Activity of serum immunoglobulins G, A, and M to six anaerobic, oral bacteria in diagnosis of periodontitis

The serum levels of IgG, IgA, and IgM-antibodies to extracts of Bacteroides gingivalis, Bacteroides ureolyticus, Capnocytophaga ochracea, Eubacterium saburreum , Fusobacterium nucleatum and Selenomonas sputigena were measured by an enzyme-linked immunosorbent assay (ELISA) in 50 subjects with a healthy periodontium, 10 patients with gingivitis, and 40 patients with periodontitis. In the healthy subjects, the levels of IgG and IgA-antibodies to the extracts were positively correlated with age up to 20 years; after this age no further increase was observed in the mean levels of antibodies to the oral bacteria. A large majority of the patients with periodontitis had significantly increased levels of IgG and IgA-antibodies to one or more of the bacterial extracts. By discriminant analysis of the data refering to all six extracts. 95% of the sera from the periodontitis group received a classification that only included 3% of the sera in the healthy group and 20% of the sera in the gingivitis group.
A simpler test based on the IgG and IgA-antibodies to extracts of B. gingivalis and E. saburreum showed a sensitivity of 75% in detecting sera from the periodontitis group. In this test, 70% of the gingivitis sera and 90% of the sera from the healthy subjects were negative.