Blood group-related antigens in human kidney: modulation of Lewis determinants in renal cell carcinoma.

Seven mouse monoclonal antibodies and the lectin Ulex europaeus, detecting blood group related antigens of the ABH and Lewis systems, have been used to determine the immunophenotype of human renal cell carcinomas. Immunohistochemical analyses have demonstrated that these antigenic systems are differentially expressed by distinct normal cell types and domains of the human nephron. In the present study we analyzed the immunophenotype of 29 primary and 15 metastatic renal carcinomas by the immunoperoxidase method. Blood type was known in all of the cases and secretor status in nine cases. ABH specificities were not detected in tumor cells of the primary tumors studied, although two of the metastases showed heterogeneous expression of H and A antigens, respectively. Lewisx (Lex) determinant was detected in 76% of primary renal cell carcinomas; however, Lex was only expressed by occasional cells in 20% of the metastatic tumors analyzed. Lewisa (Lea) was detected with a heterogeneous pattern of expression in 31% of the primary and 26% of the metastatic renal tumors studied. Lewisy (Ley) antigen expression was found in 17% of the primary and 20% of the metastatic tumors analyzed. Detection of precursor type 1 structure was observed in 28% of primary and 20% of metastatic renal cell carcinomas. The present study suggests the histogenesis of renal cell carcinoma in the proximal nephron, based on the expression of Lex and Lea antigens. It also shows: (a) an apparent deletion, downregulation or structural modification of Lex determinant in most of the metastatic tumors; (b) undetectable levels of ABH specificities in tumor cells of primary renal cell carcinoma; and (c) enhanced expression and/or neosynthesis of precursor type 1 structure and Ley determinant in some renal cell carcinomas.