Effect of initial therapy on dynamics of immunogloblin G levels to some periodontopathic bacteria in serum and gingival crevicular fluid.

Using enzyme-linked immunosorbent assay, the IgG antibody levels to specific gram-negative periodontopathic bacteria in serum of 21 adult periodontitis patients and the gingival crevicular fluid (GCF) from 42 sites with destructive lesions and 21 healthy sites were evaluated before and after initial preparation. Porphyromonas gingivalis, Bacteroides forsythus, Prevotella intermedia, Prevotella nigrescens, Campylobacter rectus, Treponema denticola and Actinobacillus actinomycetemcomitans in subgingival plaque samples from the patients were examined by indirect immunofluorescence microscopy. Subgingival plaque, GCF, and serum samples were taken at baseline and three weeks after initial preparation. For 14 patients, changes in clinical parameters due to the initial preparation were correlated with reduction of periodontopathogens and to IgG antibody levels in GCF and serum against them. P. gingivalis, T. denticola and C. rectus were found to be predominant in destructive sites. No significant differences were found in GCF IgG antibody levels between destructive and healthy sites. In destructive sites, the prevalence of P. gingivalis and C. rectus was significantly correlated with elevated IgG antibody against these microorganisms in GCF. The initial preparation resulted in significant reduction of serum IgG antibody levels against all microorganisms tested. No decrease in GCF IgG antibody was observed, but levels to P. gingivalis and C. rectus were significantly increased (p<0.05). The assessment of GCF IgG antibodies to specific periodontopathic bacteria may be of considerable value in reflecting the conditions of periodontitis.