Investigation of serum antibody titers for periodontopathic bacteria in diabetic patients

The purpose of this study was to clarify the usefulness of serum antibody titers for periodontopathic bacteria as a screening test for periodontal disease in diabetic patients. The subjects comprised 28 diabetic patients who were hospitalized in the Department of Internal Medicine of Keio University Hospital for various periods between July 2010 and December 2011 (mean age, 56.6±10.7 years；18 men, 10 women；mean illness duration, 8.7±6.3 years). Periodontal parameters, including probing pocket depth, bleeding on probing, and tooth mobility, were recorded, and blood tests including hemoglobin A1c, blood glucose level, C-peptide, hs-CRP and the serum antibody titers for four peridontopathic bacteria (Aggregatibacter-actinomycetemcomitans, Eikenella corrodens, Prevotella intermedia, and Porphyromonas-gingivalis) were examined at the time of the first visit to our department. A periodontal examination and blood tests were also performed one month after the initial periodontal therapy. Based on the serum antibody titers for P. gingivalis at the first visit, the subjects were divided into a high antibody titer group (antibody titer for P. gingivalis, 1.0 ELISA unit or more) and a low antibody titer group (less than 1.0 ELISA unit). The mean probing pocket depth was significantly deeper in the high antibody titer group than in the low antibody titer group. In addition, a statistically significant relationship was shown between the probing pocket depth and the serum antibody titer against P. gingivalis at the first visit. The serum antibody titers after the initial therapy tended to decrease, compared with the results obtained at the first visit, but the differences were not statistically significant. These results suggest that serum antibody titers for P. gingivalis are useful for the screening of periodontal disease in diabetic patients, and also suggest that the limit of the titers for P. gingivalis may be around 1.0 ELISA unit. Nihon Shishubyo Gakkai Kaishi (J Jpn Soc Periodontol) 56(4)：414-422, 2014.