Idiopathic pulmonary fibrosis (IPF) refers to the scarring of the interstitium – the supporting framework of the lungs as well as the pulmonary tissues, with fibroblast proliferation, deposition of extracellular matrix, and progressing fibrosis of the tissues.
It is a debilitating, lethal condition which progressively worsens, leading to decreasing lung volumes and hypoxemic respiratory failures — and eventually to death if left untreated. The disease has a mean overall survival time of two to three years. From 7 to 16 cases of IPF are reported every year in the U.S. per 100,000 people.
Causes of IPF
The exact causes of IPF are unknown, but past studies have attributed many cases to excessive smoking and exposure to environmental allergens and toxins. It is referred to as “idiopathic” because there are not exact proven causes.
Pathogenesis of IPF
Past studies have traced the development of IPF as a function of repeated damage caused to the alveolar epithelium. Injury causes alveolar epithelial cells to attract fibroblasts, which induce proliferation and differentiation into myofibroblasts and production of extracellular matrix (ECM). The damage caused to the epithelia is not healed properly, and the same process is repeated again, which leads to progressive damage to the lung tissues and its surroundings. As a result, scarring, honeycombing, and fibrosis are more of the effects of improper wound healing than of immunomodulation.
There is evidence of upregulation of genes related to cytokine and chemokine synthesis, and high levels of uric acid secreted during IPF. The main therapeutic focus is to normalize wound healing and re-epithelization of the alveolar lining, along with modulation of key inflammatory pathways.
Current therapies for treatment of IPF…