Background: Further development and implementation of methods for early noninvasive diagnosis for prognosis and treatment efficiency in patients with chronic hepatitis and development of effective methods of conservative therapy is an important problem of modern hepatology. Objective: To identify the correlation of proinflammatory cytokines [tumor necrosis factor alpha (TNF- ) and interleukin-6 (IL-6)] with the results of 13C-methacetin breath test (13C-MBT) (CVH), nonalcoholic steatohepatitis (NASH) and alcoholic hepatitis (AH). Materials and methods: A total of 147 patients with chronic hepatitis and 25 healthy controls were studied. Patients were divided into three groups: I (group CVH): 50 patients with CVH B and C; II (group NASH): 49 patients with NASH; III (group AH): 48 patients with AH. TNF- and IL-6 was determined by ELISA. Liver biopsy was performed in 46 patients,13C-MBT in 57 patients. A total of 96 patients with F2-F4 Metavir were selected to study patients with NASH, 30 patients with AH. Patients were divided ! \" # standard treatment (depending on the etiology of disease). The second subgroup included 57 patients who received standard $ % ! # &' $ daily. Controlled treatment period was 24 weeks. Results and discussion: Found an inverse correlation between the cumulative dose of 13CO2 and serum levels of TNF- in ! * +' /< * ' ''=# >?@ ! * +' /D G ' '=# ? ! * +' ?@ ! * +'