Idiopathic Pulmonary Fibrosis

What Is Idiopathic Pulmonary Fibrosis?

Pulmonary (PULL-mun-ary) fibrosis is a condition in which tissue deep in your lungs becomes thick and stiff, or scarred, over time. The development of the scarred tissue is called fibrosis.

As the lung tissue becomes thicker, your lungs lose their ability to move oxygen into your bloodstream, and your brain and other organs don’t receive the oxygen they need. (See the section on How the Lungs Work for more information.)

In some cases, doctors can find out what is causing the fibrosis. But in most cases, they can’t find a cause. They call these cases idiopathic pulmonary fibrosis (IPF).

IPF is a serious condition. About 200,000 Americans have it. About 50,000 new cases are diagnosed each year. IPF affects mostly people 50 to 75 years of age.

IPF varies from person to person. In some people, the lung tissue quickly becomes thick and stiff. In others, the process is much slower, and in some people, the condition stays the same for years.

There is no cure for IPF yet. Many people live only about 3 to 5 years after diagnosis. The most common cause of death related to IPF is respiratory failure. Other causes include:

• Pulmonary arterial hypertension
• Heart failure
• Pulmonary embolism
• Pneumonia
• Lung cancer

Some people may be more likely to develop IPF because of their genes (the basic units of heredity). If more than one member of your family has IPF, the condition is called familial idiopathic pulmonary fibrosis.

Today, scientists are beginning to understand more about what causes IPF, and they can diagnose it more quickly. They also are studying several medicines that may slow the progress of the disease. These efforts should lead to longer and better quality lives for people with IPF.

How the Lungs Work

The air that you breathe in through your nose or mouth travels down through your windpipe (trachea) into two tubes in your lungs called the bronchial tubes, or airways.

The airways are shaped like an upside-down tree with many branches. The trachea is the trunk. It splits into two bronchial tubes, or bronchi. Thinner tubes called bronchioles branch out from the bronchi.

The bronchioles end in tiny air sacs called alveoli. These air sacs have very thin walls, and small blood vessels called capillaries run through them. There are about 300 million alveoli in a normal lung. Scientists say that if the air sacs were opened up and placed next to one another, they would cover a tennis court.

When the air that you've just breathed in reaches these air sacs, the oxygen in the air passes through the air sac walls into the blood in the capillaries. The blood then flows into larger veins, which carry it to the heart. Your heart then pumps the oxygen-rich blood to all your body's organs. These organs can't function without an ongoing supply of oxygen.

In idiopathic pulmonary fibrosis, scarring begins in the air sac walls and the spaces around them. It makes the walls of the air sacs thicker. As a result, oxygen can't move from the air sacs into the bloodstream.

Other Names for Idiopathic Pulmonary Fibrosis

• Idiopathic diffuse interstitial pulmonary fibrosis
• Pulmonary fibrosis of unknown cause
• Pulmonary fibrosis
• Cryptogenic fibrosing alveolitis
• Usual interstitial pneumonitis
• Diffuse fibrosing alveolitis

What Causes Idiopathic Pulmonary Fibrosis?

Doctors don't know what causes idiopathic pulmonary fibrosis (IPF). They think that something inside or outside of the lungs attacks the lungs again and again over time. These attacks injure the lungs and cause scarring in the tissue inside and between the air sacs. This makes it harder for oxygen to pass through the air sac walls into the bloodstream.

Doctors think the following things may increase your chances of developing IPF:

• Cigarette smoking
• Viral infections, including Epstein Barr virus (which causes mononucleosis), influenza A virus, hepatitis C virus, HIV-a virus, and herpes virus 6
• Exposure to environmental pollutants, including inorganic dust (silica and hard metal dusts), organic dust (bacteria and animal proteins), and gases and fumes
• Use of certain medicines, including:
  • Nitrofurantoin and sulfasalazine, which are antibiotics used mostly to treat urinary tract infections, ulcerative colitis, and rheumatoid arthritis
  • Medicines to keep your heartbeat regular (for example, amiodarone or propranolol)
  • Chemotherapy or cancer medicines, such as methotrexate, cyclophosphamide, and bleomycin

Your genes may also play a role in the development of IPF. Some families have at least two members with IPF.

