Idiopathic Pulmonary Fibrosis Causes, Symptoms, Diagnosis, Treatment, Prevention

Idiopathic Pulmonary Fibrosis Causes, Symptoms, Diagnosis, Treatment, Prevention


What Is Idiopathic Pulmonary Fibrosis (IPF)?


Idiopathic Pulmonary Fibrosis (IPF) is a disease of inflammation that results in scarring, or fibrosis, of the lungs. In time, this fibrosis can build up to the point where the lungs are unable to provide oxygen to the tissues of the body.
Doctors use the word "idiopathic" (from the Greek "idio" meaning "peculiar" or "unusual" and "pathy" meaning "illness") to describe the disease, because the cause of IPF is unknown. Currently, researchers believe that IPF may result from either an autoimmune disorder, a condition in which the body's immune system attacks its own tissues, or the after effects of an infection, most likely a virus.

Whatever the trigger is for IPF, it appears to set off a series of events in which the inflammation and immune activity in the lungs--and, eventually, the fibrosis processes, too--become uncontrollable. In a few cases, heredity appears to play a part, possibly making some individuals more likely than others to get IPF.

In studies of patients with IPF, the average survival rate has been found to be 4 to 6 years after diagnosis. Those who develop IPF at a young age seem to have a longer survival.

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What Causes Idiopathic Pulmonary Fibrosis?


Sometimes doctors can find out what is causing pulmonary fibrosis (lung scarring). For example, exposure to environmental pollutants and certain medicines can cause the disease.

Environmental pollutants include inorganic dust (silica and hard metal dusts) and organic dust (bacteria and animal proteins). 

Medicines that are known to cause pulmonary fibrosis in some people include nitrofurantoin (an antibiotic), amiodarone (a heart medicine), methotrexate and bleomycin (both chemotherapy medicines), and many other medicines.

In most cases, however, the cause of lung scarring isn’t known. These cases are called idiopathic pulmonary fibrosis (IPF). With IPF, doctors think that something inside or outside of the lungs attacks them again and again over time.

These attacks injure the lungs and scar the tissue inside and between the air sacs. This makes it harder for oxygen to pass through the air sac walls into the bloodstream.

The following factors may increase your risk of IPF:

  • Cigarette smoking
  • Viral infections, including Epstein-Barr virus (which causes mononucleosis), influenza A virus, hepatitis C virus, HIV, and herpes virus 6
Genetics also may play a role in causing IPF. Some families have at least two members who have IPF.

Researchers have found that 9 out of 10 people who have IPF also have gastroesophageal reflux disease (GERD). GERD is a condition in which acid from your stomach backs up into your throat.

Some people who have GERD may regularly breathe in tiny drops of acid from their stomachs. The acid can injure their lungs and lead to Idiopathic Pulmonary Fibrosis. More research is needed to confirm this theory.

How Common Is IPF?


The exact number of people who develop IPF each year is not known. It is known, however, that equal numbers of men and women get the illness and that most cases of IPF are diagnosed when the patients are between the ages of 40 and 70.

Risk factors of Idiopathic Pulmonary Fibrosis


Factors that make you more susceptible to pulmonary fibrosis include:

Age


Although pulmonary fibrosis has been diagnosed in children and infants, the disorder is much more likely to affect middle-aged and older adults.

Smoking


Far more smokers and former smokers develop pulmonary fibrosis than do people who have never smoked.

Your occupation


You have an increased risk of developing pulmonary fibrosis if you work in mining, farming or construction or if you're exposed to pollutants known to damage your lungs.

Cancer treatments


Having radiation treatments to your chest or using certain chemotherapy drugs makes you more susceptible to pulmonary fibrosis.

Genetic factors


Some types of pulmonary fibrosis appear to run in families, so a genetic component is suspected.

What Are The Symptoms of Idiopathic Pulmonary Fibrosis?


