In vivo IL-12 and IL-8 production in hydatic patients and their possible diffusion in hydatid cysts.

Cystic echinococcosis (CE) is caused by infection with the larval stage of the cestode Echinococcus granulosus. It is one of the world's major zoonotic infections. Variability and severity of clinical expression of this parasitosis are associated with duration and intensity of infection. They are also related to the variety of human immunological responses to the hydatic antigens. The aim of this work is to study the inflammatory response associated with human hydatidosis by evaluating the possible roles of the proinflammatory cytokines in hydatic patients. We investigated the patterns of IL-12 and IL-8 in serum from Algerian hydatic patients. Serum IL-12 and IL-8 levels are significantly higher in patients with hydatidosis than in control subjects. Furthermore, cytokines secretion correlates with disease statues (cystic localizations and clinical stage). These data indicate that infection with E. granulosus is associated with high levels of circulating IL-12 and IL-8. Moreover, our data, to our knowledge, constitute the first report of IL-12 and IL-8 diffusion into the hydatid cyst. Our results underline the permeability of the cyst wall to the soluble immune system of the host. The relationship between cyst fertility and cytokine infiltration indicates a strong host-parasite interaction. All these findings have important implications for the diagnosis of hydatidosis in humans.