Effects of tumor-infiltrating CD8+ T cells, PD1/PD-L1 axis, and expression patterns of HLA class I on the prognosis of patients with malignant pleural mesothelioma who underwent extra-pleural pneumonectomy

Characterizing soluble immune checkpoint molecules and TGF-β1,2,3 in pleural effusion of malignant pleural mesothelioma

The clinical impact of soluble molecules in pleural effusion (PE) is unclear in patients with malignant pleural mesothelioma (MPM). In this single-center, retrospective, observational study, we assessed soluble forms of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein 1 (PD-1), and PD-1 ligand 1 (PD-L1) using enzyme-linked immunosorbent assays; three TGF-β isoforms were measured via multiplex assay in PE of patients with fibrinous pleuritis (FP) or MPM, to assess relationships between the levels of six molecules, clinicopathological characteristics, and efficacy of immune checkpoint inhibitors. Soluble forms of CTLA-4, PD-L1, PD-1, TGF-β1, TGF-β2, and TGF-β3 were variably produced in PE of FP (n = 34) and MPM (n = 79); we found significant relationships between the six molecules and clinicopathological features. Although none of the three soluble immune checkpoint molecules showed diagnostic or prognostic effects in patients with MPM, TGF-β2 level in PE is a useful differential diagnostic marker between FP and MPM. Both TGF-β1 and TGF-β3 levels are promising prognostic markers for MPM. Moreover, we found that higher baseline levels of PD-1 soluble forms predicted the response to anti-PD1 monotherapy. Our findings identify novel diagnostic, prognostic, and predictive biomarkers for anti-PD1 therapy in patients with MPM.

Preoperative neutrophil-to-lymphocyte ratio correlates with PD-L1 expression in immune cells of patients with malignant pleural mesothelioma and predicts prognosis

We assessed the prognostic value of five complex inflammatory and nutritional parameters, namely neutrophil-to-lymphocyte ratio (NLR), prognostic nutritional index (PNI), C-reactive protein-to-NLR ratio (C/NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) using data from patients with malignant pleural mesothelioma (MPM) undergoing extrapleural pneumonectomy (EPP). Moreover, the correlation between these five parameters and programmed cell death protein 1 ligand-1 (PD-L1) expression in the tumor microenvironment was evaluated. This study included consecutive MPM patients who underwent EPP. The histological subtype of the eligible patients (n = 61) correlated with all five parameters. Moreover, the PD-L1 expression scores for immune cells correlated with NLR and PLR, and the PD-L1 expression scores for both tumor cells and immune cells were inversely correlated with both PNI and LMR. Univariate analysis elucidated that NLR, PNI, and C/NLR were predictors of 5-year overall survival (OS), and multivariate analysis revealed that NLR was an independent predictor of 5-year OS, suggesting that NLR is a preoperative, prognostic factor for patients with MPM who are scheduled for EPP. To the best of our knowledge, this is the first study to evaluate the prognostic potentials of NLR, PNI, C/NLR, PLR, and LMR simultaneously in patients with MPM who underwent EPP.