ANTISCHISTOSOME IGG4 AND IGE RESPONSES ARE AFFECTED DIFFERENTIALLY BYCHEMOTHERAPY IN CHILDREN VERSUS ADULTS

Specific IgG4 and IgE responses and polyclonal cytokine profiles were studied in 110 Schistosoma haematobium-infected persons before and 5 w eeks after chemotherapy, Pretreatment IgG4 responses to soluble egg an tigen (SEA) correlated with intensity of infection, After chemotherapy , a significant decrease in egg output and circulating anodic antigen was associated with a substantial drop in the IgG4 response to SEA (Ig G4-SEA) in adults and in children, suggesting that egg laying is a maj or stimulus for IgG4-SEA, After chemotherapy, IgG4 and IgE to adult wo rm antigen and IgE to SEA increased in children but remained unchanged in adults. This indicates that the immunoregulatory mechanisms operat ive in S. haematobium-infected adults differ from those in infected ch ildren, The effect of treatment on cytokine profiles was determined fo llowing stimulation of whole blood with anti-CD3 antibodies, A signifi cant decrease in interleukin-4 production after treatment indicated th at reduction in helminth load may lead to a reduced number of Th2-type cells.