What is idiopathic pulmonary fibrosis?
Idiopathic pulmonary fibrosis (IPF) is a rare and poorly understood lung condition that causes scarring of the lungs.
It gets worse over time and is often fatal.
Symptoms of IPF include:
- shortness of breath especially when physically active which gradually worsens over time
- a persistent dry cough
Read more about the symptoms of idiopathic pulmonary fibrosis.
What causes pulmonary fibrosis?
The cause of IPF is still unclear but the condition appears to be connected with cells inside the lungs known as alveolar epithelial cells (AECs).
The current thinking is that the AECs become damaged and then begin to die. The body tries to repair the damage by releasing another type of cell known as fibroblasts. But the production of the fibroblasts goes out of control and they cause scarring and hardening (fibrosis) of the delicate tissues of the lungs.
Levels of fibrosis increase leading to a gradual decline in lung function resulting in the symptoms of IPF.
Exactly why the AECs become damaged in the first place is not known. A combination of genetic and environmental factors may be involved.
Read more about the possible causes of idiopathic pulmonary fibrosis.
There is currently no cure for IPF so the aim of treatment is to try to relieve symptoms and protect against anything that could further damage the lungs such as an influenza (flu) infection.
This can be done using a combination of medication and oxygen therapy (using a breathing mask and tank).
In some cases treatment might not be used, as side effects associated with some types of medication outweigh potential benefits.
Younger people with IPF who are in a relatively good state of health may be a suitable candidate for a lung transplant.
Read more about the treatment of idiopathic pulmonary fibrosis.
Who is affected
IPF is a rare condition though the number of cases have risen in recent years.
The condition usually first develops in adults aged 50 or above and is thought to be more common in men.
The outlook for IPF can be highly variable. Some people respond well to medication and remain relatively free of symptoms for many years. Other people's health quickly worsens leading to a fatal complication, such as heart failure.
It is impossible to predict an individual’s expected survival rate. In general, survival times can range from 2-5 years after diagnosis.
Idiopathic pulmonary fibrosis symptoms
The most common symptom of idiopathic pulmonary fibrosis (IPF) is shortness of breath, often when physically active, which can get worse over time.
At first, many people ignore their breathlessness (especially older patients) and blame it on getting old or being out of shape. However, as the disease progresses and lung damage becomes more severe, breathlessness can develop even with minor physical activity such as getting dressed or having a shower.
Other symptoms of pulmonary fibrosis include:
In up to half of all cases, there is also a change in the shape of the finger and toenails. This thickening of tissue at the base of the finger and toenails is known as digital clubbing. The exact cause of clubbing is unknown, but it can occur in people with various chest and heart diseases.
The strain IPF can place on your lungs and your heart can trigger a number of secondary conditions, outlined below.
You will have an increased risk of developing chest and airway infections such as:
- bronchitis – an infection of the airway of the lungs
- pneumonia – an infection of the air sacs of your lungs
- influenza (flu)
Symptoms of a chest infection include:
- worsening breathlessness
- chest pain
- a high temperature (fever) of or above 38ºC (100.4ºF)
- sweating and shivering
Around a third of people with IPF will also go on to develop pulmonary hypertension. Pulmonary hypertension is when blood pressure inside the arteries that connect the lungs to the heart is dangerously high.
Symptoms of pulmonary hypertension include:
Read more about symptoms of pulmonary hypertension.
Heart failure, where the heart is unable to pump enough blood around the body, can develop when the condition becomes severe.
This is due to a combination of factors, including a build-up of blood in the right side of the heart (the side that pumps blood to the lungs), which develops because it is difficult to pump blood through the scarred lung tissue. The poor supply of oxygen from the diseased lungs to the heart muscle also contributes to heart failure.
Heart failure can cause various symptoms, including:
- worsening breathlessness
- extreme tiredness and weakness
- swelling in the legs, ankles and feet (oedema) caused by a build-up of fluid
Read more about the symptoms of heart failure.
Idiopathic pulmonary fibrosis causes
It is not known exactly how idiopathic pulmonary fibrosis (IPF) occurs or why some people are more prone to developing it. Idiopathic means having no known cause.
