Dentists today can easily diagnose periodontal disease in its advanced symptomatic stages, but the subtle opening rounds of infection and inflammation remain mostly a blank molecular diagnostic slate. Greatly needed are informative biomarkers of early, asymptomatic chronic periodontitis that would allow for immediate intervention and change the all-too-predictable outcomes of advanced disease and tooth loss. This is now beginning to happen for localized aggressive periodontitis (LAP), a leading cause of tooth loss in children, particularly among African Americans. As reported in the Journal of Periodontology, National Institute of Dental and Craniofacial Research (NIDCR) grantees have provided biannual dental exams to a cohort of 96 healthy students (ages 11 to 17 years) at risk for LAP. The exam included the collection of a saliva sample from each student. When 7 students subsequently developed LAP, the scientists examined their saliva samples over the course of the study to evaluate levels of 21 distinct immune system-signaling molecules, or cytokines. Although 19 molecules were not detectable or present at extremely low levels, the scientists found that the cytokine macrophage inflammatory protein-1 (MIP-1) was quite elevated in the saliva samples of all 7 students. In fact, compared to the remaining 21 students who were LAP-free, the levels of the cytokine were 50-fold higher from 6 to 9 months prior to radiographic-detected bone loss, a precursor of tooth loss. The increased MIP-1 levels were related to increased probing depth and number of pockets greater than 6 mm. Taken together, the authors suggest that MIP-1 might be a biomarker of LAP that emerges from pocket sites, makes its way into saliva, and appears to parallel increasing pocket depth before radiographic evidence of bone loss. There is precedent for such an interpretation. Previous studies of the bone cancer multiple myeloma showed that MIP-1 preceded radiographic evidence of bone loss by 6 to 12 months. In the current study, MIP-1 had a 96.8% specificity and a 100% sensitivity for bone loss.
(Source: NIDCR, Science News in Brief, March 17, 2009.)
