Diversity of IgG Antibody Responses in the Patients with Various Types of Periodontitis

Abstract

Serum IgG antibodies to seven periodontopathic bacteria were assessed with an enzyme-linked immunosorbent assay (ELISA) in 56 patients with periodontitis. Patients were selected according to the severity of bone loss, and were also classified into three categories by age: juvenile periodontitis (JP), advanced destructive periodontitis (ADP), and adult periodontitis (AP). Bacteroides gingivalis, B. loescheii, Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, Eikenella corrodens, B. intermedius, and Capnocytophaga ochracea were the bacterial strains of interest. Antigens were prepared by cold ultrasonication of washed bacterial cells. Association of high- or low-IgG antibody titer to the bacteria was evaluated. High or low titers of IgG were based on ELISA measurements in 28 healthy subjects. Values exceeding 100% above or below the normal standard deviation were classified as high or low titers, respectively. Most patients with three types of periodontitis (76.8%) exhibited high-IgG antibody titers against various periodontopathic bacteria. The sera mostly included high-IgG titer against one or some of B. gingivalis, E. corrodens, F. nucleatum, and/or A. actinomycetemcomitans. B. gingivalis was predominantly associated with three categories of periodontitis (60.7%). However, high-IgG antibody titer against B. gingivalis alone was found in relatively low percentage (21.4%). Most of the cases were associated with one or more of the other periodontopathic bacteria. High-IgG titer against A. actinomycetemcomitans was found in a few patients (12.5%), who showed severe and more rapid bone loss. Nine patients (16.1%) showed lower IgG antibody titer than did the healthy control subjects. Of the nine, three patients who belonged to the JP category showed the chemotaxis dysfunction of their PMNs. Some immunodepression was suspected in these patients.