IgA class serum antibodies against three different Klebsiella serotypes inankylosing spondylitis

Objective. To investigate the possible predominance of certain Klebsiella p neumoniae capsular types in the pathogenesis of ankylosing spondylitis (AS) . Methods. The prevalence of IgA class antibodies against three different K. pneumoniae strains (with capsular types 21, 30 and 43) was studied in the s era of 177 patients with AS and of 100 healthy blood donors using an enzyme -linked immunosorbent assay. Results. The median Klebsiella-specific antibody levels were always higher in patients than in controls regardless of the serotype used as antigen. Wh en the prevalence of increased antibody levels was compared between the gro ups, it was highest against the strain with capsular type 30, whereas again st strains 21 and 43 it was similar among patients and controls. Conclusions. A broad range of Klebsiella serotypes may be involved in the p athogenesis of AS. Thus, it is important to take the different Klebsiella s erotypes into particular account in these studies.