What is ILD?

What is Interstitial Lung Disease?

Interstitial lung disease (ILD) is a broad group lung disorders, most of which cause scarring (fibrosis) and/or inflammation of the lungs.

Injury and damage occurs in the walls of the air sacs (alveoli) of the lungs and the tissue and space around the alveoli (lung interstitium). This can impair the lungs’ ability to bring oxygen into the body. Fibrosis causes stiffness in the lungs that makes it difficult to breathe. Lung damage from ILDs can be irreversible and worsens over time if not treated. 

Causes of Interstitial Lung Disease

The causes of ILD fall into four main categories:

1. Autoimmune or connective tissue disease

Conditions such as scleroderma, rheumatoid arthritis, polymyositis/dermatomyositis, vasculitis and inflammatory bowel disease can be linked to ILD.

2. Exposure to agents that damage the lungs

ILD can be caused by workplace exposure to inorganic dust such as asbestos, silica or hard metal dust. Exposures to such smoking vaping molds and birds also can cause ILD. Additionally, medications used to treat another illness such as chemotherapy drugs, amiodarone or nitrofurantoin have been linked to ILD.

3. Genetics 

Multiple members of a family may develop ILD, and some of these cases have been tracked to a single set of genes. Some inherited diseases are known to cause ILD, including Hermansky-Pudlak Syndrome, mutations in telomerase and tuberculosis sclerosis complex.

4. Idiopathic conditions

“Idiopathic” means the cause is unknown. 

Types of Interstitial Lung Disease

Some of the common forms of ILD are:

• Idiopathic (unknown) pulmonary fibrosis (IPF)

• Connective tissue or autoimmune disease-related ILD (CTD-ILD)

• Hypersensitivity pneumonitis (HP or HSP)

• Chronic eosinophilic pneumonia

• Pulmonary Langerhans cell histiocytosis

• Familial Pulmonary Fibrosis

• Drug-induced lung disease

• Sarcoidosis

• Lymphangioleiomyomatosis (LAM)

• Cryptogenic organizing pneumonia (COP)

• Smoking-related ILD

Signs and Symptoms

The most common symptoms of ILD are shortness of breath (dyspnea), cough and fatigue. 

Dyspnea is often described as a feeling of breathlessness. In most cases, shortness of breath appears over time rather than abruptly. Usually, dyspnea is first noticed during exertion or strenuous activity such as running or other intense exercise. As ILD progresses, patients may recognize shortness of breath while casually walking down the street or from room to room while indoors.

Cough related to ILD is typically dry and hacking. Fatigue or low energy is very common for ILD patients. People with systemic autoimmune or connective tissue disease may also experience muscle or joint aches, rash and other non-respiratory symptoms.

ILD typically presents with few early warning signs and worsening symptoms may be the only indicator, including:

• An increase of breathlessness or coughing
• A general feeling of poor health
• Feeling a lack of energy or fatigue
• Fever

Diagnosis

Because there are so many different types of ILD with a variety of causes, your doctor will conduct a throughout medical history and physical exam. They also may consider the following tests when ILD is suspected.

Breathing and Exercise Tests

• Lung function tests: These breathing tests measure how your lungs and airways function and enable physicians to make diagnoses, recommend ILD treatment and track progress.
• Exercise testing: A patient exercises on a treadmill or bicycle, often with EKG and blood pressure monitoring, to determine the response of the heart and lungs to physical activity. These tests may include a six-minute walk, oxygen titration and exercise tolerance.

Imaging Tests

Advanced imaging helps your doctor see the extent of the lung injury and the pattern of injury, which can help them determine the cause.

Chest X-ray: A chest X-ray is a picture of the inside of the chest, used to evaluate the lungs, heart, and other structures of the chest.

HRCT scan: A high-resolution computed tomography (HRCT) scan takes a highly detailed image of your lung compared to a chest x-ray. HRCT scans are conducted at intervals to help your doctor see if your lung disease is progressing or responding to treatment.

Lab Tests

• Arterial blood gas: This blood sample evaluates measurements of oxygen, carbon dioxide and several other parameters.
• Blood tests: Blood work may be conducted to test for autoimmune disease and other disorders that can cause ILD.

Procedures

• Bronchoscopy with bronchoalveolar lavage: This test involves inserting a tube through the nose or mouth into the trachea (windpipe) so the doctor can see the airways, check for inflammatory cells in the lungs or sample small pieces of the lung to look for evidence of a specific ILD. In bronchoalveolar lavage a small amount of sterile saline or salt water is placed in one area of the lung and then withdrawn. The fluid contains cells that will be analyzed under a microscope. Small biopsy tools may be used through the bronchoscope if indicated.
• Surgical lung biopsy: For a specific diagnosis in a small number of cases of ILD, a surgical lung biopsy is necessary to extract enough lung tissue to analyze. This may be performed with a thoracoscope to allow the surgeon to biopsy multiple areas of one lung with few very small incisions. It requires a stay in the hospital for a few days.

