MUSLIM SCHOLAR. 1

Interstitial Lung Disease(ILD)

Interstitial Lung Disease(ILD) is a group of many lung conditions. All interstitial lung disease affect the interstitium, a part of your lungs.

The interstitium is a lace-like network of tissue that goes throughout both lungs It supports your lungs tiny air sacs, called alveoli. Normally, the interstitium is so thin that it doesn’t show up on X-rays or CT scans.

Interstitial (in-tur-STISH-ul) lung disease describes a large group of disorders, most of which cause progressive scarring of lung tissue. The scarring associated with interstitial lung disease eventually affects your ability to breathe and get enough oxygen into your bloodstream.

Interstitial lung disease (ILD), sometimes also called as diffused parenchymal diseases, Diffuse parenchymal lung disease; Alveolitis; Idiopathic pulmonary pneumonitis (IPP) describes a heterogeneous collection of distinctive lung disorders classified on the grounds of shared clinical, radiographic, physiologic or pathologic factors.

Types of ILD

The classification system used to describe interstitial lung disease categorizes conditions based on clinical, histopathological or radiologic parameters.

Ø Clinical classification groups ILD by its causes to help differentiate exogenous or endogenous factors.

Ø Interstitial lung disease diseases without identifiable causes get grouped under idiopathic/primary which uses the histopathological and radiological approach as its infrastructure.

All forms of interstitial lung disease cause the interstitium to thicken. This can happen from inflammation, scarring, or a build-up of fluid. Some forms of ILD last a short time (acute); others are long-term (chronic) and don’t go away.

Some types of interstitial lung disease include:

v  Interstitial Pneumonia Bacteria, viruses, or fungi can infect the interstitium. A bacteria called Mycoplasma pneumoniae is the most common cause.

v  Idiopathic pulmonary fibrosis. This makes scar tissue grow in the interstitium.  Experts don’t know what causes it.

v  Nonspecific interstitial pneumonitis. This is an interstitial lung disease that often affects people with autoimmune conditions such as rheumatoid arthritis or scleroderma.

v  Hypersensitivity pneumonitis. This happens when dust, mold, or other things that you breathe irritate your lungs over a long time.

v  Cryptogenic organizing pneumonia (COP). COP is a pneumonia-like interstitial lung disease without an infection. You might hear your doctor call this bronchiolitis obliterans with organizing pneumonia (BOOP).

v  Acute interstitial pneumonitis. This is a sudden, severe interstitial lung disease. People who have it often need to be connected to a machine called a ventilator that breathes for them.

v  Desquamative interstitial pneumonitis. This is an interstitial lung disease that partly results from smoking.

v  Sarcoidosis. This causes interstitial lung disease along with swollen lymph nodes. It can also affect your heart, skin, nerves, and eyes.

Asbestosis. This is an interstitial lung disease caused by breathing asbestos, a fiber used in building materials.

ILD Causes

The cause of most interstitial lung disease is unknown.

Bacteria, viruses, and fungi can cause interstitial pneumonia. You can also get ILD if you regularly breathe in things that can bother your lungs. These include:

• Asbestos
• Bird proteins (such as from exotic birds, chickens, or pigeons)
• Coal dust or various other metal dusts from working in mining
• Grain dust from farming
• Silica dust
• Talc.

Many drugs can damage your lungs, especially:

·        Chemotherapy drugs. Drugs designed to kill cancer cells, such as methotrexate (Otrexup, Trexall, others) and cyclophosphamide, can also damage lung tissue.

·        Heart medications. Some drugs used to treat irregular heartbeats, such as amiodarone (Nexterone, Pacerone) or propranolol (Inderal, Innopran), may harm lung tissue.

·        Some antibiotics. Nitrofurantoin (Macrobid, Macrodantin, others) and ethambutol (Myambutol) can cause lung damage.

·        Anti-inflammatory drugs. Certain anti-inflammatory drugs, such as rituximab (Rituxan) or sulfasalazine (Azulfidine), can cause lung damage.

Lung damage can also result from autoimmune diseases such as:

·        Rheumatoid arthritis

·        Scleroderma

·        Dermatomyositis and polymyositis

·        Mixed connective tissue disease

·        Sjogren's syndrome

·        Sarcoidosis

It’s rare, but certain drugs can cause ILD:

• Some antibiotics, like nitrofurantoin
• Some anti-inflammatory drugs, like rituximab
• Chemotherapy drugs like bleomycin
• Heart medications such as amiodarone

Anyone can get interstitial lung disease, but some things can put you at higher risk:

• Age. Adults are much more likely to get ILD, but children can, too.
• Autoimmune disease like lupus, rheumatoid arthritis, and scleroderma
• Gastroesophageal reflux disease (GERD)
• Genetics. Some conditions are passed down among family members.
• Smoking
• Radiation treatments for cancer.

 

Symptoms

Ø  Shortness of breath is a main symptom of ILD. You may breathe faster or need to take deep breaths:

Ø  At first, shortness of breath may not be severe and is only noticed with exercise, climbing stairs, and other activities.

Ø  Over time, it can occur with less strenuous activity such as bathing or dressing, and as the disease worsens, even with eating or talking.

Ø  Most people with this condition also have a dry cough. A dry cough means you do not cough up any mucus or sputum.

Ø  Over time, weight loss, fatigue, and muscle and joint pain are also present.

Ø  People with more advanced ILD may have:

Ø  Abnormal enlargement and curving of the base of the fingernails (clubbing).

Ø  Blue colour of the lips, skin, or fingernails due to low blood oxygen levels (cyanosis).

