부산대학교 도서관

Background. Information regarding chronic kidney disease--mineral bone disorder (CKD-MBD) in children who undergo renal transplant is scarce. Despite successful renal transplantation, bone disorders have been described and attributed to immunosuppressive drugs (steroids and calcineurin inhibitors). Therefore, it is important to determine the prevalence and outcome of bone mineral disorders pre- and post-renal transplant. The aim of the study was to describe the prevalence and type of bone mineral disorders in children pre-renal transplant and outcomes. Methods. The Institutional Review Board and Ethics Committee approved the study. Signed consent/assent was obtained from all participants. Patients <18 years of age and under investigation for a first renal transplant were invited to participate. At transplant and 6 and 12 months after transplantation, anthropometric data were collected and blood samples were collected for serum creatinine, slope levels of tacrolimus, serum calcium, phosphorus, magnesium and alkaline phosphatase. Intact parathyroid hormone (PTH) was measured before transplant. Results. Thirty-one patients were included with a mean age of 14.6 ± 3.2 years. Females represented 52%, 18 patients had peritoneal dialysis (58%), eight hemodialysis (26%) and five patients were listed as pre-emptive transplantation (16%). All received induction with basiliximab and triple maintenance therapy with prednisone, mycophenolate mofetil and tacrolimus. One patient was changed to cyclosporine at the third post-transplant month due to diabetes mellitus. Pre-transplant PTH values were <150 pg/ml in 51.6% suggestive of low turnover bone lesions, 38.7% had PTH >300 pg/ml suggestive of high turnover bone lesions and only 9.6% had PTH between 150 and 300 pg/ml. When pre- and post-transplant studied parameters were compared, serum creatinine was statistically lower during follow-up. No difference was found in serum calcium and alkaline phosphatase, but magnesium and phosphorus values were significantly lower after transplant. Twelve patients (38.7%) had post-transplant hypophosphatemia and required supplementation. Ten patients (32%) had hypomagnesemia, seven of them with concomitant hypophosphatemia. Z-score for weight increased significantly after renal transplant; nevertheless, only patients with no hypophosphatemia during follow-up improved their Z-score for height. Glomerular filtration rate had a positive correlation with serum calcium and a negative correlation with phosphorus and magnesium (p <0.05). Tacrolimus slope levels had a significantly negative correlation with serum magnesium (r = -0.431, p <0.0001). Conclusions. In our medical center, only 9.6% of patients have PTH between the recommended values of >150 and <300 pg/ml. This situation could be prevented with adequate treatment of vitamin D analogues and phosphorus chelators. During the first post-transplant year, hypophosphatemia is seen in 38.7% and hypomagnesemia in 32% of patients. Glomerular filtration rate had a negative correlation with serum phosphorus at transplant. Tacrolimus slope levels had a negative correlation with magnesium serum values. Patients with no hypophosphatemia during the first year had better growth than those with hypophosphatemia. It is important to monitor and opportunely treat bone mineral disorders in children who undergo transplantation. [ABSTRACT FROM AUTHOR]