"Checkerboard" assessments of peridontal microbiota and serum antibody responses: A case-control study

Background: We explored the association between subgingival microbial profi les and serum IgG responses to periodontal microbiota in relation to clinic al periodontal status. Methods: One hundred thirty-one (131) periodontitis patients aged 29 to 74 years (mean 51.8) were age- and gender-matched with 74 periodontally intact controls (range 26 to 77, mean 49.3). Smoking habits and health history we re recorded and assessments of plaque, bleeding on probing, probing depth, and attachment level were performed at 6 sites per tooth on all present tee th, excluding third molars. Subgingival plaque samples were obtained from e ach tooth in one upper and one lower quadrant (maximum 14 samples/subject; 2,440 samples total) and analyzed with respect to 19 species by means of wh ole genomic DNA probes. Serum IgG antibodies against the same 19 species we re assessed by an immunoassay. Results: Cases displayed an average of 22.7 teeth, 20.3 sites with probing depth greater than or equal to6 mm, and 18.9 sites with attachment loss gre ater than or equal to6 mm. Corresponding figures for controls were 27.1, 0. 1, and 1.0, respectively. Heavy smoking was 3 times more frequent among cas es than controls (32.1% versus 9.6%). Higher levels of Porphyromonas gingiv alis, Porphyromonas endodontalis, Prevotella intermedia, Prevotella nigresc ens, Prevotella melaninogenica, Bacteroides forsythus, Fusobacterium nuclea tum, Treponema denticola, Eubacterium nodatum, Peptostreptococcus micros, a nd Campylobacter rectus were found in cases and higher levels of Eikenella corrodens, Veillonella parvula, and Actinomyces naeslundii in controls. Cas es displayed higher IgG levels against P. gingivalis and Actinobacillus act inomycetemcomitans, while controls displayed higher levels against F nuclea tum, T. denticola, E. nodatum, and Capnocytophaga ochracea. Positive correl ations between bacterial colonization and antibody responses were identifie d for 9 species in controls. In cases, however, statistically significant c orrelations were observed for only 3 species out of which only one was posi tive (V. parvula). Both bacterial levels and antibody responses declined in ages over 55 years. A logistic regression employing selected elements of b acterial colonization and antibody responses as independent variables resul ted in 81.1% correct diagnosis, with sensitivity of 83.1%, specificity of 7 7.8%, positive predictability of 86%, and negative predictability of 73.7%. Smoking did not reach statistical significance in this model. Conclusion: A combined microbial colonization/antibody response profile can effectively discriminate between periodontitis patients and periodontally intact controls.