Useful Immunochromatographic Assay of Calprotectin in Gingival Crevicular Fluid for Diagnosis of Diseased Sites in Patients with Periodontal Diseases

Calprotectin, an inflammation-related protein, is present in gingival crevicular fluid (GCF), and the determination of calprotectin is useful for diagnosing periodontal diseases. The authors have recently developed a novel immunochromatographic (IC) chip system to determine calprotectin levels in GCF. In the present study, the usefulness of this diagnostic system is investigated in patients with periodontal diseases.Thirty-six patients with periodontal diseases participated in this clinical test at multiple centers. Periodontitis sites (n = 118) and non-periodontitis (healthy) sites (n = 120) were selected after periodontal examination. GCF collection and periodontal examination were performed at baseline, after supragingival and subgingival scaling and root planing. Calprotectin levels in GCF were determined using a novel IC chip system and evaluated as a visual score and an IC reader value. Correlations between GCF calprotectin levels, clinical indicators, and changes in calprotectin levels by periodontal treatments were investigated. Receiver operating characteristic (ROC) analysis of IC reader value for GCF calprotectin was performed to predict periodontal diseases.The visual score of GCF calprotectin was highly correlated with the IC reader value. IC reader values of GCF calprotectin in the periodontitis group were higher than those of the healthy group at three dental examination stages, and they significantly decreased with periodontal treatments. Visual scores and IC reader values of GCF calprotectin were correlated to levels of clinical indicators. ROC analysis for GCF calprotectin showed an optimal cutoff value to predict periodontal diseases.Determination of GCF calprotectin using a novel IC chip system is useful for diagnosis of periodontal diseases.