Interstitial Lung Disease and Rheumatology: What You Should Know
What is interstitial lung disease?
Interstitial lung disease (ILD) refers to a group of conditions that cause inflammation and/or scarring of the lung tissue.
The lungs contain tiny air sacs that allow oxygen to move into the bloodstream. When these tissues become inflamed or scarred, the lungs can become stiff, making it harder to breathe and deliver oxygen throughout the body.
There are many different causes of ILD, including autoimmune diseases, environmental exposures, medications, infections, and sometimes causes that we do not fully understand.
As rheumatologists, we pay close attention to ILD because several autoimmune diseases can affect the lungs.
What are the symptoms of interstitial lung disease?
ILD can develop slowly, and symptoms are sometimes subtle.
Common symptoms include:
Chronic dry cough
Progressive shortness of breath, especially with activity
Increasing fatigue
Decreased exercise tolerance
Sometimes patients notice they cannot do activities they used to do easily, such as walking longer distances, exercising, or climbing stairs.
On a lung examination, we may hear crackles, which are abnormal sounds that can suggest changes in the lung tissue.
I have diagnosed ILD in patients who did not have significant symptoms but had abnormal findings on their lung examination, particularly in patients with rheumatoid arthritis (among other diseases).
Why is interstitial lung disease related to rheumatology?
Many people think of rheumatology as only treating arthritis, but autoimmune diseases can affect more than the joints. They can involve organs throughout the body, including the lungs.
In autoimmune diseases, the immune system becomes overactive and causes inflammation. When this inflammation affects the lungs over time, it can sometimes lead to scarring.
Autoimmune diseases associated with ILD include (but are not limited to):
Rheumatoid arthritis
Systemic sclerosis (scleroderma)
Sjögren’s syndrome
Dermatomyositis and polymyositis (inflammatory myopathies)
Lupus
Mixed connective tissue disease
Sometimes a patient already has a diagnosis of autoimmune disease and later develops lung involvement.
Other times, ILD is the first sign that leads us to discover an underlying autoimmune condition.
This is why patients with ILD are sometimes referred from pulmonology to rheumatology — we are looking for the underlying cause.
What are the different causes of interstitial lung disease?
Interstitial lung disease can have many different causes.
The major categories include:
Connective tissue disease-related ILD
This occurs when inflammation from an autoimmune disease affects the lung tissue.
Idiopathic ILD
Idiopathic means that we do not know the exact cause. Idiopathic pulmonary fibrosis is one example.
Environmental or occupational exposures
Certain exposures, such as asbestos, silica, or other inhaled particles, can contribute to lung injury and scarring.
Medication-related ILD
Some medications can cause inflammation or injury to the lungs (amiodarone, bleomycin, rarely methotrexate)
Other causes: Infections, radiation therapy, and other less common causes can also lead to ILD.
How is interstitial lung disease diagnosed?
The first step is recognizing when we should be concerned.
In someone with an autoimmune disease, symptoms such as a persistent dry cough, worsening shortness of breath, or declining exercise ability should prompt further evaluation.
We typically use several tools:
What are pulmonary function tests and how do they help diagnose ILD?
Pulmonary function tests measure how well the lungs are working.
These tests require effort from the patient. You will be asked to perform different breathing maneuvers, and the results provide information about lung volume, airflow, and how well oxygen moves through the lungs.
In ILD, we often see a restrictive pattern, meaning the lungs are not expanding normally. This may include:
Reduced lung volumes
Reduced total lung capacity
Reduced DLCO, which measures how well oxygen moves from the lungs into the bloodstream
These tests are also important because they allow us to monitor whether the disease is stable or progressing over time.
Why is a high-resolution CT scan used for interstitial lung disease?
A high-resolution CT scan provides a detailed view of the lung tissue.
Findings that may be seen in ILD include:
Ground-glass opacities
Areas of scarring (reticulation)
Traction bronchiectasis
Honeycombing, which represents more advanced fibrosis
The pattern on CT helps us understand the type of ILD and guide treatment decisions.
Are there different types of interstitial lung disease?
Yes. There are different patterns of ILD, and the pattern can help us understand how the disease may behave.
