BSMI and APA1 vitamin D receptor gene (VDR) polymorphisms as potential biomarkers for Sars-CoV-2-induced disease.

Abstract

The new coronavirus, the causative agent of Coronavirus Disease 2019 (COVID-19), has become the latest global emergency. Several risk factors have already been identified and associated with the disease, such as plasma concentration of Vitamin D (Vit. D). The action of Vit. D in our body is modulated by the vitamin D receptor, encoded by the vitamin D receptor gene (VDR). Thus, polymorphisms in VDR can affect the action of the Vit. D receptor and, consequently, may be related to the severity of COVID-19. Therefore, the main objective of this study is to evaluate the influence of BSMI and APAI polymorphisms of the VDR gene on the severity of COVID-19. To achieve this goal, subjects who were hospitalized at the State Hospital Sumaré, at the outpatient clinic that serves the UNICAMP community, or at the Basic Health Units of Paulínia (SP), with a positive RT-PCR test for SARS-CoV-2, will be included. The participants will be divided into two subgroups (severe-critical disease and mild-moderate disease), matched by sex and age. Genomic DNA will be extracted from whole blood, and genotyping of the BSMI and APAI polymorphisms of VDR will be performed by RT-PCR. Statistical analyses will be conducted using the SPSS software. For parametric data, the Student's t-test will be used. For non-parametric data, the Mann-Whitney test or Kruskal-Wallis test will be used. The chi-square test or Fisher's exact test will be performed to compare the frequencies of qualitative variables. Logistic/linear regression analyses may be conducted if necessary. The level of significance adopted for the study will be 5% (p<0.05).