Decoy receptor 3 levels in peripheral blood predict outcomes of acute respiratory distress syndrome.

RATIONALE: Acute respiratory distress syndrome (ARDS), a serious inflammatory reaction to acute lung injury, is associated with high mortality rates. Decoy receptor (DcR) 3 is a soluble protein with immunomodulatory effects. Biomarkers that reliably predict outcomes in ARDS are not currently available.

OBJECTIVES: Comparing DcR3 with the Acute Physiology and Chronic Health Evaluation (APACHE) II scores and three other plasma markers to explore the association of DcR3 and the clinical outcome in ARDS.

METHODS: Eighty-eight patients with ARDS were studied. Baseline APACHE II scores and clinical data were recorded. Plasma levels of DcR3, soluble triggering receptor expressed on myeloid cells (sTREM)-1, tumor necrosis factor (TNF)-alpha, and IL-6 were measured on Day 1 and later time points, and correlated with the survival status on Day 28 after the onset of ARDS. For validation, 59 patients with ARDS from another medical center were studied.

MEASUREMENTS AND MAIN RESULTS: Among the biomarkers evaluated, only DcR3 discriminated the survivors and nonsurvivors at all time points in the first week of ARDS. DcR3 independently associated with and best predicted the 28-day mortality of patients with ARDS. Plasma DcR3 levels most correlated to multiple-organ dysfunction and ventilator dependence. Compared with survivors, the nonsurvivors had higher DcR3 levels regardless of the APACHE II scores. Kaplan-Meier survival analysis showed higher mortality in patients with ARDS with higher DcR3 levels. The outcome prediction of patients with ARDS by plasma DcR3 levels was recapitulated by the validation cohort.

CONCLUSIONS: High plasma DcR3 levels correlate with development of multiple-organ dysfunction and independently predict the 28-day mortality in patients with ARDS.