Giant cell arteritis
Vasculitis of unknown aetiology, affecting mainly the branches of the aortic arch, most commonly the temporal artery. Also known as temporal arteritis or cranial arteritis, although these are less than accurate names given that the disease may not be confined to the temporal artery or cranial arteries (the temporal artery is extra-cranial).
Usually in the elderly, almost always in the over 50.
- Pain on mastication or combing hair
American College of Rheumatology criteria stipulates 3 of 5 features:
- age over 50 years
- new onset of headache
- scalp tenderness or decreased temporal artery pulsation
- ESR >50mm/hour
- positive temporal artery biopsy
- Possibly with some HLA (MHC) types;
- Certainly with polymyalgia rheumatica
A raised ESR is the classic finding.
Temporal artery biopsy is a common investigation and can rule a diagnosis of giant cell arteritis with high specificity, but is less than perfect at ruling it out due to patchy nature of the disease.
The procedure is simple enough and is done under local anaesthetic, but organising this can be difficult as a local arrangements to accommodate this may vary considerably. The biopsy may be performed by general surgeons, vascular surgeons as well as ophthamologists.
In terms of timing, treatment should not be delayed for biopsy. One study which delayed biopsy in order to preserve blood supply to an ischaemic scalp showed that biopsies may be retain pathological features up to 2 weeks after commencement of treatment. A further study showed a gradual reduction in histological features with a positive histological diagnosis of 78% in patients treated for less than 2 weeks, 65% in those treated for 2 to 4 weeks and 40% of those treated for more than 4 weeks.
Histology may show vasculitis with an inflammatory infiltrate and granulomas (consisting of giant cells, from which the name derives). There will also be discontinuity and fragmentation of the internal elastic lamina, best seen with elastic van Gieson staining or a similar stain.
Given the patchy nature of the disease, longer biopsies are associated with a higher rate of diagnosis. Minimum recommended lengths vary from 10-20mm. Biopsies less than 5mm are frequently negative in cases which meet clinical criteria and respond to steroids.
Steroids. Initially in high dose, and then guided by the changes in the indices of inflammation, a gradual reduction over months.
- ↑ Villiger PM, Adler S, Kuchen S, Wermelinger F, Dan D, Fiege V, Bütikofer L, Seitz M, Reichenbach S. Tocilizumab for induction and maintenance of remission in giant cell arteritis: a phase 2, randomised, double-blind, placebo-controlled trial. Lancet (London, England). 2016 Mar 4.(Epub ahead of print) (Link to article – subscription may be required.)
- ↑ Hunder GG, Bloch DA, Michel BA, Stevens MB, Arend WP, Calabrese LH, Edworthy SM, Fauci AS, Leavitt RY, Lie JT. The American College of Rheumatology 1990 criteria for the classification of giant cell arteritis. Arthritis and rheumatism. 1990 Aug; 33(8):1122-8.
- ↑ Morris OC, Paine MA, O'Day J. Giant cell arteritis presenting with scalp necrosis--the timing of temporal artery biopsy? Clinical & experimental ophthalmology. 2006 Sep-Oct; 34(7):715-6.(Link to article – subscription may be required.)
- ↑ Narváez J, Bernad B, Roig-Vilaseca D, García-Gómez C, Gómez-Vaquero C, Juanola X, Rodriguez-Moreno J, Nolla JM, Valverde J. Influence of previous corticosteroid therapy on temporal artery biopsy yield in giant cell arteritis. Seminars in arthritis and rheumatism. 2007 Aug; 37(1):13-9.(Link to article – subscription may be required.)
- ↑ a b Sharma NS, Ooi JL, McGarity BH, Vollmer-Conna U, McCluskey P. The length of superficial temporal artery biopsies. ANZ journal of surgery. 2007 Jun; 77(6):437-9.(Link to article – subscription may be required.)
- ↑ Taylor-Gjevre R, Vo M, Shukla D, Resch L. Temporal artery biopsy for giant cell arteritis. The Journal of rheumatology. 2005 Jul; 32(7):1279-82.
- ↑ Breuer GS, Nesher R, Nesher G. Effect of biopsy length on the rate of positive temporal artery biopsies. Clinical and experimental rheumatology. 2009 Jan-Feb; 27(1 Suppl 52):S10-3.