In this article, we take a close look at rheumatoid lung disease, including its symptoms, diagnosis, treatments, and outlook.
What causes rheumatoid lung disease?
Inflammation of the lungs is a common symptom of rheumatoid lung disease.
Rheumatoid lung disease can develop as a complication of rheumatoid arthritis or RA.
RA is a type of autoimmune disease that usually leads to inflammation in the joints, but some people also develop inflammation and scarring in other organ systems and parts of their body.
The lungs are of the most common site outside of the joints for people with RA to develop inflammation. According to the Arthritis Foundation, about 10 percent of people with RA develop some form of rheumatoid lung disease.
Forms of rheumatoid lung disease
Rheumatoid lung disease can manifest in various forms, such as:
- inflammation and scarring of the lungs, known as interstitial lung disease
- a buildup of fluid between the chest wall and the lungs called pleural effusions
- lung nodules or small growths in the lungs
The symptoms of rheumatoid lung disease may vary, depending on how the condition manifests. In some cases, such as when lung nodules develop, people may not experience any symptoms.
But in other instances, especially if rheumatoid lung disease has led to scaring of the lungs, symptoms may include:
- shortness of breath
- decreased appetite
- dry cough
- unintentional weight loss
Many of the symptoms of rheumatoid lung disease also occur in other types of interstitial lung disease, as well as other respiratory conditions. After taking a medical history and doing a physical exam, a doctor may order the following diagnostic tests:
A biopsy involves the collection of tissue for lab analysis.
During a biopsy, a doctor removes a small amount of lung tissue to check for inflammation and scarring.
A biopsy of the lung tissue can be done either through a bronchoscopy or surgically.
During a bronchoscopy, a doctor inserts a scope with a camera attached through the nose or mouth into the lung. The tool collects a small amount of tissue for examination.
A surgical lung biopsy involves a doctor inserting a needle through the chest wall or making a cut in the skin on the chest to remove a sample of tissue.
Doctors may order blood tests to measure markers of inflammation in the body, including sedimentation rate and C-reactive proteins.
A CT scan of the lungs produces cross-sectional images, which allows the doctor to view the lungs and determine whether there is any scarring. CT scans are often more helpful than X-rays when diagnosing rheumatoid lung disease.
Pulmonary function test
A pulmonary functions test (PFT) involve a series of breathing tests that measure how much air a person can blow out of their lungs, as well as the volume of gas in the lungs. A PFT helps doctors to determine if a person's lung function is below normal.
People with RA have an eight times higher risk of developing lung disease compared to the rest of the population. In people who have RA, specific factors may increase their risk of the lungs being affected.
According to one study, which involved 230 people with a history of RA, the most significant risk factor for developing rheumatoid lung disease was high levels of anti-CCP antibodies.
Anti-CCP antibodies are a type of protein that is produced by the immune system. Testing positive for anti-CCP antibodies is one indicator of RA. High levels may indicate the severity of the disease.
The following groups have additional risk factors for developing rheumatoid lung disease:
- people who smoke, especially men
- people over 60 years of age who have been diagnosed with RA
A doctor may recommend oxygen therapy to treat rheumatoid lung disease.
Treatment for rheumatoid lung disease may vary, depending on the specific manifestations of the disease and the symptoms. For instance, treatment for a pleural effusion involves inserting a needle to drain the fluid.
In some cases, such as when a person has small lung nodules that are not causing any symptoms, they may not need treatment.
If a person has inflammation and scarring of the lungs, doctors usually recommend treatment, though this will not reverse the damage to the lungs. Instead, treatment usually involves managing a person's symptoms and slowing the progression of the disease.
The following treatments can help with scarring caused by rheumatoid lung disease:
Doctors previously recommended certain types of medication to treat interstitial lung disease due to RA. This medication decreases inflammation or acts as an immunosuppressant.
But, according to research published in 2015, it is unclear whether these medications are definitely beneficial.
People can take pulmonary rehabilitation classes, which involve a mixture of exercises and education on lung disease.
At these classes, a person with rheumatoid lung disease can learn about techniques and practical strategies to manage their shortness of breath and improve their quality of life.
However, people with rheumatoid lung disease often have joint problems that can interfere with their exercises, making pulmonary rehab classes difficult.
Doctors may recommend oxygen therapy to increase people's comfort. This therapy can help people control their shortness of breath.
In some cases, a lung transplant is needed to treat interstitial lung disease. Qualifying for a lung transplant is a long process, and not every person with rheumatoid lung disease is a candidate for transplant.
There are a variety of possible lung issues associated with rheumatoid lung disease. The outlook varies, depending on the severity and type of lung complication.
People who develop RA-related scarring and interstitial lung disease often have a poor prognosis. According to research that looked at 10 studies, the median survival rate for people with interstitial lung disease due to RA was 3.2 years to 8.1 years from the time of diagnosis.
Additionally, issues affecting the lungs can change over time. Further lung complications can develop and become increasingly severe.
People who have RA are not always able to prevent rheumatoid lung disease. But some can reduce their risk by not smoking and by getting regular checkups to monitor breathing and check for lung problems. When a doctor can diagnose rheumatoid lung disease early, it may be easier to treat.