Two common patterns seen in autoimmune disease include:
UIP (usual interstitial pneumonia): This pattern is associated with more established fibrosis and can be seen in rheumatoid arthritis-associated ILD.
NSIP (nonspecific interstitial pneumonia): This pattern is commonly seen with connective tissue diseases such as scleroderma and inflammatory myopathies and may have more inflammation that can respond to treatment.
Is autoimmune-related ILD different from idiopathic pulmonary fibrosis?
Yes.
One important point is that ILD related to connective tissue disease often has a better prognosis than idiopathic pulmonary fibrosis.
This is partly because we may be able to identify and treat the underlying autoimmune inflammation contributing to lung injury.
How is interstitial lung disease treated?
Treatment depends on the cause and the type of ILD.
When ILD is related to autoimmune disease, we often use medications that help control inflammation and prevent progression.
These may include:
Mycophenolate mofetil (CellCept)
Rituximab (Rituxan)
Tocilizumab (Actemra) in selected patients
Other immunosuppressive medications depending on the specific autoimmune disease
Some patients with progressive fibrosis may benefit from antifibrotic medications, which help slow the progression of scarring.
These include:
Nintedanib (Ofev)
Pirfenidone (Esbriet)
Nerandomilast (Jascayd™)
Can interstitial lung disease be prevented?
We cannot prevent every case of ILD.
However, we believe that controlling chronic inflammation from autoimmune disease is important. The general thought is that reducing ongoing inflammation may help decrease the risk of organ damage over time.
Other important steps include:
Avoiding smoking
Staying physically active
Keeping vaccinations up to date
Reporting new respiratory symptoms early
Treating autoimmune disease is not only about controlling pain and inflammation — it is also about protecting organs such as the lungs.
Why do we screen for pulmonary hypertension in patients with ILD?
Patients with connective tissue diseases and ILD can also develop pulmonary hypertension, which is increased pressure in the blood vessels of the lungs.
Because ILD can affect oxygen levels and the lung blood vessels, the heart may have to work harder to pump blood through the lungs.
Symptoms may include:
Increasing shortness of breath
Fatigue
Reduced exercise tolerance
Dizziness
Leg swelling
Pulmonary hypertension is important to identify because it requires treatment.
Screening may include an echocardiogram, depending on the autoimmune disease and individual risk factors.
What is the prognosis for interstitial lung disease?
The prognosis depends on many factors, including the underlying cause, the type of ILD, the amount of scarring present, and response to treatment.
Some patients remain stable for many years with monitoring and appropriate therapy. Others may have progressive disease requiring more aggressive treatment.
The most important message is that ILD is not the same thing for every person.
Early recognition, careful monitoring, and individualized treatment can make a meaningful difference.
If you have an autoimmune disease and develop a persistent dry cough, worsening shortness of breath, or decreased exercise ability, it is important to discuss these symptoms with your healthcare team.
In rheumatology, our goal is not only to treat symptoms — it is to recognize complications early and protect your long-term health.
Practical Takeaways: Protecting Your Lung Health
Pay attention to changes in your baseline. If you notice that activities that used to be easy are becoming harder, you are getting more winded than usual, or you develop a persistent dry cough, bring it up with your healthcare team.
Do not assume shortness of breath is simply due to aging, being out of shape, or “getting older.” In patients with autoimmune disease, changes in breathing deserve thoughtful evaluation.
Stay consistent with your autoimmune disease treatment plan. Controlling inflammation is important not only for managing symptoms but also for protecting organs that can be affected, including the lungs.
Keep your follow-up appointments and recommended monitoring tests. Conditions like interstitial lung disease are often best managed when changes are identified early.
Stay physically active within your ability. Maintaining strength, endurance, and mobility can help support overall lung and cardiovascular health.
Avoid exposures that can harm the lungs, including smoking and significant inhalational exposures at work or home.
Be proactive and ask questions. Understanding your diagnosis, treatment options, and monitoring plan helps you become an active partner in your care.
The goal of managing autoimmune disease is not only to control symptoms but also to protect your long-term health. Paying attention to changes, staying engaged in your care, and working closely with your healthcare team can make a meaningful difference.