Fibrose

Fibrose, or fibrosis in English, is the thickening and scarring of connective tissue as a result of injury or chronic inflammation. It involves the excessive deposition of extracellular matrix, especially collagen, by activated fibroblasts and myofibroblasts. Over time, normal tissue architecture is replaced by stiff scar tissue, which can impair the function of the affected organ.

Fibrose can be localized to a single organ or part of the body, or it can be part of a systemic process. Causes include chronic infections or inflammation, autoimmune diseases, toxins and alcohol exposure, ischemia, and genetic disorders. In many cases the cause remains unknown, termed idiopathic.

Common organ-specific forms include hepatic fibrosis, pulmonary fibrosis, renal interstitial fibrosis, and cardiac fibrosis. Hepatic fibrosis results from ongoing liver injury and may progress to cirrhosis with complications such as portal hypertension. Pulmonary fibrosis involves scarring of the lung interstitium, with idiopathic pulmonary fibrosis being a major form that can cause progressive breathlessness. Renal interstitial fibrosis contributes to chronic kidney disease, while cardiac fibrosis can affect heart function after injury or in systemic diseases.

Diagnosis typically combines medical history, physical examination, imaging (such as ultrasound, CT, or MRI), and tests that assess organ stiffness or tissue characteristics. In some cases a tissue biopsy is required to confirm fibrosis and exclude other conditions.

Treatment focuses on addressing the underlying cause, slowing progression, and managing complications. Antifibrotic medications are available for certain conditions, such as idiopathic pulmonary fibrosis. Management of liver disease may include antiviral therapy or abstinence from alcohol; kidney disease involves blood pressure and metabolic control and, in advanced cases, renal replacement therapy. Prognosis varies widely by organ and etiology.