseases. Among these genetic disorders, a large class is associated with the deficiency in metabolic enzymes, resulting in both an increase in the concentration of substrates and a loss in the metabolites produced by the catalyzed reactions. The identification of therapeutic actions based on small molecules represents a challenge to medicinal chemists because the target is missing. Alternative approaches are biology-based, ranging from gene and stem cell therapy, CRISPR/Cas9 technology, distinct types of RNAs, and enzyme replacement therapy (ERT). This review will focus on the latter approach that since the 1990s has been successfully applied to cure many rare diseases, most of them being lysosomal storage diseases or metabolic diseases. So far, a dozen enzymes have been approved by FDA/EMA for lysosome storage disorders and only a few for metabolic diseases. Enzymes for replacement therapy are mainly produced in mammalian cells and some in plant cells and yeasts and are further processed to obtain active, highly bioavailable, less degradable products. Issues still under investigation for the increase in ERT efficacy are the optimization of enzymes interaction with cell membrane and internalization, the reduction in immunogenicity, and the overcoming of blood-brain barrier limitations when neuronal cells need to be targeted. Overall, ERT has demonstrated its efficacy and safety in the treatment of many genetic rare diseases, both saving newborn lives and improving patients' life quality, and represents a very successful example of targeted biologics.
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Affiliation(s)
- Marialaura Marchetti
- Biopharmanet-TEC Interdepartmental Center, University of Parma, Parco Area delle Scienze, Bldg 33., 43124, Parma, Italy
| | - Serena Faggiano
- Department of Food and Drug, University of Parma, Parco Area delle Scienze 23/A, 43124, Parma, Italy
| | - Andrea Mozzarelli
- Institute of Biophysics, National Research Council, Via Moruzzi 1, 56124, Pisa, Italy
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Nwafor DC, Brichacek AL, Ali A, Brown CM. Tissue-Nonspecific Alkaline Phosphatase in Central Nervous System Health and Disease: A Focus on Brain Microvascular Endothelial Cells. Int J Mol Sci 2021; 22:5257. [PMID: 34067629 PMCID: PMC8156423 DOI: 10.3390/ijms22105257] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 12/21/2022] Open
Abstract
Tissue-nonspecific alkaline phosphatase (TNAP) is an ectoenzyme bound to the plasma membranes of numerous cells via a glycosylphosphatidylinositol (GPI) moiety. TNAP's function is well-recognized from earlier studies establishing its important role in bone mineralization. TNAP is also highly expressed in cerebral microvessels; however, its function in brain cerebral microvessels is poorly understood. In recent years, few studies have begun to delineate a role for TNAP in brain microvascular endothelial cells (BMECs)-a key component of cerebral microvessels. This review summarizes important information on the role of BMEC TNAP, and its implication in health and disease. Furthermore, we discuss current models and tools that may assist researchers in elucidating the function of TNAP in BMECs.
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Affiliation(s)
- Divine C. Nwafor
- Department of Neuroscience, School of Medicine, West Virginia University Health Science Center, Morgantown, WV 26506, USA; (D.C.N.); (A.A.)
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, WV 26506, USA
| | - Allison L. Brichacek
- Department of Microbiology, Immunology, and Cell Biology, School of Medicine, West Virginia University Health Science Center, Morgantown, WV 26506, USA;
| | - Ahsan Ali
- Department of Neuroscience, School of Medicine, West Virginia University Health Science Center, Morgantown, WV 26506, USA; (D.C.N.); (A.A.)
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, WV 26506, USA
| | - Candice M. Brown
- Department of Neuroscience, School of Medicine, West Virginia University Health Science Center, Morgantown, WV 26506, USA; (D.C.N.); (A.A.)
