FRI0672 Anti-saccharomyces cerevisiae antibodies in spondylarthropathies: prevalence and associations with disease phenotype
Authors: R. M. Ferreira, F. Aguiar, T. M. Rocha, S. Ganhão, A. Águeda, M. Guerra, S. Pimenta, M. Bernardes, L. Costa
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background:</h3> It has been speculated that increased gut inflamation is of aetiopathogenic importance in the development of Spondylarthropathies (Spa). Serological markers, as anti-Saccharomyces cerevisiae antibodies (ASCA), which are rarely positive in healthy controls (&lt;5%), possess clinical significance in inflamatory bowel disease (IBD) management.¹ Because Spa and IBD share similarities and even subclinical intestinal inflamation may be present in a high number of Spa patients, evaluation of this antibodies has gained increasing relevance. <h3>Objectives:</h3> To investigate the status and frequency of ASCA in Spa patients and the association of these serological markers with the clinical profile. <h3>Methods:</h3> We performed a retrospective study including SpA individuals treated with biologic therapy, followed at our Rheumatology department. Classification of SpA was based on the ASAS criteria. Medical records were obtained by consulting the national database (Reuma.pt). ASCA IgA and IgG levels were measured in the period time between 2016 and 2017 and determined by ELISA. The quantitative ASCA results were expressed in RU/ml and 20 was established as the cut-off point. X<sup>2</sup> or Fisher tests were used for analysis of categorical variables and t-test or Mann-Whitney for continuous variables (SPSS 23.0). The adopted significance was of 0.05. <h3>Results:</h3> We included 231 Spa patients, 117 of which were men (51%), with a mean age of 48.6±12.5 years. The median disease duration was 17 years [min:2;max: 53]. In total, 39% of the patients had isolated axial form (n=90), 10% isolated peripheral form (n=23) and 51% presented axial and peripheral involvement (n=118). Nine patients had associated IBD [7 cases with Crohn Disease (CD) and 2 with Ulcerative Colitis (UC)] and 66 patients presented concurrent psoriasis (28.6%). Ninety-three patients (40%) were HLA-B27+ and 59 (26%) presented history of uveitis (current or previous). ASCA IgA were positive in 14% of the whole sample (n=33; 14 patients with isolated axial form, 4 with isolated peripheral form and 15 with axial and peripheral form). ASCA IgG positivity was found in 5% of the Spa (n=12; 7 patients with isolated axial form, 1 with isolated peripheral form and 4 with both forms). The median ASCA IgA and IgG titers were 72 RU/ml [min:22;max:200] and 45.5 RU/ml [min:28;max:200], respectively. We found no statistically significant difference in the number of ASCA IgA or IgG-positive patients in CD vs UC (p= 0.722;p=0.583). Current age and at diagnosis, disease duration, gender, active or past smoking habits were similar between ASCA IgA or IgG-positive and negative groups. Also, disease phenotype including peripheral arthritis, axial involvement, psoriasis, HLA-B27 positivity and uveitis were unrelated to ASCA IgA and IgG status. <h3>Conclusions:</h3> Our results showed that Spa patients presented an increase of ASCA IgA positivity, in agreement to previous data. No relationship of ASCA status was found with the demographic aspects or clinical presentation. In the future, our purpose is to investigate the relationship between antibody reactivity and endoscopic findings. <h3>Reference</h3> [1] Peeters M, et al. Diagnostic value of anti-Saccharomyces cerevisiae and antineutrophil cytoplasmic autoantibodies in inflammatory bowel disease. Am J Gastroenterol2001;96:730–4. <h3>Disclosure of Interest:</h3> None declared