RESUMO
Objective To explore the relationship between angiogenin-1/2 (Ang-1/2) and clinical parameters of idiopathic pulmonary fibrosis (IPF), and to assess the value of Ang-1/2 in predicting the prognosis of patients with IPF.Methods A retrospective analysis was conducted. Ninety-one patients diagnosed as IPF by high resolution CT (HRCT) and lung biopsy admitted to Daqing Oil Field General Hospitalfrom March 2014 to January 2015 were enrolled. The general data, serum parameters and pulmonary function parameters of all patients were collected. After treatment, all of the 91 patients were followed-up to 2 years. The patients were divided into favorable prognosis group and unfavorable prognosis group according to follow-up results. The differences in all parameters between the two groups werecompared. The relationship between Ang-1, Ang-2 and lung function parameters was analyzed by Pearson correlation analysis. Cox proportional hazard regression model was used to evaluate the effect of clinical parameters on the prognosis of patients with IPF. The effect of Ang-2 in predicting prognosis of patients with IPF was analyzed by receiver operating characteristic (ROC) curve.Results During the 2-year follow-up period, 30 of 91 patients showed a favorable prognosis, and 55 showed an unfavorable prognosis with a poor prognosis rate of 64.71%, and 6 patients withdrew from the study due to loss of follow-up and death. Compared with the favorable prognosis group, Ang-2 level in the unfavorable prognosis group was significantly increased (μg/L: 2.88±1.63 vs. 1.89±1.22,t = 2.909,P= 0.005), but Ang-1 only showed a slight increase (μg/L: 28.70±14.26 vs. 25.62±11.95,t = 1.005,P = 0.318). The results of Pearson correlation analysis showed that Ang-2 level was negatively correlated with forced expiratory volume in 1 second (FVC1) and the percentage of carbon monoxide diffusing capacity accounting for the expected value (DLCO%;r value was -0.227 and -0.206, andP value was 0.147 and 0.253, respectively), but no significant correlation between the level of Ang-1 and FVC1 as well as DLCO% was found (r value was -0.153 and -0.121, andP value was 0.147 and 0.253, respectively). Cox proportional hazard regression model analysis showed that the prognosis of patients with IPF was significantly affected by smoking time and Ang-2 (bothP 0.05). Prognostic analysis showed that the area under ROC curve (AUC) of Ang-2 for predicting prognosis of patients with IPF was 0.692, and the best diagnostic point was 0.35μg/L, the sensitivity was 61.8%, the specificity was 73.3%, the positive predictive value was 69.8%, and the negative predictive value was 65.7% which indicated that Ang-2 could predict the prognosis of patients with IPF.Conclusion Ang-2 could assess the prognosis of patients with IPF, which is expected to be used as an indicator of predicting the prognosis of patients with IPF.