Tumour-distinctive cellular immunity to renal carcinoma

The possible existence of a cellbound tumour-distinctive immune response in patients with renal adenocarcinoma (hypernephroma) was studied. The peripheral lymphocytes of the patient were mixed in vitro with autochthonous malignant and non-malignant cells and allogeneic lymphocytes in which DNA-synthesis had been blocked by Mitomycine-C in a `Mixed Lymphocyte Target Interaction' test, MLTI-test. If the tumour cells possess something on their surface, e.g. tumour-specific antigens, making them foreign to the patient's non-malignant cells, the patient's own lymphocytes should be stimulated to increased DNA-synthesis by autochthonous tumour cells but not by autochthonous non-malignant cells. Peripheral lymphocytes from three out of the first six tested patients showed increased DNA-synthesis after contact with autochthonous renal carcinoma cells in vitro. These results indicate that tumor-distinctive immune reactions exist in patients with renal carcinoma.