Pulmonary fibrosis can be seen in many types of interstitial lung diseases and is characterized by scarring of lung tissue and/or inflammation with a high risk of developing a progressive disease. When the cause of disease is unknown, the fibrosis may be termed “idiopathic” (IPF).

Idiopathic Pulmonary Fibrosis (IPF) develops in lung alveoli – tiny air-filled sacks where the exchange of oxygen and carbon dioxide takes place. The inner surface of the alveoli is covered by type 1 and type 2 epithelial cells. Type 1 epithelial cells are important for the gas-exchange in the lungs. With time, they get damaged and continuously need to be replaced. Type 2 epithelial cells divide and differentiate into new type 1 epithelial cells, thereby maintaining alveolar integrity to keep the lungs healthy and well-functioning.

In IPF, type 2 epithelial cells become dysfunctional and lose their ability to repair and maintain alveolar integrity. The loss of integrity is a starting point for scarring, leading to release of profibrotic mediators stimulating fibroblasts to produce excessive collagen fibers causing fibrosis.

Unfortunately, a diagnosis of pulmonary fibrosis is often delayed because the symptoms are similar to other lung diseases. Symptoms of pulmonary fibrosis include shortness of breath, fatigue, a dry intractable cough as well as anxiety and depression. Physical and psychological morbidity is significant, with increasing cough and shortness of breath, and worsening quality of life. The prognosis is poor, with a median survival of only two to three years for untreated IPF and five years if treated.

Specifically looking at IPF, there are approximately 3 million people worldwide living with the disease. Debilitating symptoms typically appear between the ages of 50 and 70 years and, while the disease is most common in men, the number of cases in women is increasing.

Currently, there is no cure for IPF, and only two approved medications are available, pirfenidone and nintedanib. Both medications have been shown to slow the progression of the disease; however, side effects have limited their use. Supportive treatments include the use of oxygen therapy, pulmonary rehabilitation, and lung transplantation. Pulmonary rehabilitation includes exercise training; breathing exercises; anxiety, stress, and depression management; nutritional counseling; education; and more.

Clearly, new treatments are urgently needed to reduce the significant burden of this disease.