Background:Giant cell arteritis (GCA) is a large vessel vasculitis (LVV) that affects mostly the elderly (1). Temporal artery biopsy (TAB) has been defined as the gold standard, although this has come to question (3). EULAR guidelines recommended non-invasive imaging techniques such as the temporal artery Doppler ultrasound to aid in LVV diagnosis (2). The characterization of GCA in Latin American countries, and specifically in Colombia, is scarce.Objectives:To perform a clinical, demographical, histopathological, and radiological characterization ofColombian GCA patients.Methods:Retrospective data from GCA patients at two teaching hospitals in Medellín, Colombia, was collected. A bioethics committee previously approved the research protocol. Inclusion criteria: diagnosis of GCA, based on clinical characteristics or imaging/biopsy findings. Exclusion criteria: HIV diagnosis, paraneoplastic large vessel vasculitis. Clinical, radiological, and histopathological variables were selected based on the clinicians’ expertise and the 2018 EULAR recommendations for a core data set to support observational research and clinical care in giant cell arteritis (3). The data were analyzed in SPSS v22.0 (IBM, USA).Results:Twenty-two patients were collected. Demographical and clinical characteristics are summarized in Table 1. Most patients were women (68.1%), with a mean age of 71.8 years, mean duration of symptoms of 5.3 months. In the cranial form of the disease, the most common symptoms were headache and jaw claudication (95% and 68%). Six patients experienced visual loss: complete unilateral visual loss in two, partial unilateral in two, complete bilateral in one, and partial bilateral in one patient.Sixteen patients (72.7%) underwent TAB; the most common finding was mononuclear infiltrate and internal elastic fragmentation in 43.7% of the biopsies. Giant cells were observed in 6 biopsies (37.5%). Doppler ultrasound was performed in 19 patients (86.35%), finding intima-media thickening and the halo sign t in 7 patients (36.8%).Table 1.Demographical and clinical characteristicsCharacteristicn = 22Mean age (years SD)71.8 (10.6)Female sex n (%)15 (68.1%)Mean symptoms duration (months ± SD)5.3 ± 6.8Mestizo n (%)20 (90%)Headache n (%)21 (95.4%)Jaw claudication n (%)15 (68.1%)Weight loss n (%)13 (59%)Scalp sensitivity n (%)11 (50%)Fever n (%)8 (36.3%)Presence of polymyalgia rheumatica n (%)7 (31.8%)Visual loss n (%)6 (27.2%)Amaurosis fugax n (%)1 (4.5%)Glucocorticoids n (%)22 (100%)Pulse n (%)8 (36.3%)Mean dose (mg ± SD)47.1 ± 16.7Methotrexate n (%)17 (77.7%)Azathioprine n (%)2 (9%)Tocilizumab n (%)1 (4.5%)Conclusion:In this GCA cohort, the main phenotype was cranial GCA, with 95% of the patients presenting with headache. The most common imaging study performed was Doppler ultrasound of temporal arteries, with intima-media thickening and halo sign being the most common findings. The mainstay of treatment was glucocorticoids with methotrexate as a sparing agent. To our knowledge, this study is the first to perform a specific characterization of GCA patients in the Colombian population, and it can represent the foundation of further research for these patients.References:[1]Lazarewicz K, Watson P. Giant cell arteritis. BMJ. 2019 May 30;365:l1964.[2]Dejaco C, Ramiro S, Duftner C, Besson FL, Bley TA, Blockmans D, et al. EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice. Ann Rheum Dis. 2018 May;77(5):636–43.[3]Ehlers L, Askling J, Bijlsma HWJ, Cid MC, Cutolo M, Dasgupta B, et al. 2018 EULAR recommendations for a core data set to support observational research and clinical care in giant cell arteritis. Ann Rheum Dis. 2019;78(9):1160–6.Disclosure of Interests:None declared