Methods: Each participant, referred to the Clinic of the Preventive Dentistry, Tokushima University Hospital, signed an informed consent document for salivary collection. The inclusion criteria were systemically healthy adult under 65 year-old and at least 10 teeth present. Full mouth periodontal probing depths (PPD), the deepest site at each tooth and the prevalence of teeth with bleeding on probing (BOP) positive were recorded. Subjects with periodontitis were picked out from the patients satisfying the following criteria: presence of a minimum of 2 deep PPD (≥5 mm) on the separate teeth, BOP positive at the deep pocket site and/or radiographic evidence of alveolar bone loss. Patients without periodontitis were categorized as control subjects in this study.
Results: We divided the study group into subjects with periodontitis (n = 35) and control (n = 28). By Western immunoblot analysis of sIgA directed to 5 kinds of protein belonging to heat shock protein 60 family, immunoreactivities of Campylobacter rectus GroEL and Porphyromonas gingivalis GroEL were detected significantly higher (p<0.05) in subjects with periodontitis comparing to control subjects. High level of resonance unit (RU) value was observed in saliva from patients with periodontitis (p<0.01) when BIACORE 1000 was used for the measurement of sIgA titers directed to C. rectus GroEL. Furthermore, the number of teeth with deep pocket depth (≥5 mm) showed high correlation coefficients with the RU value (r=0.50, p<0.01).
Conclusions: These results might indicate the relationship between the severity of periodontal disease and the high level of sIgA directed to GroEL from periodontopathogenic bacteria.