PURPOSE: Vitamin D has multiple vital functions within the immune system. This study aims to assess the relationship between vitamin D exposure and the incidence of infection in renal transplant recipients.

METHODS: This is a retrospective cohort study of adult renal transplant patients with ≥1 total 25-hydroxyvitamin D level post-transplant. Two groups were used: vitamin D sufficient (≥30 ng/mL) and vitamin D deficient (<30 ng/mL). The primary outcomes were: 1) incidence of infection 90 days before and after the date of a vitamin D level; and 2) incidence of infection within 1 year post-transplant for patients with a baseline vitamin D level. Multivariate logistic regression analysis and Poisson analysis was performed for each outcome.

RESULTS: There were a total of 1706 vitamin D levels during the study period among 573 patients. In retrospective cohort analysis of patients with baseline vitamin D level, logistic regression analysis found no difference in rates of any infection between groups. Poisson analysis found significantly reduced incidence rate of number of infections in sufficient group compared to deficient group (IRR 0.44 [0.31, 0.98]; p-value <0.001). In cross-sectional analysis of any post-transplant vitamin D level, logistic regression analysis found decreased risk of any infection (OR 0.95 [0.93, 0.97]; p-value <0.001) and Poisson analysis found decreased incidence rate of number of infections (IRR 0.97 [0.96, 0.98]; p-value <0.001) for vitamin D sufficient versus deficient group.

CONCLUSIONS: Based on the results of this study, there is a significantly reduced incidence rate of the number of infections within a year post-transplant in vitamin D sufficient renal transplant patients. When all vitamin D levels were included at any time point post-transplant, patients who were vitamin D sufficient had both a decreased risk of any infection as well as a reduced incidence rate of the number of infections within 90 days of the vitamin D level.

« Back to 2015 American Transplant Congress