HLA-DR and CD74 Expression and the Immune Microenvironment in Renal Cell Carcinoma

Background/Aim: Expression of human leukocyte antigen (HLA) class I and II and CD74, which functions as a chaperone of MHC class II, play essential roles in T-cell recognition. The aim of this study was to elucidate the association between the HLAs and CD74, and their correlation with the infiltrated immune cells in renal cell carcinoma (RCC). Materials and Methods: We retrospectively investigated the expression of HLA-A/B/C, HLA-DR, and CD74 in 38 patients with advanced RCC (T3/T4), and evaluated their correlations with CD4 and CD8-positive T-cell infiltration using immunohistochemistry. Results: The expression of HLA-A/B/C, HLA-DR, and CD74 on cancer cells was observed in 37, 20, and 31 patients, respectively. The density of CD8- and CD4-positive T cells showed a positive correlation with HLA-DR expression. The density of CD4-positive lymphocytes was significantly associated with CD74 expression. Conclusion: The expression of HLA-DR, rather than CD74, on cancer cells was potentially associated with the anti-cancer immune microenvironment.