Interleukin-37 gene polymorphism and susceptibility to coronavirus disease 19 among Iraqi patients.

ABSTRACT

Coronavirus disease 19 (COVID-19) is a highly contagious respiratory viral infection. Dysregulated immune response is an important feature of disease, and cytokines are among the most important mediators of dysregulated immunity. Interleukin-37 (IL-37) is one such cytokine and studies have indicated its role in pathogenesis of COVID-19. However, IL37 gene polymorphisms have not been identified in patients with COVID-19. Therefore, this case-control study (100 patients and 100 controls) was performed to understand the role six single nucleotide polymorphisms of IL37 gene (SNPs rs3811042, rs3811043, rs2466449, rs3811045, rs3811046 and rs3811047) in susceptibility to COVID-19 among cases with severe disease. These polymorphisms were identified by Sanger DNA sequencing. Results revealed that TG genotype of rs3811046 showed a significantly increased frequency in patients compared to controls (61.0 vs. 38.0%; odds ratio [OR] = 2.55; 95% confidence interval [CI] = 1.45-4.50; probability [p] = 0.002; corrected p [pc] = 0.01). GA genotype of rs3811047 also showed an increased frequency in patients but the pc-value was not significant (39.0 vs. 24.0%; OR = 2.02; 95% CI = 1.10-3.71; p = 0.033; pc = 0.165). Haplotype analysis revealed a significantly increased frequency of the haplotype G-C-A-T-T-A (in the order rs3811042, rs3811043, rs2466449, rs3811045, rs3811046 and rs3811047) in COVID-19 patients compared to controls (0.055 vs. 0.006; OR = 10.23; 95% CI = 1.53-68.14; p = 0.003; pc = 0.03). In conclusion, the study indicated that two variants of IL37 gene (rs3811046 and rs3811047) may be associated with susceptibility to COVID-19 among Iraqi population.