Fibrosis

Fibrosis
Micrograph of a heart showing fibrosis (yellow – left of image) and amyloid deposition (brown – right of image). Stained using Movat's stain.
SpecialtyPathology, rheumatology
ComplicationsCirrhosis
Risk factorsRepeated injuries, chronic inflammation.[1]

Fibrosis, also known as fibrotic scarring, is a pathological wound healing in which connective tissue replaces normal parenchymal tissue to the extent that it goes unchecked, leading to considerable tissue remodelling and the formation of permanent scar tissue.[1][2]

Repeated injuries, chronic inflammation and repair are susceptible to fibrosis, where an accidental excessive accumulation of extracellular matrix components, such as the collagen, is produced by fibroblasts, leading to the formation of a permanent fibrotic scar.[1]

In response to injury, this is called scarring, and if fibrosis arises from a single cell line, this is called a fibroma. Physiologically, fibrosis acts to deposit connective tissue, which can interfere with or totally inhibit the normal architecture and function of the underlying organ or tissue. Fibrosis can be used to describe the pathological state of excess deposition of fibrous tissue, as well as the process of connective tissue deposition in healing.[3] Defined by the pathological accumulation of extracellular matrix (ECM) proteins, fibrosis results in scarring and thickening of the affected tissue — it is in essence a natural wound healing response which interferes with normal organ function.[4]

  1. ^ a b c Wynn TA (August 2004). "Fibrotic disease and the T(H)1/T(H)2 paradigm". Nature Reviews. Immunology. 4 (8): 583–594. doi:10.1038/nri1412. PMC 2702150. PMID 15286725.
  2. ^ Birbrair A, Zhang T, Files DC, Mannava S, Smith T, Wang ZM, et al. (November 2014). "Type-1 pericytes accumulate after tissue injury and produce collagen in an organ-dependent manner". Stem Cell Research & Therapy. 5 (6): 122. doi:10.1186/scrt512. PMC 4445991. PMID 25376879.
  3. ^ "Glossary of dermatopathological terms". DermNet NZ.
  4. ^ Neary R, Watson CJ, Baugh JA (2015). "Epigenetics and the overhealing wound: the role of DNA methylation in fibrosis". Fibrogenesis & Tissue Repair. 8: 18. doi:10.1186/s13069-015-0035-8. PMC 4591063. PMID 26435749.