ATTACHMENT LOSS AND SERUM ANTIBODY-LEVELS AGAINST AUTOLOGOUS AND REFERENCE STRAINS OF ACTINOBACILLUS-ACTINOMYCETEMCOMITANS IN UNTREATED LOCALIZED JUVENILE PERIODONTITIS PATIENTS

Immunological data have been suggested to be a potential tool in the d iagnosis, classification and monitoring of periodontal diseases. Howev er, the role of circulating antibodies in periodontal patients is poor ly understood. Patients suffering from localized juvenile periodontiti s (LJP) are often reported to show high titers of serum IgG antibodies against Actinobacillus actinomycetemcomitans (A. actinomycetemcomitan s), but several affected patients do not. Most studies use well-known reference strains of the bacterium for testing against the patients' s era. The aim of the present investigation was to study the relationshi p between serum IgG antibody levels to autologous A. actinomycetemcomi tans strains and clinical attachment loss (GAL). In addition, we wante d to assess the patients' serum titers against 4 well-known reference strains of the bacterium as well as their general potential immunoglob ulin response. Intravenous blood samples were taken from 23 LJP patien ts and 10 healthy individuals, and autologous A. actinomycetemcomitans strains were cultured from 18 of the LJP patients. CAL was measured a t 4 different sites around all present teeth and assessed as a % of te eth with at least 1 site moderately greater than or equal to 2 < 5 mm) or severely (greater than or equal to 5 mm) involved. An enzyme-linke d immunosorbent assay (ELISA) was performed to evaluate the serum tite rs of IgG antibodies to A. actinomycetemcomitans antigens. No signific ant correlation was found between serum IgG antibody titers to autolog ous strains and GAL. However, there was a trend that low responders ha d more moderately affected teeth than had high responders and patients with undetectable A. actinomycetemcomitans levels, which is in agreem ent with a hypothetically protective role of the antibodies. The total counts of immunoglobulin assessed in all participants showed that the predominant class was IgG and the reference group displayed significa ntly less (p < 0.05) IgG and IgG1 counts than the LJP patients. Both t he reaction pattern against reference and autologous strains varied wi dely. We conclude that the specific antibody response against A. actin omycetemcomitans shows a weak correlation to clinical attachment level s in LJP patients.