PD-L1, PD-1 expression, TILs and IDH-1 mutation associations and their prognostic importance in GBM are planned to assessed in the study.
GBM patients who were newly diagnosed and operated between February 2006 to February 2017 were included retrospectively in the study. In initial tumor specimens PD-L1, PD-1 expression, CD4(+) ve CD8(+)TILs, IDH-1 mutation were assessed. For IDH-1 mutation analysis real time PCR tecnique was used, for PD-L1 and PD-1assessment immunohistochemistry was performed by Ventana® antibody (clon-SP263, ROCHE). For PD-1, PD-L1, CD4, CD8 TILs intensity was graded as low, moderate, dense and estimated in percents. The cut off value assumed as ≥ 5% for PD-L1, PD-1 positivity. Kaplan Meier, Cox regression tests and SPSS 23 were used.
Ninety patients were included. The mean age was 57± 12,3 and 57 (63,3%) patients were male. Fourty eight (53,3%) patients were received chemoradiotherapy and chemotherapy with temozolamide after operation. Two different staining patterns were diagnosed for PD-L1 expression as diffuse fibrillary [29 (32,2%)] and membranous staining [15(16,7%)]. Thirty (33%) patients have IDH-1 mutation. TILs were seen intensely in the perivascular field, which is rarely found in the intratumoral area and in that TILs, PD-1 staining grade was dense. We also observed a positive correlation between the density of TILs in the intratumoral/perivascular fields and the percentages of PD-L1 positivity. (p
Staining pattern of PD-L1 and the density of PD-1 positivity in TILs may be a prognostic importance in GBM.
Clinical trial identification
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Didem Şener Dede
All authors have declared no conflicts of interest.