Research of the biomarkers in pulmonary and extrapulmonary acute respiratory distress syndrome

Abstract

Objective: To explore the biomarkers that applied to pulmonary acute respiratory distress syndrome (ARDS) and extrapulmonary ARDS respectively. Methods: A total of 49 eligible patients with ARDS were selected from Department of Respiratory intensive care unite (ICU) , Department of General ICU and Department of Emergency ICU, the Second Affiliated Hospital of Nanchang University, during April 2015 and February 2016, and divided into pulmonary ARDS group (n=26) and extrapulmonary ARDS group (n=23) according to primary causes. Totally 19 cases from healthy examination personnel were served as control. Acute physiology and chronic health evaluation Ⅲ (APACHE Ⅲ) score and lung injury score of all hospitalized patients were completed within 24 hours after the diagnosis of ARDS and the serum levels of angiogenin2 (Ang-2) , surfactant protein D (SP-D), soluble receptor for advanced glycation end products (sRAGE), Krebs von den Lungen-6 (KL-6) were measured. Then the 28-day outcomes were observed. The serum levels of the biomarkers were compared between each group and correlation analysis was conducted between different indexes. Finally, The relationship between the four biomarkers and the outcome of each group was analyzed. Results: The serum level of Ang-2 in pulmonary ARDS group and extrapulmonary ARDS group was significantly higher than that in control group[1 462 (569, 3 638) and 4 568 (2 236, 8 457) vs 460 (389, 578) ng/L, all P<0.05], and the serum level of Ang-2 was significantly higher in extrapulmonary ARDS group than that in pulmonary ARDS group (P<0.05). The serum level of SP-D in pulmonary ARDS group and extrapulmonary ARDS group was significantly higher than that in control group[5.9 (2.5, 22.7) mg/L and 3.7 (1.7, 6.5) vs 1.9 (0.6, 4.4) mg/L, all P<0.05], and the serum level of SP-D was significantly higher in pulmonary ARDS group than that in extrapulmonary ARDS group (P<0.05). The serum level of sRAGE in pulmonary ARDS group and extrapulmonary ARDS group was significantly higher than that in control group[238 (101, 583) and 229 (114, 443) vs 117 (88, 176) ng/L, all P<0.05]. The serum level of KL-6 in pulmonary ARDS group was significantly higher than that in control group[10 435 (3 401, 17 607) vs 4 780 (3 962, 5 320) U/L, P<0.05]. Increased serum levels of SP-D (OR=1.089, 95% CI: 1.001-1.085) and KL-6 (OR=1.206, 95% CI: 1.016-1.432) at the early stage were the independent prognostic factors for the 28-day mortality for pulmonary ARDS. Advanced age (OR=2.622, 95% CI: 1.046-6.574) was the independent prognostic factor for the 28-day mortality for extrapulmonary ARDS. Conclusion: SP-D and KL-6 may be the serum biomarkers of pulmonary ARDS and Ang-2 may be the serum biomarker of extrapulmonary ARDS.