LAUSR

Objective In this study, we aim to classify hematological patients with the pneumonia-associated acute respiratory syndrome (ARDS) into different groups that were characterized by distinct early responsiveness to corticosteroids, describe the microbiota signatures of the non-responders and responders, and compare the prognosis of the two groups. Methods Hematological patients with ARDS were included and treated with mechanical ventilation and corticosteroid. According to the early improvement to the corticosteroid therapy, patients were classified as non-responders and responders. The lung microbiota signatures and the outcomes of the non-responders and responders were compared. Results Fifty patients were included in this study. Twenty-eight patients were classed as non-responders and 22 as responders. Compared to the non-responders, responders had higher serum levels of IL-6, IL-8, TNF-α and CRP, their lung microbiota was with lower alpha diversity and enriched with virus species. The responders had an overall higher ventilator free days than the non-responders [4 (0–6) vs 6 (0–10), p=0.034], for survivors the difference was more significant [5 (3–6) vs 8 (3–10), p=0.012]. Survival analysis showed that there was no difference in survival rate between the two groups over time (Log-rank p=0.073). When non-responders were stratified into subgroups of patients with infection or co-infection, those non-responders with co-infection had significantly lower survival rate than other patients (Log-rank p= 0.028). Conclusion For hematological patients with pneumonia-associated ARDS, the responders of corticosteroids had higher ventilator free days at day 28 than the non-responders. The microbiota signatures were distinct in the two groups. The non-responders with coinfections had the lowest survival rate when compared to the non-responders with no coinfections and the responders.