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Funck-Brentano T, Vanjak A, Ostertag A, Nethander M, Fernandez S, Collet C, Hans D, van Rietbergen B, Cohen-Solal M. Evaluation of bone density and microarchitecture in adult patients with X-linked hypophosphatemic rickets: A pilot longitudinal study. Bone 2024; 187:117179. [PMID: 38960298 DOI: 10.1016/j.bone.2024.117179] [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: 03/08/2024] [Revised: 06/24/2024] [Accepted: 06/26/2024] [Indexed: 07/05/2024]
Abstract
X-linked Hypophosphatemia (XLH) is the most common type of inherited rickets. Although the clinical features are well characterized, bone structure, mineralization, and biomechanical properties are poorly known. Our aim was to analyze bone properties in the appendicular and axial skeleton of adults with XLH. In this observational case-control study, each affected patient (N = 14; 9 females; age 50 ± 15 years) was matched by sex, age and body mass index to a minimum of two healthy controls (N = 34). Dual-energy X-ray Absorptiometry (DXA) analyses revealed that areal bone mineral density (aBMD) was higher in XLH patients at the lumbar spine (Z score mean difference = +2.47 SD, P value = 1.4 × 10-3). Trabecular Bone Score was also higher at the lumbar spine (P value = 1.0 × 10-4). High Resolution peripheral Quantitative Computed Tomography (HRpQCT) demonstrated that bone cross-sectional area was larger at the distal radius (P value = 6 × 10-3). Total and trabecular volumetric BMD were lower at both sites. Trabecular bone volume fraction was also lower with fewer trabecular numbers at both sites. However, bone strength evaluated by micro-finite element analyzes revealed unaffected bone stiffness and maximum failure load. Evaluation of bone mineralization with aBMD by DXA at the distal radius correlated with vBMD by HRpQCT measurements at both sites. PTH levels were inversely correlated with trabecular vBMD and BV/TV at the tibia. We then followed a subset of nine patients (median follow-up of 4 years) and reassessed HRpQCT. At the tibia, we observed a greater decrease than expected from an age and sex standardized normal population in total and cortical vBMD as well as a trabecularization of the cortical compartment. In conclusion, in adult patients with XLH, bone mineral density is high at the axial skeleton but low at the appendicular skeleton. With time, microarchitectural alterations worsen. We propose that noninvasive evaluation methods of bone mineralization such as DXA including the radius should be part of the management of XLH patients. Larger studies are needed to evaluate the clinical significance of BMD changes in XLH patients under conventional or targeted therapies.
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Affiliation(s)
- Thomas Funck-Brentano
- BIOSCAR UMRS 1132, INSERM, Université Paris Cité, F-75475 Paris, France; Assistance Publique des Hôpitaux de Paris, Lariboisière Hospital, DMU Locomotion, Department of Rheumatology, F-75475 Paris, France; National Reference Center For Rare Bone Diseases, Lariboisière Hospital, APHP.Nord, Filière OSCAR, F-75475 Paris, France.
| | - Arnaud Vanjak
- BIOSCAR UMRS 1132, INSERM, Université Paris Cité, F-75475 Paris, France; Assistance Publique des Hôpitaux de Paris, Lariboisière Hospital, DMU Locomotion, Department of Rheumatology, F-75475 Paris, France; National Reference Center For Rare Bone Diseases, Lariboisière Hospital, APHP.Nord, Filière OSCAR, F-75475 Paris, France.
| | - Agnes Ostertag
- BIOSCAR UMRS 1132, INSERM, Université Paris Cité, F-75475 Paris, France
| | - Maria Nethander
- Center for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, Gothenburg University, Sweden
| | - Sylvie Fernandez
- Assistance Publique des Hôpitaux de Paris, Lariboisière Hospital, DMU Locomotion, Department of Rheumatology, F-75475 Paris, France
| | - Corinne Collet
- Imagine Institut, Necker Hospital, Université Paris Cité, F-75475 Paris, France
| | - Didier Hans
- Center of Bone Diseases, Bone & Joint Department, Lausanne University Hospital, Lausanne, Switzerland
| | - Bert van Rietbergen
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Martine Cohen-Solal
- BIOSCAR UMRS 1132, INSERM, Université Paris Cité, F-75475 Paris, France; Assistance Publique des Hôpitaux de Paris, Lariboisière Hospital, DMU Locomotion, Department of Rheumatology, F-75475 Paris, France; National Reference Center For Rare Bone Diseases, Lariboisière Hospital, APHP.Nord, Filière OSCAR, F-75475 Paris, France
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Bechtold-Dalla Pozza S, Lemster S, Herzig N, Vill K, Dubinski I, Hohenfellner K. Cortical impairment and reduced muscle mass in children and young adults with nephropathic cystinosis. J Bone Miner Res 2024; 39:1094-1102. [PMID: 38864569 DOI: 10.1093/jbmr/zjae092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Revised: 05/23/2024] [Accepted: 06/11/2024] [Indexed: 06/13/2024]
Abstract
Nephropathic cystinosis is an orphan autosomal recessive lysosomal storage disease characterized by a deficiency of cystinosin, a cystine transporter protein, leading to tissue damage, primarily in the kidney and cornea. With the introduction of cystine-depleting therapy with cysteamine and the possibility to survive to adulthood, new challenges of skeletal complications are a concern, with sparse data available regarding bone development. The aim of the current study was to gain more information on bone density and geometry in these patients. Fifty-one patients (29 males, 22 females) with genetically proven nephropathic cystinosis were clinically evaluated with a medical history, physical examination, grip strength measurements, and biochemical and imaging studies. Bone mineral density, bone geometry, and muscle cross sectional area were measured, and muscle was evaluated. Results were compared with age- and gender-specific reference data. Z-scores for height (mean [M] = -1.75, standard deviation [SD] = 1.43), weight (M = -1.67, SD = 1.29), and BMI (M = -0.98, SD = 1.29) were lower than reference data. Medullary cross-sectional area (CSA) and cortical density z-scores were not compromised (M = 0.12, SD = 1.56 and M = -0.25, SD = 1.63, respectively), but cortical CSA z-scores and Strength-Strain Index (SSI) were reduced (M = -2.16, SD = 1.08, M = -2.07, SD = 1.08). Muscular deficits were reflected by reduced z-scores for muscle CSA (M = -2.43, SD = 1.27) and grip strength (M = -3.01, SD = 1.10), along with jump force (34% lower than reference value). Multiple regression analyses indicated an association of muscle mass with medullary CSA and SSI, but not with cortical CSA. While bone density parameters were normal, bone geometry was altered, resulting in a thinner cortex with possible impact on bone strength. Muscle weakness be partially responsible for altered bone geometry and could provide a potential treatment target.
