Serum IgG reactivity to subgingival bacteria in initial periodontitis, gingivitis and healthy subjects

Background/aims: Established periodontal diseases may be associated with antibody responses to periodontal pathogens, but it is not known at which stage of disease this antibody response is initiated. This study aimed to characterize the host systemic response in initial periodontitis, gingivitis, and periodontal health, to evaluate whether elevated serum antibodies to subgingival species could be detected in initial periodontitis. Method: Human systemic immune response were evaluated to 40 subgingival bacterial species in 16 healthy, 21 gingivitis, 11 initial periodontitis and 5 progressing recession adults. Subjects had minimal periodontal attachment level (AL) loss at baseline. Disease categories were determined after 12 months monitoring at three-month intervals. Increased AL loss greater than or equal to 1.5 mm (disease activity) at interproximal sites defined initial periodontitis, recession was characterized by AL loss at buccal sites. Serum IgG antibodies were evaluated semi-quantitatively by immunoblot from blood taken at baseline, active and final visits. Results: No antibody was detected from 55% of reactions. When detected, levels were below those reported for advanced periodontitis subjects. There were no major differences in serum antibody levels between healthy, gingivitis and initial periodontitis subjects, despite differences in the subgingival microbiota. Serum antibodies for more species were detected in recession subjects, compared with the other study subjects. No changes in antibody levels were detected between baseline, active, and final visits. No systematic association between species colonization and presence of systemic antibody was observed. Conclusions: This study did not detect differential elevation of mean serum antibody levels in initial periodontitis subjects, suggesting that serum antibody levels are not sensitive risk markers for initial periodontitis.