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Burton BK, Clague GE, Harding CO, Kucuksayrac E, Levy DG, Lindstrom K, Longo N, Maillot F, Muntau AC, Rutsch F, Zori RT. Long-term comparative effectiveness of pegvaliase versus medical nutrition therapy with and without sapropterin in adults with phenylketonuria. Mol Genet Metab 2024; 141:108114. [PMID: 38142628 DOI: 10.1016/j.ymgme.2023.108114] [Citation(s) in RCA: 1] [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: 08/13/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 12/26/2023]
Abstract
Phenylketonuria is characterized by intellectual disability and behavioral, psychiatric, and movement disorders resulting from phenylalanine (Phe) accumulation. Standard-of-care treatment involves a Phe-restricted diet plus medical nutrition therapy (MNT), with or without sapropterin dihydrochloride, to reduce blood Phe levels. Pegvaliase is an injectable enzyme substitution treatment approved for adult patients with blood Phe >600 μmol/L despite ongoing management. A previous comparative effectiveness analysis using data from the Phase 3 PRISM trials of pegvaliase (NCT01819727 and NCT01889862) and the Phenylketonuria Demographics, Outcomes and Safety Registry (PKUDOS; NCT00778206) suggested that pegvaliase was more effective at lowering mean blood Phe levels than sapropterin + MNT or MNT alone at 1 and 2 years of treatment. The current work augments and complements the previous analysis by including additional follow-up from the completed studies, robust methods reflecting careful consideration of issues with the distribution of Phe, and alternative methods for adjustment that are important for control of potential confounding in comparative effectiveness. Median blood Phe levels were lower, and median intact protein intakes were higher, in the pegvaliase group (n = 183) than in the sapropterin + MNT (n = 82) and MNT (n = 67) groups at Years 1, 2, and 3. In the pegvaliase group, median blood Phe levels decreased from baseline (1244 μmol/L) to Year 1 (535 μmol/L), Year 2 (142 μmol/L), and Year 3 (167 μmol/L). In the sapropterin + MNT group, median blood Phe levels decreased from baseline (900 μmol/L) to Year 1 (588 μmol/L) and Year 2 (592 μmol/L), and increased at Year 3 (660 μmol/L). In the MNT group, median blood Phe levels decreased slightly from baseline (984 μmol/L) to Year 1 (939 μmol/L) and Year 2 (941 μmol/L), and exceeded baseline levels at Year 3 (1157 μmol/L). The model-estimated proportions of participants achieving blood Phe ≤600 μmol/L were 41%, 100%, and 100% in the pegvaliase group at Years 1, 2, and 3, respectively, compared with 55%, 58%, and 38% in the sapropterin + MNT group and 5%, 16%, and 0% in the MNT group. The estimated proportions of participants achieving more stringent blood Phe targets of ≤360 μmol/L and ≤120 μmol/L were also higher in the pegvaliase group than in the other groups at Years 2 and 3. Overall, our results indicate that, compared with standard therapy, pegvaliase induces a substantial, progressive, and sustained decrease in blood Phe levels - to a much greater extent than sapropterin + MNT or MNT alone - which is expected to improve long-term outcomes in patients with phenylketonuria.
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Affiliation(s)
| | | | | | | | - Drew G Levy
- BioMarin Pharmaceutical Inc., Novato, CA, USA
| | | | | | - François Maillot
- Service de Médecine Interne, CHRU et Université de Tours, Tours, France
| | - Ania C Muntau
- University Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Frank Rutsch
- Department of General Pediatrics, Münster University Children's Hospital, Münster, Germany
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Vos EN, Demirbas D, Mangel M, Gozalbo MER, Levy HL, Berry GT. The treatment of biochemical genetic diseases: From substrate reduction to nucleic acid therapies. Mol Genet Metab 2023; 140:107693. [PMID: 37716025 DOI: 10.1016/j.ymgme.2023.107693] [Citation(s) in RCA: 1] [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: 07/07/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/18/2023]
Abstract
Newborn screening (NBS) began a revolution in the management of biochemical genetic diseases, greatly increasing the number of patients for whom dietary therapy would be beneficial in preventing complications in phenylketonuria as well as in a few similar disorders. The advent of next generation sequencing and expansion of NBS have markedly increased the number of biochemical genetic diseases as well as the number of patients identified each year. With the avalanche of new and proposed therapies, a second wave of options for the treatment of biochemical genetic disorders has emerged. These therapies range from simple substrate reduction to enzyme replacement, and now ex vivo gene therapy with autologous cell transplantation. In some instances, it may be optimal to introduce nucleic acid therapy during the prenatal period to avoid fetopathy. However, as with any new therapy, complications may occur. It is important for physicians and other caregivers, along with ethicists, to determine what new therapies might be beneficial to the patient, and which therapies have to be avoided for those individuals who have less severe problems and for which standard treatments are available. The purpose of this review is to discuss the "Standard" treatment plans that have been in place for many years and to identify the newest and upcoming therapies, to assist the physician and other healthcare workers in making the right decisions regarding the initiation of both the "Standard" and new therapies. We have utilized several diseases to illustrate the applications of these different modalities and discussed for which disorders they may be suitable. The future is bright, but optimal care of the patient, including and especially the newborn infant, requires a deep knowledge of the disease process and careful consideration of the necessary treatment plan, not just based on the different genetic defects but also with regards to different variants within a gene itself.
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Affiliation(s)
- E Naomi Vos
- Division of Genetics & Genomics, Boston Children's Hospital; and Department of Pediatrics, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States of America; Manton Center for Orphan Disease Research, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, United States of America.
| | - Didem Demirbas
- Division of Genetics & Genomics, Boston Children's Hospital; and Department of Pediatrics, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States of America; Manton Center for Orphan Disease Research, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, United States of America.
| | - Matthew Mangel
- Division of Genetics & Genomics, Boston Children's Hospital; and Department of Pediatrics, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States of America.
| | - M Estela Rubio Gozalbo
- Department of Pediatrics and Clinical Genetics, Maastricht University Medical Centre+, P. Debyelaan 25, 6229 HX Maastricht, the Netherlands; GROW, Maastricht University, Minderbroedersberg 4-6, 6211 LK Maastricht, the Netherlands; MetabERN: European Reference Network for Hereditary Metabolic Disorders, Udine, Italy; UMD: United for Metabolic Diseases Member, Amsterdam, the Netherlands.
| | - Harvey L Levy
- Division of Genetics & Genomics, Boston Children's Hospital; and Department of Pediatrics, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States of America.
| | - Gerard T Berry
- Division of Genetics & Genomics, Boston Children's Hospital; and Department of Pediatrics, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States of America; Manton Center for Orphan Disease Research, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, United States of America.
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Rovelli V, Ercoli V, Dionigi AR, Paci S, Salvatici E, Zuvadelli J, Banderali G. Low bone mineralization in phenylketonuria may be due to undiagnosed metabolic acidosis. Mol Genet Metab Rep 2023; 36:100998. [PMID: 37600232 PMCID: PMC10432846 DOI: 10.1016/j.ymgmr.2023.100998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 08/04/2023] [Accepted: 08/04/2023] [Indexed: 08/22/2023] Open
Abstract
Background Dietary intervention is to date the mainstay treatment to prevent toxic phenylalanine (Phe) accumulation in PKU patients. Despite success preventing central nervous system damage, there is increasing evidence of possible other unfavorable outcomes affecting other systems, e.g. kidney and bone; underlying mechanisms are yet to be fully elucidated. Methods This observational, cross-sectional and descriptive study investigated 20 adult with PKU evaluating biochemical parameters, BMD measurements and extrapolating data from 3-days food records and protein substitutes (PS) and special low protein foods (SLPF) composition. Results Blood gas venous analysis (VBG) indices were indicative of metabolic acidosis in 60% of PKU patients and VBG pH significantly correlated with BMD's Z-score (p-value = 0.022) even if its overall mean was in range (-1.29). Low bone mineral density for chronological age (Z-score < - 2.0) was found in 4 patients (20%). Indices of kidney function were not impaired. All used PS had a moderate excess of acidity, while SLPF were alkalizing and type/variety of consumed vegetables did not determine significant changes in acid-base equilibrium. Total intakes of potassium and magnesium were lower than expected. Discussion PKU patients seem to be at risk of metabolic acidosis, directly linked to possible low bone mineralization. This may be related to the acidic composition of PS, potentially capable of acidifying the entire diet. Reported low intakes of potassium and magnesium may be relevant to these observations. Further studies are needed to better address these topics.
