Giant Cell Arteritis: The Experience of Two Collaborative Referral Centers and an Overview of Disease Pathogenesis and Therapeutic Advancements

Purpose: Giant cell arteritis (GCA), a chronic vasculitis of the large and medium-sized arteries, affects people >50 years of age. This study assessed the prevalence of visual manifestations and other clinical features at presentation in an Italian cohort of GCA patients. Recent advances in the pathophysiology, diagnosis, and therapy of GCA are also reviewed. Methods: This retrospective, single-center study conducted by the ophthalmology and internal medicine clinics of one university recruited 56 patients from 2005 to 2016 and followed them for 11-54 months. Results: Ocular involvement was diagnosed in 19 patients (33.9%), with permanent vision loss in 19.6% (7.1% of the cohort with bilateral vision loss). Arteritic anterior and posterior ischemic optic neuropathy were diagnosed in 11 patients (57.9%) and 1 patient (5.3%), respectively, cotton wool spots in 3 patients (15.8%), central retinal artery occlusion in 2 patients (10.5%), and anterior segment ischemia and multifocal choroidal ischemia in 1 patient each (5.3%). Polymyalgia rheumatica was associated with GCA in 44.6% of the patients. The most common extra-ocular manifestation was constitutional symptoms (82.1% of the patients). Large-vessel involvement, including of the ascending aorta, aortic arch, and left axillary artery, was diagnosed by magnetic resonance or computed tomography (CT) angiography and (18)FDG positron emission/CT. Glucocorticoids (GCs) remain the standard-of-care worldwide, but methotrexate, provided as a steroid-sparing drug in 41% of the patients, resulted in earlier tapering, a lower cumulative dose of GCs, and a lower rate of relapse. Among the combinations of GCs and immunosuppressive drugs proposed to treat GCA, only tocilizumab has effectively induced and maintained disease remission. Conclusion: According to our data and literature reports: a) GCA is a systemic disease; b) its diagnosis is expedited by the adjunct use of imaging techniques; c) insights into the pathogenesis of GCA may allow an improved, differentiated therapeutic approach.