S26_ab4

Anti-Saccharomyces cerevisiae antibodies - A novel serologic marker for Behçet's disease

I. Krause¹, Y. Monselise², G. Milo¹, A. Weinberger³

Department of Medicine E¹, Department of Medicine B3, Immunology Laboratory², Rabin Medical Center, Beilinson Campus and Felsenstein Medical Research Center; Sackler Faculty of Medicine, Tel-Aviv University, Israel.

ABSTRACT
Objective
To evaluate the prevalence and clinical correlations of antibodies against Saccharomyces cerevisiae (ASCA) among patients with BD.

Methods
Twenty-seven BD patients were studied. Data from medical files and from patients' interviews was collected, regarding the entire spectrum of disease manifestations, and a severity score was calculated for each patient. IgA- and IgG-ASCA levels, determined by ELISA, were studied in all BD patients and in three control groups: patients with recurrent aphthous stomatitis (RAS), systemic lupus erythematosus (SLE) and healthy volunteers.

Results
Thirteen BD patients (48.1%) were ASCA-positive, compared to one patient in each control group (10%, p = 0.01). The mean value of IgG-ASCA in the BD patients was 20.7 ± 12.3 units, significantly higher than in patients with RAS (10.0 ± 5.5, p < 0.001), SLE (11.8 ± 9.3, p < 0.03) or healthy volunteers (10.8 ± 9.8, p < 0.02). Mean IgA-ASCA level was 16.8 ± 8.8 units in the BD patients, significantly higher compared to healthy volunteers (11.0 ± 5.0, p = 0.02) but similar to patients with RAS (17.0 ± 5.3). No correlation was found between ASCA and any BD-associated clinical manifestation nor the presence of HLA-B5. No difference was found in the rate of major oral ulcers nor in the systemic disease severity score between positive- and negative-ASCA patients (27.3% vs. 30.8%, and 7.31 ± 1.80 vs. 7.28 ± 2.27 respectively, NS).

Conclusion
The results of our study associate, for the first time, the presence of a distinct antibody, i.e. ASCA, with BD. ASCA were not linked to a specific clinical manifestation of the disease and probably do not pose an increased risk for a more severe disease course.

Key words
Behçet's disease, anti-Saccharomyces cerevisiae antibodies, aphthous stomatitis, severity, Crohn's disease.

Please address correspondence and reprint request to: Ilan Krause, MD, Department of Medicine E, Rabin Medical Center, Beilinson Campus, Petah-Tiqva, 49100, Israel.
E-mail: ikrause@post.tau.ac.il