Association of HLA class I and class II antigen expression and mortality in uveal melanoma

PURPOSE. Malignant transformation of cells is frequently associated with ab normalities in human leukocyte antigen (HLA) expression. These abnormalitie s may play a role in the clinical course of the disease, because HLA antige ns mediate interactions of tumor cells with T cells and NK cells. Uveal mel anoma is a highly malignant tumor of the eye and is characterized by a hema togenic spread to the liver. Little is known about the role of HLA expressi on in progression of this malignant disease. METHODS. In the present study HLA class I antigen, beta (2)-microglobulin ( beta (2)-m), and HLA class II antigen expression was analyzed in primary uv eal melanoma lesions by immunoperoxidase staining with monoclonal antibodie s of 65 archival clinical samples. The results were correlated with the cli nical course of the disease. RESULTS. HLA class I antigen expression and beta (2)-m expression were down regulated in 40 and 35 lesions, respectively. HLA class II antigens were ex pressed in 30 lesions. Patients with high HLA class I, including beta (2)-m , and HLA class II antigen expression in their primary melanoma lesions had a significantly decreased survival (P = 0.009, P < 0.001, and P = 0.006, r espectively). CONCLUSIONS. The findings argue against a major role of cytotoxic T-lymphoc yte (CTL)-mediated control of tumor growth in the clinical course of uveal melanoma and are compatible with a potential role of NK-cell-mediated contr ol of hematogenic metastatic spread.