1
|
Laster M, Pereira RC, Noche K, Gales B, Salusky IB, Albrecht LV. Sclerostin, Osteocytes, and Wnt Signaling in Pediatric Renal Osteodystrophy. Nutrients 2023; 15:4127. [PMID: 37836411 PMCID: PMC10574198 DOI: 10.3390/nu15194127] [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: 08/05/2023] [Revised: 09/07/2023] [Accepted: 09/19/2023] [Indexed: 10/15/2023] Open
Abstract
The pathophysiology of chronic kidney disease-mineral and bone disorder (CKD-MBD) is not well understood. Specific factors secreted by osteocytes are elevated in the serum of adults and pediatric patients with CKD-MBD, including FGF-23 and sclerostin, a known inhibitor of the Wnt signaling pathway. The molecular mechanisms that promote bone disease during the progression of CKD are incompletely understood. In this study, we performed a cross-sectional analysis of 87 pediatric patients with pre-dialysis CKD and post-dialysis (CKD 5D). We assessed the associations between serum and bone sclerostin levels and biomarkers of bone turnover and bone histomorphometry. We report that serum sclerostin levels were elevated in both early and late CKD. Higher circulating and bone sclerostin levels were associated with histomorphometric parameters of bone turnover and mineralization. Immunofluorescence analyses of bone biopsies evaluated osteocyte staining of antibodies towards the canonical Wnt target, β-catenin, in the phosphorylated (inhibited) or unphosphorylated (active) forms. Bone sclerostin was found to be colocalized with phosphorylated β-catenin, which suggests that Wnt signaling was inhibited. In patients with low serum sclerostin levels, increased unphosphorylated "active" β-catenin staining was observed in osteocytes. These data provide new mechanistic insight into the pathogenesis of CKD-MBD and suggest that sclerostin may offer a potential biomarker or therapeutic target in pediatric renal osteodystrophy.
Collapse
Affiliation(s)
- Marciana Laster
- Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, CA 90024, USA; (M.L.); (R.C.P.); (K.N.); (B.G.)
| | - Renata C. Pereira
- Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, CA 90024, USA; (M.L.); (R.C.P.); (K.N.); (B.G.)
| | - Kathleen Noche
- Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, CA 90024, USA; (M.L.); (R.C.P.); (K.N.); (B.G.)
| | - Barbara Gales
- Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, CA 90024, USA; (M.L.); (R.C.P.); (K.N.); (B.G.)
| | - Isidro B. Salusky
- Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, CA 90024, USA; (M.L.); (R.C.P.); (K.N.); (B.G.)
| | - Lauren V. Albrecht
- Department of Pharmaceutical Sciences, School of Pharmacy, University of California, Irvine, CA 92697, USA
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, CA 92697, USA
| |
Collapse
|
2
|
Sirimongkolchaiyakul O, Wesseling‐Perry K, Gales B, Markovic D, Elashoff D, Ramos G, Pereira RC, Hanudel MR, Salusky IB. Effects of primary kidney disease etiology on renal osteodystrophy in pediatric dialysis patients. JBMR Plus 2022; 6:e10601. [PMID: 35434448 PMCID: PMC9009101 DOI: 10.1002/jbm4.10601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 01/11/2022] [Indexed: 11/06/2022] Open
Abstract
Congenital diseases of the kidney and urinary tract (CAKUT) and glomerulonephritis are the main causes of chronic kidney disease (CKD) in children. Although renal osteodystrophy (ROD) and indices of mineral metabolism have been characterized in dialyzed children, the impact of primary kidney disease on ROD is unknown. We performed a cross‐sectional study of bone biopsies performed in 189 pediatric dialysis patients aged 12.6 ± 5.4 years. Patients were classified into three groups according to primary kidney disease: CAKUT (n = 82), hereditary (n = 22), or glomerular disease (n = 85). Serum concentrations of calcium, phosphate, alkaline phosphatase (ALP), parathyroid hormone (PTH), and 25(OH) vitamin D were measured at the time of biopsy. Fibroblast growth factor 23 (FGF23) levels were measured in a subset of 59 patients. Levels of calcium, phosphate, PTH, and 25(OH) vitamin D were similar across groups. CAKUT patients had higher serum ALP and lower C‐terminal FGF23 levels. Bone turnover and bone volume parameters did not differ across groups. However, osteoid volume (OV/BV), osteoid surface (OS/BS), and osteoid maturation time (OMT) were highest in the CAKUT group and lowest in the hereditary group. Multiple regression analysis revealed that calcium, phosphate, ALP, and PTH were independently associated with OV/BV and osteoid thickness (O.Th). PTH was an independent factor affecting bone formation rate. The relationship between CKD etiology and bone histomorphometric variables was abrogated after adjustment for biochemical parameters in the multivariable models. Overall, bone histology differed according to CKD etiology in the unadjusted analysis; however, this association could not be confirmed independently of biochemical parameters. Although CAKUT patients had a greater mineralization defect with elevated serum ALP levels, longitudinal studies will be needed to elucidate mediation pathways that might be involved in the complex interplay of CKD‐mineral bone disease (MBD). © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Ornatcha Sirimongkolchaiyakul
- Department of Pediatrics David Geffen School of Medicine at the University of California Los Angeles United States
- Department of Pediatrics, Faculty of Medicine Vajira Hospital Navamindrahiraj University Bangkok Thailand
| | - Katherine Wesseling‐Perry
- Department of Pediatrics David Geffen School of Medicine at the University of California Los Angeles United States
| | - Barbara Gales
- Department of Pediatrics David Geffen School of Medicine at the University of California Los Angeles United States
| | - Daniela Markovic
- Department of Medicine, Biostatistics and Biomathematics David Geffen School of Medicine at the University of California Los Angeles United States
| | - David Elashoff
- Department of Medicine, Biostatistics and Biomathematics David Geffen School of Medicine at the University of California Los Angeles United States
| | - Georgina Ramos
- Department of Pediatrics David Geffen School of Medicine at the University of California Los Angeles United States
| | - Renata C. Pereira
- Department of Pediatrics David Geffen School of Medicine at the University of California Los Angeles United States
| | - Mark R. Hanudel
- Department of Pediatrics David Geffen School of Medicine at the University of California Los Angeles United States
| | - Isidro B. Salusky
- Department of Pediatrics David Geffen School of Medicine at the University of California Los Angeles United States
| |
Collapse
|
3
|
Abreu ALCS, Soeiro EMD, Bedram LG, Andrade MCD, Lopes R. Brazilian guidelines for chronic kidney disease-mineral and bone metabolism disorders in children and adolescents. J Bras Nefrol 2021; 43:680-692. [PMID: 34910806 PMCID: PMC8823923 DOI: 10.1590/2175-8239-jbn-2021-s114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 07/09/2021] [Indexed: 11/22/2022] Open
Affiliation(s)
| | - Emília Maria Dantas Soeiro
- Universidade Federal de Pernambuco, Recife, PE, Brazil.,Instituto de Medicina Integral Professor Fernando Figueira - IMIP, Recife, PE, Brazil
| | | | | | - Renata Lopes
- Universidade Federal de São Paulo, São Paulo, SP, Brazil
| |
Collapse
|
4
|
Asadipooya K, Abdalbary M, Ahmad Y, Kakani E, Monier-Faugere MC, El-Husseini A. Bone Quality in CKD Patients: Current Concepts and Future Directions - Part I. KIDNEY DISEASES (BASEL, SWITZERLAND) 2021; 7:268-277. [PMID: 34395542 PMCID: PMC8314761 DOI: 10.1159/000515534] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 02/26/2021] [Indexed: 12/23/2022]
Abstract
BACKGROUND There is ample evidence that patients with CKD have an increased risk of osteoporotic fractures. Bone fragility is not only influenced by low bone volume and mass but also by poor microarchitecture and tissue quality. More emphasis has been given to the quantitative rather than qualitative assessment of bone health, both in general population and CKD patients. Although bone mineral density (BMD) is a very useful clinical tool in assessing bone strength, it may underestimate the fracture risk in CKD patients. Serum and urinary bone biomarkers have been found to be reflective of bone activities and predictive of fractures independently of BMD in CKD patients. Bone quality and fracture risk in CKD patients can be better assessed by utilizing new technologies such as trabecular bone score and high-resolution imaging studies. Additionally, invasive assessments such as bone histology and micro-indentation are useful counterparts in the evaluation of bone quality. SUMMARY A precise diagnosis of the underlying skeletal abnormalities in CKD patients is crucial to prevent further bone loss and fractures. We must consider bone quantity and quality abnormalities for management of CKD patients. Here in this part I, we are focusing on advances in bone quality diagnostics that are expected to help in proper understanding of the bone health in CKD patients. KEY MESSAGES Assessment of bone quality and quantity in CKD patients is essential. Both noninvasive and invasive techniques for the assessment of bone quality are available.
Collapse
Affiliation(s)
- Kamyar Asadipooya
- Division of Endocrinology, University of Kentucky, Lexington, Kentucky, USA
| | - Mohamed Abdalbary
- Division of Nephrology & Bone and Mineral Metabolism, University of Kentucky, Lexington, Kentucky, USA
- Nephrology and Dialysis Unit, Mansoura University, Mansoura, Egypt
| | - Yahya Ahmad
- Division of Nephrology & Bone and Mineral Metabolism, University of Kentucky, Lexington, Kentucky, USA
| | - Elijah Kakani
- Division of Nephrology & Bone and Mineral Metabolism, University of Kentucky, Lexington, Kentucky, USA
| | | | - Amr El-Husseini
- Division of Nephrology & Bone and Mineral Metabolism, University of Kentucky, Lexington, Kentucky, USA
| |
Collapse
|
5
|
Kusumi K, Shaikhkhalil A, Patel HP, Mahan JD. Promoting bone health in children and adolescents following solid organ transplantation. Pediatr Transplant 2021; 25:e13940. [PMID: 33341105 DOI: 10.1111/petr.13940] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 09/02/2020] [Accepted: 09/03/2020] [Indexed: 02/06/2023]
Abstract
Solid organ transplantation in children and adolescents provides many benefits through improving critical organ function, including better growth, development, cardiovascular status, and quality of life. Unfortunately, bone status may be adversely affected even when overall status is improving, due to issues with pre-existing bone disease as well as medications and nutritional challenges inherent post-transplantation. For all children and adolescents, bone status entering adulthood is a critical determinant of bone health through adulthood. The overall health and bone status of transplant recipients benefits from attention to regular physical activity, good nutrition, adequate calcium, phosphorous, magnesium and vitamin D intake and avoidance/minimization of soda, extra sodium, and obesity. Many immunosuppressive agents, especially glucocorticoids, can adversely affect bone function and development. Minimizing exposure to "bone-toxic" medications is an important part of promoting bone health in children post-transplantation. Existing guidelines detail how regular monitoring of bone status and biochemical markers can help detect bone abnormalities early and facilitate valuable bone-directed interventions. Attention to calcium and vitamin D supplementation, as well as tapering and withdrawing glucocorticoids as early as possible after transplant, can provide best bone outcomes for these children. Dual-energy X-ray absorptiometry can be useful to detect abnormal bone mass and fracture risk in this population and newer bone assessment methods are being evaluated in children at risk for poor bone outcomes. Newer bone therapies being explored in adults with transplants, particularly bisphosphonates and the RANKL inhibitor denosumab, may offer promise for children with low bone mass post-transplantation.
