Immunomorphological characteristics of renal cell carcinoma

Immunomorphological characteristics of 27 renal cell carcinoma (RCC): 18 clear cell, 6 granular (chromophilic), 2 chromophobe, 1 spindle cell (sarcomatoid) as well as of 1 oncocytoma, were analyzed. The investigation was performed on cryostat sections by immunoperoxidase technique applying a panel of monoclonal antibodies which defined: proximal (TNE3, TN5, 5D9) and distal (TN8, TN9, 7C2) tubular antigens; intercellular adhesion molecule 1 (ICAM1); HLA class II (-DQ, -DR and -DP) antigens, intermediary filaments (cytokeratin and vimentin); and antigens on tumour infiltrating mononuclear leucocytes (TT1, TT2 and LeuM3 for CD4, CD8 and CD14 antigens, respectively). All RCC with exception of chromophobe co-expressed cytokeratin and vimentin. In addition, they were usually positive for all proximal and two distal tubular markers (TN8, TN9) indicating primitive cells which could differentiate into the epithelium of both parts of tubule system as the most probable originators of in RCC. Almost all RCC but the chromophobe aberrantly expressed HLA class II antigens which great variability from case to case. The presence of HLA-DR antigens was more intensive and widespread than of HLA-DQ and -DP antigens. Expression of ICAM1 mostly correlated with presence of HLA class II antigens, particularly with -DR on tumour cells of RCC. HLA-DR antigen expression was always more prominent than mononuclear cell infiltrate (among which macrophages prevailed over T cells) which could suggest that increased histocompatibility antigen expression precedes mononuclear cell influx. In contrast to all other RCC, chromophobe tumours had quite distinct features revealing the most intense reaction with 7C2 (MAb that produced the weakest reaction with other tumour types), absence of vimentin and very weak reaction with antibodies for HLA class II Ag and ICAM1.(ABSTRACT TRUNCATED AT 250 WORDS)