Lung involvement in rheumatoid arthritis, a prospective study

Area of Science:

• Rheumatology
• Pulmonology
• Genetics

Background:

• Rheumatoid arthritis (RA) can affect the lungs, but the prevalence of various lung conditions in early RA is not well understood.
• A multicentric prospective study was designed to investigate interstitial lung disease (ILD), emphysema, bronchiolitis, and nodules in early RA patients.

Purpose of the Study:

• To determine the prevalence of different types of lung involvement in patients with early rheumatoid arthritis.
• To identify risk factors and predictors associated with lung conditions like ILD and emphysema in RA.

Main Methods:

• Recruited 258 patients with RA (disease duration 1-10 years) for comprehensive respiratory evaluation.
• Utilized high-resolution computed tomography (HRCT), pulmonary function tests (PFTs), and genetic analysis.
• Centralized review of HRCT scans and statistical analysis to identify associations and predictors.

Main Results:

• Prevalence of ILD, emphysema, and significant air trapping was 15%, 20%, and 34% respectively.
• Older age, male sex, higher disease activity, and lower diffusing capacity of the lung for carbon monoxide (D_LCO) were associated with ILD and emphysema.
• Predictors for ILD included older age, high Disease Activity Score-28, rheumatoid factor positivity, low D_LCO, and MUC5B variant; smoking pack-years predicted emphysema.

Conclusions:

• Lung involvement is prevalent in early RA, with constrictive bronchiolitis, emphysema, and ILD being common.
• Older age, uncontrolled disease, male sex, and reduced D_LCO are associated with ILD and emphysema.
• Targeted screening in high-risk RA subpopulations is advised.