Acetylator phenotype in Behçet's disease.

The purpose of this study was to determine the acetylator status in Behçet's disease (BD) patients and compare it to a matched group of normal individuals. Thirty-seven healthy volunteers and forty-one BD patients were included. Detailed history was taken from the patients. HLA-B51 was determined in the BD patients. In addition, the Clinical Manifestation Index (C.M.I.) was determined for each patient. Pathergy test was also done. After an overnight fast, each control subject and patient received a single oral dose of 100 mg of DDS. A blood sample was collected after 3 hours and the plasma was separated for determination of dapsone/monoacetyldapsone by HPLC. The frequency of slow acetylators in healthy individuals was 70.2%, while the frequency of rapid acetylators was 29.8%. The frequency of slow acetylators in BD patients was 53.7%, while the frequency of non-acetylators (undetected monoacetyldapsone MADDS in plasma) was 46.3%. There were no rapid acetylators among the BD patients. There was a strong negative association between the acetylator status and the severity of BD. In addition, acetylator status correlated with HLA-B51, in that BD patients with positive HLA-B51 were characterized by a very slow or non-acetylator status. Slow or non-acetylators had more severe BD. We conclude that BD patients have a unique acetylator status. This finding may have implications for the theories for the pathogenesis of the disease as well as for therapeutic aspects.