ANTI-SACHCCAROMYCES CEREVISIAE ANTIBODIES AND DISEASE ACTIVITY IN ANKYLOSING SPONDYLITIS: CLINICAL CORRELATIONS

J.L. Fernández-Sueiro, J.A. Pinto , M.J. López-Armada , S. Pértega , F. Galdo , F.J. Blanco Rheumatology Division, Laboratory unit, Epidemiology Unit, Hospital Universitario Juan Canalejo, La Coruña, SpainObjectives: We have showed that the presence of IgG anti-shaccaromyces cerevisiae antibodies (ASCA) is more prevalent in ankylosing spondylitis (AS), moreover HLA-B27 does not influence its presence in AS. The objective of this study was to evaluate its role as biologics markers of disease activity in AS.Methods: A) Patients: AS patients of the follow up cohort at the rheumatology division of the University Hospital Juan Canalejo, La Coruña, were the objects of the current study. These patients are visited regularly according to the standard ASAS measurements in AS. Serum samples are collected, after informed consent, and stored at 70° for further use.B) Methods: from a total of 107 patients, 77 patients were analysed, this study was performed with the samples obtained at the beginning of the cohort. Detection of ASCA IgA and IgG was performed with a commercially available kit, GA Generic Assays GmbH® (Dahlewitz, Germany). According to manufacturer instructions, a quantitative interpretation of the results was done, the test was considered positive either for IgA or for IgG when antibody levels were ≥ 20 U/ml. To analyse the correlations between ASCAS and activity of the disease, we considered BASDAI ≥> 4 (numeric scale) as the cut off value. We analysed correlations with BASRI, BASFI, ASQoL, ESR, CRP, and ASCA IgA and IgG. To compare the presence of ASCA IgA and IgG between groups, activity or not activity, we used the chi square test, and the Mann-Whitney test for comparison of numerical scales among groups.Results: From 77 patients studied, 81,8% were male. Current age was 49,5%(±8,7) years, mean follow up 14,3 (±8,7)years, HLA-B27 positive (88,3%). Uveitis 35,1%. Family history 19,5%. Enthesitis 13%. IgA increased 22,1%, IgG increased 50,6%. BASDAI <4 cm was present in 71,4% of the patients, BASDAI ≥4 28,6%. IgA was increased in 16,4% of patients with BASDAI <4 and 36,4% with BASDAI ≥4 (p=0,072), IgG was increased in 52,7% and 45,5% respectively (p=0,564). Combining the presence of IgA-IgG normal, IgA normal-IgG increased, IgA increased-IgG normal or both increased, 56,3% of the patients with BASDAI <4 had some alteration in the presence of ASCAS versus 59,1% of patients with BASADI ≥4 (p=0,827). Patients with BASDAI ≥4 showed significance differences in the following parameters; fatigue (p<0,001), enthesitis (p=0,005), BASFI (p=<0,001) VAS patient, doctor, nocturnal back pain (p=<0,001), ASQoL (p=0,001) and SF12 physical (p=0,001).Conclusion: ASCAS IgA and IgG were present in 22,1% and 50,6% respectively of the patients with ankylosing spondylitis. An increased of any of the ASCAS (IgA, IgG or both) independently of the BASDAI was present in more than 50% of the patients; however its presence did not correlate with disease activity in this cohort. This result suggest that ASCAS are not useful as biological markers of disease activity in AS. The presence of enthesitis in patients with BASDAI ≥4 underlines its clinical relevance.Supported by: Proxectos de investigación en establecimientos sanitarios públicos da comunidade autónoma de Galicia. PGIDIT05SAN32PRCitation: Ann Rheum Dis, volume 65, supplement II, year 2006, page 216Session: Spondylarthropathies including psoriatic arthritis