Application of Lactoferrin and α1-Antitrypsin in Gingival Retention Fluid to Diagnosis of Periodontal Disease

OBJECTIVES: Periodontal disease is prevalent and has an inflammation associated with not only oral but also systemic pathologies. The diagnosis by biomarkers is required for clinical practice on periodontal disease. The lactoferrin and α1-antitrypsin were both inflammation-related molecules. The present study investigated the relationship between the periodontal status and the two biomarkers in gingival retention fluid (GRF). PATIENTS AND METHODS: In 63 subjects with periodontitis, the GRF was sampled from maxillary anterior gingiva using a microbrush for 30 seconds. The lactoferrin and α1-antitrypsin levels in GRF were measured by an enzyme-link solvent immunoassay. Periodontal status was evaluated by probing pocket depth (PD) and bleeding on probing (BOP). RESULTS: There was a higher level of these biomarkers in saliva (median (ng/mL), lactoferrin: 3611.9, α1-antitrypsin: 4573.3) than in GRF (lactoferrin: 61.0, α1-antitrypsin: 54.7). There was a mild-to-moderate but significantly positive correlation in lactoferrin or α1-antitrypsin between GRF and saliva. There was a positively mild-to-moderate accuracy (area under the curve: 0.60–0.81) of lactoferrin or α1-antitrypsin in GRF or in saliva to distinguish the severity of periodontal status. The cutoff level (ng/mL) of lactoferrin in GRF for detecting ≥30% of PD ≥ 4 mm (moderate periodontitis) was 68.6 and for detecting ≥20% of BOP (clinically active periodontitis) was 61.2. The cutoff level (ng/mL) of α1-antitrypsin in GRF for detecting ≥30% of PD ≥ 4 mm was 54.5 and for detecting ≥20% of BOP was 35.3. CONCLUSIONS: The data can promote an application of the measurements of lactoferrin and α1-antitrypsin in GRF to clinical practice on periodontal disease.