Association of the Il-6 −174 G/C (Rs1800795) Polymorphism with Disease Severity and Inflammatory Markers in Patients with Covid-19

Abstract

Background: COVID-19 severity is strongly influenced by the intensity of the inflammatory response. Genetic variants regulating IL-6 production may contribute to individual differences in disease progression.
Objective: To evaluate the association of the IL6 −174 G/C (rs1800795) polymorphism with COVID-19 severity and inflammatory markers.
Materials and Methods: The study included three groups: a control group (n=40), a comparison group (n=92), and a main group (n=98). The distribution of GG, GC, and CC genotypes was assessed, together with inflammatory markers including IL-6 and CRP. Statistical analysis included χ² testing, odds ratios (OR), 95% confidence intervals, and p-values.
Results: The frequency of the GG genotype decreased from 55.0% in the control group to 41.3% in the comparison group and 24.5% in the main group (χ²=12.92; p=0.002). Conversely, the CC genotype increased from 10.0% to 13.0% and 30.6%, respectively (χ²=12.18; p=0.002). The GC genotype did not differ significantly among the groups (p=0.490). The rs1800795 polymorphism was also associated with changes in inflammatory activity.
Conclusion: The IL6 −174 G/C (rs1800795) polymorphism is associated with COVID-19 severity. The increased frequency of the CC genotype in severe cases suggests its potential value as a genetic marker for identifying patients at higher risk of an unfavorable disease course.