[The biological aspects of the therapy of parasitic diseases]

Specific drugs, most of them heterocyclic compounds, are leading in the therapy of parasitic infections despite their relative toxicity and potent mutagenicity. In some parasitic diseases chemotherapy is of low efficacy (hydatid and multilocular echinococcosis, African trypanosomiasis) or practically absent (American trypanosomiasis) mostly due to suppression or distortion of an immune response. Methods of immunocorrection using recombinant cytokines (interleukins, interferons) or their inducers are to be borrowed from the practice of treatment of oncological, lymphoproliferative diseases and other immune deficiencies. For instance, alpha-interferon and gamma-interferon inducers should be used in echinococcosis, where, as our studies have shown, the production of these cytokines is markedly suppressed. The enforcement of chemotherapeutic effect by "parachemotherapy" (Sh. D. Moshkovskiĭ, 1944), the effect of nonspecific pharmacological drugs upon the cells and tissues damaged by parasites (like Ca2+ transport blockers in drug-resistant falciparum malaria), should be used, for instance, recombinant gamma-interferon plus specific drugs in toxoplasmosis. Modern methods of immunotherapy based on the molecular mechanisms of a host-parasite relationship should be created, for instance, monoclonal antibodies to C3 receptors of membranes of cells invaded with Toxoplasma gondii. Immunotoxins such as monoclonal antibodies to myoblast receptors conjugated to 5-nitroimidazolyl-thiadiazole in Chagas' disease should be tested. The above mentioned biological approaches should increase the efficacy of chemotherapy in parasitic diseases with smaller amounts of specific drugs and less courses of treatment.