Schistosoma haematobium-induced urinary tract morbidity correlates with increased tumor necrosis factor-alpha and diminished interleukin-10 production

This study examined the hypothesis that the nature of the host cellular imm une response to schistosome ova is a risk factor for urinary tract morbidit y in areas in which Schistosoma haematobium is endemic. S. haematobium-infe cted children and adolescents with bladder pathology assessed by ultrasonog raphy had 54-fold greater tumor necrosis factor (TNF)-alpha production and a 120-fold greater ratio of TNF-alpha to interleukin (IL)-10 release by per ipheral blood mononuclear cells in response to egg antigens, in comparison with control children and adolescents matched by age, sex, and infection se verity. Mycobacterial antigens also stimulated 7-fold more TNF-alpha among subjects with bladder morbidity than in control subjects, which suggests an innate predisposition to enhanced TNF-alpha production. Levels of egg anti gen-induced IL-4 and -5 and interferon-gamma were equivalent in subjects wi th and without bladder pathology. Thus, children and adolescents predispose d to increased TNF-alpha production to S. haematobium infection are more li kely to develop an exaggerated granulomatous response to ova trapped in the bladder wall, with associated urinary tract pathology.