The Expression And Clinical Significance Of IL-8 And SP-A In BALF Of Idiopathic Pulmonary Fibrosis

Objective:IPF is a chronic interstitial lung disease with unknown cause, whose prevalence is about 2-5/10 million. Age 40-50 years, more men suffer than women. IPF is unknown, progressive and fatal, early diagnosis is particularly important. However, early diagnosis of IPF is difficult, imaging is not specific, easy to confuse with other diseases (such as other lung diseases,etc). BAL is a relatively noninvasive examine, which contribute to diagnosis, differential diagnosis and prognosis of IPF. Cytokines and proteomics in BALF can directly response inflammatory environment of lung, protein markers may have great value for diagnosis of IPF. However, the present study of SP-A in BALF in IPF patients were different. IL-8 is a multi-derived cytokines, which was found elevated in diseases. In particular, the levels of IL-8 in BALF elevated in IPF patients which showed that it can be used as a potential target in early stages of IPF. To explore the SP-A and IL-8 levels in BALF of IPF patients and their clinical significance and the value of early diagnosis of IPF, we carried out this study.Method:1. We selected 31 patients from respiratory Hospital and Outpatient in the General Hospital of Tianjin Medical University from March in 2009 to January in 2010, including 11 IPF patients, as study group,10 pneumonia patients, as group A, 10 cases who have no lung disease, as group B. All patients underwent BAL.We obtained the BALF from the right middle lobe or lingular lobe of left lung in study group, from the disease leaf in group A, from the right middle lobe or lingular lobe of left lung in group B.2. All the specimens were filtered by two-gauze to remove mucus, and record the total amount, placed in the thermos with ice, sent to the laboratory.3. Research Index:Cell Count, SP-A, IL-8:using cell centrifuge smears, stained cells and counted, the supernatant stored in -70℃refrigerator; The IL-8 and SP-A level were measured using ELISA assay. And then analyse its relationship with lung function, blood gas analysis, smoking and other factors.Results:1. In study Group, the ratio of macrophages in BALF was significantly lower than Group B (P<0.01), the ratio of macrophages of group A is lower than group B (P<0.05),the ratio of macrophages between study group and group A has no statistically significant (P> 0.05); the ratio of lymphocytes in BALF of study group is statistically higher than group A and group B (P<0.01, P<0.005);the neutrophil ratio in BALF of group A is statistically higher than group B (P<0.01), higher than study group, but no statistical significance (P> 0.05), the neutrophil ratio of study group is higher than group B with no statistical significance (p>0.05); 2. The level of SP-A in Study Group is lower than group A (P<0.005), lower than group B (P<0.05); IL-8 level in study group was higher than group B(P<0.001); IL-8 level in the group A is higher than group B (P<0.001).3. SP-A level was negatively correlated with IL-8 level in study group (r=-0.72, P<0.001).4. SP-A level in study group was negatively correlated with FEV1/FVC (r=-0.645, P<0.05), and was positively correlated with TLC%(r=0.749, P<0.05); IL-8 level was positively correlated with FEV1/FVC (r= 0.759, P<0.05).5. In study group, level of SP-A was positively correlated with PaO2 (r=0.619, p<0.05).6. there is no significant correlation between SP-A and IL-8 level in study group and smoking (P> 0.05)Conclusion:1. The ratio of neutrophil and lymphocyte in IPF patients increased, and the ratio of neutrophil in pneumonia patients also increased with no difference with IPF patients which may be related to the the different pathogenesis between them.2. IL-8 in IPF patients is higher than the ones without lung diseases, pneumonia patients have elevated IL-8, with no significant difference with IPF patients,suggesting that IL-8 has no effect on differential diagnosis between IPF and infectious diseases; IPF patients have lower level of SP-A than pneumonia patients and the ones without lung diseases, suggesting that SP-A may identificate IPF from infectious diseases.3. IL-8 and SP-A in BALF were negatively correlated, suggesting that SP-A may inhibit the release of IL-8 in IPF patients; 4. IL-8 and SP-A has correlation with lung function in IPF patients, suggesting that IL-8 and SP-A level may be associated with the severity of disease, SP-A and PaO2 have good correlation, suggesting that SP-A may affect the patient's oxygenation.5. IL-8 level and SP-A level in IPF patients between smokers and nonsmokers requires further study.