[Serum anti-subtypical Klebsiella pneumoniae antibodies in ankylosing spondylitis].

This study was performed in order to probe the possible pathogenesis of Klebsiella pneumoniae (KP) in ankylosing spondylitis (AS). 34 anti-KP antibody positive serum samples, including 26 patients with AS, 5 patients with rheumatoid arthritis (RA) and 2 healthy individuals, were selected to detect anti-subtypical KP antibodies by using an immunoblotting technique. The results showed that the number of antigenic bands to KP on nitrocellulose membrane was higher in AS patients than in RA patients and healthy individuals. Patients with AS had common antibodies response to KP components weight 64,600 (80.7%), 48,200 (61.5%) and 36,000 (65.4%), patients with RA and healthy individuals had anti-36,000 (75%) and anti-30,000 (50%) antibodies. Human anti-HLA-B27 serum and rabbit antisera against KP-derived synthetic peptide containing the hexapeptide sequence shared by HLA-B27 were able to cross react with 64,600 and 48,200 KP components. Our findings suggest that KP might play a role in the pathogenesis of AS by molecular mimicry between it and HLA-B27.