IGA1 AND IGA2 SUBCLASS ANTIBODIES AGAINST KLEBSIELLA-PNEUMONIAE IN THE SERA OF PATIENTS WITH PERIPHERAL AND AXIAL TYPES OF ANKYLOSING-SPONDYLITIS

Objective-To study further the Klebsiella specific serum antibody resp onse in patients with axial and peripheral types of ankylosing spondyl itis (AS). Methods-IgA1 and IgA2 subclass antibodies to Klebsiella pne umoniae were measured by enzyme linked immunosorbent assay in the sera of 171 patients with axial or peripheral type AS, and in sera of 100 healthy controls. The effect of 26 weeks of sulphasalazine treatment o n the antibody levels in the two types of AS was also analysed. Result s-K pneumoniae specific antibody levels of both IgA1 and IgA2 subclass es were increased in the sera of patients with AS compared with health y controls. The increased levels were present in patients with axial a nd with peripheral AS, and there were no statistically significant dif ferences in the antibody levels between these two groups. Sulphasalazi ne treatment decreased the Klebsiella specific antibody level of IgA1 subclass in patients with axial AS, but there were no statistically si gnificant changes in the IgA2 subclass, or in the patients with periph eral type AS. Conclusions-These results agree with earlier published f indings suggesting that IgA (especially Klebsiella specific IgA) may h ave a role in the pathogenetic mechanisms of both peripheral and axial types of AS. In addition, it seems that both IgA1 and IgA2 subclasses are involved in the disease process.