EN
It is estimated that more than half of the nowadays known species are pathogenic parasites. Among macroparasites gastrointestinal nematodes are one of most common and having significant impact on life and health. Those organisms reveal strong, specific immune response in host, involving primary mechanisms associated with regulatory and Th2 cells. Referring to immunomodulatory abilities of helminths, parasite infections started to be considered as a possible therapy for many autoimmune diseases. Clinical trials on 2nd and 3rd stage are conducted in spite that treatment has not been recognized as safe for common use. Despite that the safety of treatment with parasites is still controversial and widely discussed. Our knowledge about mechanisms used by helminth to moderate immune response is still inadequate to predict possible effect of long lasting parasite infection on individual patients.