Interstitial lung disease in patients with rheumatoid arthritis: comparison with cryptogenic fibrosing alveolitis over 5 years.

Objective: There is little information on the natural history of patients with rheumatoid arthritis (RA) and associated interstitial lung disease (ILD). Cryptogenic fibrosing alveolitis (CFA) is known to have a poor longterm prognosis, and we compared the 2 conditions through a longitudinal prospective study.
Methods: We previously compared baseline clinical, physiological, and radiological characteristics in 18 RA-ILD patients with 18 case controls with CFA. Clinical, physiological, and radiological assessment was repeated in all survivors at 5 years, and data on treatment and mortality were collected.
Results: The median age in each group was 77 years and 10 patients in each group were male. More patients with RA-ILD survived to 5 years (8 RA-ILD vs 2 CFA; p = 0.03), and median survival was significantly longer for patients with RA-ILD (60 mo) compared to CFA (27 mo; p <or= 0.05). Death was due to respiratory failure in half the patients with CFA, but was more often due to other causes in patients with RA. Clubbing and reduced baseline gas transfer were predictors of poor prognosis, while normal technetium clearance enhanced survival in nonsmokers.
Conclusion: Patients with RA-ILD did better than those with CFA, and died less often from respiratory failure. Patients with finger clubbing and/or low gas transfer declined more rapidly.