RESUMO
A 26-year-old male with nephropathic cystinosis treated with cysteamine and renal transplantation presented for evaluation of multiple sclerotic bone lesions, which were an incidental finding on chest computerized tomography. These lesions were in a pattern consistent with osteoblastic metastases. He did not have a history of clinically significant hyperparathyroidism or cytopenias either preceding or following his transplant. Bone and tumor markers (including alkaline phosphatase and calcium) were all normal. A percutaneous bone biopsy of the lesions showed changes compatible with cystine deposition. Our case demonstrates that sclerotic bone lesions can be a feature of cystinosis in patients with normal parathyroid function and that significant bone marrow infiltration with cystine can be present even in the absence of cytopenias.
RESUMO
BACKGROUND: Abnormal mineral metabolism is associated with increased morbidity and mortality in dialysis patients. Therefore, the goal of this study was to compare a) mineral metabolism control among a cohort of Canadian peritoneal dialysis (PD) patients to K/DOQI-defined targets and b) the effect of different treatment strategies on mineral metabolism parameters. METHODS: We looked at a cohort of 317 Canadian PD patients from 9 clinics that used the PhotoGraph™ software program which tracks mineral metabolism management. Serum phosphorus (P), calcium (Ca) and intact parathyroid hormone (iPTH) values were collected for the patients. Data were categorized and analyzed by the type of phosphate binder prescribed, vitamin D use, and dosing and reimbursement criteria for the phosphate binder, sevelamer. RESULTS: The majority of patients achieved K/DOQI-set targets for serum P. Patients who resided in Quebec (QC), which had greater access to sevelamer, had lower mean concentrations of P and Ca, were less likely to take Ca-based phosphate binders (CBBs) exclusively and were exposed to less exogenous Ca than in Ontario (ON). CONCLUSION: Availability of the phosphate binder sevelamer and reduced doses of elemental Ca were associated with more mineral metabolism parameters within suggested target ranges. Further studies that focus on patient outcomes are warranted.
