Immunohistochemical pattern of T lymphocytes population within bilharzial-associated bladder neoplasm microenvironment

The present work aimed to investigate the cellular and immunochemical pattern of T cells population in biopsy material from chronic schistosomiasis haematobium Egyptian patients complicated with bladder cancer. Digital real-time quantitative photocytometry was applied to auto-analyze 29 stained tissue sections from cases and 17 controls using STAT4, GATA3, FOXP3, and CD8 markers specific for Th1, Th2, T regulatory, and T cytotoxic cells, respectively. Area percentage showed significant high level of GATA, followed by FOXP3 and low level of both STAT and CD8 was reported. Tissue samples from five healthy bladder tissues showed significant lower optical density (OD) values. Tissue samples from 12 non-bilharzial bladder cancers showed variable OD values, reflecting wide disparity in the control group. Our results hypothesized an exclusive pattern of T population in long standing complicated schistosomiasis haematobium. Our cases were poorly controlled by unbalanced Th1/Th2 in which Th2 was dominated. FOXP3 increased significantly, however, failed to downregulate Th2, instead, the relation between Th1 and T cytotoxic was forcibly limited by the high level of FOXP3, resulting in loss of their power in defending the host against both parasite and carcinogenic changes. These results provide more clarification for the immune evasion process played by the parasite and tumor cells under the supervision of T regulatory cells. Additionally a critical role of FOXP3 is suggested in manipulating STAT4 and CD8 in favor of malignant transformation in this life-threatening parasite.