Collapse
Affiliation(s)
| | - Ala Shaikhkhalil
- Nationwide Children's Hospital, The Ohio State University, Columbus, OH, USA
| | - Hiren P Patel
- Nationwide Children's Hospital, The Ohio State University, Columbus, OH, USA
| | - John D Mahan
- Nationwide Children's Hospital, The Ohio State University, Columbus, OH, USA
| |
Collapse
|
6
|
Haffner D, Leifheit-Nestler M. CKD-MBD post kidney transplantation. Pediatr Nephrol 2021; 36:41-50. [PMID: 31858226 DOI: 10.1007/s00467-019-04421-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 10/28/2019] [Accepted: 11/12/2019] [Indexed: 12/22/2022]
Abstract
Complications of chronic kidney disease-associated mineral and bone disorders (CKD-MBD) are frequently observed in pediatric kidney transplant recipients and are associated with high morbidity, including growth failure, leg deformities, bone pain, fractures, osteonecrosis, and vascular calcification. Post-transplant CKD-MBD is mainly due to preexisting renal osteodystrophy and cardiovascular changes at the time of transplantation, glucocorticoid treatment, and reduced graft function. In addition, persistent elevated levels of parathyroid hormone (PTH) and fibroblast growth factor 23 may cause hypophosphatemia, resulting in impaired bone mineralization. Patient monitoring should include assessment of growth, leg deformities, and serum levels of calcium, phosphate, magnesium, alkaline phosphatase, 25-hydroxyvitamin D, and PTH. Therapy should primarily focus on regular physical activity, preservation of transplant function, and steroid-sparing immunosuppressive protocols. In addition, adequate monitoring and treatment of vitamin D and mineral metabolism including vitamin D supplementation, oral phosphate, and/or magnesium supplementation, in case of persistent hypophosphatemia/hypomagnesemia, and treatment with active vitamin D in cases of persistent secondary hyperparathyroidism. The latter should be done using the minimum PTH-suppressive dosages aiming at the recommended CKD stage-dependent PTH target range. Finally, treatment with recombinant human growth hormone should be considered in patients lacking catch-up growth within the first year after transplantation.
Collapse
Affiliation(s)
- Dieter Haffner
- Department of Paediatric Kidney, Liver and Metabolic Diseases, Paediatric Research Center, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| | - Maren Leifheit-Nestler
- Department of Paediatric Kidney, Liver and Metabolic Diseases, Paediatric Research Center, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.,Paediatric Research Center, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| |
Collapse
|
7
|
Rodd C. Bisphosphonates in Dialysis and Transplantation Patients: Efficacy and Safety Issues. Perit Dial Int 2020. [DOI: 10.1177/089686080102103s45] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Bisphosphonates are an old class of compounds. They were used in the 1930s as antiscaling and anticorrosion agents in washing powders and water to prevent the deposition of calcium crystals. Those basic functions were later utilized in an attempt to prevent ectopic calcifications in humans. The early studies demonstrated that bisphosphonates had a strong affinity for bone. That property was first exploited when the compounds were used for “bone scans.” Currently, the drugs are used for treatment of hypercalcemic conditions, abnormal bone remodelling, Paget disease, malignancy, and osteoporosis. Bisphosphonates have several important toxicities: acute renal failure, worsening renal function, reduced bone mineralization, and osteomalacia. For those reasons and others, this class of drugs has not yet been approved for use in children or in patients with severe renal insufficiency. The present review covers several aspects of bisphosphonates: molecular structure, routes of administration, pharmacology, mechanisms of action, toxicities, and exceptional uses in children with renal disease.
Collapse
Affiliation(s)
- Celia Rodd
- Montreal Children's Hospital, Montreal, Quebec, Canada
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
Putman MS, Simoneau T, Feldman HA, Haagensen A, Boyer D. Low bone density and fractures before and after pediatric lung transplantation. Bone 2018; 111:129-134. [PMID: 29596964 PMCID: PMC5931383 DOI: 10.1016/j.bone.2018.03.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 02/26/2018] [Accepted: 03/26/2018] [Indexed: 11/17/2022]
Abstract
INTRODUCTION Children undergoing lung transplant are at risk for low bone mineral density (BMD) and fractures. The effect of lung transplantation on bone health in pediatric patients is unknown. MATERIALS AND METHODS We performed a retrospective chart review of all patients ages 2-21 years who underwent lung transplantation at our hospital from January 2000 to January 2015. RESULTS 51 patients were studied. At the time of transplant evaluation, BMD Z-score was -2.2 ± 1.4, and 59% of patients had low BMD. BMD Z-score declined in the first year after treatment and returned to near-baseline by the third post-transplant year. Fractures occurred in 9 patients (18%) before and 15 patients (29%) after transplant. Bisphosphonate use was associated with improvement in BMD Z-score and lower mortality risk. CONCLUSIONS Pediatric patients had a high prevalence of low BMD at the time of lung transplant evaluation. BMD Z-scores declined in the year after transplant and returned to the pre-transplant level by the third post-transplant year while remaining below normal levels. Fractures were common at sites associated with significant morbidity. These findings support efforts to optimize bone health before and after pediatric lung transplantation, and future studies are needed to evaluate the role of bisphosphonates in these patients.
Collapse
Affiliation(s)
- Melissa S Putman
- Division of Endocrinology, Boston Children's Hospital, Boston, MA, United States; Endocrine Unit, Massachusetts General Hospital, Boston, MA, United States.
| | - Tregony Simoneau
- Department of Pulmonary Medicine, Connecticut Children's Medical Center, Hartford, CT, United States
| | - Henry A Feldman
- Clinical Research Center, Boston Children's Hospital, Boston, MA, United States
| | - Alexandra Haagensen
- Division of Endocrinology, Boston Children's Hospital, Boston, MA, United States
| | - Debra Boyer
- Division of Respiratory Diseases, Boston Children's Hospital, Boston, MA, United States
| |
Collapse
|
10
|
Diamond T, Elder GJ. Is there a practical role for bone biopsy in chronic kidney disease? Nephrology (Carlton) 2018; 22 Suppl 2:22-26. [PMID: 28429554 DOI: 10.1111/nep.13017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Bone biopsy is currently the only means to accurately assess renal osteodystrophy and responses to therapeutic interventions. With sedation, the technique is relatively painless, and complications are uncommon. Bone biopsy should be considered when the aetiology of symptoms or biochemical abnormalities is in question, and results may lead to changes in therapy. Although it remains prudent to use antiresorptive drugs cautiously in patients with chronic kidney disease (CKD) stages 3a-4 and low bone mineral density, bone biopsy may not be warranted before commencing therapy in these patients. Histomorphometric indices adopted for bone biopsy assessment are turnover (T), mineralisation (M) and volume (V). Often, only measurements of trabecular bone are reported; however, marked cortical changes are common in CKD and may be critical to bone structure and integrity. MicroCT of bone biopsies can rapidly assess static parameters and provides information on the cortical and trabecular compartments that may influence management. Limitations of bone biopsy include the time required for pre-biopsy tetracycline labelling and sample processing, and a paucity of facilities to process and report samples. Patients with CKD may not respond predictably to treatments, and because the biopsy sample is illustrative of activity at only one skeletal site and one point in time, assessment of real-time laboratory trends is always required. Optimally, we need a non-invasive 'virtual bone biopsy' that provides information for initiating and monitoring therapy. However, bone biopsy is the current standard by which the accuracy of investigational imaging techniques, hormonal values and biochemical turnover markers are judged.
Collapse
Affiliation(s)
- Terrence Diamond
- Department of Endocrinology, St George Hospital, University of NSW, Sydney, Australia
| | - Grahame J Elder
- Department of Renal Medicine, Westmead Hospital, Westmead, Australia.,Osteoporosis and Bone Biology Division, Garvan Institute for Medical Research, Darlinghurst, Australia
| |
Collapse
|
11
|
Pereira RC, Bischoff DS, Yamaguchi D, Salusky IB, Wesseling-Perry K. Micro-CT in the Assessment of Pediatric Renal Osteodystrophy by Bone Histomorphometry. Clin J Am Soc Nephrol 2015; 11:481-7. [PMID: 26712809 DOI: 10.2215/cjn.04810515] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 11/07/2015] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND OBJECTIVES Computed tomography (CT) measurements can distinguish between cortical and trabecular bone density in vivo. High-resolution CTs assess both bone volume and density in the same compartment, thus potentially yielding information regarding bone mineralization as well. The relationship between bone histomorphometric parameters of skeletal mineralization and bone density from microcomputed tomography (μCT) measurements of bone cores from patients on dialysis has not been assessed. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Bone cores from 68 patients with ESRD (age =13.9±0.5 years old; 50% men) and 14 controls (age =15.3±3.8 years old; 50% men) obtained as part of research protocols between 1983 and 2006 were analyzed by bone histomorphometry and μCT. RESULTS Bone histomorphometric diagnoses in the patients were normal to high bone turnover in 76%, adynamic bone in 13%, and osteomalacia in 11%. Bone formation rate did not correlate with any μCT determinations. Bone volume measurements were highly correlated between bone histomorphometry and μCT (bone volume/tissue volume between the two techniques: r=0.70; P<0.001, trabecular thickness and trabecular separation: r=0.71; P<0.001, and r=0.56; P<0.001, respectively). Osteoid accumulation as determined by bone histomorphometry correlated inversely with bone mineral density as assessed by μCT (osteoid thickness: r=-0.32; P=0.01 and osteoid volume: r=-0.28; P=0.05). By multivariable analysis, the combination of bone mineral density and bone volume (as assessed by μCT) along with parathyroid hormone and calcium levels accounted for 38% of the variability in osteoid volume (by histomorphometry). CONCLUSIONS Measures of bone volume can be accurately assessed with μCT. Bone mineral density is lower in patients with excessive osteoid accumulation and higher in patients with adynamic, well mineralized bone. Thus, bone mineralization may be accurately assessed by μCT of bone biopsy cores. Additional studies are warranted to define the value of high-resolution CT in the prediction of bone mineralization in vivo.
Collapse
Affiliation(s)
- Renata C Pereira
- Department of Pediatrics, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, California; and
| | - David S Bischoff
- Department of Medicine, Veterans Affairs Sepulveda and David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, California
| | - Dean Yamaguchi
- Department of Medicine, Veterans Affairs Sepulveda and David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, California
| | - Isidro B Salusky
- Department of Pediatrics, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, California; and
| | - Katherine Wesseling-Perry
- Department of Pediatrics, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, California; and
| |
Collapse
|
12
|
Abstract
Renal transplantation in paediatric patients usually provides excellent short-term and medium-term results. Early diagnosis of chronic kidney disease and active therapy of end-stage renal disease before and after transplantation enables the majority of children to grow and develop normally. The adverse effects of immunosuppressive medication and reduced graft function might, however, hamper long-term outcomes in these patients and can lead to metabolic complications, cardiovascular disease, reduced bone health, and malignancies. The neurocognitive development and quality of life of paediatric transplant recipients largely depend on the primary diagnosis and on graft function. Poor adherence to immunosuppression is an important risk factor for graft loss in adolescents, and controlled transition to adult care is of utmost importance to ensure a continued normal life. In this Review, we discuss the outcomes and long-term effects of renal transplantation in paediatric recipients, including consequences on growth, development, bone, metabolic, and cardiovascular disorders. We discuss the key problems in the care of paediatric renal transplant recipients and the remaining challenges that should be the focus of future research.
Collapse
|
13
|
Abstract
Dysregulated phosphate metabolism is a common consequence of chronic kidney disease, and is characterized by a high circulating level of fibroblast growth factor (FGF)-23, hyperparathyroidism, and hyperphosphataemia. Kidney transplantation can elicit specific alterations to phosphate metabolism that evolve over time, ranging from severe hypophosphataemia (<0.5 mmol/l) to hyperphosphataemia (>1.50 mmol/l) and high FGF-23 levels. The majority of renal transplant recipients develop hypophosphataemia during the first 3 months after transplantation as a consequence of relatively slow adaptation of FGF-23 and parathyroid hormone levels to restored renal function, and the influence of immunosuppressive drugs. By 3-12 months after transplantation, phosphate homeostasis is at least partially restored in the majority of recipients, which is paralleled by a substantially reduced risk of cardiovascular-associated morbidity and mortality compared with the pre-transplantation setting. Many renal transplant recipients, however, exhibit persistent abnormalities in phosphate homeostasis, which is often due to multifactorial causes, and may contribute to adverse outcomes on the cardiovascular system, kidney, and bone. Dietary and pharmacologic interventions might improve phosphate homeostasis in renal transplant recipients, but additional insight into the pathophysiology of transplantation-associated abnormalities in phosphate homeostasis is needed to further optimize disease management and improve prognosis for renal transplant recipients.