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Affiliation(s)
- Susanne Bechtold-Dalla Pozza
- Department of Pediatric Endocrinology, Dr. von Hauner Children's Hospital, LMU-University of Munich, Munich, Germany
| | - Simon Lemster
- Institute for Medical Information Processing, Biometry and Epidemiology, Faculty of Medicine, LMU-University of Munich, Munich, Germany
| | - Nadine Herzig
- Schoen Clinic Munich Harlaching, Specialist Center for Pediatric and Neuro-Orthopedics, Munich, Germany
| | - Katharina Vill
- Department of Pediatric Neurology and Developmental Medicine, Dr. von Hauner Children's Hospital, LMU-University of Munich, Munich, Germany
| | - Ilja Dubinski
- Department of Pediatric Endocrinology, Dr. von Hauner Children's Hospital, LMU-University of Munich, Munich, Germany
| | - Katharina Hohenfellner
- Department of Nephrology, Department of Pediatric Nephrology, Children's Hospital Rosenheim, Rosenheim, Germany
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Stabouli S, Sommer A, Kraft S, Schweer K, Bethe D, Bertholet-Thomas A, Batte S, Ariceta G, Brengmann S, Bacchetta J, Emma F, Levtchenko E, Topaloglu R, Willem L, Haffner D, Oh J. Addressing the psychosocial aspects of transition to adult care in patients with cystinosis. Pediatr Nephrol 2024:10.1007/s00467-024-06345-1. [PMID: 38517536 DOI: 10.1007/s00467-024-06345-1] [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: 12/27/2023] [Revised: 02/23/2024] [Accepted: 02/23/2024] [Indexed: 03/24/2024]
Abstract
Cystinosis is a rare autosomal-recessive lysosomal storage disease that progressively affects multiple organs beginning with the kidneys. Patients require lifelong multidisciplinary care for the management of kidney disease and progressive extra-renal manifestations, and thus, they are especially fragile and vulnerable during transition from pediatric to adult care. Previous documents have provided guidance to help the medical transition of these highly burdened patients. Patients and their families often experience great psychological distress and face significant social challenges; for these reasons, they often need help from psychologists, social workers, and other psychosocial professionals. Due to the rarity of the disease, most psychosocial professionals have no expertise in this disorder and require advice. To this end, a steering committee (SC) composed of six experts, including pediatric nephrologists, psychologists, and social workers with experience in the care for patients with cystinosis, have identified and addressed seven key questions related to psychosocial challenges of the disease and the burden of treatment. Ten additional international experts (the extended faculty, EF) were invited to answer these questions. Since robust evidence is lacking, as in many rare diseases, conclusions were based on collective agreement between members of the SC and the EF, and the consolidated answers were summarized into expert opinion statements. The present document contains information on the concerns and psychosocial burden of patients with cystinosis and of their caregivers, and provides practical advice for timely and appropriate support to facilitate the transition to adult care.
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Affiliation(s)
- Stella Stabouli
- 1st Department of Pediatrics, Aristotle University Thessaloniki, Hippokratio Hospital, 49 Konstantinoupoleos Str, 54642, Thessaloniki, Greece.
| | - Anna Sommer
- Department of Pediatric Nephrology, University Hamburg-Eppendorf, Hamburg, Germany
| | - Stefanie Kraft
- Department of Pediatric Nephrology, University Hamburg-Eppendorf, Hamburg, Germany
| | - Katharina Schweer
- Department of Pediatric Nephrology, University Hamburg-Eppendorf, Hamburg, Germany
| | - Dirk Bethe
- Division of Pediatric Nephrology, Center for Pediatrics and Adolescent Medicine, University Hospital, Heidelberg, Germany
| | - Aurelia Bertholet-Thomas
- Pediatric Nephrology, Rheumatology and Dermatology Unit, Reference Center for Rare Renal Diseases, Hospices Civils de Lyon & INSERM1033 Research Unit, Hospital Femme Mere Enfant, Lyon 1 University, Lyon, France
| | - Suzanne Batte
- Children's Renal & Urology Unit, Queens Medical Centre, Nottingham, UK
| | - Gema Ariceta
- Department of Pediatric Nephrology, Hospital Vall d´Hebron, University Autonomous of Barcelona, Barcelona, Spain
| | - Sandra Brengmann
- Department of Pediatrics, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Justine Bacchetta
- Pediatric Nephrology, Rheumatology and Dermatology Unit, Reference Center for Rare Renal Diseases, Hospices Civils de Lyon & INSERM1033 Research Unit, Hospital Femme Mere Enfant, Lyon 1 University, Lyon, France
| | - Francesco Emma
- Division of Nephrology, Bambino Gesù Children's Hospital - IRCCS, Rome, Italy
| | - Elena Levtchenko
- Department of Pediatric Nephrology, Emma Children's Hospital, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Rezan Topaloglu
- Department of Pediatric Nephrology, Hacettepe University School of Medicine, Ankara, Turkey
| | - Lore Willem
- Department of Child Nephrology and Organ Transplantation, Leuven University Hospital, Louvain, Belgium
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Jun Oh
- Department of Pediatric Nephrology, University Hamburg-Eppendorf, Hamburg, Germany
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Méaux MN, Alioli C, Linglart A, Lemoine S, Vignot E, Bertholet-Thomas A, Peyruchaud O, Flammier S, Machuca-Gayet I, Bacchetta J. X-Linked Hypophosphatemia, Not Only a Skeletal Disease But Also a Chronic Inflammatory State. J Clin Endocrinol Metab 2022; 107:3275-3286. [PMID: 36112422 DOI: 10.1210/clinem/dgac543] [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: 05/08/2022] [Indexed: 02/13/2023]
Abstract
