Interstitial Lung Disease

Interstitial lung disease (ILD) is actually a group of multiple conditions that are related to lung tissue scarring around the air sacs of the lungs. The conditions are progressive, meaning that they get worse with time and cannot be reversed. Ultimately ILD restricts the ability to breathe and to get enough oxygen in the body.

There are many possible causes of ILD, but the inhalation of dust, minerals, toxins, and other environmental contaminants is the most common cause. Among these is the inhalation of asbestos fibers, which can lead to a type of ILD called asbestosis. Treatment may slow down the progressive damage that occurs with ILD, but there is no cure for it and many people will completely lose the use of their lungs. Only a lung transplant can restore function, but these are rare.

What is Interstitial Lung Disease?

Interstitial lung disease is not one specific illness or condition. It is a category of more than 100 lung diseases with various possible causes; sometimes the cause of an ILD is never determined. Because there are so many ILDs they are generally categorized by cause or association with a certain disease or environmental contaminant. For instance, ILD caused by asbestos exposure is called asbestosis and belongs to the exposure category of ILDs.

What all ILDs have in common is that they cause scarring of lung tissue that gets worse over time. ILDs are specifically characterized by scarring around the alveoli or air sacs of the lungs, also known as the interstitium, or interstitial space. This space in the lungs is important for the exchange of oxygen and other gases between the lungs and capillaries. As the scarring worsens it becomes more and more difficult for this exchange to occur.

Scarring Caused by Asbestos

Interstitial lung disease caused by exposure may occur when someone inhales various types of contaminants, from silica to coal dust to dust and fumes found on farms or in welding jobs. For someone who has worked around asbestos, the inhalation of the fibers may lead to the scarring in the lungs that causes the ILD called asbestosis.

When the fibers of asbestos enter the lungs they can become embedded in tissue. Sometimes this occurs in the pleura and may lead to mesothelioma. Or, the fibers can travel further into the lungs causing damage to tissue in the interstitium. In response to this damage the body attempts to make repairs, which thickens the tissue and leaves scarring. The greater the exposure to asbestos the more extensive the scarring is. Ultimately, even when the contaminant is removed, the scarring continues to worsen progressively.

Symptoms of ILD

While various contaminants may cause an ILD through exposure, they all cause similar symptoms. These symptoms are also similar to other lung conditions, like COPD—chronic obstructive pulmonary disease—or asthma. Symptoms include shortness of breath, coughing, pains in the chest, fatigue that gets worse with exercise or exertion, fever, weight loss, and sometimes clubbed fingers. Once symptoms are obvious, the disease has likely progressed so far that extensive damage is not reversible.

Diagnosis

Diagnosing an ILD like asbestosis can be tricky because the symptoms are so similar to other conditions, many of them much more common, like COPD. If you have been exposed to asbestos or other minerals, dust, or environmental contaminants, it is important to inform your doctor for the most complete diagnosis. This will probably begin with chest X-rays to image the lungs and lung function tests. The latter determine your lung capacity and can tell you if it is diminished.

Other imaging tests, like CT scans or MRIs may also be used to give a more detailed picture of the tissues in your lungs and chest cavity. In many cases it may be necessary to perform a biopsy. This means removing a small sample of tissue that can be investigated by a pathologist who will be able to determine if the tissue is scarred by an ILD or if there is another cause of your symptoms.

Treatment for ILDs

It is important to determine the underlying cause of an ILD so that it can be treated if possible. If it is determined that your ILD is caused by asbestos, you may need to avoid any further exposure. Treatment for ILDs also include procedures and strategies that treat the scarring, limit further damage, and help you get more oxygen through your lungs.

Medications may help slow the formation of scar tissue, but do not work in all cases of ILD depending on the underlying cause. Oxygen therapy will not slow any of the damage, but it can help you breathe more easily, be more active, increase your oxygen intake, and help you feel and sleep better. Oxygen therapy simply involves being provided with supplemental oxygen, typically through an oxygen tank.

In rare cases when the damage to lung tissue is severe and the patient is otherwise healthy, a lung transplant may be a treatment option. This is not common for most people with asbestosis, but if a lung is available and a patient is a good candidate, this difficult surgery may be undertaken. It is risky and may result in the rejection of the organ, but for some patients a transplant is the best option.

Complications of Asbestosis and other ILDs

In addition to difficulty breathing or getting adequate oxygen, ILDs can cause other serious complications. High blood pressure in the lungs, or pulmonary hypertension, for instance, can be triggered by an ILD and can be life-threatening. If you have asbestosis and you smoke, you may also be at risk for lung cancer. ILDs may also cause pleural plaques and pleural effusions—thickening of lung tissue and fluid buildup around the lungs.

Prognosis

If you are diagnosed with asbestosis or another ILD, your prognosis will depend on how advanced the disease is. If caught early, asbestosis may not cause serious symptoms or complications. Early treatments can slow down the progression and mitigate symptoms. When the disease is not diagnosed until a lot of damage has been done, or if you also smoke or have been exposed to a lot of asbestos, the prognosis is likely to be worse.

ILDs caused by exposure are preventable. If you work around harmful chemicals, minerals, or dust, use protective equipment to avoid inhaling the material. This can be an important step in preventing later damage to your lung tissue. Living with ILD is uncomfortable, limiting, and ultimately may be life-threatening.