Plasma long noncoding RNA IL‐7R as a prognostic biomarker for clinical outcomes in patients with acute respiratory distress syndrome

BACKGROUND: Long non-coding RNAs (lncRNAs) regulate a variety of genes and biological processes. Lnc-IL7R plays a considerable role in the regulation of inflammation, but its prognostic potential in acute respiratory distress syndrome (ARDS) has not been fully explained. In this study, the role of lnc-IL7R as a potential biomarker in ARDS was examined. OBJECTIVE: Role of lnc-IL7R as potential biomarker in ARDS. METHODS: LncRNA-IL7R was isolated from the plasma of patients with ARDS and healthy controls and clinical indexes were obtained within 24 h after admission. The relative expression of lnc-IL7R was obtained by quantitative real-time PCR. The correlations between lnc-IL7R and continuous variables in ARDS were tested using Spearman's coefficients. RESULTS: A total of 85 ARDS patients and 49 healthy controls were included. Plasma lnc-IL7R was significantly down-regulated in ARDS compared with the levels in healthy control individuals, especially in severe ARDS (P < .01). The area under the curve (AUC) of lnc-IL7R for ARDS diagnosis was 0.87 (sensitivity 75.3%, specificity 93.9%). The lnc-IL7R levels were correlated with the severity of ARDS (ρ = -0.31, P = .0215), oxygenation index (ρ = 0.61, P < .001), APACHE II score (ρ = -0.04, P = .0230), CRP (ρ = -0.26, P = .0148) and WBC (ρ = -0.29, P = .0064). Lnc-IL7R relative value ≥ 0.33 showed the lower 28-day mortality in the patients with ARDS(P < .05).The survivors showed higher lnc-IL7R level and lower APACHE II score, SOFA score and length of mechanical ventilation than in the non-survivors (P = .0109, P < .001, P < .001 and P = .017, respectively). CONCLUSIONS: Lnc-IL7R is a novel biomarker for the diagnosis of ARDS and predicts the severity of ARDS and 28-day mortality in this patients cohort. TRIAL REGISTRATION: The study was registered with the Chinese Clinical Trial Registry (ChiCTR-DOD-16008657).