Nlrp3 Inflammasome Genetic Variants Are Associated With Risk And/Or Protection To Hospitalization Among Covid-19 Patients From Rio De Janeiro, Brazil

Abstract

Background COVID-19 has a broad spectrum of clinical manifestations, from asymptomatic to mild or moderate symptoms, reaching the most severe forms and death. The mechanisms underlying the SARS-CoV-2 infection and its clinical evolution are still unclear. Once SARS-CoV-2 infects individuals, host factors are activated by the presence of the virus inside the cells, such as the inflammasome system. The search of risk factors for COVID-19 is of relevance for clinical management. In this study, we investigated the impact of 11 single-base polymorphisms (SNPs) in the NLRP3, CARD8, AIM2, CASP-1, IFI16, and IL-1β inflammasome genes in SARS-CoV-2 infected individuals with distinct disease outcomes. Methods Patients were divided into two groups: (1) inpatients, with severe/critical disease (Hospitalized group, n=451), and (2) convalescent volunteers with prior SARS-CoV-2 infection and a history of asymptomatic to mild symptoms (Mild group, n=43). Patients hospitalized were followed up at a Hospital Center for COVID-19 Pandemic – National Institute of Infectology (INI)/FIOCRUZ, Rio de Janeiro, Brazil, from June 2020 to March 2021. The Mild group was recruited at Oswaldo Cruz Institute (IOC)/FIOCRUZ, Rio de Janeiro, Brazil, in 2020. Genotyping of the SNPs was determined by Real-Time PCR. Protection and risk estimations were performed by unconditional logistic regression models. Results Among the genotyped SNPs, significant differences in the NLRP3 rs1539019 and rs10754558 frequencies were observed between the groups. The C/C genotype (ORadj=6.31; Padj=0.026) or allele C (ORadj=1.05; Padj=0.002) in rs1539019 polymorphism were associated with the risk for hospitalization, while the C/G genotype (ORadj=0.16; Padj=0.016) or carrier-G (ORadj=0.2; Padj=0.028) in rs10754558 polymorphism were associated with protection for hospitalization. Regarding the NLRP3 genetic variants, the A-C-G-C-G haplotype (ORadj=0.14; Padj= 0.030) was associated with protection for hospitalization. No significant association was observed for the other polymorphisms. Conclusions As of our knowledge, this is the first study demonstrating the association of inflammasome NLRP3 variants with risk and/or protection for hospitalization in COVID-19. Studies linking the NLRP3 inflammasome and SARS-CoV-2 infection are still scarce due to the recent emergence of this pathogen. Our results contribute to the discussion of the impact of inflammasomes in the clinical evolution of COVID-19.