Association between polymorphisms in <i>TLR3</i>, <i>TICAM1</i> and <i>IFNA1</i> genes and covid-19 severity in Southern Brazil.
BackgroundA distinct phenotype in Coronavirus disease 2019 (Covid-19) was observed in severe patients, consisting of a highly impaired interferon (IFN) type I response, an exacerbated inflammatory response.ObjectiveThe aim of the present study was to investigate a possible association of single nucleotide polymorphisms (SNPs), in five genes related to the immune response, rs3775291 in TLR3; rs2292151 in TICAM1; rs1758566 in IFNA1; rs1800629 in TNF, and rs1800795 in IL6 with the severity of Covid-19.MethodsA cross-sectional study was performed, with non-severe and severe/critical patients diagnosed with Covid-19, by two public hospitals in Brazil. In total, 300 patients were genotyped for the SNPs, 150 with the non-severe form of the disease and 150 with severe/critical form.ResultsThe T/T genotype of TLR3 in recessive model shows 58% of protection against severe/critical Covid-19; as well as the genotypes G/A+A/A of TICAM1 in dominant model with 60% of protection, and in a codominant model G/A with 57% and A/A with 71% of protection against severe/critical Covid-19. Comparing severe and critical cases, the T/C genotype of IFNA1 in the codominant model and TC+C/C in the dominant model showed twice the risk of critical Covid- 19.ConclusionWe can conclude that rs3775291, rs2292151 and rs1758566 can influence the COVID-19 severity.