AB0295 Risk factors for progression and prognosis of rheumatoid arthritis-associated interstitial lung disease: single centre study with a large sample of chinese population

Abstract

Background: Poor prognosis has been shown in rheumatoid arthritis-associated interstitial lung disease (RA-ILD) patients, and the mortality rate was significantly higher than RA patients without ILD. Studies showed that one-third of RA-ILD patients had progressed within two years. However, factors associated with ILD progression and survival in RA-ILD have not been previously described in a large centre China cohort. Objectives: To investigate the risk factors for ILD progression and explore the prognostic factors for survival in RA-ILD patients. Methods: 791 consecutive RA patients who completed lung HRCT were considered as potential participates. 266 RA-ILD patients were finally included in this retrospective cohort study. To identify independent risk factors for ILD progression, multivariate logistic regression analyses were used. Cox hazards analysis was used to determine significant variables associated with survival. Results: 1, The mean age at diagnosis of RA-ILD was 64.80+/-10.71 years old. 162 (60.90%) were females and 104 (39.09%) were males. 2, UIP and NSIP pattern were the commonly types of RA-ILD, accounting for 37.22% and 25.94% respectively. Extent of lung involvement analysis showed that limited was predominant (130/266, 48.87%), with smaller numbers of moderate (67/266, 25.19%) and extensive (69/266, 25.94%) lung involvement. 3, The 3 year survival rate of RA-ILD patients was 81.24%, and the 5 year survival rate was 69.71%. A total of 82 deaths occurred during follow-up, of which 56 died of respiratory failure due to ILD progression and/or pneumonia, while 14 with malignancies (8 with lung cancer). 4, Logistic regression analysis showed that an increased anti-CCP antibody titer (OR: 4.03, 95% CI: 1.04-15.69, p<0.05) and DLCO%<45% (OR: 8.31, 95% CI: 2.17-31.75, p<0.01) were independent risk factors for the ILD progression. 5, Cox hazards analysis revealed that advanced age(>60 years old) of RA-ILD diagnosis (HR: 2.32, 95% CI: 1.27-4.25, p<0.05) and extensive lung involvement on HRCT (HR: 2.19, 95% CI: 1.24-3.87, p<0.05) were associated with worse survival. Treatment with cyclophosphamide (HR: 0.43, 95% CI: 0.26-0.69, p<0.01) was associated with better survival. Conclusions: In RA-ILD patients, DLCO%<45% is the strongest predictor for ILD progression. Advanced age and extensive lung involvement on HRCT, rather than the baseline UIP pattern, independently predict mortality after controlling for potentially influential variables. Furthermore, cyclophosphamide treatment helps to improve the prognosis in real-world experience.