Matrix metalloproteinases and myeloperoxidase in gingival crevicular fluid provide site-specific diagnostic value for chronic periodontitis.

Aim To identify the diagnostic accuracy of gingival crevicular fluid ( GCF) candidate biomarkers to discriminate periodontitis from the inflamed and healthy sites, and to compare the performance of two independent matrix metalloproteinase ( MMP)-8 immunoassays. Materials and Methods Cross sectional study. GCF ( N = 58 sites) was collected from healthy, gingivitis and chronic periodontitis volunteers and analysed for levels of azurocidin, chemokine ligand 5, MPO, TIMP-1 MMP-13 and MMP-14 by ELISA or activity assays. MMP-8 was assayed by immunofluorometric assay ( IFMA) and ELISA. Statistical analysis was performed using linear mixed-effects models and Bayesian statistics in R and Stata V11. Results MMP-8, MPO, azurocidin and total MMP-13 and MMP-14 were higher in periodontitis compared to gingivitis and healthy sites ( p < 0.05). A very high correlation between MPO and MMP-8 was evident in the periodontitis group ( r = 0.95, p < 0.0001). MPO, azurocidin and total levels of MMP-8, MMP-13 and MMP-14 showed high diagnostic accuracy (≥0.90), but only MMP-8 and MPO were significantly higher in the periodontitis versus gingivitis sites. MMP-8 determined by IFMA correlated more strongly with periodontal status and showed higher diagnostic accuracy than ELISA. Conclusions MPO and collagenolytic MMPs are highly discriminatory biomarkers for site-specific diagnosis of periodontitis. The comparison of two quantitative MMP-8 methods demonstrated IFMA to be more accurate than ELISA. [ABSTRACT FROM AUTHOR]