IMMUNOLOGICAL MARKERS INDICATING THE EFFECTIVENESS OF PHARMACOLOGICALTREATMENT IN HUMAN HYDATID-DISEASE

The relation of interferon-gamma (IFN-gamma), IL-4, IL-10 production a nd specific IgE, total IgG, IgG subclass expression to the effectivene ss of pharmacological treatment in human hydatid disease (Echinococcus granulosus infection) was evaluated in 27 hydatid patients divided in to four clinical groups according to their response to albendazole/meb endazole therapy (full, partial, low and non-responders). After parasi te antigen stimulation, peripheral blood mononuclear cells (PBMC) from full responders produced significantly more IFN-gamma (P=0.038), sign ificantly less IL-4 (P=0.001) and less IL-10 than PBMC from non-respon ders. PBMC from partial and low responders produced intermediate cytok ine concentrations. ELISA determining immunoglobulin production showed that sera from all non-responders had IgE and IgG4 antibodies, both r egulated by IL-4. In contrast to IgG4, IgE decreased rapidly in full r esponders. Full responders also showed the highest percentage of IgG3 reactions. Qualitative analysis of total IgG responses in hydatid pati ents' sera determined by immunoblotting showed that binding profiles t o hydatid cyst fluid antigen differed in the four groups of treated pa tients. Non-responders had the highest percentage of reactions to all subunits of antigens 5 and B, and full responders had the highest perc entage of reactions to antigen 5 alone. The high IFN-gamma production associated with a lack of IL-4 and low IL-10 production in the full re sponders, and vice versa the high IL-4 and IL-10 production associated with lack of or low IFN-gamma production in the non-responders implie s Th1 cell activation in protective immunity and Th2 cell activation i n susceptibility to hydatid disease. IgE may be a useful marker of the rapeutic success in hydatid patients with pretreatment specific IgE an tibodies. IgG subclass responses and differential immunoglobulin subcl ass binding pattern to hydatid antigens may also be useful in the immu nosurveillance of hydatid disease.