Pulmonary fibrosis: a disease of alveolar collapse and collagen deposition

ABSTRACT

Introduction: Idiopathic pulmonary fibrosis (IPF) is a relentless form of fibrotic lung disease with a median survival of approximately 3 years after diagnosis and a mortality rate that surpasses that of many types of cancer. The pathophysiology of IPF is complex as there are likely different stages of disease occurring simultaneously in the lung.

Areas covered: Some scientists consider IPF as primarily an epithelial driven disease in which dysfunctional surfactant-producing cells take an etiological precedent. Others focus on the augmented deposition of collagen within the interstitium as the primary inciting event causing fibrosis. An increase in collagen deposition augmenting the tensile strength of the pulmonary interstitium fits with the well-known restrictive nature of fibrotic lung diseases; however, it fails to explain the creation of cystic ‘honeycombing’ lesions and the preference of such lesions for the peripheral and basilar lung parenchyma.

Expert opinion: In this paper, we will review both ideas and propose incorporating them into a single pathophysiological chain-of-events that could account for all the features that characterize IPF, allowing us to envision new therapeutic approaches to improve patient outcomes.

KEYWORDS:

• Fibrosis
• collagen
• atelectasis
• Honeycombing
• alveolar epithelial cells

Declarations

One author is a speaker for Genentech, Boehriger Ingelheim, Rockpointe CME, and is a consultant for Boehringer Ingelheim. Another author is a speaker for Genentech and a consultant for Boehringer Ingelheim. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewers Disclosure

Peer reviewers on this manuscript have no relevant financial relationships or otherwise to disclose.