Interleukin-1beta level in gingival crevicular fluid of patients with active periodontitis

Previous studies revealed that interleukin-1beta (IL-1beta) was detectable in gingival crevicular fluid (GCF) of patients with periodontitis, and the level was increased in level in gingival tissue extracts of active periodontal disease sites (defined as attachment loss > or = 2.5 mm over the preceding 2 months) compared to inactive sites or healthy sites. The present study evaluated the relationship of IL-1beta level in GCF and periodontal disease status. GCF was collected with Periopaper strips from 34 disease-active and 45 disease-inactive teeth in 11 untreated periodontitis patients and from 60 teeth in 15 healthy control subjects. Disease activity was defined as attachment loss of > or = 2.5 mm in at least one site of a tooth as determined by sequential probing. The absorbed GCF volume was determined using a Periotron 6000 and the crevicular IL-1beta level was determined using IL-1beta monoclonal antibody (Otsuka Pharmaceutical, Japan). IL-1beta was below the detection level of the assay (6 pg/ml) in the healthy control group but was detected in most teeth of the periodontitis group. However, disease-active teeth had higher IL-1beta level (Mann-Whitney U-test, p < 0.05) than disease-inactive teeth (mean total IL-1beta of 5.89 +/- 7.88 pg/tooth and 1.72 +/- 2.28 pg/tooth; mean concentration of 1.6 +/- 2.5 ng/ml and 0.6 +/- 0.83 ng/ml, respectively). The level of IL-1beta showed no correlation with probing depth, but had significant correlation (p < 0.05) with the extent of attachment loss. This study suggests that the level of IL-1beta in GCF may have a predictive value for determining active and inactive periodontal status.