THE EFFECT OF RISPERIDONE AND RITANSERIN ON HUMAN-IGG AND IGM SYNTHESIS IN-VITRO

We tested risperidone and ritanserin, serotonin-S2 receptor antagonist s, for their effects an in vitro polyclonal IgG and IgM synthesis by h uman peripheral blood mononuclear cells (PBMC) stimulated with pokewee d mitogen (PWM). On the basis of the previously reported effect an imm une function in vivo risperidone in this study was tested in three dif ferent groups of PBMC: healthy donors as well as schizophrenic patient s before risperidone treatment and schizophrenic patients after the tr eatment with risperidone. IgG and IgM production after 7 days of cultu re was measured by ELISA. Risperidone decreased IgG synthesis (p<0.05) in PBMC of healthy subjects only at the highest concentration (10(-6) M) and IgG synthesis enhanced by 5-HT was antagonized by risperidone. This effect, however, was not statistically significant. Neither risp eridone nor ritanserin, in the concentration range 10(-8)-10(-6) M, af fected IgM synthesis in this group. Risperidone did not affect the pro duction of IgG and IgM by PBMC of schizophrenic subjects in PWM-stimul ated cultures both before and after risperidone therapy. The spontaneo us production of IgG in PBMC of schizophrenic subjects before therapy was decreased (p<0.05) at concentrations 10(-6)-10(-7) M of risperidon e, We conclude that risperidone and ritanserin did not increase polycl onal IgG and IgM synthesis in vitro in contrast to neuroleptics curren tly used in clinical practice.