(1224) Peripheral Vesicular-Bound Hla-g as Predictor of Graft Tolerance after Lung Transplantation

PurposeSurvival after lung transplantation (LTx) still remains limited by chronic allograft dysfunction (CLAD). Prior studies showed an association between graft cellular expression of the checkpoint HLA-G and acceptance, whereas conversely, soluble (sHLA-G) in plasma/BAL was associated with acute rejection. We investigated whether plasma levels extra-vesicular (EVs)-bound could predict CLAD.MethodsWe used data for 79 LTx recipients from COLT (Cohort For Lung Transplantation) cohortwith ≥1 available blood samples at 6-, or 12-months post-Tx, all a stable function within 1st year. Among them, 41 developed subsequent CLAD (Group CLAD=33 BOS 8 RAS) 38 remained STABLE 3 years. 20 heathy individuals (HI) were negative controls. EVs isolated size exclusion chromatography characterized nanoparticule tracking analysis. Plasma EVs-bound (sHLA-GEV) total soluble-HLA-G (sHLA-GTOT=sHLA-GEV + free sHLA-G) measured ELISA. Uni- multivariate performed to assess CLAD/survival.ResultsIn patients, mean sHLA-GEV M6 M12, significantly increased as compared those HI (M6: 30.2 vs 15,1 ng/mL, p=0.008, M12: 37.8 15.1 p=0.0009, respectively). In decreased observed M12 significant difference (mean 23.7 ng/mL 38.7 p=0.02). (p=0.01). RAS similar patients (M12: 40,5 15,6 p=0.004). whole cohort, higher freedom level > first IQR (=21.3 g/ml) post-LTx (p=0.01, Figure 1).ConclusionOur suggest that early decrease may be predictive onset. Survival CLAD. CLAD/survival. 1). Our