CONTEXT X-linked hypophosphatemia (XLH) is a rare genetic disease caused by a primary excess of fibroblast growth factor 23 (FGF23). FGF23 has been associated with inflammation and impaired osteoclastogenesis, but these pathways have not been investigated in XLH. OBJECTIVE This work aimed to evaluate whether XLH patients display peculiar inflammatory profile and increased osteoclastic activity. METHODS We performed a prospective, multicenter, cross-sectional study analyzing transcript expression of 8 inflammatory markers (Il6, Il8, Il1β, CXCL1, CCL2, CXCR3, Il1R, Il6R) by real-time quantitative polymerase chain reaction on peripheral blood mononuclear cells (PBMCs) purified from total blood samples extracted from patients and healthy control individuals. The effect of native/active vitamin D on osteoclast formation was also assessed in vitro from XLH patients' PBMCs. RESULTS In total, 28 XLH patients (17 children, among them 6 undergoing standard of care [SOC] and 11 burosumab therapy) and 19 controls were enrolled. Expression of most inflammatory markers was significantly increased in PBMCs from XLH patients compared to controls. No differences were observed between the burosumab and SOC subgroups. Osteoclast formation was significantly impaired in XLH patients. XLH mature osteoclasts displayed higher levels of inflammatory markers, being however lower in cells derived from the burosumab subgroup (as opposed to SOC). CONCLUSION We describe for the first time a peculiar inflammatory profile in XLH. Since XLH patients have a propensity to develop arterial hypertension, obesity, and enthesopathies, and because inflammation can worsen these clinical outcomes, we hypothesize that inflammation may play a critical role in these extraskeletal complications of XLH.
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Affiliation(s)
- Marie-Noëlle Méaux
- Service de Néphrologie, Rhumatologie et Dermatologie Pédiatriques, Centre de Référence des Maladies Rares du Calcium et du Phosphore, Centre de Référence des Maladies Rénales Rares Filières Maladies Rares ORKID, OSCAR et ERN ERK-Net, CHU de Lyon, 69 500 Bron, France
- INSERM, UMR 1033, Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, 69 008 Lyon, France
| | - Candide Alioli
- INSERM, UMR 1033, Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, 69 008 Lyon, France
| | - Agnès Linglart
- AP-HP, Université Paris Saclay, INSERM, Service d'endocrinologie et diabète de l'enfant, Centre de Référence des Maladies Rares du Calcium et du Phosphore, Filière de Santé Maladies Rares OSCAR, ERN endoRARE et BOND, Plateforme d'expertise des maladies rares Paris Saclay, Hôpital Bicêtre Paris-Saclay, 94 270 Le Kremlin-Bicêtre, France
| | - Sandrine Lemoine
- Département de Néphrologie, Service d'exploration Fonctionnelle rénale, Hôpital Edouard Herriot, 69 003 Lyon, France
- Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, 69 003 Lyon, France
| | - Emmanuelle Vignot
- Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, 69 003 Lyon, France
- Service de Rhumatologie, Hôpital Edouard Herriot, 69 003 Lyon, France
| | - Aurélia Bertholet-Thomas
- Service de Néphrologie, Rhumatologie et Dermatologie Pédiatriques, Centre de Référence des Maladies Rares du Calcium et du Phosphore, Centre de Référence des Maladies Rénales Rares Filières Maladies Rares ORKID, OSCAR et ERN ERK-Net, CHU de Lyon, 69 500 Bron, France
- INSERM, UMR 1033, Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, 69 008 Lyon, France
| | - Olivier Peyruchaud
- INSERM, UMR 1033, Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, 69 008 Lyon, France
| | - Sacha Flammier
- Service de Néphrologie, Rhumatologie et Dermatologie Pédiatriques, Centre de Référence des Maladies Rares du Calcium et du Phosphore, Centre de Référence des Maladies Rénales Rares Filières Maladies Rares ORKID, OSCAR et ERN ERK-Net, CHU de Lyon, 69 500 Bron, France
| | - Irma Machuca-Gayet
- INSERM, UMR 1033, Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, 69 008 Lyon, France
| | - Justine Bacchetta
- Service de Néphrologie, Rhumatologie et Dermatologie Pédiatriques, Centre de Référence des Maladies Rares du Calcium et du Phosphore, Centre de Référence des Maladies Rénales Rares Filières Maladies Rares ORKID, OSCAR et ERN ERK-Net, CHU de Lyon, 69 500 Bron, France
- INSERM, UMR 1033, Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, 69 008 Lyon, France
- Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, 69 003 Lyon, France
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O'Connell N, Oh J, Arbeiter K, Büscher A, Haffner D, Kaufeld J, Kurschat C, Mache C, Müller D, Patzer L, Weber LT, Tönshoff B, Weitz M, Hohenfellner K, Pape L. Patients With Infantile Nephropathic Cystinosis in Germany and Austria: A Retrospective Cohort Study. Front Med (Lausanne) 2022; 9:864554. [PMID: 35547226 PMCID: PMC9082678 DOI: 10.3389/fmed.2022.864554] [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: 01/28/2022] [Accepted: 03/30/2022] [Indexed: 11/13/2022] Open
Abstract
Background Infantile nephropathic cystinosis (INC) is a rare lysosomal storage disorder resulting in progressive chronic kidney disease (CKD) and a variety of extrarenal manifestations. This orphan disease remains a challenge for patients, their families and health care providers. There is currently no comprehensive study on patients' clinical course in Germany and Austria. Methods A retrospective cohort study including 74 patients at eleven centers of care was conducted. Data on time of diagnosis, CKD stage, leukocyte cystine levels (LCL), extrarenal manifestations, and treatment was collected from medical charts and subsequently analyzed using explorative statistics. Age at initiation of kidney replacement therapy (KRT) was evaluated by Kaplan-Meier analyses for different groups of patients. Results Patients were diagnosed at a median age of 15 months (IQR: 10-29, range: 0-110), more recent year of birth was not associated with earlier diagnosis. Oral cystine-depleting therapy (i.e., cysteamine) was prescribed at a median dose of 1.26 g/m2 per day (IQR: 1.03-1.48, range: 0.22-1.99). 69.2% of all 198 LCL measurements of 67 patients were within the desired target range (≤ 1 nmol cystine/mg protein). Median time-averaged LCLs per patient (n = 65) amounted to 0.57 nmol cystine/mg protein (IQR: 0.33-0.98, range: 0.07-3.13) when considering only values at least 1 year after initiation of therapy. The overall median height of 242 measurements of 68 patients was at the 7th percentile (IQR: 1-25, range: 1-99). 