Clinical effects of pre-transplant serum 25-hydroxyvitamin D level on post-transplant immunologic and non-immunologic outcomes in kidney transplant recipients

•Vitamin D is a central regulator of calcium and phosphorus intestinal absorption.•Vitamin D is associated with the modulating effects on various immune cells.•The associations between serum vitamin D level and the immune system-associated complications have not been identified yet.•Pre-transplant serum 25(OH)D level is a significant predictor of acute rejection.

BackgroundThe aim of this study was to investigate the effects of pre-transplant serum 25-hydroxyvitamin D (25(OH)D) level on non-immunologic and immunologic aspects of post-transplant clinical outcomes in kidney transplant recipients (KTRs).MethodsWe investigated 174 KTRs with low immunologic risk at baseline. We divided the patients into three groups according to baseline serum 25(OH)D level and compared the post-transplant clinical outcomes of acute rejection, infectious complications, and osteoporosis among the groups.ResultThirty cases of biopsy-proven acute rejection (BPAR) were detected during the first year after KT. In the highest tertile, the rate of acute rejection (8.6%) was significantly lower than that in the lowest tertile (25.4%) (p = 0.016), and a high 25(OH)D level was independently associated with a low incidence of BPAR in multivariate analysis. In contrast, serum 25(OH)D level did not show a significant association with overall or any specific type of infectious complication. Lipid profile, intact parathyroid hormone (PTH) level, and hemoglobin level were similar among the three tertile groups. The incidence of osteoporosis and bone mineral density (BMD) score were also similar across all three groups.ConclusionsPre-transplant serum 25(OH)D level is a significant predictor of acute rejection, but it does not predict infection or metabolic complications.