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Affiliation(s)
- Valentina Rovelli
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Vittoria Ercoli
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Alice Re Dionigi
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Sabrina Paci
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Elisabetta Salvatici
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Juri Zuvadelli
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Giuseppe Banderali
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
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Gama MI, Daly A, Ashmore C, Evans S, Moreira-Rosário A, Rocha JC, MacDonald A. Impact on Diet Quality and Burden of Care in Sapropterin Dihydrochloride Use in Children with Phenylketonuria: A 6 Month Follow-Up Report. Nutrients 2023; 15:3603. [PMID: 37630793 PMCID: PMC10459538 DOI: 10.3390/nu15163603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 08/10/2023] [Accepted: 08/12/2023] [Indexed: 08/27/2023] Open
Abstract
INTRODUCTION In phenylketonuria (PKU) changes in dietary patterns and behaviors in sapropterin-responsive populations have not been widely reported. We aimed to assess changes in food quality, mental health and burden of care in a paediatric PKU sapropterin-responsive cohort. METHODS In an observational, longitudinal study, patient questionnaires on food frequency, neophobia, anxiety and depression, impact on family and burden of care were applied at baseline, 3 and 6-months post successful sapropterin-responsiveness testing (defined as a 30% reduction in blood phenylalanine levels). RESULTS 17 children (10.8 ± 4.2 years) completed 6-months follow-up. Patients body mass index (BMI) z-scores remained unchanged after sapropterin initiation. Blood phenylalanine was stable. Natural protein increased (p < 0.001) and protein substitute intake decreased (p = 0.002). There were increases in regular cow's milk (p = 0.001), meat/fish, eggs (p = 0.005), bread (p = 0.01) and pasta (p = 0.011) intakes but special low-protein foods intake decreased. Anxiety (p = 0.016) and depression (p = 0.022) decreased in caregivers. The impact-on-family, familial-social impact (p = 0.002) and personal strain (p = 0.001) lessened. After sapropterin, caregivers spent less time on PKU tasks, the majority ate meals outside the home more regularly and fewer caregivers had to deny food choices to their children. CONCLUSION There were significant positive changes in food patterns, behaviors and burden of care in children with PKU and their families after 6-months on sapropterin treatment.
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Affiliation(s)
- Maria Inês Gama
- Birmingham Children’s Hospital, Steelhouse Lane, Birmingham B4 6NH, UK; (M.I.G.); (A.D.); (C.A.); (S.E.)
- Nutrition and Metabolism, NOVA Medical School, Faculdade de Ciências Médicas da Universidade NOVA de Lisboa, Campo dos Mártires da Pátria 130, 1169-056 Lisboa, Portugal; (A.M.-R.); (J.C.R.)
| | - Anne Daly
- Birmingham Children’s Hospital, Steelhouse Lane, Birmingham B4 6NH, UK; (M.I.G.); (A.D.); (C.A.); (S.E.)
| | - Catherine Ashmore
- Birmingham Children’s Hospital, Steelhouse Lane, Birmingham B4 6NH, UK; (M.I.G.); (A.D.); (C.A.); (S.E.)
| | - Sharon Evans
- Birmingham Children’s Hospital, Steelhouse Lane, Birmingham B4 6NH, UK; (M.I.G.); (A.D.); (C.A.); (S.E.)
| | - André Moreira-Rosário
- Nutrition and Metabolism, NOVA Medical School, Faculdade de Ciências Médicas da Universidade NOVA de Lisboa, Campo dos Mártires da Pátria 130, 1169-056 Lisboa, Portugal; (A.M.-R.); (J.C.R.)
- CINTESIS@RISE, Nutrition and Metabolism, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, 1169-056 Lisboa, Portugal
| | - Júlio César Rocha
- Nutrition and Metabolism, NOVA Medical School, Faculdade de Ciências Médicas da Universidade NOVA de Lisboa, Campo dos Mártires da Pátria 130, 1169-056 Lisboa, Portugal; (A.M.-R.); (J.C.R.)
- CINTESIS@RISE, Nutrition and Metabolism, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, 1169-056 Lisboa, Portugal
- Reference Centre of Inherited Metabolic Diseases, Centro Hospitalar Universitário de Lisboa Central, 1169-045 Lisboa, Portugal
| | - Anita MacDonald
- Birmingham Children’s Hospital, Steelhouse Lane, Birmingham B4 6NH, UK; (M.I.G.); (A.D.); (C.A.); (S.E.)
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Suitability and Allocation of Protein-Containing Foods According to Protein Tolerance in PKU: A 2022 UK National Consensus. Nutrients 2022; 14:nu14234987. [PMID: 36501017 PMCID: PMC9736047 DOI: 10.3390/nu14234987] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 11/15/2022] [Accepted: 11/17/2022] [Indexed: 11/25/2022] Open
Abstract
Introduction: There is little practical guidance about suitable food choices for higher natural protein tolerances in patients with phenylketonuria (PKU). This is particularly important to consider with the introduction of adjunct pharmaceutical treatments that may improve protein tolerance. Aim: To develop a set of guidelines for the introduction of higher protein foods into the diets of patients with PKU who tolerate >10 g/day of protein. Methods: In January 2022, a 26-item food group questionnaire, listing a range of foods containing protein from 5 to >20 g/100 g, was sent to all British Inherited Metabolic Disease Group (BIMDG) dietitians (n = 80; 26 Inherited Metabolic Disease [IMD] centres). They were asked to consider within their IMD dietetic team when they would recommend introducing each of the 26 protein-containing food groups into a patient’s diet who tolerated >10 g to 60 g/day of protein. The patient protein tolerance for each food group that received the majority vote from IMD dietetic teams was chosen as its tolerance threshold for introduction. A virtual meeting was held using Delphi methodology in March 2022 to discuss and agree final consensus. Results: Responses were received from dietitians from 22/26 IMD centres (85%) (11 paediatric, 11 adult). For patients tolerating protein ≥15 g/day, the following foods were agreed for inclusion: gluten-free pastas, gluten-free flours, regular bread, cheese spreads, soft cheese, and lentils in brine; for protein tolerance ≥20 g/day: nuts, hard cheeses, regular flours, meat/fish, and plant-based alternative products (containing 5−10 g/100 g protein), regular pasta, seeds, eggs, dried legumes, and yeast extract spreads were added; for protein tolerance ≥30 g/day: meat/fish and plant-based alternative products (containing >10−20 g/100 g protein) were added; and for protein tolerance ≥40 g/day: meat/fish and plant-based alternatives (containing >20 g/100 g protein) were added. Conclusion: This UK consensus by IMD dietitians from 22 UK centres describes for the first time the suitability and allocation of higher protein foods according to individual patient protein tolerance. It provides valuable guidance for health professionals to enable them to standardize practice and give rational advice to patients.
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Adolfsen KJ, Callihan I, Monahan CE, Greisen PJ, Spoonamore J, Momin M, Fitch LE, Castillo MJ, Weng L, Renaud L, Weile CJ, Konieczka JH, Mirabella T, Abin-Fuentes A, Lawrence AG, Isabella VM. Improvement of a synthetic live bacterial therapeutic for phenylketonuria with biosensor-enabled enzyme engineering. Nat Commun 2021; 12:6215. [PMID: 34711827 PMCID: PMC8553829 DOI: 10.1038/s41467-021-26524-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 10/12/2021] [Indexed: 11/09/2022] Open
Abstract
In phenylketonuria (PKU) patients, a genetic defect in the enzyme phenylalanine hydroxylase (PAH) leads to elevated systemic phenylalanine (Phe), which can result in severe neurological impairment. As a treatment for PKU, Escherichia coli Nissle (EcN) strain SYNB1618 was developed under Synlogic's Synthetic Biotic™ platform to degrade Phe from within the gastrointestinal (GI) tract. This clinical-stage engineered strain expresses the Phe-metabolizing enzyme phenylalanine ammonia lyase (PAL), catalyzing the deamination of Phe to the non-toxic product trans-cinnamate (TCA). In the present work, we generate a more potent EcN-based PKU strain through optimization of whole cell PAL activity, using biosensor-based high-throughput screening of mutant PAL libraries. A lead enzyme candidate from this screen is used in the construction of SYNB1934, a chromosomally integrated strain containing the additional Phe-metabolizing and biosafety features found in SYNB1618. Head-to-head, SYNB1934 demonstrates an approximate two-fold increase in in vivo PAL activity compared to SYNB1618.
