Idiopathic Pulmonary Fibrosis
Idiopathic Pulmonary Fibrosis (IPF) is a disease characterized by progressive scarring, or fibrosis, of the lungs. It is a specific type of interstitial lung disease in which the small air sacs of the lung, known as “alveoli,” gradually become replaced by fibrotic (scar) tissue. The abnormal fibrosis and scar formation typically begins in the terminal areas of the pulmonary tree lining the air sacs where gas exchange occurs. Normally, this tissue is a thin layer consisting of a few, easily permeable cells. With IPF, progressive scarring causes the normally thin and pliable tissue to thicken and become stiff, making it more difficult for the lungs to expand, preventing oxygen from readily getting into the bloodstream.
There is a corresponding increase in respiratory symptoms with dyspnea, air hunger and a non-productive cough. Idiopathic, or of unknown cause, IPF is not thought to be related to any other disease or condition, such as cancer or asthma. IPF is a uniformly fatal disease, with an estimated median survival time of two to five years.
There are no known causes for IPF. However, the disease is typically found in people between the ages of 40 and 80, and affects more men than women. Cigarette smoking may increase the risk of developing IPF. Some cases of IPF occur in patients who have family members with the disease, which suggests that genetic factors may contribute to the risk of developing IPF in certain individuals.
Although these risk factors are associated with IPF, it is important to remember that they have not been shown to cause IPF -- the cause of IPF is still unknown.
- Once considered a relatively rare disease, IPF is now recognized as the most common interstitial lung disease (interstitial refers to the tissue surrounding the alveoli).
- An estimated 100,000 people are living with IPF in the United States, and more than 30,000 new cases are diagnosed annually.
- The incidence of IPF is greater than that of ovarian cancer, similar to those of pancreatic cancer and of all leukemias combined, and nearly 30 times that of cystic fibrosis.
- 73% of patients with IPF are > 65 years of age.
- The 5-year mortality rate for patients with IPF is 50% to 70%.