History
Rheumatoid Lung was first described in 1948.1948, they published several cases of patients with RA who had severe erosive joint disease who also developed an interstitial lung and suggested there may be an association between the inflammatory joint disease and interstitial lung disease.1953, Anthony Caplan described rheumatoid nodules within the lung parenchyma, associated with pneumoconiosis in coal miners, who were exposed to coal dust.1954, rheumatoid lung nodules were found in patients with RA who were not exposed to coal dust and without pneumoconiosis. 1955 there was a short case series of about 10 patients with RA whose autopsies showed that the pleural disease was much higher in rheumatoid patients than in the general population, and much higher than what they had previously seen clinically. 1961, Cudkowicz described the first pulmonary function tests and lung biopsies were done in RA patients. Research
According to a recent study, the main risk factors for RA-ILD are advancing age, male sex, greater RA disease activity, rheumatoid factor (RF) positivity, and elevated titers of anticitrullinated protein antibodies such as anticyclic citrullinated peptide. Cigarette smoking also appears to increase risk of RA-ILD, especially in patients with human leukocyte antigen DRB1.A recently published retrospective study by a team from Beijing Chao-Yang Hospital in Beijing, China, supported three of the risk factors listed for RA-ILD and identified an additional risk factor.
This is more common in cases of bronchiolitis obliterans, pulmonary fibrosis, or pulmonary hypertension. Most complications are not fatal, but does reduce life expectancy to an estimated 5 to 10 years. Epidemiology
The prevalence of RA is around 0.3–1.2% (0.92% of Americans). Women are 2–3 times more susceptible than men. The prevalence of rheumatoid lung disease in patients with RA depends on the method used for diagnosis: chest X rays (5%), high resolution CT scans (10–40%).A study showed 582 patients with RA and 603 subjects without RA were followed for a mean of 16.4 and 19.3 years, respectively. The lifetime risk of developing ILD was 7.7% for RA patients and 0.9% for subjects without RA. The risk of developing ILD was higher in patients with older age at RA onset, among male patients and for individuals with parameters that indicate more severe RA. Survival of RA patients diagnosed with ILD was worse compared to RA patients without ILD. ILD contributed approximately 13% to the excess mortality of patients with RA patients when compared to the general population.