1633 - PD-L1 expression and tumor immune-cell infiltration in non-small cell lung cancer from HIV-infected patients

Background

Immunotherapies targeting the programmed cell death protein 1 (PD-1) to PD ligand 1 (PD-L1) checkpoint have improved prognosis in non-small cell lung cancer (NSCLC). PD-1/PD-L1 status has not been investigated in human immunodeficiency virus (HIV)-positive patients. This study sought to assess PD-L1 status and tumor immune-cell infiltration in NSCLC in HIV patients.

Methods

Consecutive HIV patients treated for NSCLC between 1996 and 2014 at Tenon hospital (Paris, France) were enrolled. PD-L1 tumor expression was assessed using immunohistochemistry (2 antibodies: L. Chen, clone 5H1 and Cell Signaling, clone E1L3N). Tumor immune cell infiltration was assessed for CD3 (SP7), CD4 (1F6), CD8 (C8/144b), CD20 (L26), CD163 (10D6) and MPO (59A5). The percentage of PD-L1- and immune-positive cells was ≥5%. The score used is the product of intensity (0, 1, 2 or 3) by positive cell percentage. The PD-L1 score was considered positive if >5. PD-L1 status and immune-cell infiltration results were compared to those of 54 NSCLCs from unknown HIV status patients.

Results

In total, 34 HIV-positive patients were evaluated: predominantly men (88.2%) with a median age of 51.1 years and adenocarcinomas (76.5%) with 38.2% stage IV. The median blood CD4 count was 480/µL (86-1120) and 64% exhibited undetectable viral load. The PD-L1 score was higher in HIV-positive patients (E1L3N clone: 0 [0-150] vs. 0 [0-26.7], p = 0.047; 5H1 clone: 0 [0-120] vs.0 [0-26.7] p = 0.66 respectively) whereas PD-L1 expression frequency did not differ between HIV-positive and HIV-undetermined patients (18.7% vs. 9.3% using E1L3N and 10% vs. 5.6% using 5H1, respectively). There was significantly greater CD8, CD20, and CD163 infiltration in the HIV-positive patients (Table).