P201 Inactive Takayasu’s Arteritis: a Case Series Analysis of Presentations to a Tertiary Vasculitis Centre

Abstract Background/Aims At diagnosis, a proportion of Takayasu’s arteritis (TAK) cases present with imaging evidence consistent with TAK without evidence of active arteritis or systemic disease. Inactive TAK is considered the end-point of a triphasic disease process characterised by a “burnt-out” non-inflammatory fibrotic state. Current EULAR/ACR guidelines recommend immunosuppressive treatment and routine imaging for active TAK but data guiding the management of inactive disease are scarce. The purpose of this case series was to examine baseline characteristics of patients presenting with inactive TAK and investigate disease progression. Methods We performed a retrospective review of the Imperial College Takayasu Arteritis Cohort. TAK diagnosis was based on imaging evidence in combination with clinical history. Disease was determined inactive by activity scoring indices (ITAS2010 + NIH) together with inflammatory markers. MR Angiogram (28/30 cases) and CT Angiogram (2/30) were utilised as imaging modalities to determine vascular involvement. Disease distribution was characterised using the Numano Classification (Table 1). Results 19% (30/158) of patients presented with “inactive disease” at diagnosis. Inactive cases had a median age of diagnosis of 37.8 years, compared to 33.8 in patients with active disease. 48% of inactive cases experienced >2 year delay in reaching diagnosis. Inactive cases did not display significantly elevated inflammatory markers (CRP 3.86, ESR 27.0) at baseline visit and demonstrated arterial lesions on angiography consistent with standard TA definitions in terms of anatomical distribution and characteristics. Inactive patients were followed up with interval MR imaging, allowing us to chart natural disease course without treatment. Of 30 total cases, only five patients developed progression of vascular lesions. Three patients displayed marginal imaging progression without active symptoms together with normal inflammatory markers; these patients did not receive immunosuppression and serial interval imaging demonstrated stable disease, suggesting a non-inflammatory aetiology. Two patients developed progression attributed to active disease, necessitating treatment with immunosuppression. Conclusion A significant proportion of patients have inactive disease at TAK diagnosis. This presents a challenge to the treating clinician and further uncertainty for patients. This case study provides evidence that cases of burnt-out TAK can be managed safely without immunosuppressive treatment using routine imaging surveillance and serum biomarkers. Disclosure S. Hanlon: None. J. Nouza: None. M. Colquhoun: None. J. Satara: None. A. Porter: None. R. Maughan: None. T. Youngstein: None. J. Mason: None.