Predictors of hyperparathyroidism in renal transplant recipients

The changes in parathyroid hormone secretion after successful renal transplantation remain to be clearly elucidated. Our study was aimed at identifying the predictors of hyperparathyroidism in renal transplant recipients. A retrospective single center study involving 37 renal transplant recipients, with a follow-up of at least one year, was performed. All transplants were performed using kidneys from living related donors. The average age of the study patients was 30 +/- 10 years, with a male-female ratio of 1.31. The mean duration on hemodialysis (HD) prior to transplantation was 25 +/- 18 months. All the grafts but one, were functional after a mean follow-up of 41 +/- 21 months. We noted a rapid reduction of the mean parathyroid hormone (iPTH) level from 383 +/- 265 pg/ml before transplantation to 125 +/- 67 pg/ml at one year and 108 +/- 66 pg/ml at two years after transplantation (p = 0.01). Bivariate analysis revealed that the level of iPTH obtained during follow-up correlated with the duration on HD (p = 0.03), the serum creatinine at 24-months (p = 0.013), and to the level of iPTH in the first year post-transplantation (p = < 0.001). Other clinical or laboratory parameters were not predictive of hyperparathyroidism after kidney transplantation. Linear regression showed that only the serum creatinine at 24-months independently correlated with the level of iPTH at last follow-up (p = 0.02). Our study suggests that short duration on HD and a functional graft are the main predictors of correction of hyperparathyroidism after renal transplantation.