Surfactant protein-D and polymorphonuclear leukocyte elastase concentrations in patients with septic acute respiratory distress

Purpose: Inhibition of surfactant activities by the protein in pulmonary edematous fluid plays a role in the occurrence of respiratory failure in acute respiratory distress syndrome (ARDS). Polymorphonuclear (PMN) elastase may be involved in surfactant-mediated damage. Accordingly, the concentrations of surfactant protein-D (SP-D) and PMN elastase were determined in patients with sepsis, and the associations of these two factors with the occurrence of ARDS and prognosis were examined. Methods: Blood samples from 33 patients with sepsis and with or without ARDS were assayed. The SP-D and PMN elastase levels were determined using an enzyme-linked immunosorbent assay. Results: SP-D levels in groups with and without ARDS were 493.9 ± 373.3 ng/ml and 91.8 ± 30.1 ng/ml, respectively. The level in the ARDS group was significantly higher than that in the group without ARDS (P = .0002). The PMN elastase levels in the groups with and without ARDS were 845.1 ± 294.0 ng/ml and 424.9 ± 81.1 ng/ml, respectively. The level in the ARDS group was significantly higher than that in the group without ARDS (P < .0001). The SP-D level in patients who survived was 157.0 ± 127.4 ng/ml and that in those who died was 625.5 ± 433.2 ng/ml. The level in the latter group was significantly higher than that in the former (P < .0001). The PMN elastase level in patients who survived was 493.7 ± 145.8 ng/ml and that in those who died was 980.9 ± 300.9 ng/ml. The level in the latter group was significantly higher than that in the former (P < .0001). A significant correlation was observed between SP-D and the PMN elastase levels (r = 0.818, P < .0001). Conclusion: In the presence of ARDS, SP-D and PMN elastase served as good indicators of severity.