PT - JOURNAL ARTICLE AU - Olivier Brugière AU - Domitille Mouren AU - Isabelle Kuzniak AU - Edgardo Carosella AU - Joel Le Maoult AU - Nathalie Rouas-Freiss TI - Late Breaking Abstract - Prediction of chronic lung allograft rejection (CLAD) by measurement of peripheral T cells linked to the inhibitory check-point HLA-G AID - 10.1183/13993003.congress-2020.4723 DP - 2020 Sep 07 TA - European Respiratory Journal PG - 4723 VI - 56 IP - suppl 64 4099 - http://erj.ersjournals.com/content/56/suppl_64/4723.short 4100 - http://erj.ersjournals.com/content/56/suppl_64/4723.full SO - Eur Respir J2020 Sep 07; 56 AB - Background: Long-term survival after lung transplantation (LTx) still remains limited because of chronic lung allograft dysfunction (CLAD) and better understanding of operational tolerance is needed.Methods: We aimed to investigate the role of the inhibitory checkpoint HLA-G expressed by different peripheral cell populations in predicting CLAD development. Data from COLT cohort (follow-up>3 years post-LTx) were investigated. Analysis by cytometry, focused on HLA-G and other markers, were performed. T-cell populations at different Time-points and their kinetics (1-12months T-cells ratio) were compared between Stable and CLAD.Results: The study included 150 patients (78 stable and 72 CLAD). Freedom from CLAD was lower in patients with 1-12 months CD4+specific/HLA-G-linked T-cells (CD4+spe/HLA-G T cells) ratio >2.64 than in patients with ratio <2.64:(Log-rank,p=0.014). Markers of « CD4+speHLA-G » T cells will be communicate at ERS-congress. At 1-mo, patients with a % of CD4+spe/HLA-G T cells (%CD4 T cells) <0.069% had a lower incidence of CLAD at 3 yrs post-Tx, versus those >0.069% (Log-rank,p=0.04).On multivariable analysis: 1) increase of 1-12mo CD4+spe/HLA-G T-cell ratio was an independent predictor of CLAD (HR=1.25;95%CI,1.09-1.44;p=0.001). 2) increase of %CD4+CD25+CD127low T cells (%CD4+T cells) was also an independent predictor of graft failure ((HR=1.1;95%CI,1.00-1.30;p=0.01).Conclusion: Our data suggest that CD4+specific/HLA-G-linked T cells appear as a contributor to graft unstability and as a new predictor of CLAD onset.FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 4723.This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).