RT Journal Article SR Electronic T1 Late Breaking Abstract - Mesenchymal stromal cells as a salvage treatment for persistent ARDS JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 3720 DO 10.1183/13993003.congress-2020.3720 VO 56 IS suppl 64 A1 Lyu, Haijin A1 Liu, Jianrong A1 Yi, Xiaomeng A1 Yuan, Xiaofeng A1 An, Yuling A1 Wei, Xuxia A1 Wang, Yanhong A1 Xian, Ying A1 Yi, Huimin YR 2020 UL http://erj.ersjournals.com/content/56/suppl_64/3720.abstract AB Aims: Mesenchymal stromal cells (MSCs) are promising but with limited safety and efficacy profiles in ARDS. To explore the safety and salvage role of Umbilical Cord derived MSCs (UCMSCs) in persistent ARDS (pARDS) patients, we collected the preliminary data from a single arm prospective study (NCT03608592) in four ICUs of a teaching hospital.Methods: Moderate to severe ARDS with unimproved oxygenation following 24 hours’ conventional therapies were defined as pARDS. A single dose (1 million/kg) of UCMSCs was infused intravenously. Infusion associated events (IAEs) and clinical outcomes were observed and compared with propensity score matched (PSM) controls.Results: Twenty-two pARDS with UCMSCs infusion with 1:1 PSM controls were finally analyzed. No prespecified IAEs was observed. Compared with PSM controls, UCMSCs significantly improved P/F, decreased lung injury (Fig1) and reduced adjusted mortality at 60 days (45% vs 55%, HR 0.25, 95% CI 0.08-0.73, P=0.01) and ventilator free days (mean difference 7.5, 95% CI 3-12, P<0.01).Conclusion: The present data showed the safety and potential survival benefit of a single dose of UCMSCs in persistent ARDS. Larger trials are warranted. Figure 1 Clinical outcomes in UCMSCs and control group. Student t test for intergroup analysis, *P<0.05, **P<0.01, ***P<0.001. RALE, Radiographic Assessment of Lung Edema score was measured according to the literature [Warren, et.al Thorax 2018, 73 (9):840-846]FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 3720.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).