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Affiliation(s)
- Kristin J Adolfsen
- Zymergen Inc. (formerly enEvolv Inc.), 100 Acorn Park Drive, Cambridge, MA, 02140, USA
| | - Isolde Callihan
- Zymergen Inc. (formerly enEvolv Inc.), 100 Acorn Park Drive, Cambridge, MA, 02140, USA
| | | | - Per Jr Greisen
- Zymergen Inc. (formerly enEvolv Inc.), 100 Acorn Park Drive, Cambridge, MA, 02140, USA
- Novo Nordisk Research Center Seattle Inc, 530 Fairview Ave N, Seattle, WA, 98109, USA
| | - James Spoonamore
- Zymergen Inc. (formerly enEvolv Inc.), 100 Acorn Park Drive, Cambridge, MA, 02140, USA
| | - Munira Momin
- Synlogic Inc, 301 Binney St, Cambridge, MA, 02139, USA
| | - Lauren E Fitch
- Zymergen Inc. (formerly enEvolv Inc.), 100 Acorn Park Drive, Cambridge, MA, 02140, USA
| | | | - Lindong Weng
- Zymergen Inc. (formerly enEvolv Inc.), 100 Acorn Park Drive, Cambridge, MA, 02140, USA
- Sana Biotechnology, 1 Tower Place Suite 500, South San Francisco, CA, 94080, USA
| | - Lauren Renaud
- Synlogic Inc, 301 Binney St, Cambridge, MA, 02139, USA
| | - Carl J Weile
- Zymergen Inc. (formerly enEvolv Inc.), 100 Acorn Park Drive, Cambridge, MA, 02140, USA
| | - Jay H Konieczka
- Zymergen Inc. (formerly enEvolv Inc.), 100 Acorn Park Drive, Cambridge, MA, 02140, USA
| | | | | | - Adam G Lawrence
- Zymergen Inc. (formerly enEvolv Inc.), 100 Acorn Park Drive, Cambridge, MA, 02140, USA
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Makukh HV, Chorna LB, Tyrkus MY, Akopyan HR, Shuvarska VI, Malakhova AY, Poliakova YO. Analysis of the PAH Gene Mutations in the Ukrainian Population: A Report from the West Ukrainian Region. CYTOL GENET+ 2021. [DOI: 10.3103/s0095452721050066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Muntau AC, Burlina A, Eyskens F, Freisinger P, Leuzzi V, Sivri HS, Gramer G, Pazdírková R, Cleary M, Lotz-Havla AS, Lane P, Alvarez I, Rutsch F. Long-term efficacy and safety of sapropterin in patients who initiated sapropterin at < 4 years of age with phenylketonuria: results of the 3-year extension of the SPARK open-label, multicentre, randomised phase IIIb trial. Orphanet J Rare Dis 2021; 16:341. [PMID: 34344399 PMCID: PMC8335897 DOI: 10.1186/s13023-021-01968-1] [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] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 07/19/2021] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND During the initial 26-week SPARK (Safety Paediatric efficAcy phaRmacokinetic with Kuvan®) study, addition of sapropterin dihydrochloride (Kuvan®; a synthetic formulation of the natural cofactor for phenylalanine hydroxylase, tetrahydrobiopterin; BH4), to a phenylalanine (Phe)-restricted diet, led to a significant improvement in Phe tolerance versus a Phe-restricted diet alone in patients aged 0-4 years with BH4-responsive phenylketonuria (PKU) or mild hyperphenylalaninaemia (HPA). Based on these results, the approved indication for sapropterin in Europe was expanded to include patients < 4 years of age. Herein, we present results of the SPARK extension study (NCT01376908), evaluating the long-term safety, dietary Phe tolerance, blood Phe concentrations and neurodevelopmental outcomes in patients < 4 years of age at randomisation, over an additional 36 months of treatment with sapropterin. RESULTS All 51 patients who completed the 26-week SPARK study period entered the extension period. Patients who were previously treated with a Phe-restricted diet only ('sapropterin extension' group; n = 26), were initiated on sapropterin at 10 mg/kg/day, which could be increased up to 20 mg/kg/day. Patients previously treated with sapropterin plus Phe-restricted diet, remained on this regimen in the extension period ('sapropterin continuous' group; n = 25). Dietary Phe tolerance increased significantly at the end of the study versus baseline (week 0), by 38.7 mg/kg/day in the 'sapropterin continuous' group (95% CI 28.9, 48.6; p < 0.0001). In the 'sapropterin extension' group, a less pronounced effect was observed, with significant differences versus baseline (week 27) only observed between months 9 and 21; dietary Phe tolerance at the end of study increased by 5.5 mg/kg/day versus baseline (95% CI - 2.8, 13.8; p = 0.1929). Patients in both groups had normal neuromotor development and growth parameters. CONCLUSIONS Long-term treatment with sapropterin plus a Phe-restricted diet in patients who initiated sapropterin at < 4 years of age with BH4-responsive PKU or mild HPA maintained improvements in dietary Phe tolerance over 3.5 years. These results continue to support the favourable risk/benefit profile for sapropterin in paediatric patients (< 4 years of age) with BH4-responsive PKU. Frequent monitoring of blood Phe levels and careful titration of dietary Phe intake to ensure adequate levels of protein intake is necessary to optimise the benefits of sapropterin treatment. Trial registration ClinicalTrials.gov, NCT01376908. Registered 17 June 2011, https://clinicaltrials.gov/ct2/show/NCT01376908 .
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Affiliation(s)
- Ania C Muntau
- University Children's Hospital, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
| | | | | | | | | | | | - Gwendolyn Gramer
- Division for Neuropaediatrics and Metabolic Medicine, Centre for Paediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Renata Pazdírková
- Department of Children and Adolescents, Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | | | | | | | | | - Frank Rutsch
- Muenster University Children's Hospital, Muenster, Germany
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Viau K, Wessel A, Martell L, Sacharow S, Rohr F. Nutrition status of adults with phenylketonuria treated with pegvaliase. Mol Genet Metab 2021; 133:345-351. [PMID: 34116943 DOI: 10.1016/j.ymgme.2021.06.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/02/2021] [Accepted: 06/04/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND Pegvaliase is an enzyme substitution therapy that reduces blood phenylalanine (Phe) in adults with phenylketonuria (PKU), and often allows normalization of protein intake (≥0.8 g protein/kg). Here we examine the nutrition status of adults with PKU consuming a normal protein intake without medical food after being treated with pegvaliase for ≥1 year. METHODS A cross-sectional study evaluating nutritional intake (3-day food record and food frequency questionnaire), anthropometrics, laboratory indices of protein, micronutrient, and essential fatty acid (EFA) status, and questionnaires evaluating food neophobia and Epicurean eating pleasure. RESULTS Participants (n = 18, 61% female) started pegvaliase 4.9 ± 2.1 years prior to enrollment and were aged 38.2 ± 8.8 years with a mean BMI of 29.2 ± 4.1 kg/m2. Participants consumed a mean of 73.2 ± 17.6 g protein/d (1.0 ± 0.3 g/kg/d). Eleven participants had low blood Phe (<30 μmol/L) with adequate protein intake and normal indices of protein status. Micronutrient and EFA concentrations were normal except for mildly low vitamin D (<30 ng/mL, n = 12). Intakes of sodium, saturated fat, and added sugars exceeded recommendations for healthy adults, though mean diet quality was comparable to a US adult reference population. Lower food neophobia scores correlated with an increased aesthetic appreciation of food. However, 53% of participants self-reported having moderate (n = 6) to high (n = 3) food neophobia. DISCUSSION Participants treated with pegvaliase consumed an unrestricted diet with adequate dietary protein and, overall, had normal protein, micronutrient, and fatty acid status. Despite low blood Phe, protein nutriture was not compromised. While nutritional deficiencies were not identified, diet quality was suboptimal and some participants reported food neophobia. Nutrition education remains an important component of care as patients adapt to a normal diet.
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Affiliation(s)
- Krista Viau
- Division of Genetics and Genomics, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, United States.
| | - Ann Wessel
- Division of Genetics and Genomics, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, United States
| | - Leslie Martell
- Division of Genetics and Genomics, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, United States
| | - Stephanie Sacharow
- Division of Genetics and Genomics, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, United States; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, United States
| | - Fran Rohr
- Met Ed, Boulder, CO 80302, United States
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Lah M, McPheron M. Palynziq clinic: One year and 43 patients later. Mol Genet Metab 2021; 133:250-256. [PMID: 34074593 DOI: 10.1016/j.ymgme.2021.05.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 04/19/2021] [Accepted: 05/16/2021] [Indexed: 01/31/2023]
Abstract
Pegvaliase-pqpz (Palynziq) is an enzyme substitution therapy FDA approved May 2018 to treat phenylketonuria in adults with blood phenylalanine levels greater than 600 μmol/L (10 mg/dL). Pegvaliase is administered via subcutaneous injection and carries a high risk of side effects including anaphylaxis. A consensus statement on its use recommends careful education and monitoring of patients. We established a dedicated Palynziq Clinic in October 2018 with detailed protocols to minimize these risks. In the first year, we evaluated 43 patients, initiated Palynziq in 37 and transitioned two trial patients to commercial drug. 13/37 patients (35.1%) have sustained blood phenylalanine levels <360 μmol/L (6 mg/dL) without adjunct sapropterin dihydrochloride treatment or medical food. The timing and dosage needed to achieve a response did not correlate with patient weight, starting phenylalanine level, starting diet, or co-treatment with sapropterin dihydrochloride. Some patients had consistently low phenylalanine levels <30 μmol/L (0.5 mg/dL) and required doses as low as 20 mg weekly. Anaphylactic episodes were reported by 21.6% (8/37 patients) versus 10% seen in the clinical trial. Rates of other side effects were similar to or less than those in the trial. Adverse reactions commonly occurred shortly after dosage increases. We provide a model for safely introducing and managing pegvaliase in adult patients with PKU.
