Immunological and immunohistochemical studies in brain tumours.
The authors have studied different brain tumours with immunohistochemical technique using fluorescence and peroxidase methods. On frozen sections reactions for fibronectin (FN), prostaglandin E2 (PGE2), carcinoembryonic antigen (CEA) with polyclonal antibodies and for lymphocyte subpopulations B, NK and Pan-T with monoclonal antibodies have been investigated. Both primary and metastatic tumours contained fibronectin in various intensity and showed increased reactions with PGE2 antibodies comparing with surrounding tissues. A well developed FN positive fibrillary network in tumour tissue confirmed the presence of angiogenesis and visualised abnormalities of the vessel walls with focal disruptions. The intracytoplasmatic location of PGE2, more intense than in surrounding tissues revealed in this study, may indicate that tumour cells are capable of its production. Since prostaglandin inhibits lymphocyte cytotoxicity against tumour cells in vitro, this may be suggestive for its activity in tumour defence reaction. CEA was not found in primary brain tumours by immunohistochemical procedure, either fluorescence or peroxidase method. It has been detected only in metastatic carcinomatous tumours in moderate intensity. Immunostaining for subpopulations of lymphocytes in tumour slices with monoclonal antibodies showed only small number of cells, in some specimens. The reasons for this failure are discussed. The meaning of all these findings mentioned above for clinical purposes is considered. The application of immunohistochemical staining may be useful in diagnosing tumour of vague or doubtful microscopic appearances.