Ultrastructure of the ectopic eosinophilopoeitic foci in the liver and small intestine of schistosomiasis mansoni infected hamsters

ABSTRACT

Extramedullary Eosinophilopoiesis in murine schistosomiasis mansoni is thought to occur only in those tissues having a heamopoietic potential. So, the aim of this work is thought to be to investigate this belief in hamster model, by the histological examination of an organ that lacks this potential; as the small intestine. Ecotopic eosinophilic foci in different stages of maturation was seen in both the liver as well as the gut wall [ilium]. The ultrastructural features of cell population in these foci, were nearly identical in both organs. Three stages of cell maturation could be identified, resembling those described in the bone marrow. Several mitotic figures was seen, not only in the early stages but also of the adult eosinophils. The latter was more encountered in the intestine than in the liver. From the findings of this study it can be assumed that, ectopic eosinophil granulocytopoiesis can occur in any infected tissue under the effect of suitable stimuli; that means a haemoietic potential is not a must in having extramedullary eosinophilopoiesis