RT Journal Article SR Electronic T1 Cytotoxic phenotype of alveolar lymphocytes (AL) in bronchoalveolar lavage fluid (BALF) from non-small cell lung cancer (NSCLC) patients JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP P3879 VO 44 IS Suppl 58 A1 Agata Gizycka A1 Joanna Chorostowska-Wynimko A1 Cezary Rybacki A1 Ewelina Wedrowska A1 Joanna Golinska A1 Piotr Kopinski YR 2014 UL http://erj.ersjournals.com/content/44/Suppl_58/P3879.abstract AB Background. T lymphocytes are key regulators of the antitumor immunity. Their ability to control local immune response in tumor microenvronment as well as induce tumor cells death is considered the most important .Aim. To evaluate phenotypic properties of AL in NSCLC with particular attention to the markers of T cell cytotoxicity.Methods. Bronchoalveolar lavage fluid (BALF) was harvested in tumor-free lung region from patients with NSCLC (n=15) and healthy volunteers as controls (n=13). AL were phenotyped by flow cytometry for specific surface markers: CD3, CD4, CD8, CD19, CD16, CD56, CD25, CD27 and CD45RO. Cytotoxicity was evaluated in both Th and Tc cells by extracellular (FasL, TRAIL) and intracellular (granzyme B) marker expression.Results. CD4/CD8 ratio was higher in NSCLC patients as compared to controls (1.2±0.3 vs 0.9±0.7 for smokers). AL from NSCLC patients demonstrated increased expression of FasL, (particularly CD4+ cells: 13±7.5 vs 2.3±1.7%, p<0,05), TRAIL (for all AL) and NK cells (8.0±2.1 vs 4.0±1.1%). Granzyme B expression was similar in NSCLC and control groups. Unexpectedly, nTreg (assessed as CD4+25+27+ cells) percentage was lower in NSCLC than in healthy controls.Conclusion. AL from NSCLC patients, including Th cells demonstrate increased cytotoxic potential (FasL+ cells, TRAIL+ cells, NK cells).