Collapse
|
14
|
Pereira RC, Valta H, Tumber N, Salusky IB, Jalanko H, Mäkitie O, Wesseling Perry K. Altered Osteocyte-Specific Protein Expression in Bone after Childhood Solid Organ Transplantation. PLoS One 2015; 10:e0138156. [PMID: 26390291 PMCID: PMC4577074 DOI: 10.1371/journal.pone.0138156] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 08/25/2015] [Indexed: 01/30/2023] Open
Abstract
Background Bone fragility is common post solid organ transplantation but little is known about bone pathology on a tissue level. Abnormal osteocytic protein expression has been linked to compromised bone health in chronic kidney disease (CKD) and immunosuppressant medications may impact osteocyte function. Methods Transiliac bone biopsies were obtained from 22 pediatric solid organ allograft recipients (average age 15.6 years) an average of 6.3 ± 1.2 years after transplantation and from 12 pediatric pre-dialysis CKD patients (average age 13.2 years). Histomorphometry and immunohistochemistry for FGF23, DMP1, sclerostin, and osteopontin were performed on all biopsies. Results FGF23 and sclerostin were increased in transplant recipients relative to non-transplant CKD, regardless of the type of allograft received and despite, in the case of liver and heart recipients, a higher GFR. Bone DMP1 expression was higher in liver or heart than in kidney recipients, concomitant with higher serum phosphate values. Osteopontin expression was higher in CKD than in transplant recipients (p<0.01). Bone FGF23 and sclerostin correlated directly (r = 0.38, p<0.05); bone FGF23 expression and osteoid thickness correlated inversely (r = - 0.46, p<0.01). Conclusions Solid-organ transplantation is associated with increased FGF23 and sclerostin expression. The contribution of these findings to compromised bone health post transplantation warrants further evaluation.
Collapse
Affiliation(s)
- Renata C. Pereira
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, United States of America
| | - Helena Valta
- Children's Hospital, Helsinki University Central Hospital, University of Helsinki, Helsinki, Finland
| | - Navdeep Tumber
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, United States of America
| | - Isidro B. Salusky
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, United States of America
| | - Hannu Jalanko
- Children's Hospital, Helsinki University Central Hospital, University of Helsinki, Helsinki, Finland
| | - Outi Mäkitie
- Children's Hospital, Helsinki University Central Hospital, University of Helsinki, Helsinki, Finland
- Folkhälsan Research Center, Helsinki, Finland
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Katherine Wesseling Perry
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, United States of America
- * E-mail:
| |
Collapse
|
15
|
The consequences of pediatric renal transplantation on bone metabolism and growth. Curr Opin Organ Transplant 2015; 18:555-62. [PMID: 23995376 DOI: 10.1097/mot.0b013e3283651b21] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW During childhood, growth retardation, decreased final height and renal osteodystrophy are common complications of chronic kidney disease (CKD). These problems remain present in patients undergoing renal transplantation, even though steroid-sparing strategies are more widely used. In this context, achieving normal height and growth in children after transplantation is a crucial issue for both quality of life and self-esteem. The aim of this review is to provide an overview of pathophysiology of CKD-mineral bone disorder (MBD) in children undergoing renal transplantation and to propose keypoints for its daily management. RECENT FINDINGS In adults, calcimimetics are effective for posttransplant hyperparathyroidism, but data are missing in the pediatric population. Fibroblast growth factor 23 levels are associated with increased risk of rejection, but the underlying mechanisms remain unclear. A recent meta-analysis also demonstrated the effectiveness of rhGH therapy in short transplanted children. SUMMARY In 2013, the daily clinical management of CKD-MBD in transplanted children should still focus on simple objectives: to optimize renal function, to develop and promote steroid-sparing strategies, to provide optimal nutritional support to maximize final height and avoid bone deformations, to equilibrate calcium/phosphate metabolism so as to provide acceptable bone quality and cardiovascular status, to correct all metabolic and clinical abnormalities that can worsen both bone and growth (mainly metabolic acidosis, anemia and malnutrition), promote good lifestyle habits (adequate calcium intake, regular physical activity, no sodas consumption, no tobacco exposure) and eventually to correct native vitamin D deficiency (target of 25-vitamin D >75 nmol/l).
Collapse
|
16
|
Abstract
Although traditional diagnosis and treatment of renal osteodystrophy focused on changes in bone turnover, current data demonstrate that abnormalities in skeletal mineralization are also prevalent in pediatric chronic kidney disease (CKD) and likely contribute to skeletal morbidities that continue to plague this population. It is now clear that alterations in osteocyte biology, manifested by changes in osteocytic protein expression, occur in early CKD before abnormalities in traditional measures of mineral metabolism are apparent and may contribute to defective skeletal mineralization. Current treatment paradigms advocate the use of 1,25(OH)2vitamin D for the control of secondary hyperparathyroidism; however, these agents fail to correct defective skeletal mineralization and may exacerbate already altered osteocyte biology. Further studies are critically needed to identify the initial trigger for abnormalities of skeletal mineralization as well as the potential effects that current therapeutic options may have on osteocyte biology and bone mineralization.
Collapse
Affiliation(s)
- Katherine Wesseling-Perry
- Pediatric Nephrology, David Geffen School of Medicine at UCLA, A2-383 MDCC, 650 Charles Young Dr, Los Angeles, CA, 93001-1835, USA,
| |
Collapse
|
17
|
Pereira RC, Jüppner H, Gales B, Salusky IB, Wesseling-Perry K. Osteocytic protein expression response to doxercalciferol therapy in pediatric dialysis patients. PLoS One 2015; 10:e0120856. [PMID: 25774916 PMCID: PMC4361624 DOI: 10.1371/journal.pone.0120856] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 01/27/2015] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Osteocytic protein expression is dysregulated in CKD and is affected by changes in mineral metabolism; however the effects of active vitamin D sterol therapy on osteocyte protein expression in advanced CKD is unknown. METHODS Eleven pediatric patients with end stage kidney disease underwent bone biopsy, were treated for 8 months with doxercalciferol, and then underwent a second bone biopsy. Bone expression of fibroblast growth factor 23 (FGF23), dentin matrix protein 1 (DMP1), and sclerostin were determined by immunohistochemistry and quantified by Ariol Scanning. Western blot analysis and qRT-PCR was performed on bone abstracts of a subset of study subjects to determine the nature (i.e. size) of FGF23 and DMP1 in bone before and after therapy. RESULTS As assessed by immunohistochemistry, bone FGF23, DMP1 and sclerostin protein all increased with therapy. In the case of FGF23, this increase was due to an increase in the full-length molecule without the appearance of FGF23 fragments. DMP1 was present primarily in its full-length form in healthy controls while 57kDa and 37kDa fragments of DMP1 were apparent in bone of dialysis patients at baseline and the 57 kDa appeared to decrease with therapy. CONCLUSION Marked changes in osteocytic protein expression accompany doxercalciferol therapy, potentially impacting bone mineralization and the skeletal response to PTH. The effects of these bone changes on long-term outcomes remain to be determined.
Collapse
Affiliation(s)
- Renata C. Pereira
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
| | - Harald Jüppner
- Endocrine Unit and Pediatric Nephrology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Barbara Gales
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
| | - Isidro B. Salusky
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
| | - Katherine Wesseling-Perry
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
| |
Collapse
|
18
|
Cseprekál O, Kis E, Dégi AA, Kerti A, Szabó AJ, Reusz GS. Bone metabolism and arterial stiffness after renal transplantation. Kidney Blood Press Res 2014; 39:507-15. [PMID: 25531154 DOI: 10.1159/000368461] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS To assess the relationship between bone and vascular disease and its changes over time after renal transplantation. Metabolic bone disease (MBD) is common in chronic kidney disease (CKD) and is associated with cardiovascular (CV) disease. Following transplantation (Tx), improvement in CV disease has been reported; however, data regarding changes in bone disease remain controversial. METHODS Bone turnover and arterial stiffness (pulse wave velocity (PWV)) were assessed in 47 Tx patients (38 (3-191) months after Tx). RESULTS Bone alkaline phosphatase (BALP), osteocalcin (OC) and beta-crosslaps were significantly higher in Tx patients, and decreased significantly after one year. There was a negative correlation between BALP, OC and steroid administered (r = -0.35; r = -0.36 respectively). PWV increased in the Tx group (1.15 SD). In patients with a follow up of <24 months, PWV was correlated with BALP and beta-crosslaps (r=0.53; r = 0.69 respectively) while in the ≥24 months group, PWV was correlated with cholesterol (r=0.38). CONCLUSIONS Increased bone turnover and arterial stiffness are present following kidney transplantation. While bone turnover decreases with time, arterial stiffness correlates initially with bone turnover, after which the influence of cholesterol becomes significant. Non-invasive estimation of bone metabolism and arterial stiffness may help to assess CKD-MBD following renal transplantation.
Collapse
Affiliation(s)
- Orsolya Cseprekál
- 1st Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | | | | | | | | | | |
Collapse
|
19
|
Bone histomorphometry before and after long-term treatment with cinacalcet in dialysis patients with secondary hyperparathyroidism. Kidney Int 2014; 87:846-56. [PMID: 25337774 PMCID: PMC4382689 DOI: 10.1038/ki.2014.349] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 08/20/2014] [Accepted: 08/21/2014] [Indexed: 01/01/2023]
Abstract
The multicenter, single-arm BONAFIDE study characterized the skeletal response to cinacalcet in adult dialysis patients with plasma parathyroid hormone (PTH) levels of 300 pg/ml or more, serum calcium of 8.4 mg/dl or more, bone-specific alkaline phosphatase over 20.9 ng/ml and biopsy-proven high-turnover bone disease. Of 110 enrolled patients, 77 underwent a second bone biopsy with quantitative histomorphometry after 6-12 months of cinacalcet treatment. The median PTH decreased from 985 pg/ml at baseline to 480 pg/ml at the end of study (weeks 44-52). Bone formation rate/tissue area decreased from 728 to 336 μm(2)/mm(2)/day, osteoblast perimeter/osteoid perimeter decreased from 17.4 to 13.9%, and eroded perimeter/bone perimeter decreased from 12.7 to 8.3%. The number of patients with normal bone histology increased from none at baseline to 20 at 12 months. Two patients had adynamic bone at the end of study with a PTH under 150 pg/ml, and one patient with overt hypophosphatemia at baseline that reoccurred during follow-up developed osteomalacia. Thus, long-term treatment with cinacalcet substantially reduced PTH, diminished the elevated bone formation rate/tissue area, lowered several biochemical markers of high-turnover bone disease toward normal, and generally improved bone histology. Twenty patients had normal bone histology at follow-up, whereas most had mild hyperparathyroidism or mixed uremic osteodystrophy.
Collapse
|
20
|
Tamminen IS, Valta H, Jalanko H, Salminen S, Mäyränpää MK, Isaksson H, Kröger H, Mäkitie O. Pediatric solid organ transplantation and osteoporosis: a descriptive study on bone histomorphometric findings. Pediatr Nephrol 2014; 29:1431-40. [PMID: 24562785 DOI: 10.1007/s00467-014-2771-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 01/15/2014] [Accepted: 01/22/2014] [Indexed: 01/08/2023]
Abstract
BACKGROUND Organ transplantation may lead to secondary osteoporosis in children. This study characterized bone histomorphometric findings in pediatric solid organ transplant recipients who were assessed for suspected secondary osteoporosis. METHODS Iliac crest biopsies were obtained from 19 children (7.6-18.8 years, 11 male) who had undergone kidney (n = 6), liver (n = 9), or heart (n = 4) transplantation a median 4.6 years (range 0.6-16.3 years) earlier. All patients had received oral glucocorticoids at the time of the biopsy. RESULTS Of the 19 patients, 21 % had sustained peripheral fractures and 58 % vertebral compression fractures. Nine children (47 %) had a lumbar spine BMD Z-score below -2.0. Histomorphometric analyses showed low trabecular bone volume (< -1.0 SD) in 6 children (32 %) and decreased trabecular thickness in 14 children (74 %). Seven children (37 %) had high bone turnover at biopsy, and low turnover was found in 6 children (32 %), 1 of whom had adynamic bone disease. CONCLUSIONS There was a great heterogeneity in the histological findings in different transplant groups, and the results were unpredictable using non-invasive methods. The observed changes in bone quality (i.e. abnormal turnover rate, thin trabeculae) rather than the actual loss of trabecular bone, might explain the increased fracture risk in pediatric solid organ transplant recipients.