Early symptoms of IPF are usually similar to those of other lung diseases. Very often, for example, patients suffer from a dry cough and dyspnea (shortness of breath). As the disease progresses, dyspnea becomes the major problem. Day-to-day activities such as climbing stairs, walking short distances, dressing, and even talking on the phone and eating become more difficult and sometimes nearly impossible. Enlargement (clubbing) of the fingertips may develop. The patient may also become less able to fight infection. In advanced stages of the illness, the patient may need oxygen all the time.

IPF can lead to death. Often the immediate cause is respiratory failure due to hypoxemia, right-heart failure, a heart attack, blood clot (embolism) in the lungs, stroke, or lung infection brought on by the disease.

What Is The Course of Idiopathic Pulmonary Fibrosis?


Although the course of IPF varies greatly from person to person, the disease usually develops slowly, sometimes over years.

The early stages are marked by alveolitis, an inflammation of the air sacs called alveoli, in the lungs. The job of the air sacs is to allow the transfer of oxygen from the lungs into the blood and the elimination of carbon dioxide from the lungs and out of the body.

As IPF progresses, the alveoli become damaged and scarred, thus stiffening the lungs. The stiffening makes breathing difficult and brings on a feeling of breathlessness (dyspnea), especially during activities that require extra effort.

In addition, scarring of the alveoli reduces the ability of the lungs to transfer oxygen. The resulting lack of oxygen in the blood (hypoxemia) may cause increases in the pressure inside the blood vessels of the lungs, a situation known as pulmonary hypertension. The high blood pressure in the lungs then puts a strain on the right ventricle, the lower right side of the heart, which pumps the oxygen-poor blood into the lungs.

How Is Idiopathic Pulmonary Fibrosis Diagnosed?


The first suspicion that a person may have IPF is usually based on the patient's symptoms and medical history. The doctor will try to confirm or rule out any suspicion by ordering one or more of the following tests:

Chest X ray


A simple chest X ray is a picture of the lungs and surrounding tissues, most often taken while the patient is standing up. In an IPF patient, the X ray usually reveals shadows, mostly in the lower part of the lungs. In addition, lung size tends to appear smaller than normal.

Computed Tomography (CT)


A computed tomography scan of the chest is a series of X rays that provide a view of the lungs that looks almost as if a slice had been made through the chest. During a CT scan, the patient lies inside a long, oval-shaped machine that permits x-ray beams to pass through the top, sides, and back of the body. A computer is used to combine all the pictures taken from these positions and thus gives the doctor a good look at what's going on inside the lungs and chest.

Blood Tests


When IPF is suspected, the doctor will analyze the patient's blood. A low level of oxygen in the arterial blood may reveal that the alveoli are not taking up enough oxygen.

Pulmonary Function Tests


Pulmonary function tests (PFTs) require the patient to breathe into a mouthpiece. The mouthpiece, in turn, is connected to a machine that measures the amount of air the patient breathes in and out over a specific period of time. The results tell the doctor how well the air passages in the lungs are functioning and how well the lungs are expanding.

Bronchoalveolar Lavage


Lung washings (bronchoalveolar lavage) are also helpful in arriving at a diagnosis of IPF. In this procedure, the doctor inserts a long, narrow, flexible, lighted tube called a bronchoscope down the windpipe and into the lungs to remove fluid (lavage) and other materials from inside the lungs. The amounts of certain cells and proteins found in the materials are measured to determine the stage of the lung disease.

Even is some or all of the results from such tests are abnormal, they are rarely sufficient to make a specific diagnosis of IPF. The only way the doctor can confirm a diagnosis of IPF is by examining the lung tissue; such tissue is usually obtained by an open lung biopsy.

Open Lung Biopsy


In an open lung biopsy, a chest surgeon makes cuts between the ribs in the chest and removes small pieces of tissue from several places in the lungs. The material is examined in the laboratory to determine how much inflammation and fibrosis are in the lungs. It is the only way to confirm whether the patient has IPF. If IPF is present, the biopsy results are also the best way to find out how far the disease has progressed and what the outlook is. In a patient with no other significant illness, recovery from an open lung biopsy is relatively quick. The hospital stay is usually 4 to 7 days; some newer procedures require less surgery, bringing hospital stays to 1 to 3 days.

