Thymosin beta4 Levels in Gingival Crevicular Fluid Correlate to Pocket Depth

Kwon, Edwin, and Leyvee Cabanilla

Thymosin beta 4 is a small actin-binding peptide with anti-inflammatory, cytoprotective, anti-apoptotic, and wound healing characteristics. Thymosin beta4 is present in tears, saliva, gingival crevicular fluid (GCF) and wound fluids. Objective: The objective of this study was to determine if thymosin beta4 levels in GCF varied in healthy human patients and in patients with periodontal disease. Methods: Adult patients of the University of Detroit Mercy School of Dentistry clinic who had given informed consent were used in this study. GCF was obtained by placing a PerioPaper collection strip (Oraflow, Inc.) in the gingival sulcus for 30 seconds. 43 GCF samples were obtained from regions of the gingiva that showed no clinical signs of disease, and from regions with periodontal disease as determined by probing depth (PD) ranging from 5 to 10 mm. The volume of GCF collected on each strip was measured using the Periotron 8000. GCF proteins were eluted and samples were analyzed by ELISA to determine thymosin beta4 concentration (Alpco Diagnostics). Results: The mean concentration of thymosin beta4 in GCF taken from all regions with a PD less than 4 mm was 5.24 + 0.19 mg/ml; from all regions with a PD greater than 4 mm the concentration was 6.15 + 0.25 (p = 0.0133). Thymosin beta4 levels inversely correlated to PD; for PD of 5 mm the concentration was 6.33 + 0.30 mg/ml, for PD of 6 mm the concentration was 5.19 + 0.50 mg/ml, for PD of 7mm the concentration was 4.55 + 0.30 mg/ml, and for PD of 10 mm the concentration was 3.99 + 0.30 mg/ml. Conclusions: Periodontal disease results in thymosin beta4 protein concentrations in GCF that are different from gingival health. GCF thymosin beta4 levels appear to vary in periodontal disease depending on probing depth, suggesting a possible link between PD and levels of inflammation.