Collapse
Affiliation(s)
- Inari S Tamminen
- Bone and Cartilage Research Unit (BCRU), University of Eastern Finland, POB 1627, Mediteknia Building, 70211, Kuopio, Finland,
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Abstract
PURPOSE OF THE REVIEW Posttransplantation mineral and bone disorder (MBD) is an important issue in the care of children after kidney transplantation (KTx) resulting in increased comorbidity, for example, bone pain, fractures, growth failure, and vascular calcifications. It is distinctly different from common forms of osteoporosis and mainly due to preexisting renal osteodystrophy at the time of KTx, glucocorticoid treatment, and reduced graft function. The purpose of this review is to give an overview of the pathogenesis and treatment of posttransplant MBD in children. RECENT FINDINGS Recent studies underline the impact of elevated levels of the phosphaturic hormone fibroblast growth factor-23 on posttransplant MBD. Glucocorticoid treatment results in impairment of bone strength, increased fracture risk, and lack of significant catch up, whereas steroid-sparing protocols allow for a normal adult height in the majority of patients. Whether the latter also improves bone strength remains to be elucidated. SUMMARY Therapeutic efforts to reduce MBD after KTx should focus on steroid-sparing immunosuppressive protocols, adequate treatment of alterations of calcium, phosphate and vitamin D metabolism, maintenance of regular physical activity, and preservation of transplant function. Preemptive KTx, that is with no prior dialysis, can prevent progressive vascular calcifications.
Collapse
Affiliation(s)
- Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Germany
| | | |
Collapse
|
22
|
Sgambat K, Moudgil A. Optimization of Bone Health in Children before and after Renal Transplantation: Current Perspectives and Future Directions. Front Pediatr 2014; 2:13. [PMID: 24605319 PMCID: PMC3932433 DOI: 10.3389/fped.2014.00013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 02/11/2014] [Indexed: 11/29/2022] Open
Abstract
The accrual of healthy bone during the critical period of childhood and adolescence sets the stage for lifelong skeletal health. However, in children with chronic kidney disease (CKD), disturbances in mineral metabolism and endocrine homeostasis begin early on, leading to alterations in bone turnover, mineralization, and volume, and impairing growth. Risk factors for CKD-mineral and bone disorder (CKD-MBD) include nutritional vitamin D deficiency, secondary hyperparathyroidism, increased fibroblast growth factor 23 (FGF-23), altered growth hormone and insulin-like growth factor-1 axis, delayed puberty, malnutrition, and metabolic acidosis. After kidney transplantation, nutritional vitamin D deficiency, persistent hyperparathyroidism, tertiary FGF-23 excess, hypophosphatemia, hypomagnesemia, immunosuppressive therapy, and alteration of sex hormones continue to impair bone health and growth. As function of the renal allograft declines over time, CKD-MBD associated changes are reactivated, further impairing bone health. Strategies to optimize bone health post-transplant include healthy diet, weight-bearing exercise, correction of vitamin D deficiency and acidosis, electrolyte abnormalities, steroid avoidance, and consideration of recombinant human growth hormone therapy. Other drug therapies have been used in adult transplant recipients, but there is insufficient evidence for use in the pediatric population at the present time. Future therapies to be explored include anti-FGF-23 antibodies, FGF-23 receptor blockers, and treatments targeting the colonic microbiota by reduction of generation of bacterial toxins and adsorption of toxic end products that affect bone mineralization.
Collapse
Affiliation(s)
| | - Asha Moudgil
- Children National Medical Center, Washington, DC, USA
| |
Collapse
|
23
|
Tsampalieros A, Griffin L, Terpstra AM, Kalkwarf HJ, Shults J, Foster BJ, Zemel BS, Foerster DL, Leonard MB. Changes in DXA and quantitative CT measures of musculoskeletal outcomes following pediatric renal transplantation. Am J Transplant 2014; 14:124-32. [PMID: 24298998 PMCID: PMC3951446 DOI: 10.1111/ajt.12524] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 08/30/2013] [Accepted: 09/27/2013] [Indexed: 01/25/2023]
Abstract
This prospective study evaluated changes in dual energy X-ray absorptiometry (DXA) whole body bone mineral content (WB-BMC) and spine areal bone mineral density (spine-BMD), and tibia quantitative computed tomography (QCT) trabecular and cortical volumetric BMD and cortical area in 56 children over 12 months following renal transplantation. At transplant, spine-BMD Z-scores were greater in younger recipients (<13 years), versus 898 reference participants (p < 0.001). In multivariate models, greater decreases in spine-BMD Z-scores were associated with greater glucocorticoid dose (p < 0.001) and declines in parathyroid hormone levels (p = 0.008). Changes in DXA spine-BMD and QCT trabecular BMD were correlated (r = 0.47, p < 0.01). At 12 months, spine-BMD Z-scores remained elevated in younger recipients, but did not differ in older recipients (≥ 13) and reference participants. Baseline WB-BMC Z-scores were significantly lower than reference participants (p = 0.02). Greater glucocorticoid doses were associated with declines in WB-BMC Z-scores (p < 0.001) while greater linear growth was associated with gains in WB-BMC Z-scores (p = 0.01). Changes in WB-BMC Z-scores were associated with changes in tibia cortical area Z-scores (r = 0.52, p < 0.001), but not changes in cortical BMD Z-scores. Despite resolution of muscle deficits, WB-BMC Z-scores at 12 months remained significantly reduced. These data suggest that spine and WB DXA provides insight into trabecular and cortical outcomes following pediatric renal transplantation.
Collapse
Affiliation(s)
- Anne Tsampalieros
- Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania
| | - Lindsay Griffin
- Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania
| | - Anniek M Terpstra
- Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania
| | - Heidi J Kalkwarf
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center
| | - Justine Shults
- Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania
| | - Bethany J Foster
- Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania
| | - Babette S Zemel
- Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania
| | - Debbie L Foerster
- Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania
| | - Mary B. Leonard
- Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Department of Biostatistics and Epidemiology, Perelman School of Medicine at the University of Pennsylvania
| |
Collapse
|
24
|
Bone and mineral disorders after kidney transplantation: therapeutic strategies. Transplant Rev (Orlando) 2013; 28:56-62. [PMID: 24462303 DOI: 10.1016/j.trre.2013.12.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 08/16/2013] [Accepted: 12/02/2013] [Indexed: 12/14/2022]
Abstract
Mineral and bone diseases (MBD) are common in patients with chronic kidney disease who undergo kidney transplantation. The incidence, types and severity of MBD vary according to the duration of chronic kidney disease, presence of comorbid conditions and intake of certain medications. Moreover, multiple types of pathology may be responsible for MBD. After successful reversal of uremia by kidney transplantation, many bone and mineral disorders improve, while immunosuppression, other medications, and new and existing comorbidities may result in new or worsening MBD. Chronic kidney disease is also common after kidney transplantation and may impact bone and mineral disease. In this article, we reviewed the prevalence, pathophysiology, and impact of MBD on post-transplant outcomes. We also discussed the diagnostic approach; immunosuppression management and potential treatment of MBD in kidney transplant recipients.
Collapse
|
25
|
Christoforidis A, Printza N, Gkogka C, Kazantzidou E, Papachristou F. A two-yr prospective study of bone health in children after renal transplantation employing two imaging techniques. Clin Transplant 2013; 27:710-7. [PMID: 24033832 DOI: 10.1111/ctr.12206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2013] [Indexed: 11/28/2022]
Abstract
The aim of this study was to prospectively and longitudinally evaluate bone properties with the use of two bone imaging techniques (dual energy X-ray absorptiometry [DXA], and quantitative ultraSonography [QUS]) in pediatric renal transplant recipients. Fourteen patients (eight boys and six girls) with a mean age of 12.25 ± 3.11 yr (range: 8-17.5 yr) completed a two-yr follow-up. Measurements of bone mineral density (BMD) by DXA at lumbar spine and hip and speed of sound (SOS) by QUS at radius and tibia were performed at the beginning and at the end of the study. A significant improvement in mean Z-score of SOS values measured at tibia (1.01 ± 1.31 vs. -0.46 ± 1.14, p = 0.005) was observed. On the contrary, mean Z-score of BMD values measured at femoral neck was significantly reduced (-1.95 ± 2.15 vs. -0.33 ± 1.13, p = 0.041). Finally, multivariate stepwise regression analyses showed that glomerular filtration rate at the beginning of the study was the best predictor of the difference in BMD Z-scores measured at lumbar spine. Additionally, values of intact parathormone (iPTH) at the beginning of the study and the change in iPTH throughout the study predicted the 72.3% of the difference in Z-score of SOS measured at radius with an inverse relationship.
Collapse
|
26
|
Bacchetta J, Wesseling-Perry K, Kuizon B, Pereira RC, Gales B, Wang HJ, Elashoff R, Salusky IB. The skeletal consequences of growth hormone therapy in dialyzed children: a randomized trial. Clin J Am Soc Nephrol 2013; 8:824-32. [PMID: 23559676 PMCID: PMC3641609 DOI: 10.2215/cjn.00330112] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 01/03/2013] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVE The effects of recombinant human growth hormone on renal osteodystrophy are unknown; thus, the effects of growth hormone (GH) on bone histomorphometry were assessed in pediatric patients with ESRD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Thirty-three patients who underwent bone biopsy between July 1994 and May 1999 were randomly assigned to therapy with or without GH. Patients were stratified by bone formation rate; all patients with high bone turnover received intraperitoneal calcitriol. Serum biochemical values were obtained monthly, and bone biopsy was repeated after 8 months. RESULTS Median patient age was 11.7 years (interquartile range [IQR], 7.6, 14.1 years); 45% of patients were male, and 52% were prepubertal. Median dialysis duration was 0.4 (IQR, 0.3, 0.8) year. Bone formation rate per bone surface increased from 15.0 (9.6, 21.8) to 154.6 (23.7, 174.3) μm(2)/μm(3) per year (P=0.05) in patients with low bone turnover treated with GH, decreased from 103.3 (57.0, 173.4) to 60.3 (20.3, 13.7) μm(2)/μm(3) per year in patients with high bone turnover receiving standard therapy (P=0.03), and was unchanged in the other two groups. Bone formation rates were higher with GH, irrespective of underlying bone histologic features (P=0.05). Parathyroid hormone did not differ between groups. GH therapy resulted in greater increases in height SD scores (estimated mean difference in change ± SD, 0.324±0.076; P<0.001), irrespective of underlying bone histologic features. CONCLUSIONS GH therapy improves height in pediatric dialysis patients, irrespective of underlying bone histologic features. Bone formation rates are higher in GH recipients, and GH therapy alters the relationship between circulating parathyroid hormone values and bone turnover.
