Fibrosis is a pathologic process, which includes
scar formation and over production of extracellular matrix, by the connective tissue, as a response to tissue damage. The molecular process is not different from normal formation of connective tissue and extracellular matrix in the normal organs. The context, the environment and the over production make the difference.
Fibrosis formation includes interaction between many cell types and
cytokines, and when the balance becomes profibrotic, there is
fibrosis formation. Major profibrotic agents are type 2 CD4 positive lymphocytes, CD40 receptor and
ligand interaction, and the following
cytokines:
IL-4,
transforming growth factor b,
platelet derived growth factor. The major antifibrotic agent is
interferon gamma. Pathologies include: in the skin pathologic
scarring as
colloid and
hypertrophic scar,
cirrhosis of liver and gallbladder, in the heart and the kidneys, pulmonary and
bone-marrow fibrosis, and scleroderma. Scleroderma is chronic
connective tissue disease, expressed clinically by
systemic sclerosis and diffuses
fibrosis of the skin and viscera. This is a progressive degenerative disorder of the blood vessels, skin, lungs, kidneys, heart and GI tract and for this reason this disease plays a major role in
fibrosis research.
Fibrosis is considered an irreversible process, at least clinically, and is usually treated by anti-inflammatory and
immunosuppressive agents. This kind of
therapy was not proven successful and sometimes it harms more than cures. Many patients suffer from fibrotic diseases and the aim is to develop
anti-fibrotic agents, targeted to the pathologic molecular process. Progressing step by step in this issue has direct clinic affect.