PMN responses in chronic periodontal disease: Evaluation by gingival crevicular fluid enzymes and elastase-alpha-1-proteinase inhibitor complex

Objectives: In the present trial, the hypothesis was examined that the local PMN responses in untreated and treated chronic periodontitis can be differentiated by gingival crevicular fluid lysosomal enzyme activities and elastase-alpha-1-proteinase inhibitor complex. Methods: In nine subjects (average age 49.2 ± 7.1 years) with chronic periodontitis, clinical parameters and markers of the PMN-derived inflammatory tissue response in gingival crevicular fluid (GCF) were assessed before and 6 months after surgical periodontal therapy. Myeloperoxidase (MPO), beta-N-acetyl-hexosaminidase (beta-NAH) and cathepsin D (CD) were analyzed as indicators of the PMN-associated host tissue destruction, and elastase-alpha-1-proteinase inhibitor complex (alpha-1-EPI) as the major serum protein inactivating PMN elastase. The total activities of the lysosomal enzymes MPO and beta-NAH were evaluated spectrophotometrically, the CD levels by liquid scintillation counting with [¹⁴C] hemoglobin as substrate, and the total alpha-1-proteinase inhibitor complex using a sandwich-immunoassay. Results: The clinical parameters revealed a statistical significant decrease at the 6-month reexamination. PD levels dropped from 5.40 to 2.88 mm (change 2.52 ± 1.04 mm), the CAL scores from 6.67 to 4.43 mm (change 2.24 ± 0.77 mm). The 30 s GCF volumes dropped from 129.8 to 68.6, displaying a change of 61.1 ± 18.6, p ≤ 0.05. The decrease in total MPO, beta-NAH and CD levels (medians: 1.7/0.6 μU MPO, 0.035/0.020 μU beta-NAH, 1.3/0.5 ng CD) following therapy was associated with a significant drop in total GCF amounts of alpha-1-EPI from 76.3 ng at baseline to 52.4 ng after 6 months. Conclusion: The clinical healing in chronic periodontal disease is associated with a downregulation of the local PMN responses following periodontal therapy. The reorganization of periodontal tissues is characterized by a decrease of lysosomal enzyme activities and the alpha-1-proteinase inhibitor complex in gingival crevicular fluid.