40.5% of the values were ≤ the 3rd percentile. Patient sex and year of birth were not associated with age at initiation of KRT, but patients diagnosed before the age of 18 months required KRT significantly later than those patients diagnosed at the age of ≥ 18 months (p = 0.033): median renal survival was 21 years (95% CI: 16, -) vs. 13 years (95% CI, 10, -), respectively. Conclusion Early diagnosis and initiation of cystine depleting therapy is important for renal survival in children with INC. Cysteamine doses and LCL showed that treatment in this cohort met international standards although there is great interindividual variety. Patient growth and other aspects of the disease should be managed more effectively in the future.
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Affiliation(s)
- Nina O'Connell
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Jun Oh
- Department of Pediatric Nephrology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Klaus Arbeiter
- Division of Pediatric Nephrology and Gastroenterology, Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Anja Büscher
- Department of Pediatrics II, University Hospital of Essen, University of Duisburg-Essen, Essen, Germany
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Jessica Kaufeld
- Department of Nephrology and Hypertension, Medical School of Hannover, Hannover, Germany
| | - Christine Kurschat
- Department II of Internal Medicine, Center for Molecular Medicine Cologne and Center for Rare Diseases Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Christoph Mache
- Children's and Adolescents' University Hospital, University of Graz, Graz, Austria
| | - Dominik Müller
- Division of Pediatric Nephrology, Charité University Medicine, Berlin, Germany
| | - Ludwig Patzer
- Children's and Adolescents' Hospital, Elisabeth Krankenhaus, Halle, Germany
| | - Lutz T Weber
- Department of Pediatric Nephrology, Children's and Adolescents' Hospital, University Hospital of Cologne, Faculty of Medicine, University of Cologne, Cologne, Germany
| | - Burkhard Tönshoff
- Department of Pediatrics I, University Children's Hospital Heidelberg, Heidelberg, Germany
| | - Marcus Weitz
- Children's and Adolescents' University Hospital, Universtiy of Tübingen, Tübingen, Germany
| | | | - Lars Pape
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany.,Department of Pediatrics II, University Hospital of Essen, University of Duisburg-Essen, Essen, Germany
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Muscle and Bone Impairment in Infantile Nephropathic Cystinosis: New Concepts. Cells 2022; 11:cells11010170. [PMID: 35011732 PMCID: PMC8749987 DOI: 10.3390/cells11010170] [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: 11/11/2021] [Revised: 12/28/2021] [Accepted: 01/01/2022] [Indexed: 11/17/2022] Open
Abstract
Cystinosis Metabolic Bone Disease (CMBD) has emerged during the last decade as a well-recognized, long-term complication in patients suffering from infantile nephropathic cystinosis (INC), resulting in significant morbidity and impaired quality of life in teenagers and adults with INC. Its underlying pathophysiology is complex and multifactorial, associating complementary, albeit distinct entities, in addition to ordinary mineral and bone disorders observed in other types of chronic kidney disease. Amongst these long-term consequences are renal Fanconi syndrome, hypophosphatemic rickets, malnutrition, hormonal abnormalities, muscular impairment, and intrinsic cellular bone defects in bone cells, due to CTNS mutations. Recent research data in the field have demonstrated abnormal mineral regulation, intrinsic bone defects, cysteamine toxicity, muscle wasting and, likely interleukin-1-driven inflammation in the setting of CMBD. Here we summarize these new pathophysiological deregulations and discuss the crucial interplay between bone and muscle in INC. In future, vitamin D and/or biotherapies targeting the IL1β pathway may improve muscle wasting and subsequently CMBD, but this remains to be proven.
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Bernardor J, Alioli C, Meaux MN, Peyruchaud O, Machuca-Gayet I, Bacchetta J. Peripheral Blood Mononuclear Cells (PBMCs) to Dissect the Underlying Mechanisms of Bone Disease in Chronic Kidney Disease and Rare Renal Diseases. Curr Osteoporos Rep 2021; 19:553-562. [PMID: 34773213 DOI: 10.1007/s11914-021-00707-6] [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: 08/12/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE OF REVIEW To describe the methods that can be used to obtain functional and mature osteoclasts from peripheral blood mononuclear cells (PBMCs) and report the data obtained with this model in two peculiar diseases, namely pediatric chronic kidney disease-associated mineral and bone disorders (CKD-MBD) and nephropathic cystinosis. To discuss future research possibilities in the field. RECENT FINDINGS Bone tissue undergoes continuous remodeling throughout life to maintain bone architecture; it involves two processes: bone formation and bone resorption with the coordinated activity of osteoblasts, osteoclasts, and osteocytes. Animal models fail to fully explain human bone pathophysiology during chronic kidney disease, mainly due to interspecies differences. The development of in vitro models has permitted to mimic human bone-related diseases as an alternative to in vivo models. Since 1997, osteoclasts have been generated in cell cultures, notably when culturing PBMCs with specific growth factors and cytokines (i.e., M-CSF and RANK-L), without the need for osteoblasts or stromal cells. These models may improve the global understanding of bone pathophysiology. They can be been used not only to evaluate the direct effects of cytokines, hormones, cells, or drugs on bone remodeling during CKD-MBD, but also in peculiar genetic renal diseases inducing specific bone impairment.
