ABSTRACT
BACKGROUND AND AIMS Immunomodulatory and anti-inflammatory properties have been hypothesized for native vitamin D (nVD). Very little is reported about nVD and risk of Sars-CoV-2 infection (COV) in renal transplant (RTx). In a cohort of renal transplanted patients (RTxp) we retrospectively evaluated: (i) nVD status in patients with (COV+) and without (COV-) COV infection;(ii) the impact of nVD status on severity of COV. METHOD The study includes 61 COV + in whom nVD status was available in the year before the infection, and 122 COV- matched 1:2 for age (53[45–64]years), gender (M = 60.7%), RTx vintage (7[2–15] years), presence of diabetes (18%), arterial hypertension (85%) and cardiac symptomatic disease (3%). Renal function, 24-h proteinuria and mineral metabolism (MM) parameters were evaluated at 1, 6 and 12 months before COV whereas nVD status was considered as the mean 25-OH-VD levels at the same timepoints. Severity of COV was based on the need for hospitalization (HOSP+: 27/61, 44.3%) and death (D+: 6/61, 9.8%). RESULTS (i) nVD levels were significantly lower in COV + than in COV- (19[12–26] ng/mL and 23[16–30] ng/mL, respectively, P = 0.01). No differences in the other biochemical parameters were found. The COV discriminative power of nVD status was evaluated by ROC curve (AUC 0.61, 95% CI: 0.54–0.68, P = 0.01), with a value of 25-OHVD 23.9 ng/mL showing the best discriminative power (sensibility 72%, specificity 47%). (ii) nVD levels showed a trend towards lower values in HOSP + COV + than HOSP-COV+ (17[8–25] ng/mL versus 20[14–26] ng/mL) and in D + COV + than D-COV+ (13[6–23] ng/mL versus 20[13–26] ng/mL), although these differences did not reach the statistical significance (P = 0.1 and P = 0.2, respectively). CONCLUSION With the limitations of the retrospective nature of the study and the small sample size, our data report that: COV + showed lower nVD levels in the year preceding the infection compared with controls with similar main demographic features and comorbid conditions No differences were found in renal function, proteinuria and other MM parameters between the two groups. No association was found between nVD levels in the year preceding the infection and COV severity.