Profiling biomarkers in gingival crevicular fluid using multiplex bead immunoassay

Objective: Biomarkers in gingival crevicular fluid (GCF) have been investigated; however, measurements were limited by the small sample volume available. The aim of this study was to determine the levels of 40 different cytokines and chemokines in GCF samples. Design: Eleven patients with generalised chronic periodontitis participating in a supportive periodontal therapy programme with remaining probing pocket depths (PDs) of >5 mm were enrolled. One healthy and two diseased sites were sampled in each subject. Forty biomarkers in GCF were examined using a multiplex bead immunoassay. Porphyromonas gingivalis from the diseased sites was quantified by real-time polymerase chain reaction. Results: Twenty-six biomarkers were detected in the GCF samples using the multiplex bead immunoassay. The levels of nine biomarkers were significantly different between the diseased and healthy sites after adjustment with Bonferroni's correction. The level of 26 biomarkers in diseased sites was compared between bleeding on probing (BOP)-positive and BOP-negative sites. Interleukin (IL)-1 beta and interferon-inducible protein (IP)-10 levels were significantly higher in BOP-positive diseased sites than BOP-negative diseased sites after adjustment for multiple comparisons (IL-1 beta, p = 0.0007, IP-10; p = 0.0009). In addition, the levels of IL-1 beta in GCF were found to be strongly correlated with the P. gingivalis ratio (r = 0.646, p = 0.0012). Conclusion: IL-1 beta levels in GCF correlate with the PDs, BOP and the presence of P. gingivalis in subgingival plaque. Multiplex bead assays can be useful in GCF studies. These findings can help in identifying new diagnostic methods in the diagnosis of periodontal disease. (C) 2012 Elsevier Ltd. All rights reserved.