Host β-globin gene fragments in crevicular fluid as a biomarker in periodontal health and disease

Background and Objective: Leukocytes and epithelium are the first line of defense in preventing bacterial invasion into periodontium. Some of these cells die in gingival crevicular fluid, whereupon their DNA is spilled out. The present study was designed to investigate the profile of host β-globin gene fragments in the gingival crevicular fluid of various periodontal conditions. Material and Methods: Gingival crevicular fluid from 40 teeth with chronic periodontitis, 30 with gingivitis and 22 that were clinically healthy were centrifuged (3000g, 10 min). The supernatant (cell-free gingival crevicular fluid) was centrifuged again (13,000g, 10 min), resulting in the pellet and the supernatant as debris and debris-free fractions, respectively. Specific primers for amplifying 110 bp, 536 bp and 2 kb amplicons of human β-globin gene were used to investigate host DNA by quantitative and qualitative polymerase chain reaction. Results: The periodontitis group showed the largest amount of host β-globin gene fragments, while the healthy group had the lowest. In the debris and debris-free fractions, the 536 bp and 2 kb amplicons were more often detected in the periodontitis group than in the other groups. Interestingly, the presence of 2 kb amplicon in the debris fraction could be used to discriminate periodontitis from gingivitis and healthy groups because we found it in 85% of periodontitis samples but only in 13% of gingivitis samples, and it was absent in the healthy group. Conclusion: This study shows the different DNA profiles of cell-free gingival crevicular fluid in periodontal health and disease. It suggests that the quantity and quality of host DNA are dependent on the disease conditions. Therefore, the β-globin gene fragments in cell-free gingival crevicular fluid may be a potential biomarker of periodontal disease progression.