Scientists have found that 9 out of 10 people with IPF also have gastroesophageal reflux disease (GERD). As a result, some scientists think that some people who have GERD may breathe in tiny drops of acid from their stomachs on a regular basis. The acid may then injure the lungs and lead to IPF. More research must be done to confirm this.

What Are the Signs and Symptoms of Idiopathic Pulmonary Fibrosis?

The signs and symptoms of idiopathic pulmonary fibrosis (IPF) develop over time. They may not even begin to appear until the disease has done serious damage to your lungs. Once they do appear, they are likely to become worse over time.

The most common signs and symptoms are:

• Shortness of breath. This is usually the main symptom. At first, you may be short of breath only during exercise. Over time, you are likely to feel breathless even at rest.
• A dry, hacking cough that doesn't get better when you treat it with over-the-counter cough medicines. Over time, you may have repeated bouts of coughing that you can't control.

Other signs and symptoms that you may develop over time include:

• Rapid, shallow breathing
• Gradual, unintended weight loss
• Fatigue (tiredness) or malaise (a general feeling of being unwell)
• Aching muscles and joints
• Enlargement of the ends of the fingers or toes, which is called clubbing

IPF may lead to other medical conditions, including: collapsed lung, lung infections, blood clots in the lungs, and lung cancer.

As your condition gets worse, you may develop other potentially life-threatening conditions, including respiratory failure, pulmonary arterial hypertension, and heart failure.

How Is Idiopathic Pulmonary Fibrosis Diagnosed?

Idiopathic pulmonary fibrosis (IPF) produces the same kind of scarring and symptoms as some other lung diseases. This makes it hard to diagnose. Seeking medical help, preferably from a pulmonologist (a doctor who specializes in lung problems), as soon as you have symptoms is important.

To diagnose IPF, your doctor will ask about your medical history, perform a physical exam, and do several tests to rule out other causes of your symptoms and learn how badly your lungs are damaged.

Medical History

A complete medical history is important. Your doctor will ask about:

• Your age
• Your history of smoking
• Things in the air at your job or elsewhere that could irritate your lungs
• Your hobbies
• Your history of legal and illegal drug use
• Other medical conditions that you have that can trigger an immune system response
• Your family's medical history
• How long you've had symptoms

Diagnostic Tests

There is no single test for diagnosing IPF. Your doctor will probably conduct several different tests, including the following.

Chest X Ray

A chest x ray takes a picture of your heart and lungs. It can show shadows that suggest scar tissue. Many people with IPF have normal chest x rays at the time they’re diagnosed.

High-Resolution Computerized Tomography

High-resolution computerized tomography (HRCT) scan is an x ray that provides sharper and more detailed images than a regular chest x ray. It can show scar tissue and how much lung damage you have. This test can help your doctor spot IPF at an early stage or rule it out. It also can help your doctor decide how likely you are to respond to treatment.

Lung Function Tests

Your doctor will do a breathing test called spirometry to find out how much lung damage you have. A spirometer is a device that measures how much air you can blow out of your lungs after taking a deep breath. It also measures how fast you can breathe the air out. If there is a lot of scarring in your lungs, you will not be able to move a normal amount of air out of them.

Pulse Oximetry

Your doctor attaches a small device to your finger or earlobe to see how much oxygen is in your bloodstream.

Arterial Blood Gas Test

The doctor takes a small amount of blood from an artery in your arm, usually in your wrist. It’s then checked for oxygen and carbon dioxide levels. This test is a more accurate way to check the level of oxygen in your bloodstream. Your blood can also be tested to see whether you have an infection that may be causing your symptoms.

Skin Test for Tuberculosis

Your doctor injects a small amount of a substance that reacts to tuberculosis (TB) under the top layer of skin on one of your arms. If you have a positive reaction, a small hard lump will develop at the injection site 48 to 72 hours after the test. This test is done to rule out TB.

Exercise Testing

Exercise testing is used to find out how well your lungs move oxygen and carbon dioxide in and out of your bloodstream when you’re active. During this test, you walk or pedal on an exercise machine for a few minutes. Electrodes attached to your chest and an EKG (electrocardiogram) machine show your heart rate, a blood pressure cuff monitors your blood pressure, and a pulse oximeter attached to a finger or ear lobe shows how much oxygen is in your blood.

