OP0304 CHILDHOOD TAKAYASU ARTERITIS: A MULTICENTRE RETROSPECTIVE STUDY
Authors: K. Evers, L. Milar, D. Eleftheriou, P. Brogan, M. Marlais, K. Tullus
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Takayasu arteritis (TA) is a rare, large vessel vasculitis affecting mainly the aorta and its major branches. Data on paediatric TA (pTA) is very scarce. <h3>Objectives:</h3> The aim of this study was to characterize clinical presentation, therapy and outcome of pTA in a global study population. <h3>Methods:</h3> We conducted an international multicentre retrospective observational study of children diagnosed with pTA. Inclusion criteria were an age of less than 18 years at initial presentation in the year 2000 or more recently. Clinical data were collected from patients' charts by the treating paediatric rheumatologist or nephrologist; data were fully anonymised for analysis purposes. Follow-up data was collected up to 2 years after diagnosis. <h3>Results:</h3> 198 patients from 20 countries were included (76% female). The median age at disease onset was 12 years. Arterial hypertension (67%), a difference in pulses between limbs (65%) and fatigue (66%) were the most common symptoms at presentation. The gastrointestinal system was the second most affected organ system. The median eGFR (estimated glomerular filtration rate) at baseline was 105 ml/min/1.73m<sup>2</sup>. Renal artery stenosis was documented in 58% of all patients and in 37% there was need for an invasive renovascular procedure. In 25 of 32 (78%) patients who had either a positron emission tomography–magnetic resonance imaging (PET-MRI) or PET-computed tomography (CT) there was evidence of active inflammation mainly of the aorta. 67% of all patients showed thickened wall abnormalities and 31% had arterial dilatations in a major vessel on any one or more anatomical imaging modality such as ultrasound, CT or MRI. Immunosuppressive treatment was primarily steroids, cyclophosphamide and methotrexate, 37% of all patients were treated with monoclonal antibodies of which 65% received an anti-tumor necrosis factor (TNF) antibody, 31% an anti-Interleukin 6 (IL-6) antibody and 4% an anti-B-cell antibody. Dialysis was necessary in 7% and one patient underwent kidney transplantation. Seven patient deaths (4%) were documented at the most recent follow-up. The renal function after two years was median eGFR 102 ml/min/1.73m<sup>2</sup>, with 67% showing normal function, 31% presenting with chronic kidney disease (CKD) stage 1, 1% with stage 2, 1% with stage 3 and no patients showed stages 4 and 5. A quarter of the patients (27%) were still symptomatic at the 2-year follow-up. The median systolic blood pressure was 117 (interquartile range 107 – 125) mmHg. 64% of all patients still had antihypertensive treatment, and 87% were still on immunosuppressive therapy. <h3>Conclusion:</h3> Our study represents the largest paediatric cohort of children diagnosed with Takayasu arteritis. Several organ systems were involved at onset and the clinical spectrum was highly variable. We will in our further analyses in more detail describe the outcome in relation to presenting symptoms and treatment. <h3>REFERENCES:</h3> <b>NIL.</b> <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>