Bes-1 DNA Fragment Encoding Streptococcal Antigen in Skin Lesions From Patients With Behçet's Disease

Although the etiology and pathogenesis of Behçet's disease (BD) is poorly understood, streptococcal infectious allergy has long been postulated as one of the triggers for the onset of the disease. Bes-1 gene encoding a streptococcal antigen, which we recently cloned, seems to be homologous to the human intraocular peptide Brn-3b. To investigate the relationship between Bes-1 and BD, polymerase chain reaction (PCR) analyses were performed to detect Bes-1 DNA in samples of lesional tissues from patients with BD and patients with other inflammatory disorders who served as control subjects. Three (one each of clinically complete type, incomplete type, and suspected type) of 11 BD cases and one phlegmone case resulting from streptococcal infection were positive for Bes-1 DNA. PCR in situ hybridization was performed to determine the distribution of Bes-1 DNA in the BD lesional skin samples, and amplification of the Bes-1 sequence was detected in the nuclei of cells in the dermal vessel walls and in infiltrating mononuclear cells in lesions taken from patients with BD. These findings indicate that Bes-1 DNA might be involved in the pathogenesis of BD.