Human Schistosomiasis mansoni: IL-10 modulates the in vitro granuloma formation

Granuloma formation and modulation around Schistosoma mansoni eggs that are trapped in host tissues play a pivotal role during schistosomiasis. It has been demonstrated that the granuloma reactions differ in patients with the different clinical forms of the disease. The pathology during murine schis tosomiasis has been correlated with a Th2 response while resistance to infe ction with a Th1 type response. In humans, very little is known about the r ole of different cytokines on the development of the disease. Here we demon strate that IL-10 is an important cytokine regulating rite in vitro granulo matous reactivity of PBMC from intestinal (INT) patients. This was evidence d by rite fact that blockage of this cytokine in the in vitro granuloma ass ay lean to a significant increase in granuloma size with cells from INT pat ients bur not with individuals in the acute phase or with the hepatosplenic (HS) form of schistosomiasis. These results demonstrate for the first lime that, in context with the model, a Th2 cytokine iii human schistosomiasis plays an important role in controlling morbidity.