The Association of Vitamin D Receptor Polymorphisms with COVID-19 Severity.

BACKGROUND

Association studies of vitamin D receptor (VDR) polymorphisms with COVID-19 severity have produced inconsistent results in different populations. Herein we examined gene polymorphisms in a Caucasian Greek cohort of COVID-19 patients.

METHODS

This was a case-control study in a tertiary university hospital in Greece including 137 COVID-19 patients with varying disease severities and 72 healthy individuals. In total 209 individuals were genotyped for the FokI (rs10735810), ApaI (rs7975232), TaqI (rs731236) and BsmI (rs1544410) single-nucleotide polymorphisms (SNP) of the gene by polymerase chain reaction and restriction fragment length polymorphism analysis (PCR-RFLPs). Statistical analyses were performed to determine the association between genotype and disease severity, adjusting for various confounding factors.

RESULTS

Genotype distribution of the studied SNPs in the control group was in Hardy-Weinberg equilibrium. The TaqI variant was differentially distributed between controls and COVID-19 patients according to the additive model ( = 0.009), and the CC genotype was significantly associated with an increased risk for severe COVID-19 according to the recessive model [OR: 2.52, 95%CI:1.2-5.29, = 0.01]. Multivariate analysis demonstrated a robust association of COVID-19 severity and TaqI polymorphism in the recessive model even after adjusting for multiple confounders, including age, sex and CRP levels [Adj.OR:3.23, 95%CI:1.17-8.86, = 0.023]. The distribution of FokI, ApaI and BsmI genotypes was similar between COVID-19 patients and controls.

CONCLUSIONS

The CC genotype of TaqI polymorphism is significantly associated with an increased risk for severe COVID-19 independently of age, sex or degree of inflammation.