1. INTRODUCTION The incidence of diseases whose pathogenesis chain includes changes in the functioning of the immune system is currently on the increase. The increasing prevalence of primary and secondary immunodeficiencies is a relevant issue in immunopathology. Secondary immunodeficiencies, caused by such factors as bacteria, viruses, helminths, chemical substances, medications, radiation, stress, etc., result in higher morbidity. Immunosuppression occurs in cases of oncological or allergic diseases, bronchial asthma, etc. immunosuppression is relevant in cases of malignant tumors whose incidence in Lithuania has been increasing with every year during the recent period. Oncological treatment involves the application of radiotherapy and chemotherapy with cytostatics that are strong immunosuppressants, and thus the restoration of the immune system with immunostimulants is becoming a relevant issue. Insufficient nutrition, disturbed nutrient resorption, negative nitrogen balance, chronic alcoholism, and drug abuse – all these factors result in the deceleration of cell proliferation and decreased T-lymphocyte counts and function. Immunodeficiency increases morbidity with infectious diseases, since the organism becomes incapable of the rapid destruction of the causative agents. Such conditions increase the probability of the spreading of the infection, and condition the increased activity of the opportunistic infections caused by adenoviruses, cytomegaloviruses, etc... [to full text]