Giant cell arteritis (GCA)
What is GCA?
Also called temporal arteritis, because of the frequent involvement of the artery at the temple (temporal artery). Also known as “cranial arteritis” and “Horton’s disease”. The name (giant cell arteritis) reflects the type of inflammatory cell involved.
It is an inflammatory autoimmune disease of large blood vessels.
What are the symptoms?
This type of artery inflammation (arteritis) causes the arteries in the head, neck, and arm area to swell to abnormal sizes.
Typical patient population
- Age over 50, most common around 70
- ~70% Females
- Northern European descent
- Normal life expectancy
- 50% also diagnosed with an inflammatory condition causing aching and stiffness of the shoulders and hips (polymyalgia rheumatica, PMR)
Diagnosis
Physical exam
- Feeling the head by hand (palpation) reveals prominent temporal arteries with or without pulsation.
- The temporal area may be tender.
- Decreased pulses may be found throughout the body
- Evidence of reduced blood supply (ischemia) may be noted on examination of the back of the eye (fundal exam).
- Whooshing sounds from turbulent blood flow (bruits) may be heard over the arteries below the collarbone and in the armpit (subclavian and axillary arteries)
Laboratory tests
- Erythrocyte sedimentation rate, an inflammatory marker, > 60 mm/h (normal 1–40 mm/h)
- C-reactive protein, another inflammatory marker, may be elevated
- LFTs, liver function tests, are abnormal particularly raised ALP- alkaline phosphatase
- Platelets may also be elevated
How can it be treated?
- Corticosteroids
- Prednisone (H02AB07)
- IL-6 inhibitors
- Tocilizumab (L04AC07)
Clinical studies
A systematic review of 11 randomized controlled trials and 104 observational studies in GCA found no unified definition of response to treatment. Most of the trials used composite endpoints, and remission and relapse were the main outcomes. Remission usually combined the absence of signs and symptoms of GCA with normal inflammatory markers (erythrocyte sedimentation rate and C-reactive protein). Some trials also defined sustained remission: remission maintained over 12 to 52 weeks, depending on the trial, together with adherence to a prespecified treatment protocol. Relapse, also called flare, was generally defined by returning symptoms together with raised inflammatory markers, mostly with a treatment component such as the need to restart or increase glucocorticoids. Drugs that act directly or indirectly on the interleukin-6 (IL-6) pathway make these markers unreliable for judging disease activity [1].
References
- https://en.wikipedia.org/wiki/Giant_cell_arteritis