It is thought that IPF is triggered when cells that line the lung alveoli (air sacs) become damaged. Affected cells try to repair themselves but the process becomes uncontrolled, resulting in thickening and scarring (fibrosis) of the alveoli and surrounding lung tissue. The amount of oxygen that can pass from the lungs into the blood is then significantly reduced.
A number of factors have been suggested as possible triggers for the initial damage to the cells lining the alveoli, including:
- Cigarette smoking – the disease is more common in current smokers or those who have smoked in the past.
- Viral infections such as the Epstein-Barr virus or hepatitis C
- Breathing in wood dust and/or metal dust – people in occupations where this can occur, such as carpentry, have a slightly higher risk o developing IPF
- Gastro-oesophageal reflux disease (GORD), a condition where the acid from your stomach rises back up into your throat – this may be accidentally inhaled into the lungs, causing damage to the alveoli
- Genetic tendency – the condition appears to run in some families
As IPF is such a rare condition it is hard to estimate how much of an impact these risk factors can have on your chance of developing IPF.
Most experts agree that the two most significant risk factors are:
- being a smoker or having smoked in the past
- exposure to wood and metal dust
Diagnosing idiopathic pulmonary fibrosis
Idiopathic pulmonary fibrosis (IPF) can be hard to diagnose because its main symptoms are similar to those of other lung diseases.
Also, little is known about its causes or how it progresses. You will usually be referred to a chest (respiratory) specialist for diagnosis.
Medical history and physical examination
Your doctor will ask about your medical history and whether there are other factors that could contribute to the diagnosis of IPF, such as whether you are a smoker, or have been exposed to occupational contaminants or have other medical conditions.
They will physically examine you, checking the sound of your breathing through a stethoscope. A ‘crackling’ sound can suggest fibrosis. They will also look for signs of clubbing on your fingers and toes.
Lung function tests (also called pulmonary function tests) assess how well your lungs work. These tests measure how quickly you can move air in and out of your lungs, how much air they can hold and how well they transfer oxygen into, and remove carbon dioxide from, your blood.
The tests require you to breathe in and out of a lung function machine. Information collected will help diagnose different lung diseases, measure their severity and check how well treatment for a particular lung disease is working.
As IPF can look like other lung diseases on a scan, your consultant may need to remove a small piece of your lung (biopsy) to confirm the diagnosis. This is considered the most reliable way of diagnosing IPF.
A biopsy of the lung can usually be obtained using a keyhole procedure. The modern technique is called video-assisted thoracoscopic surgery, or VATS.
VATS is performed under a general anaesthetic, so you are asleep throughout. A surgeon makes several small incisions (cuts) in your side and a thin tube with a camera and a light at the end (endoscope) is inserted through one of the incisions into the area between the lungs and the chest wall. The surgeon is able to see the lung tissue through the endoscope and obtain a sample, which can be examined for signs of fibrosis under a microscope.
Chest X-rays are a good way of looking for changes or abnormalities in your lungs to help diagnose particular conditions. Although major organs and blood vessels do not show up as clearly on X-rays as bones, they are still visible.
Similar to an X-ray, a CT (computerised tomography) scan can provide a sharper and more detailed image of your lungs. A radiologist (doctor specially trained to interpret medical images such as X-rays) may be able to identify a honeycomb effect in the lungs. This honeycomb effect suggests lung scarring and damage to your air sacs.
Bronchoscopy is a method of looking inside your airways. A narrow, flexible tube called a bronchoscope is introduced through your nose or throat and down into your airways. The tube has an eyepiece so the doctor can see inside. The doctor then looks for anything abnormal and can take cell samples for testing. They can also take photographs of the inside of your airways if necessary.
You usually have the test under local anaesthetic. This means you are awake for the test but your throat is numbed. The procedure can be a bit uncomfortable but does not last long.
An echocardiogram is an ultrasound examination of your heart, which may be needed if the specialist suspects you have developed heart failure.
There is currently no cure for idiopathic pulmonary fibrosis. The main aim of treatment is to relieve symptoms of the disease as much as possible and slow down its progression.
