The relationship between serum levels of surfactant protein D in COPD exacerbation severity and mortality

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality. In COPD patients, various inflammatory markers such as cytokines and acute phase proteins, which show systemic inflammation in the circulation, increase during exacerbations. In our study, we aimed to determine the relationship between serum SP-D levels and exacerbation severity, clinical course of the disease, and early mortality after discharge.

Fifty hospitalized patients with COPD acute exacerbation (46 male and 4 female) were recruited in this study. Thirty-three of the subjects (31 male and 2 female) were reevaluated after discharge. Venous blood samples were taken from all patients and followed up for exacerbation frequency, hospital admission, and mortality for 12 months.

Serum SP-D levels in the stable period of the patients were lower than exacerbation (P < 0.001). The median exacerbation period SP-D level of the patients admitted to emergency department in the first month was statistically significantly higher than that of the patients who were not admitted (P < 0.05) after discharge. There was a correlation between the rate of emergency admission and serum SP-D levels during the 12-month period after discharge (P = 0.04 (r = 0.29)).

Our study showed that serum SP-D was found to be a useful biomarker in predicting emergency admission and predictor of the health status of COPD patients but did not predict early mortality after the exacerbation.