Sometimes doctors place a catheter in an artery in one of your arms to draw samples of your blood that will provide a more accurate measure of the oxygen and carbon dioxide in it. They may also ask you to breathe into a tube that separates the air you breathe out from room air and provides a precise measure of the amount of oxygen you’ve taken in and carbon dioxide you're breathing out.

Lung Biopsy

Looking at samples of tissue from several places in your lungs under a microscope is the best way for your doctor to diagnose IPF. A lung biopsy can help your doctor rule out other causes of your condition, such as sarcoidosis, cancer, or infection. It can also show your doctor how far your condition has advanced. Doctors use several different procedures to obtain samples of your lung tissue:

• Bronchoscopy. Your doctor inserts a flexible, rubber tube with a tiny light and camera on the end through your nose or mouth into your lungs to look at your airways. He or she then inserts a forceps through the tube to collect tissue to examine. This procedure is usually done under local anesthesia on an outpatient basis.
• Bronchoalveolar lavage. During bronchoscopy, your doctor may inject a small amount of salt water (saline) through the bronchoscope into your lungs. This fluid washes the lungs and helps bring up cells from the area around the air sacs for examination under a microscope.
• Video-assisted thoracoscopy. This is the procedure that doctors use most to obtain lung tissue. Your doctor inserts a small, lighted tube with a camera (endoscope) into your chest through small incisions between your ribs. The endoscope provides a video image of the lungs and allows your doctor to collect samples of tissue. This procedure must be done in the hospital, under general anesthesia.
• Thoracotomy. Your doctor removes a few small pieces of lung tissue through an incision in the chest wall between your ribs. Thoracotomy is done in the hospital under general anesthesia.

How Is Idiopathic Pulmonary Fibrosis Treated?

The goals of treating idiopathic pulmonary fibrosis (IPF) are to prevent more lung scarring, relieve your symptoms, maintain your ability to be active and get around, keep you healthy, and improve your quality of life.

Treatment can’t remove scarring that has already happened. As a result, diagnosing and treating IPF as early as possible, before a lot of scarring has taken place, is very important.

Treatment is usually based on your age, medical history, any medical problems you may have, and how much the IPF has advanced.

Treatments can include:

• Medicines to reduce inflammation (swelling) in your lungs and/or prevent more scarring
• Oxygen therapy
• Pulmonary rehabilitation
• Lung transplantation

Medicines

The main treatment for IPF is medicine to reduce inflammation. Many doctors also add a medicine to suppress your body's immune system. These treatments can prevent further scarring and increase survival time in some people, but they don’t work for everyone.

Prednisone

The anti-inflammatory medicine that most doctors prescribe is high-dose prednisone, a corticosteroid. You usually take prednisone by mouth every day. Sometimes your doctor may give it to you through a needle or tube inserted into a vein in your arm for several days. After that, you usually take it by mouth.

Because prednisone can cause serious side effects, your doctor may prescribe it for only 3 to 6 months at first. Then, if it works for you, your doctor may reduce the dose over time and keep you on it for a longer time.

Most people who take high-dose prednisone for a long time can have side effects, including difficulty sleeping at night (insomnia), weight gain, acne, and irritability. Using prednisone for a long time also can lead to other conditions, including:

• High blood pressure.
• Hyperglycemia (high blood sugar).
• Cataracts (a cloudy area in the lens in your eyes).
• Glaucoma (a serious eye condition that can lead to blindness).
• Anxiety or depression.
• Osteoporosis (thinning of the skin and bones).
• Adrenal gland insufficiency (a condition in which the adrenal glands don’t produce enough of certain hormones). This condition should be treated by an endocrinologist—a doctor who specializes in the diagnosis and treatment of the adrenal glands.

Prednisone also can cause conditions such as diabetes and glaucoma to get worse.

Other Medicines

Many doctors prescribe a second medicine with prednisone.

