- Lung Transplantation
- Life Expectancy
- Doctors and Specialists
- How to Prevent
Idiopathic pulmonary fibrosis (IPF) is defined as a specific form of progressive fibrosis that causes interstitial pneumonia, usually in older adults and is limited to the lungs. Fibrotic (scar-like) tissue develops in the airways of the lungs, making it difficult for the body to get the oxygen it needs.
Idiopathic pulmonary fibrosis differs from pulmonary fibrosis in that the cause is unknown whereas there are known causes of pulmonary fibrosis. Though not very common, idiopathic pulmonary fibrosis is considered to be debilitating, incurable, and terminal, by many healthcare professionals and researchers.
What are the signs and symptoms of idiopathic pulmonary fibrosis?
The symptoms of idiopathic pulmonary fibrosis are not specific and are similar to many other types of pulmonary cardiac diseases. The majority of people with the disease have about a 6-month or more history of shortness of breath and/or nonproductive cough.
About 5% of people with idiopathic pulmonary fibrosis do not have symptoms, and the disease is diagnosed when he or she is being examined for other medical problems.
The signs and symptoms that may occur in some people with idiopathic pulmonary fibrosis are:
What causes idiopathic pulmonary fibrosis?
- Inclusion of the word "idiopathic" means that this type of fibrosis has an unknown cause.
- Current hypotheses include exposure to some type of agent (for example, environmental dust, viral infection, reflux, aspiration of gastrointestinal contents, and others) that leads to alveolar damage in the lungs.
- Researchers further hypothesize that in attempt to repair the alveolar damage, fibrosis and lung scarring occur to produce eventually clinical pulmonary fibrosis.
What are the stages of idiopathic pulmonary fibrosis?
Staging systems for idiopathic pulmonary fibrosis may help healthcare professionals and researchers to better define the medical condition of their patients. However, for idiopathic pulmonary fibrosis, staging systems are constantly being redefined.
- For example, the first staging systems traditionally considered the disease as mild, moderate, or severe while others considered stages as early or advanced. The stages are relatively arbitrary and loosely based on pulmonary function tests.
- Unfortunately, there are no standardized definitions for mild, moderate, and severe idiopathic pulmonary fibrosis. Though arbitrary, these staging systems give healthcare professionals a framework to diagnose and treat patients with idiopathic pulmonary fibrosis.
- Some doctors consider treatment with pirfenidone for mild to moderate disease, and lung transplantation for severe idiopathic pulmonary fibrosis.
- There are researchers that have developed novel idiopathic pulmonary fibrosis staging systems based on other criteria such as age, hospitalization, baseline lung function, and a 24-week change in function, while other researchers choose other parameters such as various physiological lung measurements.
- The patient and their physician(s) can discuss which staging system they choose to utilize.
How is idiopathic pulmonary fibrosis diagnosed?
The diagnosis of idiopathic pulmonary fibrosis is somewhat difficult. It is a diagnosis of exclusion of other known causes of interstitial lung disease including environmental and drug exposures.
Currently, there are no laboratory studies that can ultimately diagnose idiopathic pulmonary fibrosis; however, up to 30% of people with idiopathic pulmonary fibrosis may have positive tests for antinuclear antibodies and/or rheumatoid factor.
However, repeated pulmonary function tests that show declines over six months, when taken into account with other non-specific findings, add to the possible diagnosis. However, a pattern of usual interstitial pneumonia (UIP) on HRCT requires four features for diagnosis of interstitial pneumonia:
- Subplural, basal predominance of ground glass opacity
- Reticular abnormalities
- Honeycombing with or without traction bronchiectasis
- Absence of features listed as inconsistent with UIP
Bronchoscopy and surgical lung biopsy are also used to help distinguish between UIP and idiopathic pulmonary fibrosis. Consequently, the newest diagnostic criteria of idiopathic pulmonary fibrosis requires the following:
- Exclusion of other known causes of interstitial lung disease (environmental exposures, connective tissue disease, and/or drug toxicities)
- The presence of a UIP pattern, described above, on HRCT in patients not subjected to surgical biopsy
- Specific combinations of HRCT and surgical lung biopsy patterns in patients subjected to surgical lung biopsy
What is the treatment for idiopathic pulmonary fibrosis?