Medication can help reduce symptoms in some people, but not everyone. Some people, particularly elderly people whose symptoms are mild or not getting worse, may be advised not to take any medication. This is because possible side effects could be worse than the progression of the disease.
A low dose of a corticosteroid called prednisone may be prescribed. If there is no improvement after a few months, the treatment may be stopped.
Taking steroid medication, especially for a prolonged period of time, can cause side effects including:
- weight gain
- osteoporosis (brittle bones, which especially affects women after the menopause)
- cataracts (cloudy patches in the lens in the eye)
- glaucoma (an eye disease that impairs vision)
- stomach problems
Your doctor or specialist should always weigh up potential benefits of steroid treatment against the risk of side effects.
A number of other medications have been recently used to see if they could be effective in treating IPF. The most promising are described below.
N-acetylcysteine is what is known as an antioxidant. Antioxidants can have a limited effect in protecting cells against damage that can occur with aging.
There is evidence that combining N-acetylcysteine with a corticosteroid can slow the progression of IPF in the short-term. Its long-term effectiveness is uncertain.
N-acetylcysteine is available from many health shops on an over-the-counter basis. Check with the doctor in charge of your care before taking this medication as it may not be safe or suitable for everyone with IPF.
Sildenafil is a medication that can widen the blood vessels inside the lungs which should help improve blood flow while reducing blood pressure (useful if you also have pulmonary hypertension),
Research has found sildenafil can lead to a modest improvement in breathlessness which can improve a person’s range of daily activities. This in turn can lead to an improvement in quality of life.
Sildenafil may not be suitable for you if you:
- are also taking medicines or drugs that contain nitrates – organic nitrates are often used to treat angina and amyl nitrate is a recreational drug commonly known as "poppers”
- have a severe problem with your liver
- have recently had a heart attack or stroke
- have severe low blood pressure
- have certain eye conditions
Common side effects of sildenafil include:
Pirfenidone is an antifibrotic medication that may be used for treating adults with mild to moderate IPF.
More studies are needed on its long-term effects, but current research suggests pirfenidone is able to slow the progression of IPF.
Side effects of pirfenidone may include:
- abdominal pain
- tiredness (fatigue)
- photosensitivity rash (on exposure to sunshine)
Pirfenidone is currently only prescribed on a named patient basis by specialist centres.
When idiopathic pulmonary fibrosis is severe, levels of oxygen in your blood fall and you feel more breathless. In this case your specialist may prescribe you oxygen, which can help with your breathing and enable you to be more active.
You will need to take oxygen through nasal tubes or a mask from a portable machine called an oxygen concentrator. This device provides air with a much higher oxygen level than the air you breathe in naturally. The tubes from the machine are long, so you will be able to move around your home while connected.
You can also use an oxygen inhaler when you are out and about.
Pulmonary rehabilitation is a multidisciplinary treatment (involving many different types of healthcare professionals) used for many long-term lung conditions. Courses aim to help a patient come to terms with their condition, learn the best ways to deal with it and improve their ability to function on a daily basis without extreme breathlessness.
Courses in pulmonary rehabilitation are usually held locally and may include:
- education about pulmonary fibrosis
- physical exercise
- breathing exercises
- advice on nutrition
- psychological support
- a social support network
For more information, watch the above video in which a respiratory nurse specialist and patients explain pulmonary rehabilitation.
If your condition continues to get worse despite other forms of treatment, your consultant may recommend a lung transplant. The decision to have a transplant will be based on:
- how bad your condition is
- how quickly your condition is getting worse
- your age and general health
- how much your condition is likely to improve after a transplant
- whether a donor lung is available
Few people with idiopathic pulmonary fibrosis are suitable candidates for a lung transplant.
As well as medical treatments above, there are measures you can take to stay as healthy as possible:
- stop smoking
- exercise regularly and stay as fit as you can
- eat a good, balanced diet
- take the flu jab and the pneumococcal vaccination (influenza and pneumococcal bacterial infections can become severe if you have a lung disease)
- try to keep away from people with chest infections and colds