Background Acute exacerbation (AE) is recently recognized as deterioration of respiratory status in idiopathic pulmonary fibrosis. It is reported that AE also occurs in other interstitial lung diseases (ILD) such as collagen vascular diseases associated ILD (CVD-ILD). However, the characteristics and risk factors of AE in CVD-ILD are not clearly identified.

Objectives To clarify the characteristics of patients with rheumatoid arthritis-associated interstitial pneumonia (RA-IP) and to investigate the risk factors associated with AE and its survival of RA-IP.

Methods We examined the clinical features of 60 RA-IP patients admitted to our hospital between July 2010 and September 2016. We compared the characteristics between patients who developed AE (AE group) and those who didn't (non-AE group), and between patients who survived after AE (alive group) and those who died after AE (dead group), and identified variables significantly associated with AE occurrence and survival using Cox hazards analyses.

Results Thirty-six (60%) were female. Twenty-two (36.7%) developed AE and seven of them (11.7%) died with the mean follow-up period of 2.7 years. The mean age at RA diagnosis was 61.1±16.3 years in AE group and 61.5±13.1 years in non-AE group. Sex, smoking habit and high-resolution computed tomography (HRCT) pattern were not significantly different between two groups. Although there was no significant difference, more patients in AE group received methotrexate (MTX) treatment than those in non-AE group (40.9% vs. 18.9%, p=0.08), and MTX use was significantly associated with occurrence of AE in a Cox hazard analysis (Hazard ratio [HR] 1.09, 95% confidence interval [CI] 1.01–1.18). Further, age (median 70 vs. 82 years, p=0.002) and matrix metalloproteinase-3 (MMP-3) level (median 84.8 vs. 205.6 ng/mL, p=0.03) on admission were significantly higher in dead group than in alive group. Univariate analyses revealed that age ≧ 75 years (HR 10.53, 95% CI 1.26–88.15), MMP-3 ≧ 200 ng/mL (HR 15.58, 95% CI 1.38–175.8), and 3L or more oxygen use (HR 8.46, 95% CI 1.02–70.49) on admission were associated with death (Table 1).

Conclusions Our data suggest that MTX use relates to the occurrence of AE, and age, MMP-3 level, and oxygen volume on admission relate to AE survival in patients with RA-IP.

References

1. Hozumi H, Nakamura Y, Johkoh T, et al. BMJ Open 2013; 3: e003132.

2. Suda T, Kaida Y, Nakamura Y, et al. Respiratory Medicine 2009; 103: 846–853.

References

Disclosure of Interest None declared