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Affiliation(s)
- Julie Bernardor
- INSERM, UMR 1033, Faculté de Médecine Lyon Est, Université Claude Bernard Lyon1, Lyon, France.
- Centre de Référence des Maladies Rares du Calcium et du Phosphate, Filière Maladies Rares OSCAR, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, Bron, France.
- Centre de Référence des Maladies Rénales Rares, Filières Maladies Rares ORKID et ERK-Net, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, Bron, France.
- Faculté de Médecine, Université de Nice Côte d'Azur, Nice, France.
- Unité d'hémodialyse pédiatrique, Archet 2, CHU de Nice, 06202, Nice, France.
| | - Candide Alioli
- INSERM, UMR 1033, Faculté de Médecine Lyon Est, Université Claude Bernard Lyon1, Lyon, France
| | - Marie-Noelle Meaux
- INSERM, UMR 1033, Faculté de Médecine Lyon Est, Université Claude Bernard Lyon1, Lyon, France
| | - Olivier Peyruchaud
- INSERM, UMR 1033, Faculté de Médecine Lyon Est, Université Claude Bernard Lyon1, Lyon, France
| | - Irma Machuca-Gayet
- INSERM, UMR 1033, Faculté de Médecine Lyon Est, Université Claude Bernard Lyon1, Lyon, France
| | - Justine Bacchetta
- INSERM, UMR 1033, Faculté de Médecine Lyon Est, Université Claude Bernard Lyon1, Lyon, France
- Centre de Référence des Maladies Rares du Calcium et du Phosphate, Filière Maladies Rares OSCAR, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, Bron, France
- Centre de Référence des Maladies Rénales Rares, Filières Maladies Rares ORKID et ERK-Net, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, Bron, France
- Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, Lyon, France
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Response to Cysteamine in Osteoclasts Obtained from Patients with Nephropathic Cystinosis: A Genotype/Phenotype Correlation. Cells 2021; 10:cells10092498. [PMID: 34572146 PMCID: PMC8467406 DOI: 10.3390/cells10092498] [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: 07/17/2021] [Revised: 09/01/2021] [Accepted: 09/15/2021] [Indexed: 02/05/2023] Open
Abstract
Bone complications of cystinosis have been recently described. The main objectives of this paper were to determine in vitro the impact of CTNS mutations and cysteamine therapy on human osteoclasts and to carry out a genotype-phenotype analysis related to osteoclastic differentiation. Human osteoclasts were differentiated from peripheral blood mononuclear cells (PBMCs) and were treated with increasing doses of cysteamine (0, 50, 200 µM) and then assessed for osteoclastic differentiation. Results are presented as median (min-max). A total of 17 patients (mainly pediatric) were included, at a median age of 14 (2–61) years, and a eGFR of 64 (23–149) mL/min/1.73 m2. Most patients (71%) were under conservative kidney management (CKM). The others were kidney transplant recipients. Three functional groups were distinguished for CTNS mutations: cystinosin variant with residual cystin efflux activity (RA, residual activity), inactive cystinosin variant (IP, inactive protein), and absent protein (AP). PBMCs from patients with residual cystinosin activity generate significantly less osteoclasts than those obtained from patients of the other groups. In all groups, cysteamine exerts an inhibitory effect on osteoclastic differentiation at high doses. This study highlights a link between genotype and osteoclastic differentiation, as well as a significant impact of cysteamine therapy on this process in humans.
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Bakkaloglu SA, Bacchetta J, Lalayiannis AD, Leifheit-Nestler M, Stabouli S, Haarhaus M, Reusz G, Groothoff J, Schmitt CP, Evenepoel P, Shroff R, Haffner D. Bone evaluation in paediatric chronic kidney disease: clinical practice points from the European Society for Paediatric Nephrology CKD-MBD and Dialysis working groups and CKD-MBD working group of the ERA-EDTA. Nephrol Dial Transplant 2021; 36:413-425. [PMID: 33245331 DOI: 10.1093/ndt/gfaa210] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Indexed: 11/13/2022] Open
Abstract
Mineral and bone disorder (MBD) is widely prevalent in children with chronic kidney disease (CKD) and is associated with significant morbidity. CKD may cause disturbances in bone remodelling/modelling, which are more pronounced in the growing skeleton, manifesting as short stature, bone pain and deformities, fractures, slipped epiphyses and ectopic calcifications. Although assessment of bone health is a key element in the clinical care of children with CKD, it remains a major challenge for physicians. On the one hand, bone biopsy with histomorphometry is the gold standard for assessing bone health, but it is expensive, invasive and requires expertise in the interpretation of bone histology. On the other hand, currently available non-invasive measures, including dual-energy X-ray absorptiometry and biomarkers of bone formation/resorption, are affected by growth and pubertal status and have limited sensitivity and specificity in predicting changes in bone turnover and mineralization. In the absence of high-quality evidence, there are wide variations in clinical practice in the diagnosis and management of CKD-MBD in childhood. We present clinical practice points (CPPs) on the assessment of bone disease in children with CKD Stages 2-5 and on dialysis based on the best available evidence and consensus of experts from the CKD-MBD and Dialysis working groups of the European Society for Paediatric Nephrology and the CKD-MBD working group of the European Renal Association-European Dialysis and Transplant Association. These CPPs should be carefully considered by treating physicians and adapted to individual patients' needs as appropriate. Further areas for research are suggested.