• Azathioprine (Imuran^®) is a medicine that affects your immune system. Most patients take it by mouth every day. Because it can cause serious side effects, your doctor may prescribe it with prednisone for only 3 to 6 months. Then, if you don’t have serious side effects, and the drug combination seems to help you, your doctor may keep you on it long term. The most common side effects of azathioprine include:
  • Nausea, vomiting, diarrhea, and fever and chills
  • Anemia and low platelet and white blood cell counts
  • Liver problems
  • Pancreatitis or lymphoma (rarely)
• Cyclophosphamide (Cytoxan^®) is another immune system suppressant that doctors use to treat IPF. They usually add it to low doses of prednisone for patients who are getting worse while taking prednisone alone. Many patients who can't take prednisone take cyclophosphamide alone.
• Most people take cyclophosphamide by mouth every day. Some IPF patients receive it for 3 to 5 days through a needle that is inserted in a vein in the arm. After that, they take it by mouth every day. You usually start on a low dose that’s increased over time. It may take 3 to 6 months before you see any benefits from cyclophosphamide.
• The most common side effect of cyclophosphamide is a decrease in the number of blood cells that you have. This increases your chances for infection. Your doctor may order blood tests before, during, and after your treatment to see how your blood cells are affected by the drug. Other side effects can include:
  • Infertility in both men and women.
  • Nausea, diarrhea, and fatigue (tiredness).
  • Hair loss.
  • Bladder irritation. Some people who have taken cyclophosphamide for more than 2 years have developed bladder cancer. If you take cyclophosphamide, you should drink at least 8 glasses of water a day. Your doctor should test your urine at least monthly.

Other medicines that may help people with IPF include the following:

• Influenza and pneumonia vaccinations may help prevent infection and keep you healthy.
• Cough medicines or oral codeine may relieve coughing.
• Vitamin D, calcium, and a bone-building drug may help prevent bone loss if you are taking prednisone or another corticosteroid.
• Anti-reflux therapy may help control gastroesophageal reflux disease.

New Medicines Being Studied

Researchers like those in the NHLBI's Idiopathic Pulmonary Fibrosis Network are studying new treatments for IPF. Some are looking at medicines that may reduce inflammation and/or prevent or reduce scarring in IPF. These include medicines that are used to treat other conditions.

N-acetylcysteine. N-acetylcysteine is an antioxidant that’s used mostly to thin mucus in patients with other lung conditions. A recent study showed that adding it to prednisone and azathioprine helped prevent further damage to the lungs of people with IPF.

Interferon gamma-1b. Interferon gamma-1b is a manmade version of a substance that your body normally produces to help fight infections. The drug is usually injected under your skin three times a week. The most common side effects include fever, headache, muscle soreness, fatigue, and chills.

Etanercept. Etanercept is a medicine that’s used to reduce signs and symptoms of active arthritis or rheumatoid arthritis, such as joint swelling, pain, tiredness, and morning stiffness. Etanercept is also used to slow the progress of arthritis. The most common side effects are chills, cough, fever, sneezing, and sore throat.

Bosentan. Bosentan is a medicine developed to reduce high blood pressure in the blood vessels of the lungs (pulmonary arterial hypertension). You usually take this drug by mouth once or twice a day. The most common side effects include headaches, flushing, leg swelling, dizziness and fatigue, and liver problems. If you take this medicine, your doctor should test your blood often to monitor how your liver is working.

Imatinib. Imatinib is a medicine developed to treat a type of leukemia. The drug is usually given by mouth once a day. The most common side effects include fluid retention (swelling), nausea, vomiting, diarrhea, muscle cramping, and liver problems. If you take this medicine, your doctor should do frequent blood tests.

Sildenafil. Sildenafil is a medicine that is used to treat pulmonary hypertension and erectile dysfunction. It usually has few side effects.

Pirfenidone. Pirfenidone is a medicine that may decrease scarring. The drug is usually taken by mouth three times a day. The most common side effects include a rash and sun sensitivity, nausea, vomiting, loss of appetite, drowsiness, and fatigue.

Colchicine. Colchicine is a medicine that has been used to prevent or treat attacks of gout. It may slow scarring in IPF. You usually take it by mouth once or twice a day. The side effects are generally less serious than those from prednisone. They may include nausea, vomiting, stomach pain, and diarrhea.

Methotrexate. Methotrexate is an immune system suppressant that’s used to treat some cancers and autoimmune diseases. Most people take it once a week by mouth or injection. People with IPF usually take it for at least 4 to 6 months to see if it works. You may have side effects, especially if you take it at high doses.

