Expression of HLA antigens in paraffin sections of uveal melanomas

Expression of histocompatibility (HLA) antigens on tumor cells may influence the recognition of these tumor cells by the immune system. Immunological recognition may influence tumor growth and patient survival. Although HLA class I and II antigens are known to be present on several tissues in the eye, their presence on ocular tumors had not yet been demonstrated. We studied the expression of these antigens on paraffin preparations of uveal melanomas. Most tumors carried class I and beta 2m antigens on most of their cells while class II antigens were less often expressed. No association with tumor cell type or tumor size was observed. Further studies will be necessary to determine the relevance of different levels of antigen expression with regard to patient survival.