Fibrosis

Fibrosis refers to an abnormal deposition of connective tissue and certain strand proteins (collagen) in organs. Literally, microscopic scars formed within the regular organ structure increase the overall tissue stiffness and compromize organ functionality. The arguably best known example is cirrhosis (liver fibrosis), which may result from prolonged alcohol abuse. However, fibrosis can also occur in other organs, such as the heart, where it may be a late complication of myocardial infarct and ultimately lead to heart failure.

Lung fibrosis is a slowly progressing disease, frequently developing without known cause (termed idiopathic) but also in response to environmental factors, such as inhalation of mineral dust, and infectious diseases, including COVID-19. The impaired lung function leads to a generally worse oxygen supply to the body with symptoms of short breath and fatigue, and disease progress limits life expectancy to a few years after diagnosis.

The treatment of fibrotic diseases is likely to be more successful if started as early as possible. This is because current therapies cannot revert scar formation, but merely aim to slow down disease progression by inhibiting the formation of more connective tissue. In risk groups, diagnosis should ideally be possible before substantial changes in tissue structure and thus, clinical symptoms, are manifest.

There is evidence that the protein αvβ6-integrin is an early biomarker of fibrosis, since it is a key component of the fibrosis-promoting TGF-β signalling pathway. Positron emission tomography (PET) with the radiopharmaceutical Ga-68-Trivehexin can visualize the presence and distribution of αvβ6-integrin in the body ^[1]. Ga-68-Trivehexin PET might therefore enable early diagnosis and more effective treatment of fibrotic diseases, as well as an improved monitoring of ongoing therapies.

[1] Quigley et al., Eur. J. Nucl. Med. Mol. Imaging 2021, doi: 10.1007/s00259-021-05559-x
https://link.springer.com/article/10.1007/s00259-021-05559-x