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Affiliation(s)
- Sevcan A Bakkaloglu
- Department of Paediatric Nephrology, Gazi University Faculty of Medicine, Ankara, Turkey
| | - Justine Bacchetta
- Department of Paediatric Nephrology, Rheumatology and Dermatology, University Children's Hospital, Lyon, France
| | - Alexander D Lalayiannis
- Renal Unit, UCL Great Ormond Street Hospital for Children Institute of Child Health, London, UK
| | - Maren Leifheit-Nestler
- Department of Paediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School Children's Hospital, Hannover, Germany
| | - Stella Stabouli
- First Department of Paediatrics, Aristotle University Thessaloniki, Thessaloniki, Greece
| | - Mathias Haarhaus
- Division of Renal Medicine and Baxter Novum, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.,Diaverum AB, Stockholm, Sweden
| | - George Reusz
- First Department of Paediatrics, Semmelweis University, Budapest, Hungary
| | - Jaap Groothoff
- Department of Paediatric Nephrology, Emma Children's Hospital, Amsterdam, The Netherlands
| | - Claus Peter Schmitt
- Division of Paediatric Nephrology, Center for Paediatric and Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
| | - Pieter Evenepoel
- Department of Microbiology and Immunology, Laboratory of Nephrology, KU Leuven, Leuven, Belgium.,Department of Nephrology, University Hospitals Leuven, Leuven, Belgium
| | - Rukshana Shroff
- Renal Unit, UCL Great Ormond Street Hospital for Children Institute of Child Health, London, UK
| | - Dieter Haffner
- Department of Paediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School Children's Hospital, Hannover, Germany
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Adult complications of nephropathic cystinosis: a systematic review. Pediatr Nephrol 2021; 36:223-236. [PMID: 32016627 DOI: 10.1007/s00467-020-04487-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 01/18/2020] [Accepted: 01/20/2020] [Indexed: 01/13/2023]
Abstract
While nephropathic cystinosis is classically thought of as a childhood disease, with improved treatments, patients are more commonly living into adulthood. We performed a systematic review of the literature available on what complications this population faces as it ages. Nearly every organ system is affected in cystinosis, either from the disease itself or from sequelae of kidney transplantation. While cysteamine is known to delay the onset of end-stage kidney disease, its effects on other complications of cystinosis are less well determined. More common adult-onset complications include myopathy, diabetes, and hypothyroidism. Some less common complications, such as neurologic dysfunction, can still have a profound impact on those with cystinosis. Areas for further research in this area include additional study of the impact of cysteamine on the nonrenal manifestations of cystinosis, as well as possible avenues for new and novel treatments.
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11
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Ewert A, Leifheit-Nestler M, Hohenfellner K, Büscher A, Kemper MJ, Oh J, Billing H, Thumfart J, Stangl G, Baur AC, Föller M, Feger M, Weber LT, Acham-Roschitz B, Arbeiter K, Tönshoff B, Zivicnjak M, Haffner D. Bone and Mineral Metabolism in Children with Nephropathic Cystinosis Compared with other CKD Entities. J Clin Endocrinol Metab 2020; 105:5837710. [PMID: 32413117 DOI: 10.1210/clinem/dgaa267] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 05/08/2020] [Indexed: 02/06/2023]
Abstract
CONTEXT Children with nephropathic cystinosis (NC) show persistent hypophosphatemia, due to Fanconi syndrome, as well as mineral and bone disorders related to chronic kidney disease (CKD); however, systematic analyses are lacking. OBJECTIVE To compare biochemical parameters of bone and mineral metabolism between children with NC and controls across all stages of CKD. DESIGN Cross-sectional multicenter study. SETTING Hospital clinics. PATIENTS Forty-nine children with NC, 80 CKD controls of the same age and CKD stage. MAIN OUTCOME MEASURES Fibroblast growth factor 23 (FGF23), soluble Klotho, bone alkaline phosphatase (BAP), tartrate-resistant acid phosphatase 5b (TRAP5b), sclerostin, osteoprotegerin (OPG), biochemical parameters related to mineral metabolism, and skeletal comorbidity. RESULTS Despite Fanconi syndrome medication, NC patients showed an 11-fold increased risk of short stature, bone deformities, and/or requirement for skeletal surgery compared with CKD controls. This was associated with a higher frequency of risk factors such as hypophosphatemia, hypocalcemia, low parathyroid hormone (PTH), metabolic acidosis, and a specific CKD stage-dependent pattern of bone marker alterations. Pretransplant NC patients in mild to moderate CKD showed a delayed increase or lacked an increase in FGF23 and sclerostin, and increased BAP, TRAP5b, and OPG concentrations compared with CKD controls. Post-transplant, BAP and OPG returned to normal, TRAP5b further increased, whereas FGF23 and PTH were less elevated compared with CKD controls and associated with higher serum phosphate. CONCLUSIONS Patients with NC show more severe skeletal comorbidity associated with distinct CKD stage-dependent alterations of bone metabolism than CKD controls, suggesting impaired mineralization and increased bone resorption, which is only partially normalized after renal transplantation.
