Introduction: Although cardiac complications have been reported in established spondyloarthritis (SpA), little is known about peripheral axial SpA in large vessel vasculitis (LVV). The aim of this study was to assess the prevalence of SpA in patients with newly diagnosed LVV.
Method: Retrospective single-centre analysis of all newly diagnosed LVV patients was performed between January 2011 and December 2012. Vasculitides were confirmed on thoracic magnetic resonance imaging (MRI) or 18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT). Patients completed a standardized questionnaire incorporating the Berlin criteria to assess inflammatory back pain. Existing scans were reassessed for sacroiliitis and ferritin antibodies measured in all patients.
Results: Fifteen patients exhibiting new LVV were identified. Diagnosis was confirmed using MRI in nine patients and FDG-PET/CT in six. Six patients (40%) fulfilled American College of Rheumatology (ACR) criteria for giant cell arteritis (GCA) and polymyalgia rheumatica (PMR), and nine PMR only. Four patients fulfilled the Berlin criteria for inflammatory back pain, with three demonstrating sacroiliitis on imaging. All remaining patients demonstrated no sacroiliitis. One further patient with LVV lacking features of inflammatory back pain had known psoriatic arthritis (PsA). Patients with coexisting SpA were younger (mean age 57 years vs. 66 years) and had higher C-reactive protein (CRP) levels (200 mg/L vs. 85 mg/L) at presentation. Four SpA patients and seven out of nine patients with isolated LVV had ferritin antibodies.
Conclusions: We have demonstrated a higher than anticipated prevalence of SpA in LVV, given the reported 0.5-1% prevalence in the general population. Coexisting SpA should be considered in LVV patients exhibiting inflammatory back pain despite steroid initiation. Ferritin antibodies demonstrated a similarly high prevalence in aortitis and SpA as reported previously in untreated GCA and PMR.