(RS4) Predictors and Radiological Characteristics of Rheumatoid Arthritis-Associated Interstitial Lung Disease in a Multi - Ethnic Malaysian Cohort

Introduction:

Rheumatoid arthritis (RA) is commonly associated with pulmonary manifestations, in particular, interstitial lung disease. Objectives are to determine the frequency of rheumatoid arthritis-associated interstitial lung disease (RA-ILD), radiological characteristics of ILD, predictors for developing RA-ILD and impact on survival .

Results:

Of the 732 patients with RA, 7.4% (54) had ILD. Univariate analysis identified Indian ethnicity, rheumatoid factor (RF) positivity, anti-cyclic citrullinated peptide antibody titre and diabetes mellitus as risk factors for developing ILD. Multivariable logistic regression showed that RA-ILD was positively associated with female gender [Adjusted odds ratio (aOR)=3.40 (95% confidence interval (CI): 1.04, 11.17)], Indian          ethnicity [aOR=2.03 (95% CI: 1.16, 3.57)] and positive RF [aOR=2.39 (95% CI: 1.18, 4.87)]. Nonspecific interstitial pneumonia was the predominant HRCT pattern. Majority of patients had limited disease (<20% of lung involvement) and good functional exercise capacity. There was significant improvement (p<0.05) in mean forced vital capacity following treatment with immunosuppressive agents. No mortality occurred throughout the median follow-up period of 3.2 years.

Discussion/Conclusion:

RA patients of Indian ethnicity had an increased risk for developing ILD, suggesting that genetics play a crucial role. Other independent predictors were female gender and RF positivity. The pattern of HRCT thorax and extent of lung involvement influenced prognosis and survival of patients with RA-ILD.