Which are the causes of Primary Biliary Cholangitis?

Primary Biliary Cholangitis (PBC), formerly known as Primary Biliary Cirrhosis, is a chronic autoimmune liver disease that primarily affects the small bile ducts within the liver. While the exact cause of PBC remains unknown, researchers believe that a combination of genetic, environmental, and immunological factors contribute to its development.

Genetic Factors: Studies have shown that there is a genetic predisposition to PBC. Certain human leukocyte antigen (HLA) genes, specifically HLA-DR8 and HLA-DR3, have been found to be more prevalent in individuals with PBC. These genes play a role in regulating the immune system, and their presence may increase the risk of developing the disease.

Environmental Triggers: It is believed that environmental factors may trigger the development of PBC in individuals with a genetic predisposition. These triggers could include exposure to certain chemicals, infections, or toxins. However, specific environmental factors that contribute to PBC have not been definitively identified.

Autoimmune Dysfunction: PBC is classified as an autoimmune disease, which means that the body's immune system mistakenly attacks its own healthy cells and tissues. In PBC, the immune system targets the small bile ducts in the liver, leading to their inflammation and destruction. The exact reason why the immune system malfunctions in this way is not fully understood.

Hormonal Factors: PBC is more common in women than in men, suggesting that hormonal factors may play a role in its development. Estrogen, a female sex hormone, has been implicated in the progression of PBC. However, the exact mechanisms by which hormones influence the disease are still being investigated.

Other Factors: Certain medical conditions, such as autoimmune thyroid disease, Sjögren's syndrome, and Raynaud's phenomenon, are more commonly found in individuals with PBC. This suggests that there may be shared underlying mechanisms or genetic factors between these conditions and PBC.

It is important to note that while these factors are believed to contribute to the development of PBC, they do not guarantee the onset of the disease. Many individuals with genetic predisposition or exposure to environmental triggers do not develop PBC, indicating that additional factors or interactions are involved in its pathogenesis.