Abstract
The non-specific immunological parameters of 37 patients with malignant brain tumors were analysed by means of 1) purified protein derivative (PPD) skin test, 2) lymphocyte counts, and 3) phytohemagglutinin (PHA) blastogenesis. The PPD skin reaction and PHA blastogenesis were already depressed preoperatively in patients with malignant brain tumors as compared to those in normal controls. When radiotherapy was confined to the head, lymphocyte counts and PHA blastogenesis were further depressed, but gradually recovered to preoperative levels within 6 months after the completion of radiotherapy. In the cases with medulloblastoma and germinoma who received whole cerebrospinal axis irradiation, lymphocyte counts and PHA blastogenesis were more markedly depressed and took more than 6 months after completion of the radiotherapy to recover to their preoperative levels. The result of the PPD skin test, on the other hand, was not affected and was rather enhanced by radiotherapy, showing a marked dissociation from the changes in lymphocyte counts and PHA blastogenesis. The results of PPD skin test on discharge from hospital were relatively well correlated with the prognosis of the patients.
The profound immunosuppressive influence of radiotherapy and the natural course of recovery should be taken into consideration if any immunological treatments are to be undertaken with or after the course of radiotherapy.
