Anti-interleukin-4 treatment diminishes secretion of Th2 cytokines and inhibits hepatic fibrosis in murine schistosomiasis japonica.

Anti-interleukin-4 (IL-4) treatment of Schistosoma japonicum-infected mice markedly inhibited in vitro secretion of the Th2 cytokines IL-4 and IL-5 from antigen-stimulated spleen cells, but enhanced the secretion of the Th1 cytokine IFN-gamma. IL-2 secretion was unaffected. Hepatic fibrosis was markedly diminished in anti-IL-4-treated-mice at ten weeks of infection while granulomas around S. japonicum eggs in the livers were slightly-to-moderately increased in size. The number of eggs per worm pair in the tissues and feces did not differ significantly in treated and untreated mice. These findings suggest that Th2 cytokine responses are important in the genesis of schistosomal hepatic fibrosis.