TY - JOUR T1 - Intra-alveolar neutrophil-derived microvesicles predict development of primary graft dysfunction after lung transplantation JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2020.4726 VL - 56 IS - suppl 64 SP - 4726 AU - Sanooj Soni AU - Rosalba Romano AU - Kieran O'Dea AU - Brijesh Patel AU - Kate Tatham AU - Marissa Koh AU - Diianeira Tsiridou AU - Andre Simon AU - Louit Thakuria AU - Michael Wilson AU - Anna Reed AU - Nandor Marczin AU - Masao Takata Y1 - 2020/09/07 UR - http://erj.ersjournals.com/content/56/suppl_64/4726.abstract N2 - Background: Microvesicles (MV) play important roles in mediating intra-alveolar inflammation during acute lung injury. We investigated the MV profiles within bronchoalveolar lavage fluid (BALF) in patients undergoing lung transplantation and assessed relationship to the development of primary graft dysfunction (PGD).Methods: Lung transplant patients underwent bronchoscopy after completion of surgery and BALF samples (n=31) were analysed by flow cytometry for MVs derived from leucocytes (CD45+), neutrophils (CD66b+/CD11b+), monocytes (CD45+/CD14+), alveolar macrophages (CD206+/CD71+), platelets (CD31+/42b+) and epithelial (EpCAM+/T1α+) cells. MV numbers were correlated to clinical outcomes including hypoxia and development of PGD.Results: Various MV subpopulations were identified in BALF. Neutrophil-derived MVs were the largest population (10,548 (3,925-51,529)) compared to leucocyte MVs (9797 (4763-53444)), monocyte MVs (438 (196-25,627)), alveolar macrophage MVs (755 (343-6054) and platelets MVs (564 (286-953)) (MVs/µL, median (IQR)). Patients with PaO2/FiO2 (P/F) ratio ≤ 200mmHg at 72 hours had significantly higher levels of BALF neutrophil MVs than those with P/F ratio > 200mmHg (p=0.001). Patients who developed PGD also had significantly higher BALF neutrophil MVs than those who did not (p=0.03).Conclusions: We have undertaken a comprehensive evaluation of MVs within BALF of lung transplant recipients and demonstrated an association of BALF neutrophil MV numbers and PGD. Our data may suggest BALF neutrophil MVs as a potential, clinically relevant biomarker for PGD. Moreover, these MV may also have a pathogenic/inflammatory role in development of PGDFootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 4726.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). ER -