Treatment

The most appropriate course of treatment depends on the specific ILD diagnosis and the severity of the disease. Many forms of ILD can be successfully treated with medications. In other cases, doctors may determine watchful waiting without drug therapy is appropriate.

ILD Treatment Goals

The goals of ILD treatment are:

• To decrease inflammation and/or prevent the formation and progression of lung scarring
• To remove the source of the damage, when possible
• To minimize and manage potential complications of ILD
• To improve or prevent deterioration in a patient’s quality of life

Responses to various treatments can depend on many factors. Some types of ILD may improve quickly, while others may not respond at all. Even with treatment, some types of ILD progress over time. Sometimes this worsening is due to a complication of the disease or therapy. This may include conditions such as pulmonary hypertension or heart failure.

Rest assured, your doctor and care team will work with you to determine the best treatment options for your specific type of ILD.

Medications

Some medications are only effective against certain types of ILD. The primary medications that treat ILD are:

Anti-Fibrotic Medications

Anti-fibrotic medications work to stop new fibrosis from forming. They do not remove fibrosis that is already in the lungs. These medications only work on certain types of interstitial lung disease. Your doctor will determine if anti-fibrotic medications are appropriate.

Immune-Suppressing or Steroid-Sparing Medications

This class of medications are sometimes prescribed along with or in place of corticosteroids, and each has different side effects and requirements for monitoring. Some of the most prescribed immunosuppressive drugs for ILD include:

• Mycophenolate mofetil (CellCept®) or mycophenolic acid (Myfortic®)
• Azathioprine (Imuran®) 
• Cyclophosphamide (Cytoxan®)
• Rituximab (Rituxan®)

Oral Corticosteroids

Corticosteroids such as prednisone are used to treat many forms of ILD. These medications can have significant side effects and are often used only for a limited time. Side effects include: 

• A tendency to bruise easily
• Depression
• High blood pressure
• Hyper excitability
• Increased appetite
• Psychosis
• Salt and fluid retention
• Trouble sleeping 
• Weight gain

Over time, this may lead to diabetes, peptic ulcers, infections, cataracts and osteoporosis.

Therapies

Beyond medication, other treatment options for ILD include:

Oxygen Therapy: ILD can lead to low levels of oxygen in the blood. Improving oxygen levels in the blood with supplemental oxygen can help relieve strain on the heart and lungs, decreasing the symptoms of shortness of breath and fatigue. Some patients may need oxygen therapy all the time, while others may only need it during sleep or exercise. 

Starting oxygen therapy can be a complex process because of the potential stigma. There are many different options for oxygen systems, and many patients can be more active. Learn more about oxygen therapy. (link to supplemental oxygen section)

Pulmonary Rehabilitation: A pulmonary rehabilitation program is recommended for most ILD patients to help you achieve your highest level of functioning. This includes: 

• Education
• Exercise conditioning
• Breathing and energy-saving techniques
• Respiratory therapy evaluation
• Nutritional counseling
• Psychosocial support

Pulmonary rehabilitation aims to improve quality of life by:

• Decreasing respiratory symptoms and complications
• Encouraging self-management and control over daily functioning
• Improving physical condition and exercise performance
• Increasing emotional well-being
• Reducing hospitalizations

Lifestyle Management

Being diagnosed with ILD changes your life and means learning new ways to exist in the world. For example, you may have been active for your entire life, and now you can’t do things you once enjoyed. Missing out on the things that make life fun can cause a profound sense of loss that must be grieved. It is normal to feel angry, afraid, depressed, stressed and frustrated with all the changes. 

Adjusting to a serious illness is a process and won’t happen overnight. You need support from others to feel less alone in coping with these changes. You also need to learn more about your disease and how to manage it. 

Patient Resources

Living with ILD

Procedures

Lung Transplant

If ILD has worsened, lung transplantation may be an option for you. This surgery replaces one or both diseased lungs with healthy lungs from a non-living donor. With improved surgical techniques and post-transplant care, this may offer you a higher quality of life and longer survival. ILD does not recur in transplanted lungs.

After extensive evaluation to determine if lung transplant is the best option for you and that you are healthy enough for the surgery, appropriate candidates are placed on a waiting list. The position on the list is determined by disease severity. Wait times depend on your nearest transplant center.

Clinical Trials

Clinical trials help determine new treatment options for diseases and conditions. Patients with ILD have access to clinical trials and should speak with their physician to determine what trials might work best for them.