Objective. To identify specific clinical and laboratory characteristics of patients with chronic hepatitis C (CHC) and severe interferon (IFN) system suppression. Patients and methods. This study was conducted at the Clinical Department of Infectious Pathology, Research Institute of Epidemiology, Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing. We enrolled and examined 76 patients with confirmed CHC aged 18 to 80 years who had been followed up for at least 3 years. We analyzed the level of IFN-producing T-lymphocytes, IFN status, serum levels of IFN-α, -γ and -λ depending on viral and biochemical activity, and genotype. In addition to that, we evaluated the association between the IFN system parameters and age, duration of infection, genotype, viral load, and stage of liver fibrosis. The control group comprised 30 healthy individuals who had no complaints and no clinical or laboratory changes at the time of examination. Results. We identified 3 grades of IFN system suppression: grade 1–moderate (in 21% of patients), grade 2–mild (inadequate) (in 47% of patients), and grade 3–severe (in 32% of patients). We analyzed clinical and laboratory characteristics of patients with grade 3 IFN system suppression and evaluated the IFN system depending on age, duration of infection, genotype, viral and biochemical activity. We found that severe IFN system suppression correlated with duration of infection, stage of liver fibrosis with a tendency to increased levels of T-lymphocytes expressing receptors for IFN-α and IFN-γ (CD118+, CD119+). Key words: chronic hepatitis C, genotype, interferon status
γ-H2AX+CD8+ T lymphocytes cannot respond to IFN-α, IL-2 or IL-6 in chronic hepatitis C virus infection