The treatment for idiopathic pulmonary fibrosis depends upon the stage of the disease, and usually begins with medical treatment, supportive measures, and possibly surgical transplantation of the lungs.
Often, during the mild to moderate disease medical care is initiated. However, idiopathic pulmonary fibrosis sometimes progresses rapidly, so if idiopathic pulmonary fibrosis is diagnosed, a transplant surgeon should be consulted early as the person with IPF may eventually require lung transplant.
Guidelines on the treatment of idiopathic pulmonary fibrosis have been published by several institutions including the American, European, Japanese, Latin American thoracic societies and/or associations. The following is an abbreviated summary of these guidelines:
- They conditionally recommend the use of pirfenidone and nintedanib.
- They do not conditionally recommend the use of imatinib (Gleevec), warfarin (Warfarin, Jantoven), combination prednisone with N-acetylcysteine, and several other drugs.
- They conditionally recommend anti-acid medications even in idiopathic pulmonary fibrosis patients without symptoms of reflux.
- Encourage the patient to quit smoking.
- Encourage vaccination against influenza and pneumococcal infections.
- They suggest patients with hypoxemia (low oxygen in the blood, for example, pulse oximetry measured less than 88%) use oxygen therapies to maintain a saturation at least 90% during all activities, including sleeping.
Patients should discuss with their doctors on how this progressive disease is best treated on an individual basis.
Lung transplantation for idiopathic pulmonary fibrosis
Lung transplantation is considered when the patient develops severe stage (also termed end stage) idiopathic pulmonary fibrosis. Lung transplantation does show a survival benefit over medical therapy. Idiopathic pulmonary fibrosis has now replaced chronic obstructive pulmonary disease (COPD) as the most common reason for lung transplantation in the U.S.
- Any patient with idiopathic pulmonary fibrosis should be referred to a transplant surgeon to determine early on if the patient may meet criteria for a lung transplant.
- Some people may qualify for a single or a double lung transplant.
- Reported five-year survival rates for lung transplantation are about 50% to 56%.
- Criteria for a transplant vary somewhat so it is important to have the patient and the medical team (primary care physician, pulmonologist, and transplant surgeon) all agree on the potential criteria for the individual patient.
What is the life expectancy and prognosis for a person with idiopathic pulmonary fibrosis?
- Idiopathic pulmonary fibrosis has a poor prognosis. The mean survival time or "life expectancy" is about 2 to 5 years from the time of diagnosis.
- Most commonly, the person experiences an acute exacerbation of idiopathic pulmonary fibrosis and then dies because of the disease.
- Individuals with IPF who undergo lung transplant have a mortality rate of about 50% to 56% after five years so the transplant may increase the life expectancy in some people with the disease.
Which specialties of doctors treat idiopathic pulmonary fibrosis?
Although primary care physicians help manage patients with idiopathic pulmonary fibrosis, usually a pulmonologist (a lung specialist) is consulted during the diagnosis and treatment of idiopathic pulmonary fibrosis.
- Some doctors suggest a lung transplant surgeon be consulted when the patient is diagnosed with idiopathic pulmonary fibrosis unless there are contraindications (Lung transplant may be more harmful to some people.) for transplantation.
- Because of the high incidence of gastroesophageal reflux (GERD) in patients with idiopathic pulmonary fibrosis, a gastroenterologist may be consulted.
Can idiopathic pulmonary fibrosis be prevented?
- Because idiopathic pulmonary fibrosis is "idiopathic," prevention is difficult.
- However, many health-care professionals and researchers theorize that the risk of idiopathic pulmonary fibrosis may be reduced in some people if they quit smoking, and reduce or eliminate their exposure to toxins or fumes that have the potential to damage the lungs.
Support for families and friends of people with idiopathic pulmonary fibrosis
There are support groups for idiopathic pulmonary fibrosis patients and their families, including the following:
- Pulmonary Fibrosis Foundation (www.pulmonaryfibrosis.org)
- American Lung Association (www.lung.org).
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Kolb, M. et al. "Staging of idiopathic pulmonary fibrosis: past, present and future." European Respiratory Review. 23:220–224, 2014.