Bacterial IgG and IgM antibody titers in acute necrotizing ulcerative gingivitis.

IgG AND IgM ANTIBODY TITERS to eight bacterial isolates were measured by indirect immunofluorescence and ELISA in sera from acute necrotizing ulcerative gingivitis (ANUG) patients during the acute phase, from ANUG patients during the convalescent phase, from patients with gingivitis and from subjects with normal gingiva. Subjects were matched with respect to age and sex. Compared to the gingivitis and healthy groups, the ANUG groups exhibited significantly higher IgG and IgM titers to intermediate-sized spirochetes and higher IgG titers to Bacteroides melaninogenicus subsp intermedius. The findings support recent studies showing that these organisms are major bacterial components in ANUG lesions. They also suggest that these bacteria proliferate above-normal levels several weeks or months prior to the clinical onset of ANUG.