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Affiliation(s)
- Melissa Lah
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, United States of America.
| | - Molly McPheron
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, United States of America
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11
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Waisbren S, Burton BK, Feigenbaum A, Konczal LL, Lilienstein J, McCandless SE, Rowell R, Sanchez-Valle A, Whitehall KB, Longo N. Long-term preservation of intellectual functioning in sapropterin-treated infants and young children with phenylketonuria: A seven-year analysis. Mol Genet Metab 2021; 132:119-127. [PMID: 33485801 PMCID: PMC8684368 DOI: 10.1016/j.ymgme.2021.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 01/04/2021] [Accepted: 01/04/2021] [Indexed: 11/19/2022]
Abstract
Sapropterin dihydrochloride has been approved for the treatment of hyperphenylalaninemia in infants and young children with phenylketonuria (PKU). Sapropterin can reduce phenylalanine (Phe) levels in tetrahydrobiopterin (BH4)-responsive patients, potentially preventing the intellectual impairment caused by elevated Phe levels. The long-term effect of sapropterin on intellectual functioning was assessed using the Full-Scale Intelligence Quotient (FSIQ) in 62 children who began treatment before the age of 6 years. Over each 2-year interval, the estimate of mean change in FSIQ was -0.5768 with a lower limit of the 95% confidence interval (CI) of -1.60. At the end of the follow-up period (Year 7), the least squares mean estimate of the change in FSIQ from baseline was 1.14 with a lower limit of the 95% CI of -3.53. These lower limits were both within the clinically expected variation of 5 points. During the whole study period, mean blood Phe levels remained within the American College of Medical Genetics (ACMG) target range of 120-360 μmol/L. In addition, height, weight, and head circumference were maintained within normal ranges throughout follow-up, as defined by growth charts from the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) for children below and above the age of 24 months, respectively. All patients (n = 65) enrolled in this study experienced at least one adverse event, as expected from previous studies. In conclusion, long-term use of sapropterin in individuals with PKU helps to control blood Phe, preserve intellectual functioning, and maintain normal growth in BH4-responsive children who initiated treatment between the ages of 0 to 6 years.
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Affiliation(s)
- Susan Waisbren
- Harvard Medical School, Boston Children's Hospital, Boston, MA, USA
| | - Barbara K Burton
- Ann & Robert H. Lurie Children's Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Annette Feigenbaum
- The Hospital for Sick Children and University of Toronto, Toronto, Ontario, Canada
| | - Laura L Konczal
- Center for Human Genetics, University Hospitals Cleveland Medical Center and Case Western Reserve University, Cleveland, OH, USA
| | | | - Shawn E McCandless
- Section of Genetics and Metabolism, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Children's Hospital Colorado, Aurora, CO, USA
| | | | | | | | - Nicola Longo
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA.
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12
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Sarodaya N, Suresh B, Kim KS, Ramakrishna S. Protein Degradation and the Pathologic Basis of Phenylketonuria and Hereditary Tyrosinemia. Int J Mol Sci 2020; 21:ijms21144996. [PMID: 32679806 PMCID: PMC7404301 DOI: 10.3390/ijms21144996] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 07/10/2020] [Accepted: 07/13/2020] [Indexed: 12/15/2022] Open
Abstract
A delicate intracellular balance among protein synthesis, folding, and degradation is essential to maintaining protein homeostasis or proteostasis, and it is challenged by genetic and environmental factors. Molecular chaperones and the ubiquitin proteasome system (UPS) play a vital role in proteostasis for normal cellular function. As part of protein quality control, molecular chaperones recognize misfolded proteins and assist in their refolding. Proteins that are beyond repair or refolding undergo degradation, which is largely mediated by the UPS. The importance of protein quality control is becoming ever clearer, but it can also be a disease-causing mechanism. Diseases such as phenylketonuria (PKU) and hereditary tyrosinemia-I (HT1) are caused due to mutations in PAH and FAH gene, resulting in reduced protein stability, misfolding, accelerated degradation, and deficiency in functional proteins. Misfolded or partially unfolded proteins do not necessarily lose their functional activity completely. Thus, partially functional proteins can be rescued from degradation by molecular chaperones and deubiquitinating enzymes (DUBs). Deubiquitination is an important mechanism of the UPS that can reverse the degradation of a substrate protein by covalently removing its attached ubiquitin molecule. In this review, we discuss the importance of molecular chaperones and DUBs in reducing the severity of PKU and HT1 by stabilizing and rescuing mutant proteins.
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Affiliation(s)
- Neha Sarodaya
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 04763, Korea; (N.S.); (B.S.)
| | - Bharathi Suresh
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 04763, Korea; (N.S.); (B.S.)
| | - Kye-Seong Kim
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 04763, Korea; (N.S.); (B.S.)
- College of Medicine, Hanyang University, Seoul 04763, Korea
- Correspondence: (K.-S.K.); or (S.R.)
| | - Suresh Ramakrishna
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 04763, Korea; (N.S.); (B.S.)
- College of Medicine, Hanyang University, Seoul 04763, Korea
- Correspondence: (K.-S.K.); or (S.R.)
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13
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Lipids and phenylketonuria: Current evidences pointed the need for lipidomics studies. Arch Biochem Biophys 2020; 688:108431. [DOI: 10.1016/j.abb.2020.108431] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 05/06/2020] [Accepted: 05/20/2020] [Indexed: 02/06/2023]
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14
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Evers RAF, van Vliet D, van Spronsen FJ. Tetrahydrobiopterin treatment in phenylketonuria: A repurposing approach. J Inherit Metab Dis 2020; 43:189-199. [PMID: 31373030 DOI: 10.1002/jimd.12151] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 07/01/2019] [Accepted: 07/04/2019] [Indexed: 12/24/2022]
Abstract
In phenylketonuria (PKU) patients, early diagnosis by neonatal screening and immediate institution of a phenylalanine-restricted diet can prevent severe intellectual impairment. Nevertheless, outcome remains suboptimal in some patients asking for additional treatment strategies. Tetrahydrobiopterin (BH4 ) could be one of those treatment options, as it may not only increase residual phenylalanine hydroxylase activity in BH4 -responsive PKU patients, but possibly also directly improves neurocognitive functioning in both BH4 -responsive and BH4 -unresponsive PKU patients. In the present review, we aim to further define the theoretical working mechanisms by which BH4 might directly influence neurocognitive functioning in PKU having passed the blood-brain barrier. Further research should investigate which of these mechanisms are actually involved, and should contribute to the development of an optimal BH4 treatment regimen to directly improve neurocognitive functioning in PKU. Such possible repurposing approach of BH4 treatment in PKU may improve neuropsychological outcome and mental health in both BH4 -responsive and BH4 -unresponsive PKU patients.
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Affiliation(s)
- Roeland A F Evers
- Division of Metabolic Diseases, University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, Groningen, The Netherlands
| | - Danique van Vliet
- Division of Metabolic Diseases, University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, Groningen, The Netherlands
| | - Francjan J van Spronsen
- Division of Metabolic Diseases, University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, Groningen, The Netherlands
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15
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Krämer J. Sustaining benefits of nutritional therapy in young adults with phenylketonuria - A 2 year prospective study. Mol Genet Metab Rep 2020; 22:100573. [PMID: 32099818 PMCID: PMC7026618 DOI: 10.1016/j.ymgmr.2020.100573] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 01/31/2020] [Indexed: 01/09/2023] Open
Abstract
Introduction Phenylketonuria (PKU) is an inborn error of metabolism, which is caused by a deficiency in the enzyme phenylalanine hydroxylase (PAH). Life-long Phe-free diet impairs quality of life, especially in adolescents and young adults which take responsibility over their diet and therapy from their parents, but expect freedom in daily routine. Methods and results 105 patients with PKU were screened for eligibility for participating in this study. Data of 21 patients with genetic predictive value (GPV) ≤5 and age between 14 and 30 years were included in the analysis. Mean age of the study population was 22.6 ± 7.5 years, 8 patients (38%) were female. At baseline, structured counselling by a professional nutrionist was performed. Mean Phe-level at baseline was 926 ± 432 μmol/l, after six months Phe-levels were significantly reduced to 709 ± 314 μmol/l (p = .039), in total 4 additional patients (38% of the population) reached values within the therapeutic goal. After 12, 18 and 24 months, mean Phe-level elevated significantly to initial level (869 ± 427 μmol/l; p = .311). Mean daily intake of natural protein at baseline was 32.3 ± 24.3 g per day. There was a significant decrease after 6 months (26.9 ± 18.8 g/day; p = .049) and 12 months (25.9 ± 16.2 g/day; p = .30) compared to baseline. Values at 18 months (27.5 ± 9.2 g/day; p = .26) and 24 months (35.0 ± 22.3 g/day; p = .87) did not differ. Mean daily supplementation of Phe-free amino acids was 26.2 ± 19.2 g per day. In all follow-up examinations a significant increase compared to baseline values was calculated (42.4 ± 17.6 g/day after 6 moths (p = .028), 52.1 ± 29.9 g/day after 12 months (p ≤.01), 38.7 ± 20.3 g/day after 18 months (p < .01) and 39.3 ± 21.9 g/day after 24 months (p = .014)). At baseline, mean total protein intake (natural protein plus supplements) was 0.97 ± 0.42 g per kg body weight (g/kgBW). After 24 months the protein intake was within recommended levels. (1.23 ± 0.33 g/kgKB; p = .013). After 24 months, plasma Vitamin B12 increased to 424.8 ± 176.9 pg/ml (baseline 368.6 ± 205.6 pg/ml; p = .049) and Vitamin D increased to 30.4 ± 9.9 ng/ml (baseline 24.5 ± 10.1 ng/ml; p = .06). Conclusion Counselling by a professional nutrionist in young adults with PKU has clear short-term effects on plasma Phe-levels. Easy applicable therapeutic recommendations, as additional intake of amino acid supplement, are well tolerated and result in strict therapy adherence up to 24 months. Apart from that, the effects on Phe-levels seem only to sustain for about 6 months. More frequent nutritional counselling, i.e. at least two times per year, is recommended to preserve positive effects on Phe-levels. Lack of Vitamin B12 and Vitamin D still are common in PKU patients, but not necessarily need to be substituted. They can effectively be equalized by a well-balanced diet within 24 months.
