[Analysis of tumor-infiltrating lymphocyte in primary malignant lymphoma of the central nervous system using double immunofluorescence staining method].

Three cases of malignant lymphoma were examined immunohistochemically using anti-Leu monoclonal antibodies (MAB) against B lymphocytes, T lymphocytes subsets, NK cells, IL-2 receptor. In all three cases tumor cells were stained with anti-B cell's MABs, that is they were diagnosed as B cell type of malignant lymphoma. Moderate tumor-infiltrating lymphocytes in the parenchyma or around blood vessels were observed, and majority of these cells were T lymphocytes, demonstrating Leu 2a or Leu 3a + 3b positive phenotypes. IL-2 receptor positive cells also found in the parenchyma of these tumors. T lymphocyte subsets, such as Leu 2a positive cells and Leu 3a + 3b positive cells, were analyzed by means of double immunofluorescence staining method using the combination of Leu 2a and Leu15, or Leu 3a + 3b and Leu 8 MABs. This method demonstrated that most of Leu 2a positive cells were negative for Leu 15 and that the majority of Leu 3a + 3b positive cells were negative for Leu 8. These results suggested that tumor-infiltrating lymphocytes in the malignant lymphoma were mainly activated cytotoxic or helper T cells.