SPECIFIC ANTIBODY REACTIVITY AGAINST A 110-KILODALTON ACTINOBACILLUS-ACTINOMYCETEMCOMITANS PROTEIN IN SUBJECTS WITH PERIODONTITIS

The purpose of the present study was to determine the serum immunoglob ulin A (IgA), IgM, and IgG reactivities against proteins of Actinobaci llus actinomycetemcomitans in patients with periodontitis, Serum sampl es from 20 patients with early-onset periodontitis, 20 patients with a dult periodontitis, and 20 age- and sex-matched healthy controls were assessed by immunoblot analysis. IgG antibody reactivity against a sar cosyl-insoluble 110-kDa protein of A. actinomycetemcomitans was detect ed in 65 and 45% of patients with early-onset periodontitis and adult peritonitis, respectively, and IgA antibodies against this protein wer e found in 70 and 55% of these patients, respectively, However, contro l subjects showed no IgG reactivity, and Iga antibodies against the sa rcosyl-insoluble 110-kDa protein were detected in only 5% of the patie nts (P < 0.05), There was no IgM antibody reactivity against this prot ein in any of the diseased or healthy subjects, The sensitivity and sp ecificity of serum IgA antibody reactivity against the 110-kDa protein in detecting subgingival A. actinomycetemcomitans infection, as deter mined by PCR, were 77 and 66%, respectively. The results of the study indicated that the sarcosyl-insoluble 110-kDa protein is a potential c andidate for use in the serodiagnosis of periodontal disease.