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Affiliation(s)
- Johannes Krämer
- Corresponding author at: University of Ulm, Division of Pediatric Neurology and Inborn Errors of Metabolism, Eythstr. 24, 89075 Ulm, Germany.
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16
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Krämer J. Case-control study about the acceptance of Pegvaliase in Phenylketonuria. Mol Genet Metab Rep 2020; 22:100557. [PMID: 31956507 PMCID: PMC6957785 DOI: 10.1016/j.ymgmr.2019.100557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 12/21/2019] [Indexed: 10/25/2022] Open
Abstract
Introduction Pegvaliase is a novel enzyme substitution therapy approved by the European Drug Administration (EDA) in May 2019 for the treatment of Phenylketonuria (PKU) in adults and children ≥16 years of age. The pegylated phenylalanine ammonia lyase is isolated from bacteria and therefore provokes multifarious immunogenic reactions. Thus, the selection of the right patient for a potential harmful treatment is essential for patient's contentedness and long-term therapy compliance. Methods and results 101 patients with PKU were screened for eligibility for an additional treatment with Pegvaliase. 51 patients were included in the study, 26 received a structural information about the new treatment for in mean 43 ± 12 min and clinical data and plasma Phe-levels were assessed. After 4 weeks of consideration the willing of treatment initiation as well as reasons for denial are registered. 7 patients (27%) concluded in beginning of treatment. Phe-level in this (acceptance) group were higher (1180 ± 231 μmol/l) compared to the denial group (930 ± 278 μmol/l, p = .01). After 4 weeks Phe-levels in the acceptance group remained stable (1264 ± 311 μmol/l, p = .26) while Phe-levels in the denial group decreased (779 ± 226 μmol/l, p < .01). Main reasons for denial of therapy were fear of adverse effects (47%), no need for additional treatment (26%) and the subcutaneous way of application (21%). Conclusion PKU patients have reservations against an invasive subcutaneous treatment for their disease. This is mainly caused by the form of application by syringe and the potential harmful side effects. Only less than one-third of the patients in our cohort are willing to start treatment. Besides that, most PKU patients seem to have untapped potential for self-contained reduction of Phe-levels only by being focused on their diet.
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Affiliation(s)
- Johannes Krämer
- Division of Inborn Errors of Metabolism, Children's Hospital, University of Ulm, Ulm, Germany.,Division of Pediatric Neurology, Children's Hospital, University of Ulm, Ulm, Germany
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17
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Zori R, Ahring K, Burton B, Pastores GM, Rutsch F, Jha A, Jurecki E, Rowell R, Harding C. Long-term comparative effectiveness of pegvaliase versus standard of care comparators in adults with phenylketonuria. Mol Genet Metab 2019; 128:92-101. [PMID: 31439512 PMCID: PMC9013411 DOI: 10.1016/j.ymgme.2019.07.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 07/30/2019] [Accepted: 07/30/2019] [Indexed: 12/20/2022]
Abstract
Phenylketonuria (PKU) is caused by phenylalanine hydroxylase (PAH) deficiency, resulting in high blood and brain Phenylalanine (Phe) concentrations that can lead to impaired brain development and function. Standard treatment involves a Phe-restricted diet alone or in conjunction with sapropterin dihydrochloride in responsive patients. The Food and Drug Administration approved pegvaliase enzyme substitution therapy for adults with blood Phe >600 μmol/L in the US. Recently, the European Commission also approved pegvaliase for treatment of PKU patients aged 16 years or older with blood Phe >600 μmol/L. The analyses presented below were conducted to provide comparative evidence on long-term treatment effectiveness of pegvaliase versus standard of care in adults with PKU. Adult patients (≥18 years) with baseline blood Phe >600 μmol/L who had enrolled in the pegvaliase phase 2 and phase 3 clinical trials were propensity score-matched to historical cohorts of patients treated with "sapropterin + diet" or with "diet alone". These cohorts were derived from the PKU Demographics, Outcome and Safety (PKUDOS) registry and compared for clinical outcomes including blood Phe concentration and natural intact protein intake after 1 and 2 years. Propensity scores were estimated using logistic regression with probability of treatment as outcome (i.e. pegvaliase, "sapropterin + diet", or "diet alone") and patient demographic and disease severity covariates as predictors. An additional analysis in adult PKU patients with baseline blood Phe ≤600 μmol/L comparing non-matched patient groups "sapropterin + diet" to "diet alone" using PKUDOS registry data only was also conducted. The analyses in patients with baseline blood Phe >600 μmol comparing pegvaliase with "sapropterin + diet" (N = 64 matched pairs) showed lower mean blood Phe concentrations after 1 and 2 years with pegvaliase (505 and 427 μmol/L) versus "sapropterin + diet" (807 and 891 μmol/L); mean natural intact protein intake after 1 and 2 years was 49 and 57 g/day respectively with pegvaliase versus 23 and 28 g/day with "sapropterin + diet". The analysis comparing pegvaliase with "diet alone" (N = 120 matched pairs) showed lower mean blood Phe at 1 and 2 years with pegvaliase (473 and 302 μmol/L) versus "diet alone" (1022 and 965 μmol/L); mean natural intact protein intake after 1 and 2 years was 47 and 57 g/day with pegvaliase and 27 and 22 g/day with "diet alone". Considerably more patients achieved blood Phe ≤600, ≤360, and ≤120 μmol/L and reductions from baseline of ≥20%, ≥30%, and ≥50% in blood Phe after 1 and 2 years of pegvaliase versus standard treatments. The analysis in patients with baseline blood Phe ≤600 μmol/L showed lower blood Phe after 1 and 2 years with "sapropterin + diet" (240 and 324 μmol/L) versus "diet alone" (580 and 549 μmol/L) and greater percentages of patients achieving blood Phe targets ≤600, ≤360, and ≤120 μmol/L and reductions from baseline of ≥20%, ≥30%, and ≥50% in blood Phe. These results support pegvaliase as the more effective treatment option to lower Phe levels in adults with PKU who have difficulty keeping blood Phe ≤600 μmol/L with "diet alone". For patients with blood Phe ≤600 μmol/L, adding sapropterin to dietary management is an appropriate treatment option, for those responsive to the treatment.
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Affiliation(s)
- Roberto Zori
- University of Florida Health, Gainesville, FL, USA.
| | - Kirsten Ahring
- Copenhagen University Hospital, Department of Paediatrics, PKU Clinic, Copenhagen, Denmark.
| | | | - Gregory M Pastores
- Mater Misericordiae University Hospital, University College Dublin, Dublin, Ireland.
| | - Frank Rutsch
- Münster University Children's Hospital, Department of General Pediatrics, Münster, Germany.
| | | | | | | | - Cary Harding
- Oregon Health & Science University, Portland, OR, USA.
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Eshraghi P, Noroozi Asl S, Bagheri S, Chalak V. Response to sapropterin hydrochloride (Kuvan®) in children with phenylketonuria (PKU): a clinical trial. J Pediatr Endocrinol Metab 2019; 32:885-888. [PMID: 31237861 DOI: 10.1515/jpem-2018-0503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 04/23/2019] [Indexed: 01/29/2023]
Abstract
Background Phenylketonuria (PKU) is one of the most common types of inborn error of metabolism. The mainstay of therapy for PKU has been dietary phenylalanine (Phe) restriction. Sapropterin dihydrochloride has been shown to be effective in reducing Phe levels in PKU patients. Methods This study was a clinical trial performed in the pediatric endocrine clinic of Imam Reza Hospital, Mashhad, Iran. Results All children between 1 and 10 years of age with a diagnosis of PKU whose serum Phe levels were between 120 and 360 μmol/L, in Khorasan Razavi province in the north-east of Iran, were enrolled. Twenty-four patients were enrolled in the study. Intervention: A free diet for 72 h was allowed and then a 20-mg/kg/day dose of Kuvan® was administered. More than 30% reduction in blood Phe levels was described as responsive. Eight patients responded to the loading test and were eligible for the second stage of the study. In this stage, Phe powder in combination with Kuvan was provided. Patients' serum Phe was measured weekly for 3 months. All eight patients showed Phe tolerance in 3 months, and their serum Phe levels remained within the range. Conclusions Treatment with Kuvan can help reduce blood Phe levels in our pediatric PKU population and allows patients to follow a more liberal diet.
