The perivascular microenvironment in Epstein –Barr virus positive primary central nervous system lymphoma: The role of programmed cell death 1 and programmed cell death ligand 1

It has been shown that high expression of certain immune checkpoint molecules, including those of the programmed death protein 1/programmed death ligand 1 (PD‐1/PD‐L1) axis, can be utilized to regulate immunosuppression in the microenvironment of malignant neoplasms. For the purpose of clarifying the immune‐escape mechanism of primary central nervous system lymphomas (PCNSLs), particularly in Epstein–Barr virus (EBV)‐positive cases, markers for PD‐1, PD‐L1, tumor‐associated macrophages (TAMs), and tumor‐infiltrating lymphocytes (TILs) in 39 surgical specimens of PCNSLs (17 EBV‐positive, 22 EBV‐negative) were investigated by immunohistochemistry. Staining for PD‐L1 was scored as follows: (−), no staining; (1+), 0–30% positive cells; (2+), 30–60% positive cells; and (3+), >60% positive cells. In EBV‐positive cases, PD‐L1 was detected in both lymphoma cells and TAMs in 12/17 cases, and in TAMs only in 4/17 cases. The mean number of PD‐1, TIA‐1 (a marker for cytotoxic T‐cells), and FOXP3 (a marker for regulatory T‐cells)‐positive TILs in EBV‐positive cases was 36.4 ± 45.9, 390 ± 603, and 9.88 ± 15.1, respectively. In EBV‐negative cases, PD‐L1 was detected in both lymphoma cells and TAMs in 11/22 cases, and in TAMs only in 4/22 cases. The mean of PD‐1, TIA‐1 and FOXP3‐positive lymphocytes in EBV‐negative cases was 67.3 ± 82.0, 158 ± 206 and 9.32 ± 17.5, respectively. We found no significant ...
Source: Neuropathology - Category: Neurology Authors: Tags: Original Article Source Type: research