Sequential study of macrophage migration inhibition factor in renal cell carcinoma patients

Preliminary investigation of cell-mediated immunity (CMI) in 49 patients harboring renal cell carcinoma (RCC) by the migration inhibition factor (MIF) tests as compared to 47 patients with simple renal cysts or normal kidneys established the specificity (85%) and reproducibility of this test. A retrospective analysis of the results of the MIF test was conducted in 35 patients followed for a minimum 20-month period. A marked difference was observed between the group of patients with localized disease who remained disease free and those with metastatic lesions and disease progression. The first group sustained their positive response of the MIF tests for a longer time during the study period, while the latter had a decrease of the MIF test response shortly after surgery. This difference may indicate that immune response as reflected in the positive MIF test has a role in RCC patients' defense mechanism.