What is pulmonary fibrosis?
"Fibrosis" is a term used to refer to scarring, so pulmonary fibrosis means scarring throughout the lungs. Pulmonary fibrosis can be caused by many conditions including chronic inflammatory processes (sarcoidosis, Wegener's granulomatosis ), infections, environmental agents (asbestos, silica, exposure to certain gases), exposure to ionizing radiation (such as radiation therapy to treat tumors of the chest), chronic conditions (lupus, rheumatoid arthritis), and certain medications.

In a condition known as hypersensitivity pneumonitis, fibrosis of the lung can develop following a heightened immune reaction to inhaled organic dusts or occupational chemicals. This condition most often results from inhaling dust contaminated with bacterial, fungal, or animal products.

In some people, chronic pulmonary inflammation and fibrosis develop without an identifiable cause. Most of these people have a condition called idiopathic pulmonary fibrosis (IPF) that does not respond to medical therapy, while some of the other types of fibrosis, such as nonspecific interstitial pneumonitis (NSIP), may respond to immune suppressive therapy.

Synonyms (other names) for various types of pulmonary fibrosis that have been used in the past include chronic interstitial pneumonitis, Hamman-Rich Syndrome, and diffuse fibrosing alveolitis

How is the pulmonary fibrosis treated?
The treatment options for idiopathic pulmonary fibrosis are very limited. There is no evidence that any medications can help this condition, since scarring is permanent once it has developed. Lung transplantation is the only therapeutic option available. At times, this diagnosis can be difficult to make even with tissue biopsy reviewed by pathologists with specific experience in this field. Research trials using different drugs that may reduce fibrous scarring are ongoing. Since some types of lung fibrosis can respond to corticosteroids (such as Prednisone) and/or other medications that suppress the body's immune system, these types of drugs are sometimes prescribed in an attempt to decrease the processes that lead to fibrosis.

The immune system is felt to play a central role in the development of many forms of pulmonary fibrosis. The goal of treatment with immune suppressive agents such as corticosteroids is to decrease lung inflammation and subsequent scarring. Responses to treatment are variable. Once scarring has developed, it is permanent. Those whose conditions improve with immune suppressive treatment probably do not have idiopathic pulmonary fibrosis.

The toxicity and side effects of treatments can be serious. Therefore, patients with pulmonary fibrosis should be followed by a lung specialist experienced in this condition. The lung specialist will determine the need for treatment, the duration of treatment, and will monitor the response to therapy along with any side effects. Only a minority of patients respond to corticosteroids alone, so other immune-suppressing medications are used in addition to corticosteroids. These include gamma-interferon, cyclophosphamide, azathioprine, methotrexate, penicillamine, and cyclosporine. The anti-inflammatory medication colchicine has also been used with limited success. Ongoing trials are underway using newer drugs such as gamma interferon, mycophenolate mofetil (Cellcept), and pirfenidone.

Pulmonary fibrosis can cause decreased oxygen levels in the blood. A decrease in blood oxygen level (hypoxia) can lead to elevated pressure in the pulmonary artery (the vessel that carries blood from the heart to the lungs to receive oxygen), a condition known as pulmonary hypertension, which can in turn lead to failure of the right ventricle of the heart. Therefore, patients with pulmonary fibrosis are frequently treated with supplemental oxygen to prevent pulmonary hypertension.

There is also evidence that patients suffering from pulmonary fibrosis may be at increased risk for blood clots that travel to the lung (pulmonary emboli), and therefore anticoagulation (blood thinning) therapy may be indicated