Analysis of fibronectin expression in the Bilharzial granulomas and of laminin in the transformed urothelium in Schistosoma haematobium infested patients

The bilharzial granulomas and urothelial transformation are common findings in Schistosoma haematobium infested patients. We hypothesize that the distribution of extrinsic (fibronectin, FN) and intrinsic basement membrane (BM) proteins (laminin, LN) is altered during the evolution of these lesions. Methods: To test this hypothesis, 70 cystectomy specimens, entailing variable associations of normal and dysplastic urothelium (all cases), and bilharzial granulomas were examined for FN and LN protein expression. Results: The biharzial granulomas were formed of admixture of CD3(+) T cells, CD68(+) histiocytes and CD220B cells. The CD3(+) T cells and and CD68(+) histiocytes were the predominant cell populations. Increased deposition of FN occurred with the evolution from cellular (loose fibrillary network, 20 cases) to fibrocellualr (dense fibrillary network, 30 cases) to fibrotic (tight conglomerates, 20 cases) granulomas. Alternatively, BM staining for LN was linear and continuous underlying normal and metaplastic urothelium. In dysplastic urothelium (20 cases), it showed breaks in continuity. Conclusions: Alterations of FN and LN occur during the development of the bilharzial granuloma and urothelial transformation.