Collapse
Affiliation(s)
| | | | | | | | | | - He-jing Wang
- Department of Biomathematics, David Geffen School of Medicine at UCLA, Los Angeles, California, and
| | - Robert Elashoff
- Department of Biomathematics, David Geffen School of Medicine at UCLA, Los Angeles, California, and
| | | |
Collapse
|
27
|
Bacchetta J, Wesseling-Perry K, Gilsanz V, Gales B, Pereira RC, Salusky IB. Idiopathic juvenile osteoporosis: a cross-sectional single-centre experience with bone histomorphometry and quantitative computed tomography. Pediatr Rheumatol Online J 2013; 11:6. [PMID: 23418950 PMCID: PMC3639801 DOI: 10.1186/1546-0096-11-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2012] [Accepted: 02/12/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Idiopathic juvenile osteoporosis (IJO) is a rare condition of poorly understood etiology and pathophysiology that affects otherwise healthy children. This condition is characterized clinically by bone pain and vertebral fractures; spontaneous recovery is observed after puberty in the majority of cases. Although decreased trabecular bone turnover has been noted previously, cortical and trabecular bone characteristics as determined by quantitative computed tomography (QCT) and their relationship to bone histomorphometry are unknown. METHODS All children with a clinical diagnosis of IJO who were followed in our center since 1995 and who had undergone at least one diagnostic bone biopsy were included in this cross-sectional analysis. RESULTS Fifteen patients (11 males/4 females) with median ages of 5.8 and 10.2 years at first symptoms and at referral, respectively, were included in the analysis. Histomorphometric analysis demonstrated decreased trabecular bone turnover (BFR/BS) in the majority of patients with heterogeneous parameters of trabecular mineralization and volume. QCTresults demonstrated that bone mineral density (BMD) was reduced in both trabecular/lumbar and cortical/femoral bone: Z score: -2.1 (-3.6;-1.0) and -0.9 (-8.2;1.4)in the two compartments, respectively. In the eight patients who underwent both bone biopsy and QCT, cortical BMD was associated with trabecular separation and with trabecular bone formation rate (r = 0.898 and -0.881, respectively, both p < 0.05). CONCLUSIONS This series confirms that IJO is characterized by impaired trabecular architecture that can be detected by both bone biopsy and QCT. The association between bone biopsy and QCT results may have implications for diagnosis, treatment, and follow-up of these children.
Collapse
Affiliation(s)
- Justine Bacchetta
- David Geffen School of Medicine, Division of Pediatric Nephrology, University of California, 10833 Le Conte Boulevard, Los Angeles, CA, USA
| | - Katherine Wesseling-Perry
- David Geffen School of Medicine, Division of Pediatric Nephrology, University of California, 10833 Le Conte Boulevard, Los Angeles, CA, USA
| | - Vicente Gilsanz
- Department of Radiology, Hospital Los Angeles, Los Angeles, CA, USA
| | - Barbara Gales
- David Geffen School of Medicine, Division of Pediatric Nephrology, University of California, 10833 Le Conte Boulevard, Los Angeles, CA, USA
| | - Renata C Pereira
- David Geffen School of Medicine, Division of Pediatric Nephrology, University of California, 10833 Le Conte Boulevard, Los Angeles, CA, USA
| | - Isidro B Salusky
- David Geffen School of Medicine, Division of Pediatric Nephrology, University of California, 10833 Le Conte Boulevard, Los Angeles, CA, USA
| |
Collapse
|
28
|
Abstract
PURPOSE OF REVIEW Mineral and bone disorders (MBDs), inherent complications of moderate and advanced chronic kidney disease, occur frequently in kidney transplant recipients. However, much confusion exists about the clinical application of diagnostic tools and preventive or treatment strategies to correct bone loss or mineral disarrays in transplanted patients. We have reviewed the recent evidence about prevalence and consequences of MBD in kidney transplant recipients and examined diagnostic, preventive and therapeutic options to this end. RECENT FINDINGS Low turnover bone disease occurs more frequently after kidney transplantation according to bone biopsy studies. The risk of fracture is high, especially in the first several months after kidney transplantation. Alterations in minerals (calcium, phosphorus and magnesium) and biomarkers of bone metabolism (parathyroid hormone, alkaline phosphatase, vitamin D and FGF-23) are observed with varying impact on posttransplant outcomes. Calcineurin inhibitors are linked to osteoporosis, whereas steroid therapy may lead to both osteoporosis and varying degrees of osteonecrosis. Sirolimus and everolimus might have a bearing on osteoblast proliferation and differentiation or decreasing osteoclast-mediated bone resorption. Selected pharmacologic interventions for the treatment of MBD in transplant patients include steroid withdrawal, and the use of bisphosphonates, vitamin D derivatives, calcimimetics, teriparatide, calcitonin and denosumab. SUMMARY MBD following kidney transplantation is common and characterized by loss of bone volume and mineralization abnormalities, often leading to low turnover bone disease. Although there are no well established therapeutic approaches for management of MBD in renal transplant recipients, clinicians should continue individualizing therapy as needed.
Collapse
|
29
|
Griffin LM, Kalkwarf HJ, Zemel BS, Shults J, Wetzsteon RJ, Strife CF, Leonard MB. Assessment of dual-energy X-ray absorptiometry measures of bone health in pediatric chronic kidney disease. Pediatr Nephrol 2012; 27:1139-48. [PMID: 22350304 PMCID: PMC4532320 DOI: 10.1007/s00467-012-2116-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Revised: 01/06/2012] [Accepted: 01/18/2012] [Indexed: 12/20/2022]
Abstract
BACKGROUND Dual-energy X-ray absorptiometry (DXA) techniques are limited in childhood chronic kidney disease (CKD) by the confounding effect of short stature and opposing parathyroid hormone effects on trabecular and cortical bone. Peripheral quantitative computed tomography (pQCT) is not subject to these limitations. METHODS Lumbar spine (LS) and whole-body (WB) DXA and tibia pQCT scans were obtained in 88 stage 4-5 CKD and >650 healthy participants, ages 5-21 years. Sex- and race-specific Z-scores were generated for bone mineral density (BMD) and bone mineral content (BMC) by DXA, relative to age and adjusted for height Z-score (LS-BMD-Z and WB-BMC-Z), and compared to pQCT Z-scores for trabecular BMD (TrabBMD-Z) for age and cortical BMC (CortBMC-Z) for age and tibia length. RESULTS LS-BMD-Z [0.50 (95% C.I. 0.28, 0.73), p<0.0001] and TrabBMD-Z [0.53 (0.27, 0.79), p<0.0001] were greater in CKD, and WB-BMC-Z [-0.36 (-0.53, -0.19), p<0.0001] and CortBMC-Z [-0.48 (-0.70, -0.27), p<0.0001] were lower, compared to reference participants. Z-scores were correlated at trabecular (LS-BMD-Z and TrabBMD-Z: R=0.36) and cortical (WB-BMC-Z and CortBMC-Z: R=0.64) sites in CKD; similar to correlations in reference participants. CONCLUSIONS Lumbar spine and whole-body DXA suggested greater trabecular BMD and lower cortical BMC in CKD, consistent with pQCT results; however, correlations were modest. Studies are needed to identify methods that predict fracture in childhood CKD.
Collapse
Affiliation(s)
- Lindsay M. Griffin
- Department of Pediatrics, Children’s Hospital of Philadelphia, 3535 Market Street, Room 1564, Philadelphia, PA 19104, USA
| | - Heidi J. Kalkwarf
- Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
| | - Babette S. Zemel
- Department of Pediatrics, Children’s Hospital of Philadelphia, 3535 Market Street, Room 1564, Philadelphia, PA 19104, USA
| | - Justine Shults
- Department of Biostatistics and Epidemiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Rachel J. Wetzsteon
- Department of Pediatrics, Children’s Hospital of Philadelphia, 3535 Market Street, Room 1564, Philadelphia, PA 19104, USA
| | - C. Frederic Strife
- Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
| | - Mary B. Leonard
- Department of Pediatrics, Children’s Hospital of Philadelphia, 3535 Market Street, Room 1564, Philadelphia, PA 19104, USA. Department of Biostatistics and Epidemiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| |
Collapse
|
30
|
Terpstra AM, Kalkwarf HJ, Shults J, Zemel BS, Wetzsteon RJ, Foster BJ, Strife CF, Foerster DL, Leonard MB. Bone density and cortical structure after pediatric renal transplantation. J Am Soc Nephrol 2012; 23:715-26. [PMID: 22282589 PMCID: PMC3312505 DOI: 10.1681/asn.2011050480] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 10/30/2011] [Indexed: 01/24/2023] Open
Abstract
The impact of renal transplantation on trabecular and cortical bone mineral density (BMD) and cortical structure is unknown. We obtained quantitative computed tomography scans of the tibia in pediatric renal transplant recipients at transplantation and 3, 6, and 12 months; 58 recipients completed at least two visits. We used more than 700 reference participants to generate Z-scores for trabecular BMD, cortical BMD, section modulus (a summary measure of cortical dimensions and strength), and muscle and fat area. At baseline, compared with reference participants, renal transplant recipients had significantly lower mean section modulus and muscle area; trabecular BMD was significantly greater than reference participants only in transplant recipients younger than 13 years. After transplantation, trabecular BMD decreased significantly in association with greater glucocorticoid exposure. Cortical BMD increased significantly in association with greater glucocorticoid exposure and greater decreases in parathyroid hormone levels. Muscle and fat area both increased significantly, but section modulus did not improve. At 12 months, transplantation associated with significantly lower section modulus and greater fat area compared with reference participants. Muscle area and cortical BMD did not differ significantly between transplant recipients and reference participants. Trabecular BMD was no longer significantly elevated in younger recipients and was low in older recipients. Pediatric renal transplant associated with persistent deficits in section modulus, despite recovery of muscle, and low trabecular BMD in older recipients. Future studies should determine the implications of these data on fracture risk and identify strategies to improve bone density and structure.
Collapse
MESH Headings
- Adolescent
- Age Factors
- Anthropometry
- Bone Demineralization, Pathologic/diagnostic imaging
- Bone Demineralization, Pathologic/etiology
- Bone Demineralization, Pathologic/physiopathology
- Bone Density/physiology
- Case-Control Studies
- Chi-Square Distribution
- Child
- Child, Preschool
- Cohort Studies
- Female
- Follow-Up Studies
- Hospitals, Pediatric
- Humans
- Imaging, Three-Dimensional
- Kidney Failure, Chronic/etiology
- Kidney Failure, Chronic/physiopathology
- Kidney Failure, Chronic/surgery
- Kidney Transplantation/adverse effects
- Kidney Transplantation/methods
- Male
- Multivariate Analysis
- Parathyroid Hormone/blood
- Reference Values
- Risk Assessment
- Sex Factors
- Statistics, Nonparametric
- Tibia/diagnostic imaging
- Tibia/pathology
- Tomography, X-Ray Computed/methods
- Young Adult
Collapse
Affiliation(s)
- Anniek M. Terpstra
- Department of Epidemiology, Biostatistics and Health Technology Assessment, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Heidi J. Kalkwarf
- Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio
| | - Justine Shults
- Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
- Department of Biostatistics and Epidemiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania; and
| | - Babette S. Zemel
- Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Rachel J. Wetzsteon
- Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Bethany J. Foster
- Department of Pediatrics, Montreal Children's Hospital, Montreal, Quebec, Canada
| | - C. Frederic Strife
- Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio
| | - Debbie L. Foerster
- Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Mary B. Leonard
- Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
- Department of Biostatistics and Epidemiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania; and
| |
Collapse
|
31
|
Wesseling-Perry K, Pereira RC, Tseng CH, Elashoff R, Zaritsky JJ, Yadin O, Sahney S, Gales B, Jüppner H, Salusky IB. Early skeletal and biochemical alterations in pediatric chronic kidney disease. Clin J Am Soc Nephrol 2012; 7:146-52. [PMID: 22052943 PMCID: PMC3265337 DOI: 10.2215/cjn.05940611] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2011] [Accepted: 09/27/2011] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND OBJECTIVES The relationship between parathyroid hormone, fibroblast growth factor 23 (FGF-23), and indices of bone turnover and mineralization in children with early CKD is unknown; thus, this study characterizes the features of renal osteodystrophy and their relationship to biochemical markers of mineral metabolism. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Fifty-two patients 2-21 years of age with predialysis CKD underwent tetracycline-labeled bone biopsy. Anthropomorphic measurements and biochemical values were obtained at the time of biopsy. RESULTS Serum phosphorus levels were increased in 4% of patients with stage 3 CKD and 43% of those with stage 4/5 CKD. Parathyroid hormone concentrations were elevated in 36% of patients with stage 2, 71% with stage 3, and 93% with stage 4/5 CKD, whereas FGF-23 values were elevated in 81% of all patients, regardless of CKD stage. Bone turnover was normal in all patients with stage 2, but was increased in 13% with stage 3 and 29% with stage 4/5 CKD. Defective mineralization was present in 29% of patients with stage 2, 42% with stage 3, and 79% with stage 4/5 CKD. Defective skeletal mineralization was associated with lower serum calcium levels and increased parathyroid hormone concentrations. CONCLUSIONS Elevated circulating FGF-23 levels and defects in skeletal mineralization early in the course of CKD suggest that factors other than the traditional markers of mineral deficiency play a crucial role in the development of renal bone disease.
