Effect of praziquantel on human lymphocyte proliferation in vitro.

The antischistosomal drugs tartar emetic and niridazole exert immunosuppression both in vitro and in vivo. In the present study the influence of praziquantel (Biltricide), a potent schistosomicidal drug, on human lymphocyte proliferation in vitro was investigated. Praziquantel 80 micrograms/ml significantly reduced thymidine incorporation by human blood mononuclear cells stimulated with mitogens and antigens, whereas no effect could be detected in concentrations below 40 micrograms/ml. Thus, praziquantel, in concentrations as high as 30 times the peak serum concentration during therapy, has no suppressive effect on human lymphocyte proliferation in vitro.