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Affiliation(s)
- Peyman Eshraghi
- Department of Pediatric Endocrinology and Metabolism, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Samaneh Noroozi Asl
- Department of Pediatric Endocrinology and Metabolism, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Sepideh Bagheri
- Assistant Professor of Pediatrics, Department of Pediatrics, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran, Phone: +989155255451
| | - Vajiheh Chalak
- Department of Pediatrics, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
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Muntau AC, Adams DJ, Bélanger-Quintana A, Bushueva TV, Cerone R, Chien YH, Chiesa A, Coşkun T, de Las Heras J, Feillet F, Katz R, Lagler F, Piazzon F, Rohr F, van Spronsen FJ, Vargas P, Wilcox G, Bhattacharya K. International best practice for the evaluation of responsiveness to sapropterin dihydrochloride in patients with phenylketonuria. Mol Genet Metab 2019; 127:1-11. [PMID: 31103398 DOI: 10.1016/j.ymgme.2019.04.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/14/2019] [Accepted: 04/13/2019] [Indexed: 12/26/2022]
Abstract
Phenylketonuria (PKU) is an inherited metabolic disease caused by phenylalanine hydroxylase (PAH) deficiency. As the resulting high blood phenylalanine (Phe) concentration can have detrimental effects on brain development and function, international guidelines recommend lifelong control of blood Phe concentration with dietary and/or medical therapy. Sapropterin dihydrochloride is a synthetic preparation of tetrahydrobiopterin (6R-BH4), the naturally occurring cofactor of PAH. It acts as a pharmacological chaperone, reducing blood Phe concentration and increasing dietary Phe tolerance in BH4-responsive patients with PAH deficiency. Protocols to establish responsiveness to sapropterin dihydrochloride vary widely. Two meetings were held with an international panel of clinical experts in PKU management to develop recommendations for sapropterin dihydrochloride response testing. At the first meeting, regional differences and similarities in testing practices were discussed based on guidelines, a literature review, outcomes of a global physician survey, and case reports. Statements developed based on the discussions were sent to all participants for consensus (>70% of participants) evaluation using a 7-level rating system, and further discussed during the second meeting. The experts recommend sapropterin dihydrochloride response testing in patients with untreated blood Phe concentrations of 360-2000 μmol/L, except in those with two null mutations. For neonates, a 24-h sapropterin dihydrochloride loading test is recommended; responsiveness is defined as a decrease in blood Phe ≥30%. For older infants, children, adolescents, and adults, a test duration of ≥48 h or a 4-week trial is recommended. The main endpoint for a 48-h to 7-day trial is a decrease in blood Phe, while improved Phe tolerance is the endpoint to be assessed during a longer trial. Longer trials may not be feasible in some locations due to lack of reimbursement for hospitalization, while a 4-week trial may not be possible due to limited access to sapropterin dihydrochloride or public health regulation. A 48-h response test should be considered in pregnant patients who cannot achieve blood Phe ≤360 μmol/L with a Phe-restricted diet. Durability of response and clinical benefits of sapropterin dihydrochloride should be assessed over the long term. Harmonization of protocols is expected to improve identification of responders and comparability of test results worldwide.
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Affiliation(s)
- Ania C Muntau
- University Children's Hospital, University Medical Center Hamburg Eppendorf, Hamburg, Germany.
| | - Darius J Adams
- Atlantic Health System, Morristown Medical Center, Morristown, NJ, USA.
| | | | - Tatiana V Bushueva
- National Medical Research Center of Children's Health of the Ministry of Health of the Russian Federation, Moscow, Russia.
| | - Roberto Cerone
- G. Gaslini Institute, University of Genova, Genova, Italy.
| | | | - Ana Chiesa
- Centro de Investigaciones Endocrinologicas "Dr Cesar Bergadá" CEDIE, CONICET, Hospital de Niños Ricardo Gutierrez, Fundacion de Endocrinologia Infantil, Buenos Aires, Argentina.
| | - Turgay Coşkun
- Hacettepe University Faculty of Medicine, Ankara, Turkey.
| | - Javier de Las Heras
- Hospital Universitario de Cruces, Biocruces Health Research Institute and University of the Basque Country UPV/EHU, Vizcaya, Spain.
| | - François Feillet
- Children's University Hospital, CHU Brabois, Vandoeuvre les Nancy, France.
| | - Rachel Katz
- Ann and Robert Lurie Children's Hospital of Chicago, Chicago, IL, USA.
| | | | - Flavia Piazzon
- Associação de Pais e Amigos dos Excepcionais de São Paulo (APAE DE SÃO PAULO), São Paulo, SP, Brazil.
| | - Fran Rohr
- Boston Children's Hospital, Boston, MA, USA.
| | - Francjan J van Spronsen
- Beatrix Children's Hospital, University Medical Center of Groningen, University of Groningen, Groningen, the Netherlands.
| | - Paula Vargas
- Hospital Materno Infantil Presidente Vargas, Porto Alegre, RS, Brazil.
| | - Gisela Wilcox
- University of Manchester & Salford Royal NHS Foundation Trust, Salford, UK.
| | - Kaustuv Bhattacharya
- Genetic Metabolic Disorders Service, University of Sydney, Children's Hospital Westmead Clinical School, Sydney, NSW, Australia.
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Dobrowolski SF, Tourkova IL, Robinson LJ, Secunda C, Spridik K, Blair HC. A bone mineralization defect in the Pah enu2 model of classical phenylketonuria involves compromised mesenchymal stem cell differentiation. Mol Genet Metab 2018; 125:193-199. [PMID: 30201326 PMCID: PMC6542264 DOI: 10.1016/j.ymgme.2018.08.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 08/20/2018] [Accepted: 08/20/2018] [Indexed: 11/29/2022]
Abstract
Osteopenia is observed in some patients affected by phenylalanine hydroxylase (PAH) deficient phenylketonuria (PKU). Bone density studies, in diverse PKU patient cohorts, have demonstrated bone disease is neither fully penetrant nor uniform in bone density loss. Biochemical assessment has generated a muddled perspective regarding mechanisms of the PKU bone phenotype where the participation of hyperphenylalaninemia remains unresolved. Osteopenia is realized in the Pahenu2 mouse model of classical PKU; although, characterization is incomplete. We characterized the Pahenu2 bone phenotype and assessed the effect of hyperphenylalaninemia on bone differentiation. Employing Pahenu2 and control animals, cytology, static and dynamic histomorphometry, and biochemistry were applied to further characterize the bone phenotype. These investigations demonstrate Pahenu2 bone density is decreased 33% relative to C57BL/6; bone volume/total volume was similarly decreased; trabecular thickness was unchanged while increased trabecular spacing was observed. Dynamic histomorphometry demonstrated a 25% decrease in mineral apposition. Biochemically, control and PKU animals have similar plasma cortisol, adrenocorticotropic hormone, and 25-hydroxyvitamin D. PKU animals show moderately increased plasma parathyroid hormone while plasma calcium and phosphate are reduced. These data are consistent with a mineralization defect. The effect of hyperphenylalaninemia on bone maturation was assessed in vitro employing bone-derived mesenchymal stem cells (MSCs) and their differentiation into bone. Using standard culture conditions, PAH deficient MSCs differentiate into bone as assessed by in situ alkaline phosphatase activity and mineral staining. However, PAH deficient MSCs cultured in 1200 μM PHE (metric defining classical PKU) show significantly reduced mineralization. These data are the first biological evidence demonstrating a negative impact of hyperphenylalaninemia upon bone maturation. In PAH deficient MSCs, expression of Col1A1 and Rankl are suppressed by hyperphenylalaninemia consistent with reduced bone formation and bone turnover. Osteopenia is intrinsic to PKU pathology in untreated Pahenu2 animals and our data suggests PHE toxicity participates by inhibiting mineralization in the course of MSC bone differentiation.
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Affiliation(s)
- Steven F Dobrowolski
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States.
| | - Irina L Tourkova
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Lisa J Robinson
- Department of Pathology, Ruby Memorial Hospital, West Virginia University, Morgantown, WV, United States
| | - Cassandra Secunda
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Kayla Spridik
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Harry C Blair
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States; Veteran's Affairs Medical Center, Pittsburgh, PA, United States
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Abstract
Inborn errors of metabolism comprise a wide array of diseases and complications in the pediatric patient. The rarity of these disorders limits the ability to conduct and review robust literature regarding the disease states, mechanisms of dysfunction, treatments, and outcomes. Often, treatment plans will be based on the pathophysiology associated with the disorder and theoretical agents that may be involved in the metabolic process. Medication therapies usually consist of natural or herbal products. Established efficacious pediatric doses for these products are difficult to find in tertiary resources, and adverse effects are routinely limited to single case reports. This review article attempts to summarize some of the more common inborn errors of metabolism in a manner that is applicable to pharmacists who will provide care for these patients.
