Protective effect of serum antibodies against a 110-kilodalton protein of Actinobacillus actinomycetemcomitans following periodontal therapy

Thirty-four adult patients with untreated periodontitis were randomly assig ned to receive full mouth scaling alone or scaling with an adjunctive antim icrobial therapy, both followed by supportive periodontal therapy. At 24 mo nths, specific serum immunoglobulin A (IgA), IgG and IgG subclass antibody reactivities against a 110-kDa protein of Actinobacillus actinomycetemcomit ans were assessed by Western blot. In patients harboring A. actinomycetemco mitans intraorally, the IgG(4) antibody reactivity against the 110-kDa prot ein of A. actinomycetemcomitans was associated with significantly increased survival rates of teeth and of sites not exhibiting 2 mm or more of probin g attachment loss. The same trend was found for IgG(3) and IgG(2) antibody reactivities, but it was statistically insignificant. No association with c linical treatment outcome was observed for IgA, IgG and IgG(1) antibody rea ctivities. The results indicated that systemic IgG(4) antibody reactivity a gainst the 110-kDa protein of A. actinomycetemcomitans may have a protectiv e effect against periodontal disease progression in patients harboring A. a ctinomycetemcomitans and receiving periodontal therapy.