The aim of the study was to identify differences in the immune response in chronic opisthorchiasis with or without clinical manifestations of hepatobiliary system diseases. A comparison of laboratory parameters of immune system functioning (lymphocyte phenotypes detected by flow cytometry, concentrations of immunoglobulins and cytokines, indicators of nonspecific resistance) in patients with chronic opisthorchiasis (caused by Opisthorchis felineus) lacking clinical manifestations and with manifestations of cholecystitis, cholangitis, pancreatitis, gastritis, gastroduodenitis, confirmed by ultrasound and FGDS. It was found that the immunological parameters of the innate immune response were increased in all patients with chronic opisthorchiasis compared with the control group of apparently healthy subjects, which indicates activated macrophage-phagocytic arm in patients with opisthorchiasis invasion. The indicator of the stimulated HCT test is maximal in chronic opisthorchiasis without hepatobiliary system diseases, in case of comorbidity with such diseases it declines, but remains significantly higher than the values of the control group. This may be due to the exhaustion in the reserve capabilities of bactericidal neutrophil systems in patients with symptoms of damage to the hepatobiliary system due to prolonged inflammation. Indicators of the cellular arm in patients with chronic opisthorchiasis without clinical manifestations of hepatobiliary system diseases demonstrate a decrease in the absolute and relative level of cytotoxic T-lymphocytes. In the group with picture of hepatobiliary system disorders, an even deeper imbalance of indicators is revealed: the relative and absolute level of lymphocytes, the absolute count of T-lymphocytes are reduced, which may indicate about involvement of cellular immunity in the pathogenesis of complications of chronic opisthorchiasis. In all examined patients with chronic opisthorchiasis, the humoral immune response was also activated the total immunoglobulin E was significantly increased; at the same time, in patients with hepatobiliary system lesions, this parameter increases even more and a decrease in B-lymphocytes is detected. In all patients with chronic opisthorchiasis, there is also an increased level of proinflammatory cytokine IL-8, which rises even more in the group with hepatobiliary system diseases. The data obtained indicate the involvement of all arms of the immune response in a prominent inflammatory process when chronic opisthorchiasis is complicated by clinically overt hepatobiliary system diseases: the degree of deviation in the indicators of the innate and adaptive immune response from the norm and from those in uncomplicated opisthorchiasis increases.
