13 Risk Factors for RA-associated Interstitial Lung Disease Save

Interstitial lung disease (ILD) is the most widespread and fatal pulmonary complication of rheumatoid arthritis (RA). A recent metanalysis shows the pooled prevalence of RA-ILD was approximately 18.7%. 

This systematic review included 56 studies with 11,851 RA-ILD patients. The overall prevalence of RA-ILD was 18.7% (95% CI 15.8-21.6).

Prevalent RA-ILD was associated with several risk factors: 

1. male sex (ORs = 1.92 95% CI 1.70-2.16)
2. older age (WMDs = 6.89, 95% CI 3.10-10.67)
3. smoking history (ORs =1.91, 95% CI 1.48-2.47)
4. pulmonary comorbidities (HRs = 2.08, 95% CI 1.89-2.30)
5. longer RA duration (ORs = 1.03, 95% CI 1.01-1.05)
6. older age of RA onset (WMDs =4.46, 95% CI 0.63-8.29)
7. positive RF (HRs = 1.15, 95%CI 0.75-1.77; ORs = 2.11, 95%CI 1.65-2.68)
8. positive ACPA (ORs = 2.11, 95%CI 1.65-2.68)
9. higher ESR (ORs = 1.008, 95%CI 1.002-1.014)
10. moderate and high DAS28 (≥3.2) (ORs = 1.87, 95%CI 1.36-2.58)
11. rheumatoid nodules (ORs = 1.87, 95% CI 1.18-2.98)
12. Leflunomide use (ORs = 1.42, 95%CI 1.08-1.87) 
13. steroid use (HRs= 1.70, 1.13-2.55). 

The use of biological agents was found to be protective (HRs = 0.77, 95% CI 0.69-0.87).

Up to one in five RA patients will develop RA-ILD. These 13 predictors may allow for earlier identification and tracking, so as to avoid the devastating outcomes seen with RA-ILD.