Ø  Symptoms of the other diseases such as arthritis or trouble swallowing (scleroderma), associated with ILD.

Exams and Tests

The health care provider will perform a physical exam. Dry, crackling breath sounds may be heard when listening to the chest with a stethoscope.

The following tests may be done:

Ø  Blood tests to check for autoimmune diseases

Ø  Bronchoscopy with or without biopsy

Ø  Chest x-ray

Ø  High resolution CT (HRCT) scan of the chest

Ø  MRI chest

Ø  Echocardiogram

Ø  Open lung biopsy

Ø  Measurement of the blood oxygen level at rest or when active

Ø  Blood gases

Ø  Pulmonary function tests

Ø  Six-minute walk test (checks how far you can walk in 6 minutes and how many times you need to stop to catch your breath)

People who are heavily exposed to known causes of lung disease in the workplace are usually routinely screened for lung disease. These jobs include coal mining, sand blasting, and working on a ship.

MANAGEMENT AND TREATMENT

There’s no cure for interstitial lung disease. Treatment for ILD usually focuses on treating underlying disease and improving your symptoms. Your healthcare provider might prescribe physical therapy, supplemental oxygen or medication to reduce inflammation or slow down the disease.

Medications.

• Corticosteroids. Drugs like prednisone can help reduce inflammation.
• Anti-fibrotic and cytotoxic drugs. These medications can slow down lung scarring. They include azathioprine, cyclophosphamide, pirfenidone and nintedanib.
• Biologic drugs. Medications like rituximab are sometimes used to treat autoimmune diseases and other causes of ILD.
• Treatment for GERD. Gastroesophageal reflux disease (GERD) can make ILD worse, so your provider may prescribe medications to keep stomach acid down.

• Pulmonary rehabilitation. Breathing exercises and physical therapy can make your lungs stronger and breathing easier.
• Oxygen therapy. Your provider will prescribe extra oxygen if you don’t have enough getting to your blood or tissues. It’s delivered through a mask or tube in your nose.

Some treatments for interstitial lung disease can weaken your immune system. Your doctor will monitor you closely for complications if you’re taking one of these medications.

Treatments for Interstitial Lung Disease

The treatment you get depends on the type of ILD you have and its cause.

Antibiotics. These treat most interstitial pneumonias. Pneumonias caused by a virus usually get better on their own. Pneumonias caused by a fungus are rare but are treated with antifungal drugs.

Corticosteroids. In some forms of interstitial lung disease, inflammation in your lungs causes damage and scarring. Corticosteroids cause your immune system’s activity to slow. This lessens the amount of inflammation in your lungs and the rest of your body.

Inhaled oxygen. If you have low oxygen levels because of interstitial lung disease, inhaled oxygen may help your symptoms. Regular use of oxygen might also protect your heart from damage caused by low oxygen levels.

Lung transplant. In advanced interstitial lung disease that has severely impaired you, you may need a lung transplant. Most people who have a lung transplant for interstitial lung disease make large gains in their quality of life and their ability to exercise.

Azathioprine (Imuran). This drug also slows down the immune system. It’s not shown to improve interstitial lung disease, but some studies suggest it might help.

N-acetylcysteine (Mucomyst). This potent antioxidant may slow the decline of lung function in some forms of interstitial lung disease. You’ll take it in combination with other treatments.

Other drugs are considered controversial for interstitial lung disease treatment, including:

• Cyclophosphamide (Cytoxan)
• Cyclosporine
• Methotrexate
• Nintedanib (Ofev)
• Pirfenidone (Esbriet)

 These medicines affect the way your immune system works. If your doctor thinks you need one, they’ll keep a close watch on you while you’re taking it. These medications can have serious side effects.

 

Complications

Interstitial lung disease can lead to a series of life-threatening complications, including:

·        High blood pressure in your lungs (pulmonary hypertension). Unlike systemic high blood pressure, this condition affects only the arteries in your lungs. It begins when scar tissue or low oxygen levels restrict the smallest blood vessels, limiting blood flow in your lungs. This in turn raises pressure within the pulmonary arteries. Pulmonary hypertension is a serious illness that becomes progressively worse.

·        Right-sided heart failure (cor pulmonale). This serious condition occurs when your heart's lower right chamber (right ventricle) — which is less muscular than the left — has to pump harder than usual to move blood through obstructed pulmonary arteries. Eventually the right ventricle fails from the extra strain. This is often a consequence of pulmonary hypertension.

·        Respiratory failure. In the end stage of chronic interstitial lung disease, respiratory failure occurs when severely low blood oxygen levels along with rising pressures in the pulmonary arteries and the right ventricle cause heart failure.

PREVENTION

Many causes of interstitial lung disease aren’t preventable. You can reduce your risk of ILD by managing underlying conditions and avoiding breathing in harmful substances.

• Avoid or wear a respirator (a mask that filters particles from the air) when working around harmful substances, such as asbestos, metal dusts or chemicals.
• Avoid or wear a respirator when working around things that can cause chronic allergic reactions, like hay, grain, bird droppings or feathers and heating and cooling systems.
• If you have a connective tissue disease or sarcoidosis, talk to your healthcare provider about ways to manage your illness to prevent ILD.
• Don’t smoke or quit smoking.

Life expectancy

The life expectancy for interstitial lung disease depends on the cause and severity. Some people with mild ILD can live normal lives without treatment or with minimal treatment. Your outlook (prognosis) is better if your disease isn’t getting worse (it’s stable).

For people with the most severe and rapidly worsening forms of interstitial lung disease, life expectancy is around 3-5 years after diagnosis.