[Expression on major histocompatibility complex antigen and effect of IFN-alpha on renal cell carcinoma]

Eighteen patients with renal cell carcinoma subjected to nephrectomy were examined for expression of major histocompatibility complex (MHC) class-I and -II antigens by staining with monoclonal antibodies. The neoplastic tissue and normal tissue were examined by the indirect immuno-peroxidase method. Only four of the eighteen patients expressed class-I antigen and no patient expressed class-II antigen in the neoplastic tissue. The normal tissue of all patients expressed class-I antigen. Subsequently, carcinoma tissue was incubated in the tissue culture medium RPMI1640 containing various concentrations of interferon (IFN)-alpha (0, 10, 30, 100 IU/ml) for 24 hours. The incubation of the renal cell carcinoma tissue with the medium without IFN-alpha did not affect the expression of class-I. Furthermore, the relationship between IFN-alpha concentration and the expression of MHC antigens was investigated. Groups incubated with 10, 30, and 100 IU/ml interferon showed enhanced expression of class-I compared with the control group (p < 0.05, p < 0.001, p < 0.05, respectively). The expression in the 100 IU/ml group tended to decrease. Staging and grading in patients did not correlate with class-I expression statistically. The expression of MHC class-II antigen remained unexpressed by IFN-alpha treatment. There results suggest some relationship between the expressed MHC class-I antigen and IFN-alpha therapy in renal cell carcinoma. Further, the interferon concentration giving the greatest degree of class-I expression was suggested to be the best therapeutic dose of IFN-alpha, and the expression level of MHC class-I antigen was considered to be of prognostic value.