EFFECT OF TREATMENT ON TITER, FUNCTION, AND ANTIGEN RECOGNITION OF SERUM ANTIBODIES TO ACTINOBACILLUS-ACTINOMYCETEMCOMITANS IN PATIENTS WITH RAPIDLY PROGRESSIVE PERIODONTITIS

Although periodontal treatment by scaling and root planing (SCRP) is k nown to induce bacteremia, the effect of this procedure on the host im mune response is not known. We have determined pre- and post-SCRP immu noglobulin G antibody titers to antigens of Actinobacillus actinomycet emcomitans in the sera of 22 patients with rapidly progressive periodo ntitis. We also assessed the ability of these sera to enhance phagocyt osis and killing of A. actinomycetemcomitans by human polymorphonuclea r leukocytes by using a polymorphonuclear leukocyte chemiluminescence (CL) assay. Specific anti-A. actinomycetemcomitans antibody titers wer e significantly increased at 6 and 12 months after beginning treatment , and CL values were significantly increased at 12 months, whereas mea n interproximal pocket depths were significantly decreased at 12 month s after beginning treatment. When patients were classified as either s eropositive (twice the median titer of control subjects; n = 10) or se ronegative (n = 12), both median titers and CL values were significant ly increased for the seronegative group at 6 end 12 months after treat ment. In the seropositive group, only the median titer was significant ly increased at 12 months. Western blot (immunoblot) patterns for six seronegative and six seropositive patients differed remarkably at the baseline. Before treatment, all of the seropositive patients recognize d high-molecular-mass lipopolysaccharide (LPS) and a large number of p rotein components. Patterns were virtually unaffected by therapy. Befo re treatment, only one of the seronegative patients recognized the LPS smear and none reacted strongly with protein components. Following tr eatment, slight LPS staining was observed for five of six seronegative patients and detection of protein bands was enhanced in ail cases. We conclude that treatment by SCRP induces a humoral immune response, es pecially in seronegative patients, and that response may play a role i n the observed beneficial effects of periodontal treatment.