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.