SIGNIFICANCE OF SERUM ANTIBODY AGAINST SURFACE-ANTIGENS OF ACTINOBACILLUS-ACTINOMYCETEMCOMITANS IN PATIENTS WITH ADULT PERIODONTITIS

This study was undertaken to examine the prevalence of Actinobacillus actinomycetemcomitans, its serotype distribution and the serum immune responses against its surface antigens in 41 Japanese patients with ad ult periodontitis. The dominant A. actinomycetemcomitans serotype isol ated was serotype c. Immunoblot analysis of 3 serotypes of A. actinomy cetemcomitans-sonicated antigens and the patient sera revealed that th e reactivities with serotype c were the most frequent and that heat-st able surface serotype-specific antigen appeared to be immunodominant. Elevated serum immunoglobulin G titers to extracted lipopolysaccharide and fimbriae antigen of A. actinomycetemcomitans were noted for the p atient sera by enzyme-linked immunosorbent assay. High serum immunoglo bulin G titers to the fimbriae antigen detected in patients without cu ltivable A. actinomycetemcomitans suggested the possibility that the e licited antibody to the antigen played a role in eliminating A. actino mycetemcomitans from the periodontal lesions.