What is Giant Cell Arteritis?
Giant cell arteritis, also known as temporal arteritis or granulomatous arteritis, is a systemic inflammatory disease mostly affecting arteries in the cranial (head) region. Inflammation of the artery wall means that vessels effectively become smaller, causing impaired blood flow and reduced oxygen supply to tissues.
The most commonly affected arteries are around the temples, eye and jaw. Patients typically complain of severe headaches, scalp tenderness, blurred vision and jaw pain. Most seriously, permanent loss of vision can occur if GCA is not treated. Other symptoms include pain/cramps in the arms and numbness/tingling in the skin.
A related condition is polymyalgia rheumatica (PMR), which shows as muscle pain in the neck, shoulder and pelvis. GCA and PMR often occur together.
Who is at Risk of GCA?
- Age: Giant cell arteritis generally occurs in the elderly and is rarely seen in people younger than 50.
- Sex: Women show a greater incidence than men.
- Genetics: People with certain tissue types show a strong predisposition for GCA and it is most common in people of Northern European and Scandinavian descent.
What Causes GCA?
The exact causes of GCA are not clearly understood at present, but it is known that pathological immune responses are involved. A variety of infections have been implicated as immune ‘triggers’ in GCA for example Herpes virus, CMV and Mycoplasma.
Once activation of the immune system occurs, immune cells are attracted to the vessel wall. This immune infiltrate is composed mostly of CD4 T cells, macrophages and giant cells.
Diagnosis of GCA
It is important that GCA is distinguished from other forms of vessel inflammation (vasulitis). The 1990 American College of Rheumatology recommendation states that at least three of the following are required for a diagnosis of GCA:
- Age greater than 50 years
- Temporal artery abnormality (tenderness, reduced pulse)
- Raised Erythrocyte Sedimentation Rate (ESR)
- Tissue biopsy showing artery wall inflammation and immune cell infiltrate
The histological examination (tissue biopsy) is generally taken as the most definite diagnosis of GCA.
Treatments for GCA
Treatments for GCA aim to reduce the inflammation, increase the blood flow through the arteries and limit the damage done to tissues by the reduced oxygen supply. Commonly used drugs are: corticosteroids, methotrexate and aspirin
Giant Cell Arteritis in Transplanted Liver – a Case Report
In 2008 a case of possible GCA in a 68 year old liver transplant patient was published in the New England Journal of Medicine. At the time, there had been no other published reports of GCA in patients after organ transplantation.
Patients receiving organ transplants are given immunosuppressive drugs to prevent immune rejection of the ‘foreign’ tissue. Therefore, immune mediated conditions such as GCA are considered unlikely in such patients. However the patient showed the classic symptoms of GCA; headache, disturbed vision, jaw pain and elevated ESR.
The patient did not undergo a biopsy and alternatives to GCA are proposed in this report. One alternative is that because of immunosuppressive therapy, the patient was vulnerable to sinus infections, which could have caused his symptoms.
One opinion expressed in this report is that GCA is not seen in transplant patients because it occurs in the elderly. Up until recently, organ transplantation was rarely carried out in elderly patients.
Giant Cell Arteritis, S.S.L. Chew, N.M Kerr & H.V. Danesh-Meyer. Journal of Clinical Neuroscience, 2009 (16) P1263-1268
A 68-Year-Old Man with Headache and Visual Changes after Liver Transplantation, M.Seton, M.Pleiss, J.A. Fishman, P.A. Caruso, E.T. Hedley-Whyte. New England Journal of Medicine 2008, 358, P2619-28