The most serious possible side effect is liver damage. Your doctor should monitor how your liver is working every month that you’re on this drug. If you take methotrexate for more than 2 years, you may want to have a liver biopsy to make sure your liver hasn’t been damaged and that you can continue to take the medicine.

Other side effects may include nausea, mouth sores, skin rash, a decrease in infection-fighting white blood cells (requiring regular blood tests to check white cell levels), and an allergic reaction in the lungs that goes away when you stop taking the drug (this is very rare).

Your doctor should also monitor your white blood cells each month while you’re on methotrexate. You can often reduce your chances of having bad side effects from methotrexate by taking folic acid.

Penicillamine. Penicillamine is used to treat rheumatoid arthritis and to prevent kidney stones. It’s available in pill or capsule form. Several small studies have shown that penicillamine can improve lung function in some IPF patients, but more research is needed.

Penicillamine can cause serious side effects. The most common include nausea, vomiting, diarrhea, dyspepsia, and anorexia.

Cyclosporine. Cyclosporine is another immune system suppressant. It’s used mostly to prevent rejection of kidney, liver, and heart transplants. Some doctors think it may help people with IPF reduce their dose of corticosteroids while waiting for a lung transplant. More research is needed.

Oxygen Therapy

When the amount of oxygen in your blood gets low, you may need oxygen therapy to help reduce your shortness of breath and let you be more active. Oxygen is usually given through nasal prongs or a mask. At first, you may need it only during exercise and sleep. As your condition gets worse, you may need it all the time.

Pulmonary Rehabilitation

Pulmonary rehabilitation is now the standard of care for people with ongoing lung disease. It usually involves treatment by a team of specialists in a specialized clinic. The goal is to teach you how to manage your condition and function at your best.

Services usually include:

• Physical conditioning training
• Breathing exercises and retraining, so that it takes less energy for you to breathe
• Anxiety, stress, and depression management
• Nutritional counseling
• Support groups

Lung Transplantation

Early referral for surgery to replace one of your lungs with a healthy lung from a human donor is usually recommended if you:

• Are younger than 65
• Have no other medical problems
• Are not being helped by medicines

Single lung transplantation can improve your quality of life and help you live longer.

Complications can include rejection by the body of the transplanted lung and infection. You may have to take medicines for life to reduce the chances that your body will reject the transplanted lung.

Because the supply of donor lungs is limited, asking for an evaluation for a transplant as soon as possible is important.

Living With Idiopathic Pulmonary Fibrosis

There is no cure for idiopathic pulmonary fibrosis (IPF) yet. Understanding that your symptoms may get worse over time is important. As your symptoms get worse, you may not be able to do many of the things that you did before you had IPF.

If you're still smoking, the most important thing you can do is stop. Ask your doctor or nurse about smoking cessation programs and products that can help. Avoid secondhand smoke as well. Ask family members and friends not to smoke in front of you or in your home, car, or workplace.

Ongoing medical care is important. Treatment by a pulmonologist who specializes in IPF is usually recommended. These specialists are usually located at major medical centers.

Treatment may relieve your symptoms and even slow or stop the fibrosis (scarring). Following your treatment plan is very important. You should:

• Take your medicines as your doctor prescribes
• Make any changes in diet or exercise that your doctor recommends
• Keep all of your appointments with your doctor
• Enroll in pulmonary rehabilitation

Being as active as you can is important to both your physical and mental health. It can help you maintain your strength and lung function and reduce stress. Try moderate exercise, such as walking or riding a stationary bike. Ask your doctor about using oxygen while you do this.

As your condition advances, use a wheelchair or motorized scooter, or stay busy with activities that aren't physical in nature.

As your condition worsens, you may need oxygen full time. Some people with IPF carry portable oxygen when they go out.

You should also follow a healthy diet. Eating smaller, more frequent meals may relieve stomach fullness, which can make it difficult to breathe. If you need help with your diet, ask your doctor to arrange for a dietitian to work with you.

Getting plenty of rest can increase your energy and help you deal with the stress of living with a serious disease like IPF.

Maintain a positive attitude. Practicing relaxation techniques may help you do this. It may also help you avoid excessive oxygen intake caused by tension or overworked muscles.