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Brantley KD, Douglas TD, Singh RH. One-year follow-up of B vitamin and Iron status in patients with phenylketonuria provided tetrahydrobiopterin (BH4). Orphanet J Rare Dis 2018; 13:192. [PMID: 30373601 PMCID: PMC6206913 DOI: 10.1186/s13023-018-0923-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 10/02/2018] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND People with Phenylketonuria (PKU) who respond to tetrahydrobiopterin (BH4) often decrease dependence on medical food (MF) following increased phenylalanine (phe) tolerance. Responders to BH4 may experience a reduction in certain nutrients if not compensated through intact foods or supplements. This study investigated B6, B12, folate, and iron status based on blood levels and dietary intake in patients with PKU responsive to BH4 over 1 year. METHODS Fifty-eight patients with PKU, ages 4-50 years were recruited and initiated on BH4 therapy. Patients were monitored for BH4 response, and nutritional status was recorded at regular intervals over 12 months. The analysis included 33 patients with known BH4 response status and complete nutritional data. Nutrient intake was determined by National Data System for Research (NDSR) analysis of self reported 3 day diet records and compared to Dietary Reference Intakes (DRIs). Blood biomarkers were analyzed by Quest Diagnostics and compared to laboratory reference ranges. Patient laboratory values were compared to controls from the National Health and Examination Survey (NHANES). Differences in nutrient intakes across time points were examined, stratified by age, using nonparametric methods. Statistical analyses were completed with SAS 9.4, with significance set at α = 0.05. RESULTS Medical food intake declined among pediatric (p < 0.01) and adult (p = 0.06) BH4 responders over 1 year. Among those < 18 years of age, mean percent of calories obtained from MF declined from 21.3 to 4.7%. In adults, percent calories from MF dropped from 19.5 to 4.0%. Though maintaining laboratory and dietary values within reference ranges, responders < 18 years experienced a significant decline in serum B12 (p = 0.01), dietary folate (p = 0.006), and dietary iron (p = 0.004) over the study. CONCLUSION Although mean dietary and laboratory values for B12, B6, folate, and iron in BH4 responders and non-responders were adequate at baseline and 12-month follow-up, responders experienced a significant decline in serum B12 over 1 year, which may be explained by decreased intake of fortified MF. Both response groups had lower serum B12 than NHANES controls at baseline and 12 months. Results indicate a need to monitor B12 concentrations and consider micronutrient supplementation, with special attention to pediatric patients with PKU.
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Affiliation(s)
| | - Teresa D Douglas
- Department of Human Genetics, Metabolic Nutrition Program, Emory University School of Medicine, Atlanta, GA USA
| | - Rani H Singh
- Department of Human Genetics, Metabolic Nutrition Program, Emory University School of Medicine, Atlanta, GA USA
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23
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Isabella VM, Ha BN, Castillo MJ, Lubkowicz DJ, Rowe SE, Millet YA, Anderson CL, Li N, Fisher AB, West KA, Reeder PJ, Momin MM, Bergeron CG, Guilmain SE, Miller PF, Kurtz CB, Falb D. Development of a synthetic live bacterial therapeutic for the human metabolic disease phenylketonuria. Nat Biotechnol 2018; 36:857-864. [DOI: 10.1038/nbt.4222] [Citation(s) in RCA: 251] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Accepted: 07/20/2018] [Indexed: 01/01/2023]
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24
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Ohashi A, Mamada K, Harada T, Naito M, Takahashi T, Aizawa S, Hasegawa H. Organic anion transporters, OAT1 and OAT3, are crucial biopterin transporters involved in bodily distribution of tetrahydrobiopterin and exclusion of its excess. Mol Cell Biochem 2017; 435:97-108. [PMID: 28534121 PMCID: PMC5632347 DOI: 10.1007/s11010-017-3060-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 05/04/2017] [Indexed: 01/05/2023]
Abstract
Tetrahydrobiopterin (BH4) is a common coenzyme of phenylalanine-, tyrosine-, and tryptophan hydroxylases, alkylglycerol monooxygenase, and NO synthases (NOS). Synthetic BH4 is used medicinally for BH4-responsive phenylketonuria and inherited BH4 deficiency. BH4 supplementation has also drawn attention as a therapy for various NOS-related cardio-vascular diseases, but its use has met with limited success in decreasing BH2, the oxidized form of BH4. An increase in the BH2/BH4 ratio leads to NOS dysfunction. Previous studies revealed that BH4 supplementation caused a rapid urinary loss of BH4 accompanied by an increase in the blood BH2/BH4 ratio and an involvement of probenecid-sensitive but unknown transporters was strongly suggested in these processes. Here we show that OAT1 and OAT3 enabled cells to take up BP (BH4 and/or BH2) in a probenecid-sensitive manner using rat kidney slices and transporter-expressing cell systems, LLC-PK1 cells and Xenopus oocytes. Both OAT1 and OAT3 preferred BH2 and sepiapterin as their substrate roughly 5- to 10-fold more than BH4. Administration of probenecid acutely reduced the urinary exclusion of endogenous BP accompanied by a rise in blood BP in vivo. These results indicated that OAT1 and OAT3 played crucial roles: (1) in determining baseline levels of blood BP by excluding endogenous BP through the urine, (2) in the rapid distribution to organs of exogenous BH4 and the exclusion to urine of a BH4 excess, particularly when BH4 was administered, and (3) in scavenging blood BH2 by cellular uptake as the gateway to the salvage pathway of BH4, which reduces BH2 back to BH4.
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Affiliation(s)
- Akiko Ohashi
- Department of Anatomy, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda, Tokyo, 101-8310, Japan.
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Chiyoda, Tokyo, 101-8310, Japan.
| | - Kaori Mamada
- Department of Biosciences, Teikyo University of Science and Technology, Uenohara, Yamanashi, 401-0193, Japan
| | - Tomonori Harada
- Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine, Itabashi, Tokyo, 173-8610, Japan
| | - Masako Naito
- Department of Anatomy, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda, Tokyo, 101-8310, Japan
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Chiyoda, Tokyo, 101-8310, Japan
| | - Tomihisa Takahashi
- Department of Anatomy, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda, Tokyo, 101-8310, Japan
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Chiyoda, Tokyo, 101-8310, Japan
| | - Shin Aizawa
- Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine, Itabashi, Tokyo, 173-8610, Japan
| | - Hiroyuki Hasegawa
- Department of Anatomy, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda, Tokyo, 101-8310, Japan
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van Wegberg AMJ, MacDonald A, Ahring K, Bélanger-Quintana A, Blau N, Bosch AM, Burlina A, Campistol J, Feillet F, Giżewska M, Huijbregts SC, Kearney S, Leuzzi V, Maillot F, Muntau AC, van Rijn M, Trefz F, Walter JH, van Spronsen FJ. The complete European guidelines on phenylketonuria: diagnosis and treatment. Orphanet J Rare Dis 2017; 12:162. [PMID: 29025426 PMCID: PMC5639803 DOI: 10.1186/s13023-017-0685-2] [Citation(s) in RCA: 407] [Impact Index Per Article: 58.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 07/11/2017] [Indexed: 12/22/2022] Open
Abstract
Phenylketonuria (PKU) is an autosomal recessive inborn error of phenylalanine metabolism caused by deficiency in the enzyme phenylalanine hydroxylase that converts phenylalanine into tyrosine. If left untreated, PKU results in increased phenylalanine concentrations in blood and brain, which cause severe intellectual disability, epilepsy and behavioural problems. PKU management differs widely across Europe and therefore these guidelines have been developed aiming to optimize and standardize PKU care. Professionals from 10 different European countries developed the guidelines according to the AGREE (Appraisal of Guidelines for Research and Evaluation) method. Literature search, critical appraisal and evidence grading were conducted according to the SIGN (Scottish Intercollegiate Guidelines Network) method. The Delphi-method was used when there was no or little evidence available. External consultants reviewed the guidelines. Using these methods 70 statements were formulated based on the highest quality evidence available. The level of evidence of most recommendations is C or D. Although study designs and patient numbers are sub-optimal, many statements are convincing, important and relevant. In addition, knowledge gaps are identified which require further research in order to direct better care for the future.
