Association between interleukin-6-174G/C single nucleotide polymorphism with the COVID-19 severity

Interleukin-6 is one of the cytokines whose increase and role in the pathogenesis of Covid-19 has been reported in various studies. Interleukin-6 affects environmental factors and genes, including polymorphic sites in the IL-6 gene. In the present study, the rs1800795 polymorphism located in the IL6 gene region was investigated.

Participants in this study were divided into outpatient (n=245) and inpatient (n=245) groups due to COVID-19. Peripheral blood samples were taken from patients and their DNA was extracted, then rs1800795 polymorphism genotype was measured by Tetra Arms PCR. Data were analyzed using SPSS software and Chi-Square and t-test students.

The mean age of patients in the outpatient group was        41.6±12.3 years but in the inpatient group was 61±17.1 years (P-value <0.001); There was also a significant difference in the frequency of smokers and patients with kidney problems (P-value <0.05) as well as patients with hypertension, diabetes mellitus and a history of heart disease (P-value <0.001) in outpatient and inpatient groups. The frequency of G alleles in the inpatient group was significantly lower than the outpatient group (P-value = 0.045).

The frequency of polymorphism variants of rs1800795 interleukin-6 varies in different groups of Covid-19 patients with varying degrees of clinical symptoms, and the G allele may possibly play a protective role against COVID-19.