Bone remodeling-associated salivary biomarker MIP-1α distinguishes periodontal disease from health

Background and Objective: The field of salivary diagnostics lacks an accepted and validated biomarker of alveolar bone remodeling. To address this, we examined levels of salivary biomolecules specifically associated with biological aspects of bone remodeling in subjects with chronic periodontitis in a case-control study. Material and Methods: Levels of macrophage inflammatory protein-1a (MIP-1a), osteoprotegerin, C-telopeptide pyridinoline cross-links of type I collagen and b-C-terminal type I collagen telopeptide in unstimulated whole saliva of 80 subjects (40 subjects with moderate to severe chronic periodontitis and 40 sex-and age-matched healthy control subjects) were measured using enzyme immunosorbent assays. Saliva was collected before clinical examination, which included probing depth, clinical attachment loss and bleeding on probing. Results: The mean level of MIP-1a in subjects with periodontitis was 18-fold higher than in healthy subjects (p < 0.0001). Clinical periodontal indices correlated significantly with MIP-1a levels (p < 0.0001). Of the biomolecules examined, MIP-1a demonstrated the greatest ability to discriminate between periodontal disease and health as determined by the area under the curve (0.94) and classification and regression tree analysis (sensitivity 94% and specificity 92.7%). Osteoprotegerin levels were elevated 1.6-fold (p = 0.055), whereas C-telopeptide pyridinoline cross-links of type I collagen and b-C-terminal type I collagen telopeptide levels were below the level of detection in the majority of subjects. Conclusion: These findings suggest that the chemokine MIP-1a may aid in identifying periodontitis. Future longitudinal studies are warranted to determine whether this biomarker can help in ascertaining the progression of bone loss in subjects with periodontal disease.