Anti-Saccharomyces cerevisiae antibodies (ASCA) in spondyloarthritis: Prevalence and associated phenotype.

Objective: The aim of the study was to compare the prevalence of ASCA in spondyloarthrites (SpA) patients and to investigate the association between ASCA status and disease phenotype.

Methods: We performed a case-control study including SpA individuals fulfilling the ESSG SpA criteria. The following data were collected for analysis: gender, age, disease duration, clinical or associated features of SpA, treatments, HLAB27 and ASCA status. A control group of patients without SpA was also analyzed.

Results: A total of 235 patients with SpA and 54 control patients were studied. The median age of SpA patients (53.6% of male patients, 52.2% of HLAB27) was 46.0 [IQR 35.0-57.0] years old. Disease duration was 60.0 [IQR 24.0-156.0] months. Inflammatory bowel diseases were observed in 11% of SpA patients. ASCA positivity was significantly higher in SpA patients than in control patients (25.5% [95% CI 20.1-31.6] (IgG: 9.8%; IgA: 21.7%) vs. 7.4% [95% CI 2.1-17.9], P=0.004). Multivariate analysis revealed that ASCA positivity was associated with peripheral involvement (OR: 3.30 [1.26-8.62], P=0.015), presence of IBD (OR: 3.43 [1.15-10.20], P=0.026), past of present history of uveitis (OR: 4.36 [1.08-17.64], P=0.039) and arthritis (OR: 3.78 [1.57-9.15], P=0.003).

Conclusion: Our results provided evidence that SpA patients had an increased prevalence of ASCA and that ASCA positivity might be associated with a particular phenotype, notably peripheral involvement and uveitis.