PT - JOURNAL ARTICLE AU - Rieneke van de Ven AU - Anna-Larissa N. Niemeijer AU - Anita G.M. Stam AU - Sayed M.S. Hashemi AU - Christian G. Slockers AU - Johannes M. Daniels AU - Erik Thunnissen AU - Egbert F. Smit AU - Tanja D. de Gruijl AU - Adrianus J. de Langen TI - High PD-1 expression on regulatory and effector T-cells in lung cancer draining lymph nodes AID - 10.1183/23120541.00110-2016 DP - 2017 Apr 01 TA - ERJ Open Research PG - 00110-2016 VI - 3 IP - 2 4099 - http://openres.ersjournals.com/content/3/2/00110-2016.short 4100 - http://openres.ersjournals.com/content/3/2/00110-2016.full SO - erjor2017 Apr 01; 3 AB - The treatment of advanced nonsmall cell lung cancer (NSCLC) with PD-1/PD-L1 immune checkpoint inhibitors has improved clinical outcome for a proportion of patients. The current challenge is to find better biomarkers than PD-L1 immunohistochemistry (IHC) that will identify patients likely to benefit from this therapy. In this exploratory study we assessed the differences in T-cell subsets and PD-1 expression levels on T-cells in tumour-draining lymph nodes (TDLNs) and peripheral blood mononuclear cells (PBMCs).To evaluate this, flow cytometric analyses were performed on endobronchial ultrasound-guided (EBUS) fine-needle aspirates (FNA) from TDLNs of patients with NSCLC, and the results were compared to paired PBMC samples. For a select number of patients, we were also able to obtain cells from a non-TDLN (NTDLN) sample.Our data show that the frequency of PD-1+ CD4+ and CD8+ T-cells, as well as the PD-1 expression level on activated regulatory T (aTreg) and CD4+ and CD8+ T-cells, are higher in TDLNs than in PBMCs and, in a small sub-analysis, NTDLNs.These elevated PD-1 expression levels in TDLNs may reflect tumour-specific T-cell priming and conditioning, and may serve as a predictive or early-response biomarker during PD-1 checkpoint blockade.PD-1 in NSCLC tumour-draining lymph nodes as a potential biomarker http://ow.ly/QedU30bqJ6d