Immunohistochemical analysis of HLA class II antigens and tumor infiltrating mononuclear cells in renal cell carcinoma: Correlation with clinical andhistopathological data

Cryostat sections of 37 renal cell carcinomas (RCC) - 25 clear cell type, 1 0 granular and 2 chromophobe - were studied with indirect immunoperoxidase method applying monoclonal antibodies (MoAb) to HLA-DR, -DP and -DQ antigen s for analysis of HLA class II antigens, and anti-CD14, -CD3, -CD4 and -CD8 MoAb for tumor infiltrating mononuclear cells (TIM). Number of positive ce lls was estimated semiquantitatively and results of immunohistochemical inv estigation were correlated with clinical (patient age and sex, tumor size a nd TNM stage) and histopathological (cytology, histology, grade) characteri stics of RCC. All RCC expressed HLA-DR, 92% -DQ and 73% -DP antigens with l evel of expression in hierarchy DR>-DQ>-DP, but no statistically important correlation could be established with any of the histopathological or clini cal parameters analyzed. Monocytes were more abundant than T lymphocytes an d CD4+ than CD8+ T cells, whereas tumors with T lymphocyte predominance and approximately equal number of CD4+ and CD8+ T cells had greatest average d iameter. Inadequate activation of T lymphocytes by tumor cells (despite cap ability of antigen presentation) could be the reason for association of par ameters which indicates more aggressive tumor behavior with aberrant HLA cl ass II antigen expression on RCC.