Background: Chemokines are central in the activation and direction of leukocyte subsets to target tissues. However, the monocyte chemoattractant protein-3 (MCP-3) has not been associated with chronic periodontitis. Chronic periodontitis is an infection showing episodic supporting tissue destruction. The aim of this study is to determine the levels and expression of MCP-3 in periodontal sites characterized by active periodontal connective tissue destruction.
Methods: The study population consisted of 15 patients with a progression of periodontitis (15 of 56 patients), 18 patients with chronic periodontitis, and 10 healthy subjects without periodontal disease. As determined by the tolerance method, the 15 patients with moderate to advanced chronic periodontitis showed a progression of periodontitis over a 4-month period. Periodontitis was characterized by at least six sites with a probing depth >or=5 mm, clinical attachment level >or=3 mm, and radiographic bone loss. Gingival crevicular fluid was collected using a paper strip. The total protein concentration was determined. An enzyme-linked immunosorbent assay was performed to determine the total amount of MCP-3, and an immunoWestern blot was conducted to assess molecular MCP-3 forms. To determine the MCP-3 expression by immunohistochemistry, gingival biopsies were obtained from patients with chronic periodontitis and healthy subjects during third-molar extraction surgery. Statistical analyses were performed using statistical software. Data were expressed as subject means +/- SD, using the chi(2) and Student t tests.
Results: The total amount and concentration of chemokine MCP-3 were significantly higher in patients with chronic periodontitis than in healthy subjects (8.25 pg versus 0.53 pg, P = 0.006 and 2.95 pg/microl versus 0.45 pg/microl, P = 0.04, respectively). Active sites showed a significantly higher total amount and concentration of MCP-3 than inactive sites (11.12 versus 2.88 pg, P value = 0.005 and 3.95 versus 1.02, P value = 0.005, respectively). Western blot and immunohistochemical staining confirmed the presence of MCP-3 in periodontal disease, with observable differences between patients with chronic periodontitis and healthy subjects.
Conclusions: MCP-3 was highly expressed in patients with chronic periodontitis, particularly in those with progressive periodontal lesions. MCP-3 could be involved in the recruitment of inflammatory cells toward periodontal tissues during the progression of the disease.