Which are the causes of Giant Cell Arteritis (GCA)?

Giant Cell Arteritis (GCA), also known as temporal arteritis, is a chronic inflammatory disease that primarily affects the medium and large arteries, particularly those in the head and neck. The exact cause of GCA is not fully understood, but it is believed to involve a combination of genetic, environmental, and immune system factors.

Genetic Factors: There is evidence to suggest that certain genetic variations may predispose individuals to develop GCA. Studies have shown an increased risk of GCA in individuals with specific human leukocyte antigen (HLA) genes, which play a crucial role in the immune system's response to foreign substances.

Environmental Factors: Although the precise environmental triggers of GCA remain unclear, some studies have suggested a potential association with infections. Viral and bacterial infections have been proposed as potential triggers, as they can activate the immune system and lead to inflammation in the arteries. However, more research is needed to establish a definitive link.

Immune System Dysfunction: The immune system is thought to play a central role in the development of GCA. It is believed that an abnormal immune response triggers inflammation in the arteries, leading to the characteristic symptoms of the disease. The exact mechanisms underlying this immune dysfunction are not fully understood, but it is believed to involve a complex interplay between various immune cells and molecules.

Age and Gender: GCA primarily affects individuals over the age of 50, with the highest incidence occurring in individuals over 70 years old. Women are also more commonly affected than men, although the reasons for this gender disparity are not well understood.

Other Risk Factors: Certain factors may increase the risk of developing GCA. These include a history of polymyalgia rheumatica (a related inflammatory condition), Caucasian ethnicity (GCA is more common in individuals of Northern European descent), and a family history of GCA.

It is important to note that while these factors may increase the likelihood of developing GCA, they do not guarantee its occurrence. GCA is a complex disease with multifactorial causes, and further research is needed to fully elucidate its underlying mechanisms.