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, WV 26506, USA
- Department of Microbiology, Immunology, and Cell Biology, School of Medicine, West Virginia University Health Science Center, Morgantown, WV 26506, USA;
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GSK3β rephosphorylation rescues ALPL deficiency-induced impairment of odontoblastic differentiation of DPSCs. Stem Cell Res Ther 2021; 12:225. [PMID: 33823913 PMCID: PMC8022410 DOI: 10.1186/s13287-021-02235-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 02/21/2021] [Indexed: 11/23/2022] Open
Abstract
Background Premature exfoliation of the deciduous teeth is a common manifestation in childhood patients with hypophosphatasia (HPP), which is an autosomal inherited disease caused by ALPL mutations. Dysplasia of the cementum, dentin, and alveolar bone has been proposed to be the main reasons for the exfoliation of teeth, while the extraordinarily complex intracellular mechanisms remain elusive. Dental pulp stem cells (DPSCs) have been demonstrated to successfully regenerate functional pulp-dentin-like tissue. Dental pulp cells derived from HPP patients impaired mineralization; however, insight into the deeper mechanism is still unclear. Methods The effects of ALPL on odontoblastic differentiation of DPSCs from HPP patient were assessed by Alizarin Red staining, immunofluorescent staining, Western blot and RT-PCR, and micro-CT assays. Result Here, we found DPSCs from HPP patient exhibited low ALP activity and impaired odontoblastic differentiation. Meanwhile, we found that loss of function of ALPL reduced phosphorylation of GSK3β in DPSCs. While GSK3β rephosphorylation improved odontoblastic differentiation of HPP DPSCs with LiCl treatment. Finally, we demonstrated systemic LiCl injection ameliorated tooth-associated defects in ALPL+/− mice by enhanced phosphorylation of GSK3β in the teeth. Conclusions Our study indicates that ALPL regulates odontoblastic differentiation of DPSCs and provides useful information for understanding how ALPL deficiency led to tooth dysplasia and, ultimately, may inform efforts at improvement tooth defects in HPP patients. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-021-02235-7.
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Laroche M, Couture G, Faruch M, Ruyssen-Witrand A, Porquet-Bordes V, Salles JP, Degboe Y. Hypophosphatasia: A Case of Two Patients With Spinal Cord Compression From Increase in Ligamentous Ossifications During Treatment. JBMR Plus 2021; 5:e10449. [PMID: 33869986 PMCID: PMC8046109 DOI: 10.1002/jbm4.10449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 11/08/2020] [Indexed: 11/20/2022] Open
Abstract
Treatment with asfotase alfa has transformed the prognosis of hypophosphatasia in children and improves the bone and muscle signs in adults. The doses used in adults are the same as in children, whereas bone remodeling is different between them. We report on the cases of two patients treated with 1 mg/kg/day of asfotase alfa who developed spinal cord compression from spinal ossifications during treatment. The first patient, 50 years old, presented after 2 years of treatment with quadraparesis secondary to an increase in ossifications of the cervical vertebral ligaments. The neurological damage was resolved after laminectomy, and the patient was then treated for 18 months with doses of 80 mg per week, without recurrence of the bone and muscle signs. The second patient, 26 years old, 78 kg, developed pain and cervical stiffness with pyramidal tract irritation secondary to ossifications of the vertebral ligaments. This improved with a reduction of doses to 80 mg/week, which then, after 6 months of follow‐up, enabled maintained improvement of the bone and muscle pain that was initially obtained. To our knowledge, these are the first reported cases of increased spinal ligamentous ossifications with neurological complications. Biological monitoring in adults does not seem to enable asfotase alfa doses to be adjusted. The levels of serum alkaline phosphatase (ALP) while on the recommended treatment of 1 mg/kg/day are significantly supraphysiological (5000 to 20,000 IU) and the assays of pyrophosphate and pyridoxal phosphate are not correlated with clinical efficacy. In both of our patients, the treatment with 80 mg of asfotase alfa per week, which was proposed after the occurrence of spinal complications, seemed as effective, after a follow‐up of 18 months and 6 months, as the initial treatment for improving the bone and muscle signs, and could be provided as “attack” doses after healing of the pseudoarthroses. © 2021 American Society for Bone and Mineral Research © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Michel Laroche
