The pathogenesis of liver fibrosis in schistosomiasis japonica: Sequential qualitative and quantitative immunohistochemical study of extracellular components in schistosomal egg granulomas in murine Liver

Summary

A combined morphological and qualitative and quantitative immunohistochemical study of fibronectin (FN) in schistosomal egg granulomas was carried out to investigate sequential behavior of FN and to define the sequence of events in hepatic fibrosis in schistosomiasis, as well as to verify the factors which initiate and promote the process. The results showed that FN could be demonstrated as early as 4 weeks after infection, reached the highest staining intensity at the 6th week, and decreased gradually as fibrosis progressed. In the early stage, FN might be produced by macrophages and sinusoidal cells, acting as a chemotactant for fibroblasts. In the later stages, FN might be derived primarily from fibroblasts and play an important role in guiding collagen deposition. It can be concluded that FN might be the initiating factor for the fibrogenesis and that the inflammatory infiltrate around granulomas is the origin of FN, which might be attributable to the continuous fibrosis of granulomas, and, finally, to the development of clay pipe-stem fibrosis.