Impaired thymus-derived lymphocyte function in patients with malignant brain tumour.

Cell-mediated immunity was evaluated in 28 patients with malignant glioma, using in vivo and in vitro tests of lymphocyte function. The results were compared to those found in patients with carcinomatosis (11 subjects), benign brain tumours (9), other neurological disorders (20) and normal, healthy controls (21). Significant impairments of delayed hypersensitivity responses to common antigens was found in patients with malignant glioma and in those with generalised malignancy. A less significant depression of lymphocyte responses was also detected in patients with meningioma. The impairment in cell-mediated immunity was shown not be due to a serum blocking factor. Our data indicate that there is defective T cell function in patients with glioma, similar to that reported in cases with malignancies outside the central nervous system. This impaired immunity may have clinical significance.