- Centre de Rhumatologie du Centre Hospitalo-Universitaire de Toulouse [Rheumatology Center of Toulouse University Hospital] Toulouse France
| | - Guillaume Couture
- Centre de Rhumatologie du Centre Hospitalo-Universitaire de Toulouse [Rheumatology Center of Toulouse University Hospital] Toulouse France
| | - Marie Faruch
- Service de Radiologie du Centre Hospitalo-Universitaire de Toulouse [Department of Radiology of Toulouse University Hospital] Toulouse France
| | - Adeline Ruyssen-Witrand
- Centre de Rhumatologie du Centre Hospitalo-Universitaire de Toulouse [Rheumatology Center of Toulouse University Hospital] Toulouse France
| | - Valérie Porquet-Bordes
- Endocrinologie, Maladies Osseuses, Hôpital des Enfants, Centre de Référence des Maladies Rares du Métabolisme du Calcium et Phosphate, European Reference Network on rare bone diseases, Centre Hospitalo-Universitaire de Toulouse Toulouse France
| | - Jean Pierre Salles
- Endocrinologie, Maladies Osseuses, Hôpital des Enfants, Centre de Référence des Maladies Rares du Métabolisme du Calcium et Phosphate, European Reference Network on rare bone diseases, Centre Hospitalo-Universitaire de Toulouse Toulouse France.,INSERM UMR 1043 CNRS5825, Centre de Physiopathologie de Toulouse Purpan, Centre de Physiopathology Toulouse Purpan, Université de Toulouse Toulouse France
| | - Yannick Degboe
- Centre de Rhumatologie du Centre Hospitalo-Universitaire de Toulouse [Rheumatology Center of Toulouse University Hospital] Toulouse France.,INSERM UMR 1043 CNRS5825, Centre de Physiopathologie de Toulouse Purpan, Centre de Physiopathology Toulouse Purpan, Université de Toulouse Toulouse France
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An 8-month-old infant with hypercalcemia and hyperphosphatemia-Answers. Pediatr Nephrol 2021; 36:563-566. [PMID: 32588225 DOI: 10.1007/s00467-020-04666-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 06/04/2020] [Accepted: 06/08/2020] [Indexed: 10/24/2022]
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Abstract
In chronic kidney disease (CKD), disturbance of several metabolic regulatory mechanisms cause premature ageing, accelerated cardiovascular disease (CVD), and mortality. Single-target interventions have repeatedly failed to improve the prognosis for CKD patients. Epigenetic interventions have the potential to modulate several pathogenetic processes simultaneously. Alkaline phosphatase (ALP) is a robust predictor of CVD and all-cause mortality and implicated in pathogenic processes associated with CVD in CKD.
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Broomfield AA, Padidela R, Wilkinson S. Pulmonary Manifestations of Endocrine and Metabolic Diseases in Children. Pediatr Clin North Am 2021; 68:81-102. [PMID: 33228944 DOI: 10.1016/j.pcl.2020.09.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Advances in technology, methodology, and deep phenotyping are increasingly driving the understanding of the pathologic basis of disease. Improvements in patient identification and treatment are impacting survival. This is true in endocrinology and inborn errors of metabolism, where disease-modifying therapies are developing. Inherent to this evolution is the increasing awareness of the respiratory manifestations of these rare diseases. This review updates clinicians, stratifying diseases spirometerically; pulmonary hypertension and diseases with a predisposition to recurrent pulmonary infection are discussed. This division is artificial; many diseases have multiple pathologic effects on respiration. This review does not cover the impact of obesity.
