Risk factors for the prognosis of rheumatoid arthritis-associated interstitial lung disease: a multicenter retrospective clinical study / 中华风湿病学杂志

ABSTRACT

Objective:To explore the impact of clinical features, serological indicators, and pulmonary function test (PFT) on the prognosis of rheumatoid arthritis-associated interstitial lung disease (RA-ILD).Methods:Clinical data of RA-ILD patients who were diagnosed by HRCT and were followed up in Changhai Hospital or Yancheng First People's Hospital from 2011 to 2021 were collected Respiratory functional impairment of the patients was evaluated according to the changes of HRCT score and PFT, and the patients were divided into progressive group and stable group. COX survival analysis and ROC curve were used to determine the factors related to the progression of RA-ILD.Results:Finally 98 RA-ILD patients were included. The mean age of ILD onset was (62.9±12.1) years old, the median course of RA was 7.0 (1.0, 15.3)years, and the median follow-up time was 36.5 months (14.0, 79.5). There were 49 cases in the progressive group, and the clinical characteristics and laboratory tests of the two groups were compared. The results showed that: progressive time [(23(8.5,43.0)months vs 63(32.5,90.9) months, Z=-4.55, P=0.001)], HRCT score [(115(109,135) vs 111(105,116), Z=-2.70, P=0.007)], forced vital capacity(FVC) predicted [(70.1±15.7)% vs (80.8±19.7)%, t=2.12, P=0.039)], diffusing capacity of the lungs for CO(DLCO) predicted [(57.5±16.3)% vs (83.4±18.8)%, t=4.87, P=0.001)], male [(44.9% vs 18.4%, χ2=7.97, P=0.005)], UIP pattern [(36(73.5%) vs 9(18.4%), χ2=29.96, P<0.001)], RF>200 U/ml[(21(65.6%) vs 18(41.9%), χ2=4.15, P=0.042)], anti-CCP>75 U/ml [(42(91.3%) vs 35(71.4%), χ2=6.10, P=0.013], all had significantly different between the two groups. In multivariate analyses, UIP[ HR(95% CI)=3.25(1.62,6.50), P<0.001], anti-CCP antibody >75 U/ ml[ HR(95% CI)=3.85 (1.20,12.33), P=0.023] and smoking [ HR (95% CI): 5.74(1.10, 30.13), P=0.039] were significantly correlated with the progression of pulmonary fibrosis in RA-ILD patients. PFT was performed in only 44 patients with RA-ILD. The univariate analyses and ROC curve suggested that DLCO predicted [ HR (95% CI)=1.04 (1.02,1.06), P<0.001] was a significant risk factor for the progression of RA-ILD, and the area under curve (AUC) of DLCO was 0.845 [95% CI=(0.729,0.961)]. Conclusion:UIP pattern, high titer of anti-CCP antibody, smoking, and reduced DLCO predicted % may be potential predictors for poor prognosis of RA-ILD patients.