Giant Cell Arteritis - Beyond the Headache

Yolanda      Farhey

doi:10.2174/157339712802083768

Abstract

Giant Cell Arteritis (GCA) is a chronic granulomatous vasculitis preferentially targeting large and mediumsized arteries but may be generalized; Vessel inflammation prominently involves the cranial branches of arteries originating in aortic arch.

Headache is prevalent, appearing in two thirds of patients, classic in temporal region; may occur in occipital region or generalized accompanied in half a cases by “jaw claudication”. It is recognized today that this is in fact a systemic vasculitis with four possible phenotypes: large vessel vasculitis, cranial vasculitis, systemic inflammatory disease presentation and the polymyalgia rheumatica (PMR).

Understanding the multiple aspects of Giant Cell Arteritis and the extensive involvement helps recognizing the dangerous complications: the vision loss, the aneurysms and dissecting aneurysms, the mesenteric insufficiency and the limb vascular occlusion and treat them.

Scientific information now exists on the pathogenesis of GCA. Studies revealed the role of Th1 and Th17 cells and the network of cytokines and the implication in treatment. Studies in untreated and treated GCA patients have indicated that two cytokine networks contribute to the vasculitic immune pathology (IFN-γ axis and Il-17 axis). Also the majority of the studies have found a significant increased level of circulating IL-6 in patients with active disease Production of IL6 correlates with severity of systemic symptoms.

The biopsy of temporal arteries is still the gold standard for diagnosis but the involvement of large vessels makes us look for the best studies to evaluate and re-evaluate after treatment that particular type of arteries. The review approaches studies that give information on vessel structure versus vessel inflammation (MRI/MRA, PET scan, and ultrasound).

The first line of treatment is still the steroids, with a sense of urgency in complication to start sooner, use larger doses and decide on intravenous versus oral approach. Methotrexate and anti-tumor necrosis α inhibitors disappointed in studies and are not routinely recommended at this time. New treatments are connecting cytokine profile to its blocker trying to be more specific in managing a certain phenotype of GCA.

Keywords: Giant cell arteritis, large vessel vasculitis, cranial arteritis, ischemic optic neuropathy, cytokines, temporal artery biopsy, positron emission tomography, glucocorticosteroids.