Schistosomal pigment in human and murine infections with Schistosoma mansoni

Schistosomal pigment was studied by optical and electron microscopy in liver biopsies of patients with different clinical forms of schistosomiasis and in livers of mice experimentally infected with Schistosoma mansoni. Phagosomal and residual forms of the pigment are described. The quantity of pigment is low in subclinical and in hepatointestinal forms of schistosomiasis; it is high in young patients with the hepatosplenic form, and low in the old ones. The participation of the pigment in the pathogenesis of schistosomal lesions is discussed.