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Affiliation(s)
- A. M. J. van Wegberg
- Division of Metabolic Diseases, Beatrix Children’s Hospital, University Medical Center Groningen, PO BOX 30.001, 9700 RB Groningen, The Netherlands
| | - A. MacDonald
- Dietetic Department, Birmingham Children’s Hospital, Birmingham, UK
| | - K. Ahring
- Department of PKU, Kennedy Centre, Glostrup, Denmark
| | - A. Bélanger-Quintana
- Metabolic Diseases Unit, Department of Paediatrics, Hospital Ramon y Cajal Madrid, Madrid, Spain
| | - N. Blau
- University Children’s Hospital, Dietmar-Hoppe Metabolic Centre, Heidelberg, Germany
- University Children’s Hospital Zürich, Zürich, Switzerland
| | - A. M. Bosch
- Department of Paediatrics, Division of Metabolic Disorders, Academic Medical Centre, University Hospital of Amsterdam, Amsterdam, The Netherlands
| | - A. Burlina
- Division of Inherited Metabolic Diseases, Department of Paediatrics, University Hospital of Padova, Padova, Italy
| | - J. Campistol
- Neuropaediatrics Department, Hospital Sant Joan de Déu, Universitat de Barcelona, Barcelona, Spain
| | - F. Feillet
- Department of Paediatrics, Hôpital d’Enfants Brabois, CHU Nancy, Vandoeuvre les Nancy, France
| | - M. Giżewska
- Department of Paediatrics, Endocrinology, Diabetology, Metabolic Diseases and Cardiology of the Developmental Age, Pomeranian Medical University, Szczecin, Poland
| | - S. C. Huijbregts
- Department of Clinical Child and Adolescent Studies-Neurodevelopmental Disorders, Faculty of Social Sciences, Leiden University, Leiden, The Netherlands
| | - S. Kearney
- Clinical Psychology Department, Birmingham Children’s Hospital, Birmingham, UK
| | - V. Leuzzi
- Department of Paediatrics, Child Neurology and Psychiatry, Sapienza University of Rome, Via dei Sabelli 108, 00185 Rome, Italy
| | - F. Maillot
- CHRU de Tours, Université François Rabelais, INSERM U1069, Tours, France
| | - A. C. Muntau
- University Children’s Hospital, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - M. van Rijn
- Division of Metabolic Diseases, Beatrix Children’s Hospital, University Medical Center Groningen, PO BOX 30.001, 9700 RB Groningen, The Netherlands
| | - F. Trefz
- Department of Paediatrics, University of Heidelberg, Heidelberg, Germany
| | - J. H. Walter
- Medicine, Manchester Academic Health Sciences Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester, UK
| | - F. J. van Spronsen
- Division of Metabolic Diseases, Beatrix Children’s Hospital, University Medical Center Groningen, PO BOX 30.001, 9700 RB Groningen, The Netherlands
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Thomas J, Nguyen-Driver M, Bausell H, Breck J, Zambrano J, Birardi V. Strategies for Successful Long-Term Engagement of Adults With Phenylalanine Hydroxylase Deficiency Returning to the Clinic. JOURNAL OF INBORN ERRORS OF METABOLISM AND SCREENING 2017. [DOI: 10.1177/2326409817733015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Janet Thomas
- University of Colorado School of Medicine, Aurora, CO, USA
| | | | - Heather Bausell
- Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL, USA
| | - Jane Breck
- Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, PA, USA
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Bernstein L, Burns C, Sailer-Hammons M, Kurtz A, Rohr F. Multiclinic Observations on the Simplified Diet in PKU. J Nutr Metab 2017; 2017:4083293. [PMID: 29057118 PMCID: PMC5615976 DOI: 10.1155/2017/4083293] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 07/10/2017] [Accepted: 07/25/2017] [Indexed: 11/24/2022] Open
Abstract
Phenylketonuria is an inborn error of metabolism that historically has been treated with a strict phenylalanine-restricted diet where all foods are weighed and measured. This is cumbersome and difficult for patients and caregivers, especially patients with high phenylalanine blood concentrations who often have neurocognitive deficits. The Simplified Diet is an alternative approach that allows for increased flexibility, promotes healthy food choices, and is easier to manage than a traditional diet for PKU. This paper describes the implementation of the Simplified Diet and outlines education, counseling strategies, and challenges encountered by three metabolic clinics in the United States.
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Affiliation(s)
- Laurie Bernstein
- Inherited Metabolic Diseases Clinic, Children's Hospital Colorado, Aurora, CO, USA
| | - Casey Burns
- Inherited Metabolic Diseases Clinic, Children's Hospital Colorado, Aurora, CO, USA
| | | | - Angela Kurtz
- Metabolic Nutrition Program, Division of Medical Genetics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Frances Rohr
- Department of Nutrition, Boston Children's Hospital, Boston, MA, USA
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Rossi L, Pierigè F, Antonelli A, Bigini N, Gabucci C, Peiretti E, Magnani M. Engineering erythrocytes for the modulation of drugs' and contrasting agents' pharmacokinetics and biodistribution. Adv Drug Deliv Rev 2016; 106:73-87. [PMID: 27189231 DOI: 10.1016/j.addr.2016.05.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 04/29/2016] [Accepted: 05/09/2016] [Indexed: 01/14/2023]
Abstract
Pharmacokinetics, biodistribution, and biological activity are key parameters that determine the success or failure of therapeutics. Many developments intended to improve their in vivo performance, aim at modulating concentration, biodistribution, and targeting to tissues, cells or subcellular compartments. Erythrocyte-based drug delivery systems are especially efficient in maintaining active drugs in circulation, in releasing them for several weeks or in targeting drugs to selected cells. Erythrocytes can also be easily processed to entrap the desired pharmaceutical ingredients before re-infusion into the same or matched donors. These carriers are totally biocompatible, have a large capacity and could accommodate traditional chemical entities (glucocorticoids, immunossuppresants, etc.), biologics (proteins) and/or contrasting agents (dyes, nanoparticles). Carrier erythrocytes have been evaluated in thousands of infusions in humans proving treatment safety and efficacy, hence gaining interest in the management of complex pathologies (particularly in chronic treatments and when side-effects become serious issues) and in new diagnostic approaches.
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29
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A Multiplatform Metabolomics Approach to Characterize Plasma Levels of Phenylalanine and Tyrosine in Phenylketonuria. JIMD Rep 2016; 32:69-79. [PMID: 27300702 PMCID: PMC5362559 DOI: 10.1007/8904_2016_568] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 04/15/2016] [Accepted: 04/18/2016] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Different pathophysiological mechanisms have been described in phenylketonuria (PKU) but the indirect metabolic consequences of metabolic disorders caused by elevated Phe or low Tyr concentrations remain partially unknown. We used a multiplatform metabolomics approach to evaluate the metabolic signature associated with Phe and Tyr. MATERIAL AND METHODS We prospectively included 10 PKU adult patients and matched controls. We analysed the metabolome profile using GC-MS (urine), amino-acid analyzer (urine and plasma) and nuclear magnetic resonance spectroscopy (urine). We performed a multivariate analysis from the metabolome (after exclusion of Phe, Tyr and directly derived metabolites) to explain plasma Phe and Tyr concentrations, and the clinical status. Finally, we performed a univariate analysis of the most discriminant metabolites and we identified the associated metabolic pathways. RESULTS We obtained a metabolic pattern from 118 metabolites and we built excellent multivariate models to explain Phe, Tyr concentrations and PKU diagnosis. Common metabolites of these models were identified: Gln, Arg, succinate and alpha aminobutyric acid. Univariate analysis showed an inverse correlation between Arg, alpha aminobutyric acid and Phe and a positive correlation between Arg, succinate, Gln and Tyr (p < 0.0003). Thus, we highlighted the following pathways: Arg and Pro, Ala, Asp and Glu metabolism. DISCUSSION We obtain a specific metabolic signature related to Tyr and Phe concentrations. We confirmed the involvement of different pathophysiological mechanisms previously described in PKU such as protein synthesis, energetic metabolism and oxidative stress. The metabolomics approach is relevant to explore PKU pathogenesis.
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30
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Brown CS, Lichter-Konecki U. Phenylketonuria (PKU): A problem solved? Mol Genet Metab Rep 2015; 6:8-12. [PMID: 27014571 PMCID: PMC4789336 DOI: 10.1016/j.ymgmr.2015.12.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 12/15/2015] [Accepted: 12/15/2015] [Indexed: 11/30/2022] Open
Abstract
Phenylketonuria (PKU) is a rare metabolic disorder characterized by impaired conversion of phenylalanine (Phe) to tyrosine. If left untreated, the resultant accumulation of excess blood Phe can cause physiological, neurological, and intellectual disabilities. The National PKU Alliance (NPKUA) conducted a survey of its membership to assess current health status and interest in new treatments for PKU. Of the 625 survey respondents, less than half (46.7%) reported blood Phe within (120–360 μmol/L) — the range recommended by the American College of Medical Genetics and Genomics (ACMG). The survey results also showed that younger (≤ 18 years) individuals were about 3-times as successful in keeping their blood Phe concentrations within the recommended clinical range compared with adults. Blood Phe over 360 μmol/L was reported in one-quarter (25.5%) of ≤ 18 year old individuals and almost two-thirds (61.5%) of adults. A little more than half (51.7%) of respondents reported having difficulty in managing their PKU, including the maintenance of a Phe-restricted diet. Individuals with PKU desire new treatments that would allow them to increase their intake of natural protein, discontinue or reduce their intake of medical foods (medical formula and foods modified to be low in protein), improve their mental health (including a reduction in depression and anxiety), and a reduction of their blood Phe concentrations. Respondents preferred oral administration of any newly developed therapies and, in general, disliked therapeutic injections. Injections at home were preferred over injections at a clinic. Payers, government agencies, clinicians, and industry partners should consider patient input when developing and approving new therapies and treatments for PKU.
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Affiliation(s)
| | - Uta Lichter-Konecki
- Section of Neurology, St. Christopher's Hospital for Children, Dept. of Pediatrics, Drexel University College of Medicine, United States
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