Can Rheumatoid Arthritis Affect My Lungs?
RA can affect the lungs and the lining of the lungs, a complication referred to as rheumatoid lung disease. Rheumatoid lung disease occurs in approximately 25% of all patients with RA.
Although RA occurs more commonly in women, men with RA seem to get rheumatoid lung disease more frequently. Other risk factors for this problem include smoking and development of severe joint symptoms early in the course of the disease.
Rheumatoid lung disease occurs in approximately 25% of all patients with RA.
Rheumatoid lung disease is not a single disease, but rather a collection of diseases of the lung that are caused by RA. The most common rheumatoid lung diseases are interstitial lung disease and pleural effusions.
Interstitial lung disease affects the lung tissue itself. In this disease, the air sacs (alveoli) of the lungs and their supporting structures become scarred by inflammation. As a consequence of the scarring, the lungs work less efficiently and it becomes harder to breathe.
Pleural effusions comprise a collection of fluid around the lung. In this condition, the lining of the lung, called the pleura, becomes inflamed and produces fluid. This is similar to the way the joints of a person with RA become inflamed and swollen with fluid. If a large amount of fluid collects around the lung, it can compress the lung and make it difficult to breathe.
The symptoms of rheumatoid lung disease include shortness of breath, cough (usually without producing sputum or phlegm), chest pain (which is worse when taking deep breaths), and fever. Your physician may also hear “crackling” sounds or a “rubbing” when he or she listens to your lungs with a stethoscope. These are not universal findings in all patients with RA, however. Decreased breath sounds or normal breath sounds can occur, even with severe lung disease.
If your physician suspects that you may have rheumatoid lung disease, he or she may order the following tests:
- Pulmonary function test. This test measures how much air your lungs can hold and how fast your lungs can expel the air.
- X-rays. A chest x-ray or a computerized tomography (CT) scan may show abnormalities consistent with rheumatoid lung disease.
- Echocardiogram. An echocardiogram examines your heart using sound waves. It may show that the heart is having difficulty pushing blood through the scarred lungs, a condition called pulmonary hypertension.
- Thoracentesis of pleural effusions. A needle is inserted into fluid around the lung and a sample is taken. Examination of this fluid may show characteristics of rheumatoid lung disease.
- Lung biopsy. A lung biopsy may show findings consistent with rheumatoid lung disease. The biopsy can be performed by inserting a needle through the chest wall, threading a flexible scope through the mouth and into the lungs, or conducting chest surgery to obtain an “open lung” biopsy.
The cause of rheumatoid lung disease is not well understood, though it is believed to be related to the generalized inflammatory process that occurs in the joints of a person with RA. Methotrexate (a medication that is often prescribed to treat RA) has been associated with lung fibrosis on rare occasions. Shortness of breath or chest pain in patients who are taking methotrexate as RA therapy should prompt a physician’s evaluation.
Currently, there are no effective treatments for rheumatoid lung disease. Physicians sometimes prescribe corticosteroids and immunosuppressive therapies to help treat the complications of this disease.
Worsening of lung fibrosis has been described in patients who were taking antitumor necrosis factor (TNF) inhibitors, such as Humira, Enbrel, and Remicade. Although we do not know if these agents cause a worsening of the lung disease, physicians should discuss this risk with their patients who have signs of rheumatic lung disease and who are considering treatment with these agents.