Study supports role of environmental factors in giant cell arteritis

This case study reports the occurrence of giant cell arteritis (GCA) in a conjugal pair from the southern Gulf Coast of the United States. There have been three previous reports of GCA in married couples, all of whom originated in Northern Europe or the Northern United States. While the pathogenesis of GCA remains unclear, genetic, environmental, immune and other factors may be contributory.

The current study involved a husband and wife diagnosed with GCA 10 years apart, the wife at age 66 in 2002 and the husband later at age 76. The spouses were not consanguineous, but both were of Scottish-English ancestry and had lived in the Gulf Coast for most of their lives. They were both were fair skinned and reported spending approximately two months each year at a lake house, with increased sunlight exposure during that period. Numerous studies have documented a higher occurrence of GCA in individuals of Northern European descent.

Some reports suggest that genetic factors may be important in the etiology of GCA, and the immune system is heavily involved in GCA. However, environmental factors may also play a role. The authors note that solar radiation may accelerate the fragmentation and degeneration of elastin fibers, a histologic feature of temporal artery biopsies.

The wife admitted to having much greater exposure to sunlight than her husband did, and she developed GCA symptoms 10 years earlier. Both patients had long histories of smoking, which has been found to increase the risk of GCA significantly in women.