Relationship between serum surfactant protein B and disease intensity and exacerbation in chronic obstructive lung disease

Purpose: Chronic Obstructive Pulmonary Disease (COPD) is a disease that progress with exacerbations and is an important cause of mortality and morbidity with an increasing frequency in the society. The aim of this study is to compare the surfactant protein B levels in the blood between the group with a low number of exacerbations (A-B) and the group with a higher number (C-D) according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) staging for chronic obstructive pulmonary disease. In this research, a biomarker that is thought to be used in the follow-up and treatment of COPD, which does not have a biomarker defined yet and on which studies are ongoing, will be examined. Materials and Methods: A total of 40 patients, all of whom were in the stable period of the disease, who were 50 years old and above, who had a similar duration and amount of smoking history, and who applied to the outpatient clinic of Department Chest Diseases at Çukurova University Medical School, were included in the study. Patients with COPD exacerbation, using steroids or antibiotics for the last 1 month, and those with concomitant lung disease, lung cancer or suspicion were excluded. Demographic data, laboratory tests, pulmonary function tests, chest radiographs of the patients were recorded. Patients with normal pulmonary function tests (FEV1 / FVC≥ 70%, FEV1 and FVC >80%) constituted the control group, while patients with obstruction (FEV1 / FVC <70%) were included in the disease group and their attacks, hospital admissions accompanied by their mMRC scores and GOLD stages as A, B, C, D determined and saved. Group A and B patients were recorded as mild COPD group, C and D groups as severe COPD group. Serums from venous blood samples of patients were obtained properly, and surfactant protein B (SFTPB) levels were detected by Enzyme-Linked Immuno-Sorbent Assay (ELISA) method, and the results between the patient group and the healthy smokers were compared. Results: SFTPB level was found higher in healthy smokers than the patient group (p = 0.001). SFTPB levels of mild and severe COPD patients were found to be similar (p> 0.05). SFTPB level was found to be higher in active smokers compared to those who quit smoking in the patient and control groups (p> 0.05). There was no correlation between cigarette pack x year amount and SFTPB levels (p> 0.05). There was no correlation between FEV1 (lt), FVC (lt), FEV1 / FVC% values and SFTPB level (p> 0.05). Conclusion: In this study, serum SFTPB levels were higher in healthy smokers compared to stable COPD patients. Serum SFTPB levels were higher in active smokers compared to quitters. There was no relationship between serum SFTPB levels and the amount of smoking and respiratory function tests. SFTPB molecule seems unlikely to be a biomarker for all COPD phenomena such as disease severity, acute exacerbation, stable period, response to treatment. Keywords: COPD, Smoking, Surfactant protein B