Expression And Clinical Significance Of SP-A In Plasma Of COPD Patients At Moderate Altitude

Objective: To detect the expression of SP-A in plasma of patients with acute exacerbation of COPD(AECOPD)and stable stage of COPD and healthy adults at moderate altitude area,and to compare the expression of SP-A in plasma of patients with AECOPD and healthy adults at low altitude area,and to analyze the relationship between SP-A and pulmonary function indicators.To further discuss the role and clinical significance of SP-A in the occurrence and development of COPD at moderate altitude.Methods: a.30 COPD patients in acute exacerbation stage,30 COPD patients in stable stage and 30 healthy controls were randomly selected from November 2017 to November 2018 in Qinghai People’s Hospital as moderate altitude AECOPD group,stable stage group and control group.b.30 COPD patients with acute exacerbation and 20 healthy controls in Zhenping County People’s Hospital of Nanyang City in Henan Province were randomly selected in the same period as low altitude AECOPD group and control group.All subjects were enrolled strictly according to inclusion exclusion criteria.Fasting venous blood 4ml was taken from subjects and anticoagulated with EDTA in the morning,centrifuged with 3000r/min for 10 minutes within 2 hours,and the upper plasma was stored in EP tube and stored in refrigerator at-80℃.The SP-A concentration in plasma of each group was detected by ELISA.At the same time,lung function indicators were detected,such as: FVC,FEV1,FEV1/FVC and FEV1% pred.Results: 1.The plasma SP-A level in patients with acute exacerbation of COPD at moderate altitude areas was markedly higher than that in patients with stable COPD and the people of control group(P < 0.01);and the plasma SP-A level in patients with stable COPD at moderate altitude areas was also markedly higher than that in the people of control group(P < 0.01);2.The plasma SP-A concentration in patients with acute exacerbation of COPD at moderate altitude areas was significantly higher than that in patients with acute exacerbation of COPD at low altitude areas(P < 0.01),and the plasma SP-A concentration in patients with low altitude AECOPD group was distinctly higher than that in control group(P < 0.01);3.The plasma SP-A concentration in patients with acute exacerbation of COPD at middle altitude areas was negatively correlated with the FEV1% pred,with the correlation coefficient(r=-0.461 P < 0.05),and it was also negatively correlated with FEV1/FVC,with the correlation coefficient(r=-0.556 P < 0.05);the plasma SP-A concentration in patients with acute exacerbation of COPD at low altitude areas was negatively correlated with FEV1% pred and with FEV1/FVC,and the respective correlation coefficients were(r=-0.590 P < 0.05)and(r=-0.441 P < 0.05);the plasma SP-A concentration was also negatively correlated with FEV1% pred and FEV1/FVC in patients with stable middle altitude,with the correlation coefficients were(r=-0.438 P < 0.05)and(r=-0.695 P<0.05).Conclusions: 1.The expression of SP-A in plasma of COPD patients at moderate altitude areas increased,which is even more significant in acute exacerbation stage.SP-A may participate in the occurrence and development of COPD.2.The plasma SP-A concentration of AECOPD patients at moderate altitude areas is higher than that of patients in low altitude areas at the same period.The expression of SP-A in plasma may be related to altitude.3.The expression of SP-A in plasma is correlated with pulmonary function,which may be helpful to assess the degree of airflow limitation in COPD patients.