Post-transplant bone disease: diagnostic and therapeutic process

Background: Post-transplant bone disease (PTBD) represents an important cause of morbidity and mortality in kidney transplant recipients (KTRs): the pathogenesis is closely linked both to the pre-transplant and post-transplant period. Persistent hyperparathyroidism and the use of steroids are the most important risk factors for PTBD; bone turnover markers (BTMs) and their trend are a marker in fracture risk stratification. The aim of this study is to evaluate a cohort of de novo KTRs in an epidemiological, biochemical and instrumental way to identify patients with higher fracture risk and establish an early specific therapeutic approach. Patients and Methods: Clinical, biochemical and instrumental data were measured at time 0 (from the third to the sixth month from KT) and time 1 (after 24 months from KT). Results and Discussion: Thirty-two de novo KTRs were enrolled in the study with 21-31% of osteoporosis at different skeletal sites at time 0. BTMs represented a condition of high and low bone turnover for 16-22% and 6-19% of KTRs, respectively. An inverse correlation has been demonstrated between the values of densitometric tests and PTH value and cumulative dose of steroids. BMD change after KT was extremely variable and related to both cumulative dose of steroids and persistent hyperparathyroidism. Compared with patients with no change, patients with stability or gain of BMD had higher levels of BTMs and a greater decrease of BTMs from T0 to T1. Conclusions: PTBD is one of the most important problems after KT with secondary hyperparathyroidism and steroids as key risk factors. BTMs and their change after KT are associated with BMD changes: the resolution of high bone turnover was responsible for BMD gain or stability. An evaluation of BTMs in the early post-transplant period could help to identify patients with higher fracture risk to early treat with anti-fracturative therapy.