[Close association of Streptococcus sanguis and Behçet's disease].

The oral flora of patients with Behçet's disease was investigated and compared to that of controls. The proportion of Streptococcus (S.) sanguis in the flora of patients with this disease was always higher than that of healthy controls. It is noteworthy that serotypes of S. sanguis in the oral flora of patients were different from controls. Immune responses against S. sanguis were also examined in the patients. Antibody titers against S. sanguis were higher in patients than in controls. Furthermore, the patients showed significantly increased skin reactivity to S. sanguis. These results suggest that uncommon serotypes of S. sanguis play an important role in the pathogenesis of Behçet's disease.