Can Idiopathic Pulmonary Fibrosis Be Treated?


The best chance of slowing the progress of IPF is by treatment as soon as possible. Most IPF patients require treatment throughout life, usually under the guidance of a lung specialist. Some major medical centers and large teaching hospitals do research on the disease and provide consultation and treatment to patients.
Treatment for IPF may vary a great deal. It depends on many things, including the age of the patient and stage of the disease. The aim of treatment is to reduce the inflammation of the alveoli and stop the abnormal process that ends in fibrosis. Once scar tissue has formed in the lung, it cannot be returned to normal.

How Is Idiopathic Pulmonary Fibrosis Treated?


Drugs are the primary way that IPF is treated. They are usually prescribed for at least 3 to 6 months. This gives the doctor time to see if a particular treatment is effective. A combination of tests is used to monitor how well a particular drug is working. The dose may have to be adjusted so that the medicine gives the best possible results with the least side effects. Most side effects are reduced when the dose is made smaller or the drug is stopped. Commonly used drugs are prednisone and cytoxan. Oxygen administration and, in special cases, transplantation of the lung are other choices.

Prednisone


A corticosteroid, prednisone, is the most common drug given to patients with IPF. About 25 to 35 percent of all patients respond favorably to this medicine. No one knows exactly how corticosteroids work or why some patients do well on prednisone while others do not. Patients take prednisone by mouth every morning, starting with a high dose for the first 4 to 8 weeks. As they improve, they gradually take smaller amounts. Changes in mood are one of the more common side effects of prednisone; most patients, however, can handle the mood changes--anxiety, depression, or sleeplessness--once they know what is causing the problem. A less common side effect is a rise in blood-sugar levels.

Cytoxan


Cyclophosphamide, also referred to as cytoxan, may be taken together with prednisone, or instead of it. Like prednisone, cytoxan is swallowed each day. One of the more serious side effects of cyclophosphamide is leukopenia, a condition in which the number of white blood cells drops to a dangerously low level. Leukopenia can be controlled by regularly checking the blood count and adjusting the dose of cytoxan if necessary.

Other Medicines


Azathioprine, penicillamine, chlorambucil, vincristine sulfate, and colchicine have been used in a few patients with IPF. Their effectiveness in treating IPF, however, has not been adequately tested.

Oxygen


In addition to treatment with medicine, some patients may need oxygen, especially when blood oxygen becomes low. This treatment helps resupply the blood with oxygen. As a result, breathlessness is reduced, the patient can be more active, and the severity of pulmonary hypertension decreases.

Exercise


Regular exercise may be useful for patients with IPF. A daily walk or regular use of a stationary bicycle or treadmill can improve muscle strength and breathing ability and also increase overall strength. If needed, supplemental oxygen should be used; sometimes it is the only way a patient is able to do a reasonable amount of activity.

Lung Transplantation


Lung transplantation, either of both lungs or only one, is an alternative to drug treatment for patients in the severe, final stages of IPF. It is most often performed in patients under 60 years of age who do not respond to any form of treatment. The 1-year survival rate is approximately 60 percent.

How to Prevent Idiopathic Pulmonary Fibrosis


There is no proven way to prevent IPF. However, avoiding smoking may help.

How Will IPF Affect A Patient's Lifestyle?


Many IPF patients, particularly those in the early stages of the disease, respond to drug treatment and can continue to go about most of their normal activities, including working. Some patients with advanced IPF need to carry oxygen with them.

In addition to getting proper treatment, IPF patients can help themselves by following the same sensible health measures that everyone should observe. These include eating a healthy diet, maintaining proper weight, exercising regularly, and getting enough rest. Above all, IPF patients should not smoke. Pregnancy is not advisable because the illness puts an extra load on the heart and lungs.

As with many chronic illnesses, emotional support and psychological counseling can be of much help to the patient. Most doctors and patients agree that it is important for both patient and family to be as informed as possible about IPF. In this way, everyone involved can understand the illness and apply that information to what is happening in his or her own life.