Giant Cell Arteritis
A 70-year journey to unravel a medical mystery
I was always in good health. I never missed work and then all of a sudden it was like my world came undone. I could tell it was something bad.
GCA is a formidable enemy. Its complexity, both in terms of how it is caused and the non-specific symptoms it triggers, has been a major challenge for doctors and researchers since it was first described in medical literature in 1890, with the mention of a man with “red streaks” on his forehead.3
A history of giant cell arteritis
Since then, experts have battled to unravel its complex causes, not just to relieve its debilitating symptoms but to find a cure. What is known about GCA is that it is an inflammatory disease which affects the body’s medium and large arteries.1 It targets mainly the arteries supplying the head, as well as the aorta – the main artery in the human body – and its branches that supply the neck and arms.1
Depending on which arteries are affected, GCA reveals itself in many ways, which is why it is so tough to diagnose. Immune system cells invade the walls of arteries, setting off a chain reaction of inflammation.1,9 Inflammation thickens the artery walls, causing them to narrow and reducing the flow of blood.9 This in turn causes the devastating symptoms suffered by patients - severe headaches, scalp tenderness, jaw pain and sight problems.1 In some cases the blood vessel can close completely and when this happens to the arteries serving the eye, sudden blindness can occur. What is still not known is what triggers this immune attack.1
The most severe and feared symptom is the loss of vision, either temporarily or more serious, irreversible vision loss.
Steroids have been the mainstay of treatment for GCA for almost 70 years with little progress discovering effective, but less toxic, ways of tackling it.2 Steroids suppress the immune system, and block the inflammatory process, but how exactly they tackle GCA is not known.2 Trying to unravel the mechanism by which steroids treat GCA is leading the way to potentially discover new GCA treatment options. The aim is to find a treatment that could break the devastating inflammatory cascade triggered by the disease to get people into remission quickly without needing to resort to steroids.
Progress is already being made to work out the complex role of all the different immune cells and biological pathways that are implicated in the disease.
As more is understood about the immune system it will hopefully reveal not only why GCA develops, but more importantly how it can be stopped.
- 1. Bhat S, et al. Giant cell arteritis. Midlife and Beyond, GM. Rheumatology. 2010; 071-079.
- 2. Ponte C, et al. Giant cell arteritis: Current treatment and management. World J Clin Cases, 2015; 3(6): 484-494.
- 3. Hunder G. History of giant cell arteritis (GCA) polymyalgia rheumatic (PMR). Rheumatology. 2005; 44(suppl 3):iii1.
- 4. Hunder G et al. The American College of Rheumatology 1990 Criteria for the Classification of Giant Cell Arteritis. Arthritis & Rheum. 1990; 33(8):1122-1128.
- 5. Salvarani C., et al. Laboratory investigations useful in giant cell arteritis and Takayasu’s arteritis. Clin Exp Rheumatol 2003; 21(Suppl. 32):S23-S28.
- 6. Chatterjee S., et al. Clinical Diagnosis and Management of Large Vessel Vasculitis: Giant Cell Arteritis. Curr Cardiol Rep (2014) 16:498. DOI 10.1007/s11886-014- 0498-z.
- 7. Mazlumzadeh M., et al. Treatment of giant cell arteritis using induction therapy with high-dose glucocorticoids: a double-blind, placebo-controlled, randomized prospective clinical trial. Arthritis Rheum. 2006;54(10):3310-8.
- 8. Villiger P., et al. Tocilizumab for induction and maintenance of remission in giant cell arteritis: a phase 2, randomised, double-blind, placebo-controlled trial. The Lancet. Published online 4 March 2016. http://dx.doi.org/10.1016/S0140-6736(16)00560-2.
- 9. GCA pathophysiology. BMJ best practice. [Internet; cited 2017 Nov 7]. Available at: http://bestpractice.bmj.com/best-practice/monograph/177/basics/pathophysiology.html