SURFACTANT PROTEIN D AS A SIGN OF EXACERBATION OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE

Abstract

The purpose of this study is to evaluate and compare the levels of surfactant protein D in the blood serum of patients with chronic obstructive pulmonary disease with a stable course and those without chronic obstructive pulmonary disease. Materials and methods. The present study involved 122 patients with a confirmed diagnosis of chronic obstructive pulmonary disease (the main group) and 20 patients without this disease and other pulmonary or severe somatic diseases (the control group). This investigation was carried out at the Research Institute of Pulmonary Diseases. Spirometry was performed using a portable battery-powered ultrasound spirometer (Easy One; ndd Medical Technologies, Zurich, Switzerland). The SP-D level was determined in venous blood using a "sandwich" variant of solid-phase ELISA using a set of reagents from BioVendor (Czech Republic). Blood sampling and spirometry were performed simultaneously in patients with stable chronic obstructive pulmonary disease and healthy control groups in order to accurately correlate lung function with the level of SP-D in blood serum. Results. The mean age of the main and control groups was 55.9±4.4 and 53.3±2.8 years, respectively. Men made up 59.0% in the main group, women 41.0%, in the control group 55.0% and 45.0%, respectively. Smokers in the main and control groups amounted to 57.4% and 45.0%. FEV1, FVC and FEV1/FVC in patients with chronic obstructive pulmonary disease were lower than controls by 55.72% (p=0.001), 43.23% (p=0.001) and 35.28% (p=0.036), respectively. The level of SP-D in the blood serum of patients with chronic obstructive pulmonary disease and the control group was 372.68±98.16 ng/ml and 164.22±42.80 ng/ml (t=1.95, p=0.053), respectively. SP-D in smokers of the main group was 2.2 times (p=0.011) higher than the control level, and in non-smokers it was 2.5 times (p=0.053). During the exacerbation, the protein level was higher by 19.7% (p=0.042). In CLBL, SP-D correlated with FEV1 (r = −0.815; p<0.001), with FVC (r = −0.822; p<0.001), with FEV1/FVC (r = −0.644; p<0.001). Conclusion. SP-D can be characterized as a specific protein for the lungs, which can be analyzed in the blood as a biomarker for early diagnosis of acute exacerbations of chronic obstructive pulmonary disease and may reflect the severity of the disease.