Association between polymorphisms in , and genes and covid-19 severity in Southern Brazil.

Background: A 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.

Objective: The 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 ; rs2292151 in ; rs1758566 in ; rs1800629 in , and rs1800795 in with the severity of Covid-19.

Methods: A 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.

Results: The T/T genotype of in recessive model shows 58% of protection against severe/critical Covid-19; as well as the genotypes G/A+A/A of 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 in the codominant model and TC+C/C in the dominant model showed twice the risk of critical Covid-19.

Conclusion: We can conclude that rs3775291, rs2292151 and rs1758566 can influence the COVID-19 severity.