The splenic follicle in human hepatosplenic schistosomiasis mansoni: A histological, immunohistochemical and morphometric study

ABSTRACT

Complex immune responses to Schistosoma mansoni infection, modulated by CD4+ and CD8+ T-Lymphocytes, underlie the different clinical presentations. In the peripheral blood from patieeeents with the hepatosplenic form the CD4+/CD8+ T-lymphocytes ratio is diminished. In order to investigate the participation of spleen in that immune response, the immunoarchitecture of the splenic follicules from 25 patients with hepatosplenic schistosomiasis and from four control individuals were studied by indirect immunoperoxidase technique and semiautomatic morphometry. The results showed that the folicular area (um²) was 17.2por cento greater in the schistosomatic group than in control individuals. The in situ CD4+/CD8+T-lymphocyte area ratio was reduced due to a significant increase of the expression of CD8+ suppressor lymphocytes. These results are similar to those described in peripheral blood and splenic homogenates, ad reinforce the importance of spleen in the modulation of the immune response observed in schistomomotic patients