Investigation Of Relationship Between Surfactant Protein D And Acute Exacerbation Of Chronic Obstructive Pulmonary Disease

Objective: To investigate regulation of serum surfactant protein d(sp-d) during acute exacerbation of chronic obstructive pulmonary disease(AECOPD),and explore relationship between concentration of serum sp-d and AECOPD.Method: 44 patients with AECOPD were enrolled in our study. C-reaction protein(CRP),leukocyte counts and percentage of neutrophil were detected at first day of hospitalization. Sp-d was detected in 2 days and at 5th and 15th day respectively, and compared with control group including 11 health people. Referring to ATS/ERS,S classification of severity for AECOPD , patients were divided into respiratory failure group and non-respiratory failure group; According to effect of treatment on AECOPD, patients were divided into efficacy and inefficacy group; According to GOLD classification,patients were divided into I+II stage group and III+IV stage group. Sp-d of each group was compared at different time points. Relationship among clinic factors(including quantity of cigarette, body mass index(BMI),forced expiration volume in 1 second% predicted(FEV1%predicted),and forced expiration volume in 1 second to forced vital capacity ratio(FEV1/FVC)) and sp-d was investigated by correlated analysis, and multiple regression equation was built by significant correlated factors. Receiver operating characteristic curves(ROC curve) for diagnosis of AECOPD were drawn with sp-d of acute exacerbation phase and stable phase ,compared with ROC curves of CRP , leukocyte counts and ratio of neutrophil .Results :1) Concentration was elevated markedly and there was no significant difference between each others at 5th,10th and 15th day. But they were significantly different from concentration of control group, stable group, and 2 days group( P<0.05 ) .There was no significant difference among last three groups.2) Concentration of sp-d at 5th day was significantly correlated with BMI(r=0.38),FEV1% predicted of stable phase(r=0.66),FEV1/FVC of stable phase (r=0.44),building regression equation(Y=82.506X+5.768(r=0.646)).3) Diagnosis effect of sp-d was better than CRP, leukocyte counts and ratio of neutrophil at 5th,10th and 15th day. 4) Sp-d of respiratory failure group had no significant difference from non-respiratory failure group. 5) There was no significant different concentration of sp-d between efficacy group and inefficacy group. 6) Sp-d of I+II stage group was significantly different from III+IV stage group at 5th and 10th day.7) Sp-d was negatively correlated with smoking quantity at 5th and 10th day.Conclusions: 1) Sp-d, which was significantly increased from 5th to 15th, may be a good biomarker for diagnosis of AECOPD. 2) Sp-d, which was negatively correlated with severity of COPD in exacerbation phase, can partly estimate FEV1% predicted of stable phase at 5th day of AECOPD.