Idiopathic pulmonary fibrosis (IPF) is a rare chronic and progressive lung disorder with high lethality and considerable morbidity.
IPF has been linked to exposure to certain types of dust, viral infections, a family history of IPF, gastro-oesophageal reflux disease, smoking (NHS).
NUMBERS AT A GLANCE – EPIDEMIOLOGY
The mean age of IPF onset is around 65 years (Fell et al., 2009). IPF is estimated to be affecting 3 million people worldwide due to its rising incidence (George et al., 2020) and estimates of incidence data (per 10,000 of the population) indicate a range from 0.35 to 1.30 in Asia–Pacific countries, 0.09 to 0.49 in Europe, and 0.75 to 0.93 in North America (Maher et al., 2021).
IPF clinical symptoms tend to develop gradually and worsen over time with a life expectation of 2-5 years after diagnosis. These include shortness of breath, a persistent dry cough, tiredness, loss of appetite and weight loss, rounded and swollen fingertips (NHS). Mental health is also inevitably affected by these symptoms with multiple studies indicating that depression and anxiety are common consequences of IPF (Lee et al., 2017). Eventually IPF leads to respiratory failure and death. Unfortunately, lung transplantation is the only treatment that improves outcome of this devastating disease (George et al., 2020).
The current treatment for IPS includes two approved antifibrotic drugs which do not cure the disease but slow the decline of lungs function.
In the respiratory system oxygen is taken in and carbon dioxide is eliminated. This fundamental process happens in the alveoli.
Alveoli take an intimate contact with the surrounding capillaries. Alveoli walls and capillaries are in fact one cell thick. This small thickness can guarantee that the inhaled oxygen travels quickly from the alveoli to the blood stream.
Similarly, carbon dioxide exits the blood into the alveoli to be exhaled (Figure 1).
IPF arises as a result of repetitive injury of the lung capillary cells and of the alveolar epithelial cells. Wound healing in IPF is highly aberrant and characterized by an accumulation of inflammatory cells followed by activation of fibroblasts. The subsequent deposition of extracellular matrix (ECM) results in the loss of tissue architecture and end-stage scar tissue (fibrosis) (Nishi et al., 2007). This highly compromises lung function (Figure 2).
The absence of a biomarker complicates the diagnosis of this disease. Importantly, it was shown that galectin-3 is a potent pro-fibrotic agent. Numerous studies demonstrate that Galectin-3 is capable of modulating the actitivity of fibroblasts and macrophages (Chen et al., 2017; Dang et al., 2012; Farnworth et al., 2008; Henderson et al., 2006, 2008; MacKinnon et al., 2008; Mackinnon et al., 2012, 2013b).