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Affiliation(s)
- Alexander A Broomfield
- Willink Biochemical Genetics Unit, Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK.
| | - Raja Padidela
- Department of Paediatric Endocrinology, Royal Manchester Children's Hospital, Manchester, UK; Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Stuart Wilkinson
- Respiratory Department Royal Manchester Children's Hospital, Manchester University, NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
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New therapeutic options for bone diseases. Wien Med Wochenschr 2021; 171:120-125. [PMID: 33512621 DOI: 10.1007/s10354-020-00810-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 12/28/2020] [Indexed: 02/07/2023]
Abstract
In recent years, new treatment options for both common and rare bone diseases have become available. The sclerostin antibody romosozumab is the most recently approved drug for the therapy of postmenopausal osteoporosis. Its anabolic capacity makes it a promising treatment option for severe osteoporosis. Other sclerostin antibodies for the treatment of rare bone diseases such as osteogenesis imperfecta are currently being investigated. For rare bone diseases such as X‑linked hypophosphatemia (XLH) and hypophosphatasia (HPP), specific therapies are now also available, showing promising data in children and adults with a severe disease course. However, long-term data are needed to assess a sustained benefit for patients.
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Zhang Z, Nam HK, Crouch S, Hatch NE. Tissue Nonspecific Alkaline Phosphatase Function in Bone and Muscle Progenitor Cells: Control of Mitochondrial Respiration and ATP Production. Int J Mol Sci 2021; 22:ijms22031140. [PMID: 33498907 PMCID: PMC7865776 DOI: 10.3390/ijms22031140] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 01/17/2021] [Accepted: 01/20/2021] [Indexed: 12/23/2022] Open
Abstract
Tissue nonspecific alkaline phosphatase (TNAP/Alpl) is associated with cell stemness; however, the function of TNAP in mesenchymal progenitor cells remains largely unknown. In this study, we aimed to establish an essential role for TNAP in bone and muscle progenitor cells. We investigated the impact of TNAP deficiency on bone formation, mineralization, and differentiation of bone marrow stromal cells. We also pursued studies of proliferation, mitochondrial function and ATP levels in TNAP deficient bone and muscle progenitor cells. We find that TNAP deficiency decreases trabecular bone volume fraction and trabeculation in addition to decreased mineralization. We also find that Alpl−/− mice (global TNAP knockout mice) exhibit muscle and motor coordination deficiencies similar to those found in individuals with hypophosphatasia (TNAP deficiency). Subsequent studies demonstrate diminished proliferation, with mitochondrial hyperfunction and increased ATP levels in TNAP deficient bone and muscle progenitor cells, plus intracellular expression of TNAP in TNAP+ cranial osteoprogenitors, bone marrow stromal cells, and skeletal muscle progenitor cells. Together, our results indicate that TNAP functions inside bone and muscle progenitor cells to influence mitochondrial respiration and ATP production. Future studies are required to establish mechanisms by which TNAP influences mitochondrial function and determine if modulation of TNAP can alter mitochondrial respiration in vivo.
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Affiliation(s)
- Zhi Zhang
- Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Rd, Dearborn, MI 48128, USA;
| | - Hwa Kyung Nam
- School of Dentistry, University of Michigan-Ann Arbor, 1011 N University Avenue, Ann Arbor, MI 48103, USA; (H.K.N.); (S.C.)
| | - Spencer Crouch
- School of Dentistry, University of Michigan-Ann Arbor, 1011 N University Avenue, Ann Arbor, MI 48103, USA; (H.K.N.); (S.C.)
| | - Nan E. Hatch
- School of Dentistry, University of Michigan-Ann Arbor, 1011 N University Avenue, Ann Arbor, MI 48103, USA; (H.K.N.); (S.C.)
- Correspondence: ; Tel.: +1-734-764-6567
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TNAP as a New Player in Chronic Inflammatory Conditions and Metabolism. Int J Mol Sci 2021; 22:ijms22020919. [PMID: 33477631 PMCID: PMC7831495 DOI: 10.3390/ijms22020919] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/14/2021] [Accepted: 01/14/2021] [Indexed: 12/19/2022] Open
Abstract
This review summarizes important information on the ectoenzyme tissue-nonspecific alkaline phosphatase (TNAP) and gives a brief insight into the symptoms, diagnostics, and treatment of the rare disease Hypophosphatasia (HPP), which is resulting from mutations in the TNAP encoding ALPL gene. We emphasize the role of TNAP beyond its well-known contribution to mineralization processes. Therefore, above all, the impact of the enzyme on central molecular processes in the nervous system and on inflammation is presented here.
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