The aim of the study was to identify polymorphisms in important mediators of the immune response in association with ANAs, which could contribute to the development of autoimmunity in hepatitis C. The study included 87 patients with chronic hepatitis C who were evaluated for the presence of ANA (indirect immunofluorescence) and for polymorphisms in the FOXP3, IFNG, IL6, IL8, IL10, MBL2, CRP, TGFΒ1 and TNFA genes (real-time PCR). The gene discussed is TNF; the disease is chronic hepatitis C virus infection.