The Investigation Of The Relationship Between The Serous Levels Of C-reactive Protein,Interleukin-18 And The Quality Of Life And Lung Function In Patients With Chronic Obstructive Pulmonary Disease

Objective : To investigate the relationships between serum C-reactive protein(CRP),interleukin-18(IL-18) and quality of life, pulmonary function of the patients with chronic obstructive pulmonary disease (COPD) (including stable COPD and acute exacerbation of COPD), and the the value of the SGRQ.Methods:1. Objects:1)AECOPD group:Thirty-nine patients with an acute exacerbation (AECOPD) who were hospitalized in the Second Xiangya Hospital from October 2008 to March 2009 with the age of 50-75 years old were chosen into this group.2) Stable COPD group:Twenty-one patients with the age of 50-75 years old whose pathogenetic condition had been stable for over 4 weeks, and regularly accepted the clinic services of our hospital from October 2008 to March 2009 were chosen into this group.The patients of above two groups were all male smokers. The diagnostic code accorded with the COPD guide published in 2007. All the patients didn't accept Anti-inflammatory treatment, nutritional support, didn't have incorporate tumor, connective tissue diseases, hepatic or renal dysfunction, diabetes and other wasting diseases.3) Control group:Twenty-two healthy male with the age of 50-75 years old who had no systemic infectious diseases in recent 2 months were chosen into this group. Twelve of them were smokers and other ten were non-smokers.2. Pulmonary function test:All patients of the AECOPD group and stable COPD group accepted pulmonary function test. Determination indexes included forced expiratory volume at the first minute(FEV₁), percentage of forced expiratory volume at the first minute(FEV₁%) , forced vital capacity(FVC )and FEV₁/FVC.3. St George's Respiratory Questionnaire (SGRQ): All patients completed the SGRQ assessment.4. Measure the serous levels of CRP and IL-18:1) Sample collection:We collected 3 milliliter blood from all subjects and extracted the serum through centrifuge for 15 minutes with a speed of 3000r/min, and then preserved the serum into the refrigerator with the temperature subzero 70 degree.2) Measure method:We measured the levels of CRP with Beckman Coulter Immage and related reagents in the clinical laboratory of the Second Xiangya Hospital. We also measured the levels of IL-18 with Double-antibody sandwich ABC-ELISA method.Results:(1) Serum levels of CRP and IL-18:Serum levels of CRP and IL-18 among the three groups were significantly different. Serum levels of CRP in AECOPD group were significantly higher than those of the stable COPD group and the control group (P<0.01), serum levels of CRP in COPD group were significantly higher than those of the control group (P<0.01). In the control group, serum levels of CRP of smokers and non-smokers were similar. Serous levels of IL-18 in AECOPD group were significantly higher than those of the stable COPD group and the control group (P<0.01), serum levels of IL-18 in COPD group were higher than those of the control group (P<0.01). In the control group, serum levels of IL-18 of smokers were significantly higher than that of non-smokers (P<0.05).(2) The relationship between serum levels of CRP,IL-18 and lung function:According to linear correlation analysis, serum levels of CRP inAECOPD group showed a negative correlation with FEV₁% andFEV₁/FVC (r=-0.395, -0.316, P<0.05). Serum levels of CRP in COPDgroup showed a negative correlation with FEV₁% and FEV₁/FVC(r=-0.575, -0.501, P<0.05 ) . Serum levels of IL-18 in AECOPD group showed a negative correlation with FEV₁% and FEV₁/FVC (r=-0.494, -0.662, P<0.01) .Serum levels of IL-18 in COPD group showed a negative correlation with FEV₁% and FEV₁/FVC(r=-0.672, P<0.01; r=-0.513, P<0.05)(3) Comparison of SGRQ scores among the AECOPD group,COPD group and control group:The total and symptoms, activity limitation, disease impact scores of SGRQ in AECOPD group were significantly higher than those of COPD group and the control group (P<0.05) . Also, those of the COPD group were higher than those of the control group (P<0.001).(4) The relationship between serum levels of CRP,IL-18 and SGRQ scores:Serum levels of CRP in AECOPD group showed a positive correlation with the total and symptom, disease impact scores of SGRQ. Serum levels of CRP in COPD group showed a positive correlation with the total and symptom, activity limitation scores of SGRQ. Serum levels of IL-18 in AECOPD group showed a positive correlation with the total and symptom, activity limitation scores of SGRQ. Serum levels of IL-18 in COPD group showed a positive correlation with the disease impact and activity limitation scores of SGRQ.(5) The relationship between the SGRQ scores and lung function in patients with COPD: In patients with COPD, FEV₁% and FEV₁/FVC were negative related to total and the three sectional scores of SGRQ well, especially the FEV₁%. The disease impact scores of SGRQ in COPD group showed the best negative correlation with FEV₁% (r=-0.644, P<0.01) and FEV₁/FVC (r=-0.544, P<0.05).Conclusions:(1) CRP and IL-18 were involved in the process of inflammatory reaction of COPD. They could be markers of the acute exacerbation period of COPD.(2) The serum levels of CRP and IL-18 might be related to lung dysfunction and the lower quality of life in the patients with COPD.(3) SGRQ was an effective, susceptible and feasible method to evaluate the life quality of the patients with COPD.