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Affiliation(s)
- Annika Ewert
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School Children's Hospital, Hannover, Germany
| | - Maren Leifheit-Nestler
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School Children's Hospital, Hannover, Germany
| | | | - Anja Büscher
- Department of Pediatrics II, University Hospital Essen, Essen, Germany
| | | | - Jun Oh
- Division of Pediatric Nephrology, University Children's Hospital Hamburg, Hamburg, Germany
| | - Heiko Billing
- Division of Pediatric Nephrology, University Children's Hospital Tübingen, Tübingen, Germany
| | - Julia Thumfart
- Department of Pediatric Gastroenterology, Nephrology and Metabolism, Charite Hospital, Berlin, Germany
| | - Gabriele Stangl
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Anja C Baur
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Michael Föller
- Institute of Physiology, University of Hohenheim, Stuttgart, Germany
| | - Martina Feger
- Institute of Physiology, University of Hohenheim, Stuttgart, Germany
| | - Lutz T Weber
- Division of Pediatric Nephrology, Children´s and Adolescents´ Hospital, University of Cologne, Faculty of Medicine and University Hospital, Cologne, Germany
| | | | - Klaus Arbeiter
- Division of Pediatric Nephrology and Gastroenterology, Medical University Vienna, Austria
| | - Burkhard Tönshoff
- Department of Pediatrics I, University Children's Hospital Heidelberg, Heidelberg, Germany
| | - Miroslav Zivicnjak
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School Children's Hospital, Hannover, Germany
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School Children's Hospital, Hannover, Germany
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12
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Machuca-Gayet I, Quinaux T, Bertholet-Thomas A, Gaillard S, Claramunt-Taberner D, Acquaviva-Bourdain C, Bacchetta J. Bone Disease in Nephropathic Cystinosis: Beyond Renal Osteodystrophy. Int J Mol Sci 2020; 21:ijms21093109. [PMID: 32354056 PMCID: PMC7246679 DOI: 10.3390/ijms21093109] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 04/23/2020] [Accepted: 04/27/2020] [Indexed: 12/20/2022] Open
Abstract
Patients with chronic kidney disease (CKD) display significant mineral and bone disorders (CKD-MBD) that induce significant cardiovascular, growth and bone comorbidities. Nephropathic cystinosis is an inherited metabolic disorder caused by the lysosomal accumulation of cystine due to mutations in the CTNS gene encoding cystinosin, and leads to end-stage renal disease within the second decade. The cornerstone of management relies on cysteamine therapy to decrease lysosomal cystine accumulation in target organs. However, despite cysteamine therapy, patients display severe bone symptoms, and the concept of “cystinosis metabolic bone disease” is currently emerging. Even though its exact pathophysiology remains unclear, at least five distinct but complementary entities can explain bone impairment in addition to CKD-MBD: long-term consequences of renal Fanconi syndrome, malnutrition and copper deficiency, hormonal disturbances, myopathy, and intrinsic/iatrogenic bone defects. Direct effects of both CTNS mutation and cysteamine on osteoblasts and osteoclasts are described. Thus, the main objective of this manuscript is not only to provide a clinical update on bone disease in cystinosis, but also to summarize the current experimental evidence demonstrating a functional impairment of bone cells in this disease and to discuss new working hypotheses that deserve future research in the field.
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Affiliation(s)
- Irma Machuca-Gayet
- Pathophysiology, Diagnosis and Treatment of Bone Diseases, INSERM UMR 1033, 69008 Lyon, France; (I.M.-G.); (T.Q.); (D.C.-T.)
| | - Thomas Quinaux
- Pathophysiology, Diagnosis and Treatment of Bone Diseases, INSERM UMR 1033, 69008 Lyon, France; (I.M.-G.); (T.Q.); (D.C.-T.)
- Centre de Référence des Maladies Rénales Rares, Centre de Référence des Maladies Rares du Calcium et du Phosphore, Hôpital Femme Mère Enfant, 69500 Bron, France;
| | - Aurélia Bertholet-Thomas
- Centre de Référence des Maladies Rénales Rares, Centre de Référence des Maladies Rares du Calcium et du Phosphore, Hôpital Femme Mère Enfant, 69500 Bron, France;
| | - Ségolène Gaillard
- INSERM CIC 1407, CNRS UMR 5558 and Service de Pharmacotoxicologie Clinique, Hospices Civils de Lyon, 69500 Bron, France;
| | - Débora Claramunt-Taberner
- Pathophysiology, Diagnosis and Treatment of Bone Diseases, INSERM UMR 1033, 69008 Lyon, France; (I.M.-G.); (T.Q.); (D.C.-T.)
| | | | - Justine Bacchetta
- Pathophysiology, Diagnosis and Treatment of Bone Diseases, INSERM UMR 1033, 69008 Lyon, France; (I.M.-G.); (T.Q.); (D.C.-T.)
- Centre de Référence des Maladies Rénales Rares, Centre de Référence des Maladies Rares du Calcium et du Phosphore, Hôpital Femme Mère Enfant, 69500 Bron, France;
- Faculté de Médecine Lyon Est, Université de Lyon, 69008 Lyon, France
- Correspondence: ; Tel.: +33-4-27-85-61-30
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Battafarano G, Rossi M, Rega LR, Di Giovamberardino G, Pastore A, D'Agostini M, Porzio O, Nevo N, Emma F, Taranta A, Del Fattore A. Intrinsic Bone Defects in Cystinotic Mice. THE AMERICAN JOURNAL OF PATHOLOGY 2019; 189:1053-1064. [PMID: 30794806 DOI: 10.1016/j.ajpath.2019.01.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 01/09/2019] [Accepted: 01/24/2019] [Indexed: 01/22/2023]
Abstract
Cystinosis is a rare lysosomal storage disorder caused by loss-of-function mutations of the CTNS gene, encoding cystinosin, a symporter that mediates cystine efflux from lysosomes. Approximately 95% of patients with cystinosis display renal Fanconi syndrome, short stature, osteopenia, and rickets. In this study, we investigated whether the absence of cystinosin primarily affects bone remodeling activity, apart from the influences of the Fanconi syndrome on bone mineral metabolism. Using micro-computed tomography and histomorphometric and bone serum biomarker analysis, we evaluated the bone phenotype of 1-month-old Ctns-/- knockout (KO) male mice without tubulopathy. An in vitro study was performed to characterize the effects of cystinosin deficiency on osteoblasts and osteoclasts. Micro-computed tomography analysis showed a reduction of trabecular bone volume, bone mineral density, and number and thickness in KO mice compared with wild-type animals; histomorphometric analysis revealed a reduction of osteoblast and osteoclast parameters in tibiae of cystinotic mice. Decreased levels of serum procollagen type 1 amino-terminal propeptide and tartrate-resistant acid phosphatase in KO mice confirmed reduced bone remodeling activity. In vitro experiments showed an impairment of Ctns-/- osteoblasts and osteoclasts. In conclusion, cystinosin deficiency primarily affects bone cells, leading to a bone loss phenotype of KO mice, independent from renal failure.
