Modern immunological and molecular genetic studies showed that tuberculosis is accompanied by an imbalance in the production of immunoregulatory cytokines by mononuclear leukocytes. T allele and homozygous TT genotype of T-330G polymorphism in the IL2 gene, T allele and TT genotype of C-590T polymorphism in the IL4 gene, and CC genotype of A-1188C polymorphism in the IL12B gene are immunogenetic factors that have protective activity against susceptibility to pulmonary tuberculosis. Susceptibility to tuberculous infection is associated with A1A2 genotype of the polymorphic region +3953 A1/A2 in the IL1B gene; G allele and TG and GG genotypes of T-330G polymorphism in the IL2 gene; C allele and CC and CT genotypes of C-590T polymorphism in the IL4 gene; and AC genotype of the polymorphic region A-1188C in the IL12 gene.

Immunopathogenesis of chronic viral hepatitides was studied by modern immunological, molecular, genetic methods. We revealed an imbalance in the production of immunoregulatory cytokines by mononuclear leukocytes (primarily of the Th2 type). The risk of progression and chronic course of viral hepatitides in Caucasian population was associated with alleles of promoter regions -330G and -592A in the IL-2 and IL-10 genes, respectively, as well as with the T/T genotype of the polymorphic region C590T in the IL-4 gene. The C/C genotype of the IL-10 gene promoter region C592A was shown to be a factor determining resistance to long-term persistence of hepatitis B and C viruses.