Cell-mediated immune assay in children with Schistosoma haematobium infection and the effect of niridazole therapy.

Forty-five children with Schistosoma haematobium infections were studied utilizing a whole-blood culture technique to assay lymphocyte blast transformation responses. The mitogenic lectins, phytohaemagglutinin (PHA) and pokeweek mitogen (PWM), and heterologous schistosomal antigens from adult worms and eggs were used. Responsiveness to PHA was intact but PWM responses were significantly impaired. Varying responses to schistosomal adult worm antigens were evident. Responses to soluble egg antigens were consistently low. No correlation of lymphocyte transformation responses was evident with egg excretion rates or clinical data. Treatment, primarily with niridazole, resulted in augmented cellular immune responses to PHA, PWM and adult worm antigens and two and eight weeks post-therapy. Anti-egg antigen responses did not significantly change. It was evident that niridazole did not induce cellular immunodepression. The role of schistosome-specific immune modulation is discussed.