Modulation of in vitro lymphocyte proliferation in patients with Schistosomiasis haematobium, Schistosomiasis mansoni and mixed infections.

Cell-mediated immunity to mitogens, nonparasitic and parasitic antigens was evaluated by means of in vitro lymphocyte proliferation in 37 African patients infected with S. haematobium, S. mansoni, or both parasites as well as in an uninfected control group. Lymphocytes of patients with schistosomiasis mansoni or schistosomiasis haematobium monoinfection could be similarly stimulated by a delipidized extract of S. mansoni adults. There was also no difference in lymphocyte responsiveness to stimulation by PHA, PWM, ConA, and PPD between these groups and as compared with uninfected controls. In the mixed infection patient group, stimulation by mansoni antigen - as well as by PPD, PHA, PWM - was significantly suppressed (p less than 0.01). Of particular interest, in cultures stimulated by the specific antigen the degree of in vitro suppression was inversely correlated to the intensity of infection (r = 0.54, p less than 0.025).