Cytotoxic antibodies in preoperative glioma patients: a diagnostic assay.

The use of a microcytotoxicity test for complement-dependent serum antibodies cytotoxic to cultured astrocytoma cells has been explored as an aid in the diagnosis of brain tumors. Fourteen of 21 randomly selected preoperative glioma patients (67%) had antibodies detectable by this assay in contrast to 4 of 21 normal blood donors (19%). Five of the glioma patients (24%) were strongly positive (cytotoxic index greater than 80-80) while none of the controls was in this range. Although positive responses were seen in patients with tumors of every grade, only 6 of 11 patients with astrocytomas of Grades I-III were positive as compared to 8 of 9 patients with Grade IV astrocytomas. The microcytotoxicity test used is simple, inexpensive and capable of being performed on an outpatient basis. It is concluded that this assay has usefulness both as a screening technique and as a diagnostic adjunct for patients suspected of having brain tumors.