Blood lymphocyte subsets in patients with primary intracranial tumours. Correlation to histological tumour type and anatomical site.

The blood lymphocyte population of 118 patients with primary intracranial tumours and healthy volunteers was examined with respect to its size and cellular composition using various rosette tests. The patients had not undergone any surgical intervention or received any treatment with ionizing irradiation or cytotoxic drugs. However, some of them were treated with corticosteroids. It was observed that non-steroid treated patients with oligodendrogliomas, but not patients with other histological types of tumours, had a significantly reduced proportion of "active" T-lymphocytes forming rosettes with sheep erythrocytes (a type of T-lymphocyte which is activated by foetal calf serum). These patients as well as those with astrocytomas, malignant gliomas (anaplastic astrocytomas and glioblastomas) or miscellaneous tumours (mainly meningiomas) had normal proportions of lymphocytes with receptors for the Fc-part of IgG or C'3 and cells forming rosettes with sheep erythrocytes under more conventional conditions. Patients who were treated with corticosteroids had an increased frequency of lymphocytes with the above Fc-receptor. An association between site of the lesions and cellular composition of the blood lymphocyte population was not detected. The results give further support for the view that the immunological system may be changed in patients with oligodendrogliomas.