Isotypic antibody response to plaque anaerobes in periodontal disease

BACKGROUND: It has been suggested that locally produced immunoglobulin (Ig)A could be more protective than IgG and that there could be a relationship between crevicular fluid-specific IgA levels and the onset of periodontal disease. This study was designed to investigate this hypothesis regarding specific immune responses towards 4 plaque anaerobes in gingival crevicular fluid and saliva from patients with periodontopathies and controls. METHODS: Gingival crevicular fluid (GCF) and whole saliva were collected from 35 adults with periodontitis and 24 periodontally healthy adults (controls). Antigens were extracted from Actinomyces actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, and Fusobacterium nucleatum and used to set up specific enzyme-linked immunosorbent assay (ELISA) tests to assess IgA and IgG levels to these microorganisms in the fluids collected. RESULTS: The crevicular fluid of periodontitis patients contained significantly higher levels of IgG to the 4 microorganisms tested than that of controls (P < 10(-6) for all comparisons). IgA levels to the 4 bacteria were statistically significantly much higher in control crevicular fluid (P < 10(-7) for all comparisons). Controls also had statistically significantly higher levels of specific salivary IgA than patients (P < 0.02 for all comparisons). CONCLUSIONS: These data support the potentially protective role of specific IgA directed to oral microorganisms involved in the onset and development of periodontal disease.