DISTRIBUTION OF ENDOGENOUS TUMOR-NECROSIS-FACTOR-ALPHA IN GLIOMAS

Aims-To determine the distribution and cellular origin of endogenous t umour necrosis factor alpha (TNF alpha) in the cellular components of human gliomas. Methods-Frozen sections of 26 gliomas (four astrocytoma s (As); two oligoastrocytomas (OA); one anaplastic astrocytoma (AA); o ne anaplastic oligoastrocytoma (AOA); 18 glioblastomas (GB)) were exam ined immunohistochemically using antihuman TNF alpha and anti-Leu-M5 ( CD11c) antibodies. Additional studies with double immunohistochemical procedures were performed with anti-glial fibrillary acidic protein an d anti-neurofilament antibodies. Results-Eighty per cent of the AA, AO A, and GB (16 of 20) had a positive reaction for TNF alpha, but only 1 7% of As and OA (one of six) were positive. Positive cells were seen i n both the tumour tissue and adjacent brain tissues. TNF alpha protein was detected not only in the tumour cells but also in the endothelium of tumour vessels as well as reactive astrocytes and neurons. Conclus ions-Endogenous TNF alpha is present in cells of various origins in gl ial tumours including tumour vessels; however, the role of TNF alpha m ay be different in different types of cells or altered microenvironmen t.