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Affiliation(s)
- Giulia Battafarano
- Bone Physiopathology Group, Multifactorial Disease and Complex Phenotype Research Area, Bambino Gesù Children's Hospital, Rome, Italy
| | - Michela Rossi
- Bone Physiopathology Group, Multifactorial Disease and Complex Phenotype Research Area, Bambino Gesù Children's Hospital, Rome, Italy
| | - Laura R Rega
- Laboratories of Nephrology, Bambino Gesù Children's Hospital, Rome, Italy
| | | | - Anna Pastore
- Molecular Genetics and Functional Genomics, Division of Genetic and Rare Diseases, Bambino Gesù Children's Hospital, Rome, Italy
| | | | - Ottavia Porzio
- Clinical Laboratory, Bambino Gesù Children's Hospital, Rome, Italy; Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Nathalie Nevo
- INSERM U1163, Université Paris Descartes, Institut Imagine, Hôpital Necker Enfants Malades, Paris, France
| | - Francesco Emma
- Laboratories of Nephrology, Bambino Gesù Children's Hospital, Rome, Italy; Division of Nephrology, Department of Pediatric Subspecialities, Bambino Gesù Children's Hospital, Rome, Italy
| | - Anna Taranta
- Laboratories of Nephrology, Bambino Gesù Children's Hospital, Rome, Italy.
| | - Andrea Del Fattore
- Bone Physiopathology Group, Multifactorial Disease and Complex Phenotype Research Area, Bambino Gesù Children's Hospital, Rome, Italy
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14
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Florenzano P, Ferreira C, Nesterova G, Roberts MS, Tella SH, de Castro LF, Brown SM, Whitaker A, Pereira RC, Bulas D, Gafni RI, Salusky IB, Gahl WA, Collins MT. Skeletal Consequences of Nephropathic Cystinosis. J Bone Miner Res 2018; 33:1870-1880. [PMID: 29905968 DOI: 10.1002/jbmr.3522] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 05/18/2018] [Accepted: 06/06/2018] [Indexed: 01/03/2023]
Abstract
Nephropathic cystinosis is a rare lysosomal storage disorder. Patients present in the first year of life with renal Fanconi syndrome that evolves to progressive chronic kidney disease (CKD). Despite the multiple risk factors for bone disease, the frequency and severity of skeletal disorders in nephropathic cystinosis have not been described. We performed systematic bone and mineral evaluations of subjects with cystinosis seen at the NIH (n = 30), including history and physical examination, serum and urine biochemistries, DXA, vertebral fracture assessment, skeletal radiographs, and renal ultrasound. Additionally, histomorphometric analyses are reported on six subjects seen at the UCLA Bone and Mineral Metabolism Clinic. In NIH subjects, mean age was 20 years (range, 5 to 44 years), 60% were CKD stages G1 to G4, and 40% had a renal transplant. Mean bone mineral density (BMD) Z-scores were decreased in the femoral neck, total hip, and 1/3 radius (p < 0.05). Low bone mass at one or more sites was present in 46% of subjects. Twenty-seven percent of subjects reported one or more long bone fractures. Thirty-two percent of subjects had incidental vertebral fractures, which were unrelated to transplant status. Long-bone deformity/bowing was present in 64%; 50% had scoliosis. Diffuse osteosclerosis was present in 21% of evaluated subjects. Risk factors included CKD, phosphate wasting, hypercalciuria, secondary hyperparathyroidism, hypovitaminosis D, male hypogonadism, metabolic acidosis, and glucocorticoid/immunosuppressive therapy. Sixty-one percent of the non-transplanted subjects had ultrasonographic evidence of nephrocalcinosis or nephrolithiasis. Histomorphometric analyses showed impaired mineralization in four of six studied subjects. We conclude that skeletal deformities, decreased bone mass, and vertebral fractures are common and relevant complications of nephropathic cystinosis, even before renal transplantation. Efforts to minimize risk factors for skeletal disease include optimizing mineral metabolism and hormonal status, combined with monitoring for nephrocalcinosis/nephrolithiasis. © 2018 This article is a U.S. Government work and is in the public domain in the USA.
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Affiliation(s)
- Pablo Florenzano
- Section on Skeletal Disorders and Mineral Homeostasis, National Institutes of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA.,Endocrinology Department, School of Medicine, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Carlos Ferreira
- Medical Genetics Branch, National Human Genome Research Institute (NHGRI), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Galina Nesterova
- Medical Genetics Branch, National Human Genome Research Institute (NHGRI), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Mary Scott Roberts
- Section on Skeletal Disorders and Mineral Homeostasis, National Institutes of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Sri Harsha Tella
- Section on Skeletal Disorders and Mineral Homeostasis, National Institutes of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Luis Fernandez de Castro
- Section on Skeletal Disorders and Mineral Homeostasis, National Institutes of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Sydney M Brown
- Section on Skeletal Disorders and Mineral Homeostasis, National Institutes of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Adom Whitaker
- Section on Skeletal Disorders and Mineral Homeostasis, National Institutes of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Renata C Pereira
- Division of Nephrology, Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Dorothy Bulas
- Division of Radiology, Children's National Health System, Washington, DC, USA
| | - Rachel I Gafni
- Section on Skeletal Disorders and Mineral Homeostasis, National Institutes of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Isidro B Salusky
- Division of Nephrology, Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - William A Gahl
- Medical Genetics Branch, National Human Genome Research Institute (NHGRI), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Michael T Collins
- Section on Skeletal Disorders and Mineral Homeostasis, National Institutes of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
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