Two Subsets of Large Vessel Vasculitis Characterized by the Absence or Presence of Spondyloarthritis or its Associated Diseases

BACKGROUND Whilst large vessel vasculitis (LVV) predominantly occurs in isolation, associations with other infectious and non-infectious diseases have been reported. Limited data describing associations with various autoimmune diseases (AI), including spondyloarthritis exists. The aim of this study was to characterize the association of LVV and spondyloarthritis or its associated diseases (SpAD). METHODS A single centre, retrospective study of patients ≥50yrs with first presentation LVV between 01.06.2008-01.06.2015 was performed. Patients were categorized according to SpA or associated disease, other AI or idiopathic LVV (iLVV). Clinical, laboratory and imaging findings were compared. Kaplan-Meyer survival analysis, with relapse taken as the primary end-point, was performed. RESULTS LVV was confirmed in 62 pts, of who 16/62 (26%) had SpA or associated disease. In these patients, LVV presented earlier (59.2 SpAD vs. 68.1 AI and 70.3yrs iLVV; p=0.01) and occurred predominantly in spring compared to autumn and winter in non-SpA patients, was associated with more centralised pattern of distribution (p=0.05) and was more likely to exhibit a refractory course (p=0.05). Overall relapse rates were similar across groups. Smoking-status influenced age of onset in all groups, being associated with earlier onset. CONCLUSION A clear association between LVV and SpAD exists. LVV associated with SpAD has a particular phenotype characterised by earlier onset, thorax-limited disease and increased risk of a refractory course. Given on-going LVV treatment trials further genetic and pathophysiological characterization appears warranted, to evaluate potential variation in treatment response and optimize future care.