Rheumatoid arthritis affects the lungs and raises the risk of interstitial lung disease. Rheumatoid arthritis is an autoimmune type of arthritis, and although it primarily affects the joints, it can affect other body parts and organs, too.
According to researchers, respiratory conditions are the second leading cause of death among rheumatoid arthritis patients. Some are a result of rheumatoid arthritis directly, while others are a byproduct of rheumatoid arthritis treatments.
Interstitial lung disease (ILD) is a pulmonary condition characterized by the progressive and irreversible scarring of lung tissue. ILD is the most serious and common lung disease among rheumatoid arthritis patients. Symptoms may take years to appear, but once they do appear the risk of mortality is already quite high. Symptoms of ILD include breathlessness, dry cough, wheezing, chest pain, and the clubbing of fingernails.
A 2008 study found that rheumatoid arthritis patients who smoke are at a higher risk of asymptomatic ILD, compared to those who do not. Treatment of rheumatoid arthritis with methotrexate is also a risk factor for ILD.
ILD isn’t the only lung disease which rheumatoid arthritis is associated with. In fact, it is also linked to pulmonary fibrosis, nodules, pleurisy, and effusions.
As mentioned, treatment for rheumatoid arthritis can increase the risk of lung diseases, too. Biologic agents have been found to worsen outcomes in patients with already diagnosed ILD, but on the other hand, some may improve outcomes. Specifically, the anti-TNF (anti-tumor necrosis factor) drugs, such as etanercept, infliximab, and adalimumab, have all been reported to worsen ILD in some cases, and many doctors are wary of using these agents in patients who are already breathless as a result of this. On the other hand, anti-B cell drug rituximab is associated with stabilization and even improvement in some patients with ILD.
Other drugs that may increase the risk of lung disease in rheumatoid arthritis include steroids and azathioprine.
Treating lung disease in rheumatoid arthritis is commonly done with glucocorticoid treatment. In cases where ILD is resistant to glucocorticoid treatment, doctors may prescribe cyclophosphamide, cyclosporine, or azathioprine, though research is limited on their effectiveness.
Some prevention tips against lung disease in rheumatoid arthritis include smoking cessation and regular checkups, as ILD may progress for many years without symptoms and when symptoms appear it may be too late. Regular lung checkups can help spot any issues early on so treatment can begin right away.