Analysis of some polymorphic <i>IL-6</i>, <i>IL-10</i> gene variants in individuals with psychoneurological manifestations of long COVID

The aim of the study was to investigate the characteristics of psychoneurological status and allelic distribution of some polymorphic loci in the IL-6 (interleukin-6), IL-10 (interleukin-10) genes in patients with long COVID. Materials and methods. The study group consisted of 130 patients (aged 18–60) with a known history of COVID-19 and a temporal association between the disease and the development of health complaints. The control group included 116 individuals with no acute infectious or somatic pathologies, chronic diseases, or complaints about somatic or mental health. The genetic markers examined were polymorphic variants of rs1800795 (IL-6) and rs1800871 (IL-10). Nucleotide sequences including these SNPs were obtained using direct Sanger sequencing. Results. Psychoneurological symptoms in individuals with long COVID occurred in 1/3 cases and were characterized by pronounced polymorphism. Significant intergroup differences were found in the genotype distribution of the IL-6 gene polymorphism (–174GC) (p 0.0001). A marked reduction in the frequency of the “wild-type” homozygous GG genotype was observed (6.92% vs 28%; p 0.001), which may reflect its potential protective role against developing neuro-COVID complications or association with the severe COVID-19. A predominance of the heterozygous GC genotype was found in the study group (69.23% versus 50%; p = 0.0032). Analysis of IL-10 genotype (–819CT) distribution also revealed differences between the groups (p = 0.0388). Conclusion. Damage to the nervous system largely determine the clinical symptoms of post-COVID disorders. The role of polymorphic variants (–174GC) of IL-6 (rs1800795) and (–819CT) of IL-10 (rs1800871) in modulating the immune response and the pathogenesis of post-COVID syndrome has been identified.