Diagnostic accuracy of a point-of-care aMMP-8 test in the discrimination of periodontal health and disease

Abstract

Aim: To assess the diagnostic utility of an oral rinse active matrix metalloproteinase-8 (aMMP-8) point-of-care test (POCT) for differentiating periodontal health, gingivitis, as well as different stages and grades of periodontitis.

Materials & methods: The aMMP-8 index test was undertaken in 408 consecutive adults, followed by a full-mouth periodontal examination. The reference standard was the 2017 World Workshop classification of periodontal diseases. Sensitivity, specificity, and the area under the receiver operating characteristic curve (AUROC) were assessed.

Results: 68.6% of the participants were diagnosed with periodontitis, including Stages I (15.9%), II (15.9%), III (29.7%) and IV (7.1%). A positive aMMP-8 POCT was associated with periodontitis after adjusting for age, gender, tobacco smoking and systemic diseases, while it was unable to differentiate among the stages/grades of periodontitis and between gingivitis/periodontal health. This test showed a sensitivity of 33.2% and a specificity of 93.0% for detecting periodontitis (threshold level >10 ng/ml). The levels of aMMP-8 adjusted by the number of teeth present (aMMP-8/NTP) performed better for periodontitis (sensitivity: 67.1%; specificity: 68.8%). Notably, aMMP-8/NTP were strongly predictive for Stage IV periodontitis (threshold level =0.4312 ng/ml) (sensitivity: 89.7%; specificity: 73.6%; and AUROC: 0.856). The test performance greatly improved in combination with age and smoking, with a sensitivity of 82.5%, a specificity of 84.4%, and an AUROC of 0.883.

Conclusion: This aMMP-8 POCT is able to detect periodontitis with better specificity than sensitivity across the spectrum of its severity. This test may be useful for periodontal screening in conjunction with subject characteristics and/or other sensitive screening tools. Further validation studies are needed.

Keywords: diagnosis; gingivitis; matrix metalloproteinase-8; periodontal health; periodontitis; point-of-care test; screening; sensitivity and specificity.

FIGURE 1

Standards for Reporting Diagnostic Accuracy (STARD) flow diagram of the study for various periodontal case definitions. Different thresholds of aMMP‐8 level or aMMP‐8/NTP showed different diagnostic performance for periodontitis

FIGURE 2

The quantitative aMMP‐8 levels by periodontal case definitions and periodontitis grade. Modified aMMP‐8 levels according to (a) case definitions and (b) periodontitis grade; aMMP‐8/NTP according to (c) case definitions and (d) periodontitis grade. Each dot represents one participant; the horizontal bars in each graph display the medians and interquartile ranges (IQR). Kruskal–Wallis tests were used to assess aMMP‐8 level or aMMP‐8/NTP differences among case definitions and the grading of periodontitis. *** p < 0.001. NS, not significant. Stage I, stage I periodontitis; stage II, stage II periodontitis; stage III, stage III periodontitis; and stage IV, stage IV periodontitis

FIGURE 3

Associations between the quantitative aMMP‐8 levels and periodontal clinical parameters using Spearman's rank correlation coefficient: (a) aMMP‐8 concentrations and the number of bleeding sites: Rho = 0.381, p < 0.001 (subjects with positive POCT, n = 102), Rho = 0.221, p < 0.001 (all subjects, n = 408); (b) aMMP‐8 concentrations and the number of periodontal pockets (PD ≥ 4 mm): Rho = 0.489, p < 0.001 (subjects with positive POCT, n = 102), Rho = 0.318, p < 0.001 (all subjects, n = 408); (c) aMMP‐8 concentrations and the number of bleeding pockets (PD ≥ 4 mm): Rho = 0.478, p < 0.001 (subjects with positive POCT, n = 102), Rho = 0.295, p < 0.001 (all subjects, n = 408); (d) aMMP‐8 concentrations and the number of pockets (PD ≥ 6 mm): Rho = 0.254, p = 0.01 (subjects with positive POCT, n = 102), Rho = 0.238, p < 0.001 (all subjects, n = 408); and (e) aMMP‐8 concentrations and the number of bleeding pockets (PD ≥ 6 mm): Rho = 0.285, p = 0.004 (subjects with positive POCT, n = 102), Rho = 0.252, p < 0.001 (all subjects, n = 408). Red dot, subject with a positive aMMP‐8 POCT and green dot, subject with a negative aMMP‐8 POCT

FIGURE 4

Receiver operating characteristic (ROC) curves: (a) ROC curves of model 1 (blue line), model 2 (red line) and model 3 (green line) for predicting periodontitis from the whole population; (b) ROC curves of model 1 (blue line), model 2 (red line) and model 3 (green line) for predicting stage I/II periodontitis from non‐periodontitis; (c) ROC curves of model 1 (blue line), model 2 (red line) and model 3 (green line) for predicting stage III/IV periodontitis from the whole population; and (d) ROC curves of model 1 (blue line), model 2 (red line) and model 3 (green line) for predicting stage IV periodontitis from the whole population. Please see text for definition of the various models