Join a support group to help you adjust to living with IPF. Talk to others who have the same symptoms so you can see how they're coping. To find a local support group, talk to your doctor or check your telephone directory.

Avoid situations that can make your symptoms worse, such as traveling by air or living at or traveling to high altitudes where the air is thin and the amount of oxygen in the air is low.

Key Points

• Pulmonary fibrosis is a condition in which tissue deep in your lungs becomes thick and stiff, or scarred, over time. The development of the scarred tissue is called fibrosis. As the tissue becomes thicker, your lungs lose their ability to move oxygen into your bloodstream, and your brain and other organs don't receive the oxygen they need.
• Doctors don't know what causes most cases of pulmonary fibrosis. They call these cases idiopathic pulmonary fibrosis (IPF).
• IPF varies from person to person. In some people, the lung tissue quickly becomes thick and stiff. In others, the process is much slower, and in some people, the condition stays the same for years.
• At present, there is no cure for IPF. Many people live only 3 to 5 years after diagnosis.
• Doctors don't know what causes IPF. They think that something inside or outside of the lungs attacks the lungs again and again over time. These attacks injure the lungs and cause scarring in the tissue inside and between the air sacs.
• Some things that may increase your chances of developing IPF include: cigarette smoking, viral infections, exposure to certain environmental pollutants, use of certain drugs, and having gastroesophageal reflux disease.
• Your genes (the basic units of heredity) may also play a role in the development of IPF. Some families have at least two members with IPF.
• The most common symptoms of IPF are shortness of breath and a dry, hacking cough.
• Other symptoms that you may develop over time include rapid, shallow breathing; gradual, unintended weight loss; fatigue (tiredness) or malaise (a general feeling of being unwell); aching muscles and joints; and enlargement of the fingers or toes, which is called clubbing.
• IPF may lead to other serious medical conditions, including a collapsed lung, lung infections, blood clots in the lungs, and lung cancer.
• As your condition gets worse, you may develop other potentially life-threatening conditions, including respiratory failure, pulmonary arterial hypertension, and heart failure.
• To diagnose IPF, your doctor will do a detailed medical history, a physical exam, and several diagnostic tests, including a chest x ray, high-resolution computerized tomography, lung function tests, pulse oximetry, arterial blood gas tests, a skin test for tuberculosis, and exercise testing.
• Looking at samples of tissue from several places in your lungs under a microscope is the best way for your doctor to diagnose IPF. Video-assisted thoracoscopy is the procedure that doctors use most to collect the tissue. Your doctor inserts a small, lighted tube with a camera (endoscope) into your chest through small incisions between your ribs. The endoscope provides a video image of the lungs and allows your doctor to collect tissue samples. This procedure must be done in the hospital under general anesthesia.
• Treatment can't remove scarring that has already happened. Therefore, diagnosing and treating IPF as early as possible (before a lot of scarring has occurred) is very important.
• Recommended treatments include medicines to reduce inflammation (swelling) in your lungs and/or prevent more scarring, oxygen therapy, pulmonary rehabilitation, and lung transplantation. Pulmonary rehabilitation is now the standard of care for people with ongoing lung disease.
• The main treatment for IPF is medicine, such as prednisone, to reduce inflammation. Many doctors also add a drug to suppress your body's immune system. These treatments can prevent further scarring and increase survival time in some people, but they don't work for everyone.
• Other medicines that may help people with IPF include flu and pneumonia vaccinations; cough medicines or oral codeine; vitamin D, calcium, and a bone-building drug; anti-reflux therapy; and antioxidants.
• If you're still smoking, the most important thing you can do is stop. Avoid secondhand smoke as well.
• Ongoing medical care is important. Treatment by a pulmonologist who specializes in IPF is usually recommended.
• Taking your medicines as your doctor prescribes, making any changes in diet or exercise that your doctor recommends, keeping all of your appointments with your doctor, and enrolling in pulmonary rehabilitation are important.
• Other things you can do for both your physical and mental health include being as active as you can, following a healthy diet, getting plenty of rest, joining a support group, and, as your condition advances, using a wheelchair or motorized scooter and staying busy with activities that aren't physical in nature.

Source : http://www.nhlbi.nih.gov/health/dci/Diseases/ipf/ipf_summary.html