Collapse
Affiliation(s)
- Katherine Wesseling-Perry
- Department of Pediatrics, David Geffen School of Medicine at UCLA, A2-383 MDCC, 650 Charles Young Drive, Los Angeles, CA 90095, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Govindarajan S, Khandelwal N, Sakhuja V, Jha V. Bone mineral density in patients with end-stage renal disease and its evolution after kidney transplantation. Indian J Nephrol 2011; 21:85-9. [PMID: 21769169 PMCID: PMC3132344 DOI: 10.4103/0971-4065.82140] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Renal transplantation is associated with abnormalities of the structure and function of the musculoskeletal system. No data are available on bone health in Indian patients with end-stage renal disease (ESRD) and its evolution after transplantation. Consecutive ESRD patients who underwent living donor renal transplantation were studied prospectively. Bone mineral density (BMD) was measured at lumbar vertebrae using quantitative computed tomography (CT) scan before transplantation and after 3 and 6 months. T and Z scores were calculated by comparing with normal control data, and values were correlated with various clinical and biochemical parameters. Of the 56 patients enrolled (mean age, 33.7 years; 47 males), 40 completed the 6-month follow-up. The vertebral trabecular bone density at the time of transplantation was 172±53 mg/cc and the average Z score was 0.26±1.7. There was a significant decline in BMD at 3 months (11.8%; P<0.0001) and 6 months (16%; P<0.0001) after transplantation. Both T and Z scores showed a significant decline at 3 and 6 months. There was a significant decline in intact parathormone (iPTH) levels after transplantation, but 15 (37.5%) patients continued to have raised iPTH 6 months after transplantation. The iPTH levels at 6 months had significant correlation with BMD decline (r=0.43, P=0.006). We conclude that Indian ESRD patients have relatively well-preserved BMD, but the density declines rapidly after transplantation. A significant proportion of patients exhibit persistent hyperparathyroidism 6 months after transplantation, which correlates with bone loss.
Collapse
Affiliation(s)
- S Govindarajan
- Department of Nephrology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | | | | | | |
Collapse
|
33
|
Guzzo I, Di Zazzo G, Laurenzi C, Ravà L, Giannone G, Picca S, Dello Strologo L. Parathyroid hormone levels in long-term renal transplant children and adolescents. Pediatr Nephrol 2011; 26:2051-7. [PMID: 21556715 DOI: 10.1007/s00467-011-1896-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2010] [Revised: 03/14/2011] [Accepted: 03/15/2011] [Indexed: 12/26/2022]
Abstract
Secondary hyperparathyroidism is a common complication of chronic renal failure. Kidney transplantation corrects renal insufficiency and most metabolic abnormalities but hyperparathyroidism persists in 50% of children after transplantation. The aim of this study was to investigate parathyroid hormone (PTH) course and potential risk factors for hyperparathyroidism in children after renal transplant. We collected data from 145 transplanted children (mean follow-up 4.7 years). Intact PTH level (iPTH) rapidly decreased in the first 6 months post-transplant and continued to decline in the following years. iPTH was above the normal range in 69.1% of the patients at the time of transplant and in 47% 1 year later, this improvement continuing thereafter. Hypercalcemia was present in 20.3% of the patients before transplant and in 6.3 and 4.1% of patients 6 months and 1 year after transplant, respectively. Hypophosphatemia was present in 5.5% of the patients at 6 months, and 45.5% of the patients needed phosphorus supplements during the first 6 months after transplant. Multivariate analysis indicated pre-transplant hyperparathyroidism, dialysis duration, creatinine clearance and hypophosphatemia as predictors of persistent hyperparathyroidism. In kidney transplanted children, serum iPTH normalized in the long term in the majority of cases. Thus, parathyroidectomy should be reserved for selected patients.
Collapse
Affiliation(s)
- Isabella Guzzo
- Nephrology and Urology Department, Bambino Gesù Children's Hospital and Research Institute (IRCCS), Piazza S. Onofrio 4, 00165 Rome, Italy.
| | | | | | | | | | | | | |
Collapse
|
34
|
Mäyränpää MK, Tamminen IS, Kröger H, Mäkitie O. Bone biopsy findings and correlation with clinical, radiological, and biochemical parameters in children with fractures. J Bone Miner Res 2011; 26:1748-58. [PMID: 21351145 DOI: 10.1002/jbmr.373] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In children the diagnosis of osteoporosis is based on fracture history and DXA-derived BMD. Bone biopsy is an invasive but accurate method for studying bone characteristics. In this study we evaluated bone biopsy findings and their correlation with noninvasive measures of bone health. Transiliac bone biopsy was performed on 24 consecutive children (17 boys, median age 12 years, range 6 to 16 years) evaluated for suspected primary osteoporosis. Biopsy findings were compared with normative data and correlated with clinical, radiological, biochemical, and densitometric findings. The patients had sustained altogether 64 nonvertebral fractures (median 2.5) from low- or moderate-energy traumas, and 14 patients (58%) had vertebral fractures. The median lumbar spine BMD Z-score was -1.2 (range -3.1 to +1.0). Hypovitaminosis D was present in 58%. Histomorphometry showed low bone volume in 7 patients and normal bone volume in 17. Bone turnover was high in 7, low in 7, and normal in 10 patients. Histomorphometric findings correlated poorly with fracture history, serum bone turnover markers, and DXA findings. Vitamin D deficiency and low lumbar BMD were associated with high bone turnover in the biopsy. These findings underscore the difficulties in diagnosing pediatric osteoporosis. Bone histomorphometry gives additional information and may be useful when considering bisphosphonate treatment in children with suspected primary osteoporosis.
Collapse
Affiliation(s)
- Mervi K Mäyränpää
- Department of Pediatric Surgery, Children's Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland.
| | | | | | | |
Collapse
|
35
|
Derakhshan A, Behbahan AG, Lotfi M, Omrani GH, Fallahzadeh MH, Basiratnia M, Al-Hashemi GH. Bone mineral disorders in pediatric and adolescent renal transplant recipients. Pediatr Transplant 2011; 15:367-75. [PMID: 21429060 DOI: 10.1111/j.1399-3046.2011.01492.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Incomplete resolution of abnormalities of mineral metabolism associated with CRF results in the relatively high prevalence of ROD in pediatric kidney recipients. This non-randomized, cross-sectional, and analytic-descriptive study on bone density, vitamin D, and mineral metabolism was performed in 57 children and adolescents who had received a total of 60 renal allografts in Shiraz, Iran. The height and weight of the patients were measured; their serum calcium (Ca), phosphorus (P), Alk-P, PTH, 25(OH)-vitamin D(3), BUN, creatinine, and electrolyte levels were analyzed, and a complete blood count was performed. In addition, standard radiologic bone assessments, which included conventional left hand-wrist radiography and bone mineral densitometry by the DXA technique, were carried out. Special pediatric software was used for age-related interpretation of the Z-scores of BMD. SPSS(®) software (version 15) was used for statistical analyses. We studied 57 patients (27 males [47.4%]) with a mean age of 18.7 ± 4.25 (9-27) yr and a mean age at transplantation of 13.1 ± 3.46 (4.5-20) yr. They had a post-transplantation follow-up of 67.1 ± 33.8 (6-132) months, and all had well-functioning allografts at enrollment. The mean height age of the patients was 11.9 ± 1.8 (6-15.5), and the mean bone age was 15.6 ± 3.3 (7-19) yr, which corresponded to mean height-age and bone-age retardations of 5.7 ± 2.3 (0.5-10.5) and 1.22 ± 1.47 (0-7) yr, respectively. Hyperphosphatemia and hypercalcemia were each found in nine patients (15.8%), hypophosphatemia in five (8.8%), and hypocalcemia in none of the patients. Seven out of 57 patients (12.3%) had a (Ca×P) product of more than 55 mg(2)/dL(2). Hyperparathyroidism was found in 27 (47.3%) and vitamin D(3) deficiency in four (7%) of the cases. The serum level of Alk-P was higher than the age-related normal range in 20 patients (35%). Left hand-wrist radiography showed no radiologic sign of ROD in any patient. The mean BMD Z-score was -1.77 ± 1.13 (-4.2-1.1) for the lumbar spine and -1.64 ± 0.89 (-3.9 to 1.9) for the femoral neck. "Stepwise backward regression" revealed a significant inverse correlation between the serum level of PTH and the GFR of the transplanted kidney; this correlation was independent from the influence of other variables such as Ca, P, and Alk-P (p = 0.011, β = -1.556). Bone age and height age both showed significant correlations with age at transplantation and serum levels of P (p < 0.001), but only bone age had a meaningful correlation with Alk-P (p = 0.036). The BMD Z-scores showed statistically meaningful correlations with the serum level of Alk-P, which were independent from the influence of other variables such as Ca, P, and PTH (p ≤ 0.002). Our study revealed a relatively high prevalence of bone mineral disorder in pediatric kidney recipients, which suggests the need for a routine program for periodic screening of these patients to facilitate early diagnosis of either persistent or evolving manifestations of disturbed mineral metabolism, especially ROD.
Collapse
Affiliation(s)
- Ali Derakhshan
- Department of Pediatric Nephrology, Nephro-Urology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | | | | | | | | | | |
Collapse
|
36
|
Brodersen LA, Nielsen PR, Thiesson HC, Marckmann P. Vitamin D status in children and adolescents with kidney transplants. Pediatr Transplant 2011; 15:384-9. [PMID: 21366811 DOI: 10.1111/j.1399-3046.2011.01493.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Hypovitaminosis D is highly prevalent in adult kidney-transplanted patients. The knowledge of vitamin D status in kidney-transplanted children and adolescents is sparse. The present study investigated the vitamin D status of a cohort of kidney-transplanted children and adolescents, and the association between vitamin D status and plasma concentrations of PTH, ionized calcium, and phosphate. The study included 35 patients with a functioning graft. Their mean age was 12.0 yr, and the mean graft age was 2.8 yr. Forty percent of the patients were vitamin D insufficient (P-25-hydroxyvitamin D 40-75 nm), and 14% were deficient (P-25-hydroxyvitamin D < 40 nm). S-25-hydroxyvitamin D was inversely associated with PTH (p = 0.02) and positively associated with S-1,25-dihydroxyvitamin D (p = 0.02). There was no significant association between S-1,25-dihydroxyvitamin D and PTH. In conclusion, we found hypovitaminosis D in 54% of the study population despite the fact that samples were collected in spring and summer months. Hypovitaminosis D was associated with adverse effects on PTH and 1,25-dihydroxyvitamin D. Our data suggest that it is warranted to monitor vitamin D status of kidney-transplanted children and adolescents and indicate that correction of hypovitaminosis D might have favorable effects on calcium-phosphate metabolism.
