@article {BocchinoP3151, author = {Marialuisa Bocchino and Domenico Galati and Marina De Martino and Maria Napolitano and Annamaria Trotta and Anna Stanziola and Alessandro Sanduzzi}, title = {Frequencies and dynamics of peripheral immune cell subsets in idiopathic pulmonary fibrosis: Preliminary results and clinical implications}, volume = {40}, number = {Suppl 56}, elocation-id = {P3151}, year = {2012}, publisher = {European Respiratory Society}, abstract = {Involvement of the immune response in the pathogenesis of idiopathic pulmonary fibrosis (IPF) is not well clarified. Emerging T cell subsets including IL-17 secreting T helper cells (TH17) and regulatory T lymphocytes (Treg) expressing TGF-beta may exert antithetical actions. Distribution and phenotype characteristics of peripheral immune cells along with TH17/Treg dynamics were investigated by multi-parametric flow cytometry in 15 IPF patients (mean age 63 yrs; 13 men) and 10 age- and sex-matched healthy subjects. Proportions of CD4+ and CD8+ T cells and of B (CD20+) lymphocytes were similar in the two groups. Frequencies of NKT (CD3+CD56+) and NK cells (CD3-CD56+CD16+) were reduced in IPF (p\<0.0001 for NK cells), the 24\% of the latter co-expressing CD161 and CD152a (versus 4.2{\textpm}3.3; p=0.001). IPF patients displayed higher Treg proportions (CD4+CD25highFoxP3+) (0.71{\textpm}0.4 vs 0.3{\textpm}0.13; p\<0.05). No differences in the distribution of highly suppressive Treg (CD13+) cells were found. Upon stimulation, Treg expression of TGF-beta was similar in the two groups. Conversely, frequencies of IL-17-espressing CD4+ cells were significantly lower in IPF (0.92{\textpm}0.56 vs 0.21{\textpm}0.11; p\<0.001). This finding was associated with an increased TGF-beta/IL-17 ratio in IPF (2.18{\textpm}1.15 vs 0.38{\textpm}0.2; p=0.001). This study first provides evidence in IPF of a peripheral Treg/TH17 functional imbalance along with a depletion of NK cells which display an inhibitory phenotype. Dynamics of Treg/TH17 cells may represent a non invasive tool for disease severity assessment and treatment monitoring. Efforts are requested to thoroughly delineate these observations at the lung level.}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/40/Suppl_56/P3151}, eprint = {https://erj.ersjournals.com/content/40/Suppl_56/P3151.full.pdf}, journal = {European Respiratory Journal} }