Collapse
|
37
|
Wesseling-Perry K, Tsai EW, Ettenger RB, Jüppner H, Salusky IB. Mineral abnormalities and long-term graft function in pediatric renal transplant recipients: a role for FGF-23? Nephrol Dial Transplant 2011; 26:3779-84. [PMID: 21441401 DOI: 10.1093/ndt/gfr126] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Although current guidelines recommend the evaluation of mineral and bone metabolism in patients with all stages of chronic kidney disease (CKD), the prevalence of altered mineral ion homeostasis in the pediatric posttransplant population is unknown. Moreover, the contribution of abnormal mineral ion metabolism to graft outcomes in this population has not been evaluated. METHODS Serum calcium, phosphorus, 25(OH)vitamin D, 1,25(OH)(2)vitamin D, parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF-23) levels were evaluated 4.9 ± 0.5 years after transplantation in 68 stable pediatric renal allograft recipients. Patients were subsequently followed for 2 years. RESULTS At baseline, mean estimated glomerular filtration rate (GFR) was 60 ± 2 mL/min/1.73 m(2). Serum calcium and phosphorus values were within the reference interval. PTH values were elevated but did not differ by CKD stage. 25(OH)vitamin D levels were low in nearly half of all subjects. Tubular reabsorption of phosphate and 1,25(OH)(2)vitamin D values were lower, while FGF-23 and PTH values were higher in more advanced stages of CKD. Thirty percent of patients with FGF-23 values >110 RU/mL had a decrease in GFR of >50% (P < 0.05) and FGF-23 values predicted future episodes of rejection. CONCLUSIONS Despite normal serum calcium and phosphorus levels in the majority of prevalent pediatric renal transplant recipients, abnormalities in PTH, 25(OH)vitamin D and FGF-23 are common. FGF-23 levels may be associated with increased risk for deterioration of kidney function and episodes of rejection.
Collapse
|
38
|
Grenda R, Karczmarewicz E, Rubik J, Matusik H, Płudowski P, Kiliszek M, Piskorski J. Bone mineral disease in children after renal transplantation in steroid-free and steroid-treated patients--a prospective study. Pediatr Transplant 2011; 15:205-13. [PMID: 21199211 DOI: 10.1111/j.1399-3046.2010.01448.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
UNLABELLED Bone disease may persist after transplantation. Different approaches aiming to ameliorate this problem have been investigated. The aim of the study was to compare the long-term effect of three medical interventions: (i) two prophylactic oral doses of 50 mg ibandronate; (ii) daily oral dose of 0.25 μg of 1α-OHD3 (both of these regimens in patients receiving steroids), and (iii) steroid minimization immunosuppressive protocol in patients with no other specific prophylaxis. PATIENTS A total of 37 children, at a mean age of 13.33±3.49 yr, dialyzed for 15.93±16.7 months before transplantation, were divided into three groups, depending on medical intervention. Bone mineral content and density (BMC, BMD, DXA), serum markers of bone resorption and formation (CTX, P1NP), calcium, phosphate, 25OHD3/1.25 (OH)2D3 and PTH concentration were evaluated during two yr of follow-up. The mean values of BMD in the whole population and among the three subgroups remained within the age- and gender-matched normal range during follow-up. PATIENTS from groups II (alphacalcidiol) and III (steroid minimization) showed a significant decrease in BMD Z-scores over time, and this effect was determined with increasing age using multivariate analysis. PATIENTS receiving two doses of ibandronate maintained unchanged Z-scores for BMD and BMC over time.
Collapse
Affiliation(s)
- Ryszard Grenda
- Department of Nephrology, Kidney Transplantation and Hypertension, The Children's Memorial Health Institute, Warsaw, Poland.
| | | | | | | | | | | | | |
Collapse
|
39
|
Seeherunvong W, Wolf M. Tertiary excess of fibroblast growth factor 23 and hypophosphatemia following kidney transplantation. Pediatr Transplant 2011; 15:37-46. [PMID: 20946192 PMCID: PMC3022970 DOI: 10.1111/j.1399-3046.2010.01405.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Hypophosphatemia caused by inappropriate urinary phosphate wasting is a frequent metabolic complication of the early period following kidney transplantation. Although previously considered to be caused by tertiary hyperparathyroidism, recent evidence suggests a primary role for persistently elevated circulating levels of the phosphorus-regulating hormone, FGF23. In the setting of a healthy renal allograft, markedly increased FGF23 levels from the dialysis period induce renal phosphate wasting and inhibition of calcitriol production, which contribute to hypophosphatemia. While such tertiary FGF23 excess and resultant hypophosphatemia typically abates within the first few weeks to months post-transplant, some recipients manifest persistent renal phosphate wasting. Furthermore, increased FGF23 levels have been associated with increased risk of kidney disease progression, cardiovascular disease, and death outside of the transplant setting. Whether tertiary FGF23 excess is associated with adverse transplant outcomes is unknown. In this article, we review the physiology of FGF23, summarize its relationship with hypophosphatemia after kidney transplantation, and speculate on its potential impact on long-term outcomes of renal allograft recipients.
Collapse
Affiliation(s)
- Wacharee Seeherunvong
- Division of Pediatric Nephrology, Department of Pediatrics, University of Miami Miller School of Medicine, Miami, Florida
| | - Myles Wolf
- Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida
| |
Collapse
|
40
|
Wesseling-Perry K, Bacchetta J. CKD-MBD after kidney transplantation. Pediatr Nephrol 2011; 26:2143-51. [PMID: 21394466 PMCID: PMC3203246 DOI: 10.1007/s00467-011-1829-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 02/11/2011] [Accepted: 02/12/2011] [Indexed: 01/01/2023]
Abstract
Successful kidney transplantation corrects many of the metabolic abnormalities associated with chronic kidney disease (CKD); however, skeletal and cardiovascular morbidity remain prevalent in pediatric kidney transplant recipients and current recommendations from the Kidney Disease Improving Global Outcomes (KDIGO) working group suggest that bone disease-including turnover, mineralization, volume, linear growth, and strength-as well as cardiovascular disease be evaluated in all patients with CKD. Although few studies have examined bone histology after renal transplantation, current data suggest that bone turnover and mineralization are altered in the majority of patients and that biochemical parameters are poor predictors of bone histology in this population. Dual energy X-ray absorptiometry (DXA) scanning, although widely performed, has significant limitations in the pediatric transplant population and values have not been shown to correlate with fracture risk; thus, DXA is not recommended as a tool for the assessment of bone density. Newer imaging techniques, including computed tomography (quantitative CT (QCT), peripheral QCT (pQCT), high resolution pQCT (HR-pQCT) and magnetic resonance imaging (MRI)), which provide volumetric assessments of bone density and are able to discriminate bone microarchitecture, show promise in the assessment of bone strength; however, future studies are needed to define the value of these techniques in the diagnosis and treatment of renal osteodystrophy in pediatric renal transplant recipients.
Collapse
Affiliation(s)
- Katherine Wesseling-Perry
- Department of Pediatrics, David Geffen School of Medicine at UCLA, A2-383 MDCC, 650 Charles Young Drive, Los Angeles, CA 90095, USA.
| | - Justine Bacchetta
- Department of Pediatrics, David Geffen School of Medicine at UCLA, A2-383 MDCC, 650 Charles Young Drive, Los Angeles, CA 90095 USA
| |
Collapse
|
41
|
Bakkaloglu SA, Wesseling-Perry K, Pereira RC, Gales B, Wang HJ, Elashoff RM, Salusky IB. Value of the new bone classification system in pediatric renal osteodystrophy. Clin J Am Soc Nephrol 2010; 5:1860-6. [PMID: 20634327 PMCID: PMC2974387 DOI: 10.2215/cjn.01330210] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Accepted: 05/28/2010] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Although lesions of renal osteodystrophy have traditionally been defined by bone turnover, alterations in skeletal mineralization and volume are also prevalent and may contribute to significant morbidity in patients with chronic kidney disease (CKD). The study presented here was undertaken to compare the traditional spectrum of renal osteodystrophy defined by bone turnover to a new classification system that includes T (turnover), M (mineralization), and V (volume) and to determine the value of biochemical parameters as predictors of specific TMV lesions. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Pediatric patients (n = 161) treated with peritoneal dialysis were enrolled into the study. RESULTS Increased bone turnover and abnormal mineralization were prevalent (57% and 48%, respectively); bone volume was normal or increased in all subjects. Predictive algorithms for different skeletal diagnoses were established by Classification and regression tree analysis. Serum parathyroid hormone (PTH) less than 400 pg/ml in combination with alkaline phosphatase values less than 400 IU/L provided the highest correct prediction rate for patients with both normal bone turnover and normal mineralization. Levels of PTH were higher and serum calcium levels were lower in patients with defective mineralization, irrespective of bone turnover. CONCLUSIONS Although no single biochemical marker is able to provide a complete assessment of renal osteodystrophy, a combination of serum calcium, alkaline phosphatase, and PTH levels may lead to a more precise noninvasive assessment of turnover and mineralization abnormalities in this population.
Collapse
Affiliation(s)
- Sevcan A Bakkaloglu
- Department of Pediatrics, David Geffen School of Medicine at University of California–Los Angeles, Los Angeles, California, USA.
| | | | | | | | | | | | | |
Collapse
|
42
|
Chu KH, Cheuk A, Lee W, Yim KF, Tang HL, Fung KS, Lee KC, Tong KL, Chan HWH. Renal Bone Disease: 25-year Experience From a Single Center. Int J Organ Transplant Med 2010. [DOI: 10.1016/s1561-5413(10)60012-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
|
43
|
Calcitriol and doxercalciferol are equivalent in controlling bone turnover, suppressing parathyroid hormone, and increasing fibroblast growth factor-23 in secondary hyperparathyroidism. Kidney Int 2010; 79:112-9. [PMID: 20861820 DOI: 10.1038/ki.2010.352] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We compared the effects of calcitriol and doxercalciferol, in combination with either calcium carbonate or sevelamer, on bone, mineral, and fibroblast growth factor-23 (FGF-23) metabolism in patients with secondary hyperparathyroidism. A total of 60 pediatric patients treated with peritoneal dialysis were randomized to 8 months of therapy with either oral calcitriol or doxercalciferol, combined with either calcium carbonate or sevelamer. Bone formation rates decreased during therapy and final values were within the normal range in 72% of patients. A greater improvement in eroded surface was found in patients treated with doxercalciferol than in those given calcitriol. On initial bone biopsy, a mineralization defect was identified in the majority of patients which did not normalize with therapy. Serum phosphate concentrations were controlled equally well by both binders, but serum calcium levels increased during treatment with calcium carbonate, and serum parathyroid hormone levels were decreased by 35% in all groups. Baseline plasma FGF-23 values were significantly elevated and rose over fourfold with calcitriol and doxercalciferol, irrespective of phosphate binder. Thus, doxercalciferol is as effective as calcitriol in controlling serum parathyroid hormone levels and suppressing the bone formation rate. Sevelamer allows the use of higher doses of vitamin D. Implications of these changes on bone and cardiovascular biology remain to be established.
Collapse
|
44
|
Wesseling-Perry K, Harkins GC, Wang HJ, Elashoff R, Gales B, Horwitz MJ, Stewart AF, Jüppner H, Salusky IB. The calcemic response to continuous parathyroid hormone (PTH)(1-34) infusion in end-stage kidney disease varies according to bone turnover: a potential role for PTH(7-84). J Clin Endocrinol Metab 2010; 95:2772-80. [PMID: 20382692 PMCID: PMC2902063 DOI: 10.1210/jc.2009-1909] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
CONTEXT Factors contributing to PTH resistance in dialysis patients remain elusive. OBJECTIVES The study assessed the skeletal and biochemical response to 46 h of PTH(1-34) infusion in dialysis patients. DESIGN The study was a prospective, controlled assessment of response to PTH(1-34). SETTING The study was performed at the University of California, Los Angeles, General Clinical Research Center. PARTICIPANTS Nineteen dialysis patients and 17 healthy volunteers were studied. INTERVENTION PTH(1-34) was infused at a rate of 8 pmol/kg x h for 46 h. Bone biopsy was performed in all dialysis patients. MAIN OUTCOME MEASURES Serum calcium, phosphorus, 1,25-dihydroxyvitamin D, PTH (four separate assays), and FGF-23 were determined at baseline and h 7, 23, 35, and 46 of the infusion. RESULTS Serum calcium levels rose in healthy volunteers (9.2 +/- 0.1 to 11.9 +/- 0.3 mg/dl; P < 0.01) and in dialysis patients with adynamic/normal bone turnover (9.0 +/- 0.3 to 10.7 +/- 0.7 mg/dl; P < 0.05) but did not change in dialysis patients with high bone turnover. Serum phosphorus levels declined in healthy volunteers (3.9 +/- 0.1 to 3.5 +/- 0.1 mg/dl; P < 0.05) but increased in all dialysis patients (6.7 +/- 0.4 to 8.0 +/- 0.3 mg/dl; P < 0.05). Full-length PTH(1-84) declined in all subjects; however, PTH(7-84) fragments declined only in healthy subjects and in dialysis patients with normal/adynamic bone but remained unchanged in dialysis patients with high bone turnover. CONCLUSIONS The skeleton of dialysis patients with high bone turnover is resistant to the calcemic actions of PTH. PTH(7-84) may contribute to this phenomenon.
Collapse
Affiliation(s)
- Katherine Wesseling-Perry
- David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, California 90095, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Sakhaee K. Post-renal transplantation hypophosphatemia. Pediatr Nephrol 2010; 25:213-20. [PMID: 19603188 PMCID: PMC4469188 DOI: 10.1007/s00467-009-1252-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Revised: 06/05/2009] [Accepted: 06/10/2009] [Indexed: 12/22/2022]
Abstract
An understanding of the pathophysiologic mechanisms of post-renal transplant (PRT) bone disease is of important clinical significance. Although bone disease occurs after all solid organ transplantation, the cumulative skeletal fracture rate remains high in PRT subjects while reaching a plateau with other transplantations. One major difference in the pathophysiology of PRT bone disease is, perhaps, due to persistent renal phosphorus (Pi) wasting. Novel phosphaturic agents have recently been suggested to participate in the development of bone disease in PRT subjects. However, it is unclear as of yet whether these factors alone or in conjunction with excess parathyroid hormone (PTH) secretion play a key role in the development of negative Pi balance and consequent bone disease in this population. In this review, I present a natural history of PRT hypophosphatemia and persistent renal Pi leak, provide pathophysiologic insight into these developments, and discuss the difficulty in diagnosing these phenotypes in both adult and pediatric populations.
Collapse
Affiliation(s)
- Khashayar Sakhaee
- Department of Internal Medicine, Charles & Jane Pak Center for Mineral Metabolism & Clinical Research, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-8885, USA.
| |
Collapse
|
46
|
Geary DF, Hodson EM, Craig JC. Interventions for bone disease in children with chronic kidney disease. Cochrane Database Syst Rev 2010:CD008327. [PMID: 20091666 DOI: 10.1002/14651858.cd008327] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Bone disease is common in children with chronic kidney disease (CKD) and when untreated may result in bone deformities, bone pain, fractures and reduced growth rates. OBJECTIVES To investigate the benefits and harms of interventions for preventing and treating bone disease in children with CKD. SEARCH STRATEGY The Cochrane Renal Group's specialised register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, reference lists and abstracts were searched without language restriction. SELECTION CRITERIA Randomised controlled trials (RCTs) comparing different interventions used to prevent or treat bone disease in children with CKD stages 2-5D compared with placebo, no treatment or other agents were included. Studies examining different routes or frequency of treatment were also included. DATA COLLECTION AND ANALYSIS Data were extracted by two authors. The random-effects model was used and results were reported as risk ratios or risk differences for dichotomous outcomes and mean differences for continuous outcomes with 95% confidence intervals. MAIN RESULTS Fifteen RCTs (369 children) were identified. Compared with oral calcitriol, intraperitoneal calcitriol significantly reduced the level of serum parathyroid hormone (PTH) but there were no significant differences in bone histology or other biochemical measures (2 RCTs). There were no significant differences detected in growth, PTH, serum calcium or phosphorus between daily versus intermittent calcitriol (3 RCTs). Vitamin D therapy significantly reduced PTH levels compared with placebo or no treatment. The number of children with hypercalcaemia did not differ significantly between groups (4 RCTs). No significant differences were detected in growth rates, bone histology or biochemical parameters between calcitriol and either dihydrotachysterol or ergocalciferol (2 RCTs). Though fewer episodes of hypercalcaemia were reported with sevelamer, no significant differences were detected in serum calcium, phosphorus and PTH levels between calcium-containing phosphate binders and either aluminium hydroxide or sevelamer (4 RCTs). AUTHORS' CONCLUSIONS Bone disease, assessed by changes in PTH levels, is improved by all vitamin D preparations. However no consistent differences between routes of administration, frequencies of dosing or vitamin D preparations have been demonstrated. Though fewer episodes of high calcium levels occurred with the non calcium-containing binder, sevelamer, compared with calcium-containing binders, there were no differences in serum phosphorus and calcium overall and phosphorus values were reduced to similar extents. All RCTs were small with few data available on patient-centred outcomes (growth, bone deformities) and limited data on biochemical parameters resulting in considerable imprecision of results thus limiting the applicability to care of children with CKD.
Collapse
Affiliation(s)
- Denis F Geary
- Department of Paediatrics, Hospital for Sick Children, 555 University Ave, Toronto, ON, Canada, M5G 1X8
| | | | | |
Collapse
|
47
|
Pereira RC, Jűppner H, Azucena-Serrano CE, Yadin O, Salusky IB, Wesseling-Perry K. Patterns of FGF-23, DMP1, and MEPE expression in patients with chronic kidney disease. Bone 2009; 45:1161-8. [PMID: 19679205 PMCID: PMC2783834 DOI: 10.1016/j.bone.2009.08.008] [Citation(s) in RCA: 182] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Revised: 07/05/2009] [Accepted: 08/05/2009] [Indexed: 02/02/2023]
Abstract
Fibroblast growth factor 23 (FGF-23), dentin matrix protein 1 (DMP1), and matrix extracellular phosphoglycoprotein (MEPE) are skeletal proteins involved in the regulation of phosphate homeostasis and bone metabolism. Circulating FGF-23 levels are increased in patients with chronic kidney disease (CKD); however, FGF-23 skeletal expression and its regulation by DMP1 and MEPE have yet to be evaluated. Thus, expression of these three proteins was characterized by immunohistochemistry in 32 pediatric and young adult patients with CKD stages 2-5. When compared to normal controls, bone FGF-23 and DMP1 expression were increased in all stages of CKD; significant differences in bone FGF-23 and DMP1 expression were not detected between pre-dialysis CKD and dialysis patients. Bone MEPE expression in CKD did not differ from controls. FGF-23 was expressed in osteocyte cell bodies located at the trabecular periphery. DMP1 was widely expressed in osteocyte cell bodies and dendrites throughout bone. MEPE was also expressed throughout bone, but only in osteocyte cell bodies. Bone FGF-23 expression correlated directly with plasma levels of the protein (r=0.43, p<0.01) and with bone DMP1 expression (r=0.54, p<0.01) and expression of both proteins were inversely related to osteoid accumulation. Bone MEPE expression was inversely related to bone volume. In conclusion, skeletal FGF-23 and DMP1 expression are increased in CKD and are related to skeletal mineralization. The patterns of expression of FGF-23, MEPE, and DMP1 differ markedly in trabecular bone, suggesting that individual osteocytes may have specialized functions. Increases in bone FGF-23 and DMP1 expression suggest that osteocyte function is altered early in the course of CKD.
Collapse
Affiliation(s)
- Renata C. Pereira
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Harald Jűppner
- Pediatric Nephrology Unit and Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | | | - Ora Yadin
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Isidro B. Salusky
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | | |
Collapse
|
48
|
Calcium, phosphate and parathyroid metabolism in kidney transplanted patients. Int Urol Nephrol 2009; 41:1029-38. [PMID: 19701690 DOI: 10.1007/s11255-009-9631-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Accepted: 08/03/2009] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Impaired kidney function is common in kidney-transplanted patients and complications of chronic kidney disease (CKD), such as mineral and bone disorders (MBD) are also prevalent in this population. Similarly to other stages of CKD, increasing evidence supports the association between MBD and cardiovascular risk after kidney transplantation as well. Still, little is known about the prevalence, clinical correlates of MBD and its management in transplanted patients. In this study, we aimed to examine the characteristics of MBD and its associations with clinical parameters in a large prevalent cohort of patients after kidney transplantation. METHODS Nine hundred and ninety stable patients followed at a single kidney transplant outpatient clinic were included in the study. Detailed medical history, demographic data and routine laboratory results, including Ca, P and intact PTH were collected. Estimated GFR was calculated using the abbreviated MDRD formula, patients were stratified into three groups based on eGFR. Target levels for Ca, P and iPTH were based on CKD stages according to the NKF-K/DOQI guidelines. Standard statistical procedures, binomial and multinomial regressions were used in the analysis. RESULTS The mean age was 51 years, 57% were males and 21% were diabetic, with 72 months (median) post-transplantation. Most of the patients were in CKD stage 3. Serum phosphorus showed strong negative correlation with graft function in CKD stages 4-5 (r = -0.633, P < 0.001). Hyperphosphatemia was independently associated with the time spent on dialysis before transplantation, serum iPTH and CKD stages 4-5. iPTH showed negative correlation with eGFR in CKD stages 3-5 (rho = -0.289, P < 0.001) and weak positive correlation with time spent on dialysis prior to transplant (rho = 0.114, P < 0.001). Both hyperparathyroidism (42%) and relative hypoparathyroidism (15%) were frequent. The prescription of P-binders (6%) and vitamin D analogs (33%) was sporadic. CONCLUSION Disturbances of bone and mineral metabolism after transplantation are prevalent and are strongly correlated with the kidney function, similarly to non-transplanted CKD patients. MBD in this population is not adequately managed.
Collapse
|
49
|
Wesseling-Perry K, Pereira RC, Wang H, Elashoff RM, Sahney S, Gales B, Jüppner H, Salusky IB. Relationship between plasma fibroblast growth factor-23 concentration and bone mineralization in children with renal failure on peritoneal dialysis. J Clin Endocrinol Metab 2009; 94:511-7. [PMID: 19050056 PMCID: PMC2646517 DOI: 10.1210/jc.2008-0326] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
CONTEXT Fibroblast growth factor (FGF)-23 is produced in bone, and circulating levels are markedly elevated in patients with end-stage kidney disease, but the relationship between plasma levels of FGF-23 and bone histology in dialysis patients with secondary hyperparathyroidism is unknown. OBJECTIVE The aim of the study was to evaluate the correlation between plasma levels of FGF-23 and bone histology in pediatric patients with end-stage kidney disease who display biochemical evidence of secondary hyperparathyroidism. DESIGN We performed a cross-sectional analysis of the relationship between plasma FGF-23 levels and bone histomorphometry. SETTING The study was conducted in a referral center. STUDY PARTICIPANTS Participants consisted of forty-nine pediatric patients who were treated with maintenance peritoneal dialysis and who had serum PTH levels (1st generation Nichols assay) greater than 400 pg/ml. INTERVENTION There were no interventions. MAIN OUTCOME MEASURE Plasma FGF-23 levels and bone histomorphometry were measured. RESULTS No correlation existed between values of PTH and FGF-23. Bone formation rates correlated with PTH (r = 0.44; P < 0.01), but not with FGF-23. Higher FGF-23 concentrations were associated with decreased osteoid thickness (r = -0.49; P < 0.01) and shorter osteoid maturation time (r = -0.48; P < 0.01). CONCLUSIONS High levels of FGF-23 are associated with improved indices of skeletal mineralization in dialyzed pediatric patients with high turnover renal osteodystrophy. Together with other biomarkers, FGF-23 measurements may indicate skeletal mineralization status in this patient population.
Collapse
Affiliation(s)
- Katherine Wesseling-Perry
- Department of Pediatrics, David Geffen School of Medicine at University of California Los Angeles, A2-383 MDCC, 10833 LeConte Boulevard, Los Angeles, California 90095, USA.
| | | | | | | | | | | | | | | |
Collapse
|
50
|
|