Crevicular fluid level of β-glucuronidase in relation to clinical periodontal parameters and putative periodontal pathogens in early-onset periodontitis

. Analysis of β‐glucuronidase (βG) in the gingival crevicular fluid (GCF) provides an indication of neutrophil influx into the crevicular environment. The aim of this study was to test the hypotheses that: (1) βG is significantly elevated in individuals with early‐onset periodontitis (EOP) and that βG activity correlates with disease severity: and (2) βG level may reflect the local bacterial challenge in the gingival crevice. The study subjects consisted of a sub‐sample of individuals examined in the National Survey of Oral Health of United States Children, which was undertaken during the 1986/87 school year. A total of 249 individuals were selected based on presence or absence of clinical attachment loss at baseline. The individuals were examined a second time 6 years later and the clinical attachment loss was assessed, and subgingival plaque and GCF were collected. The subjects were classified into 3 types of EOP and a control group, βG activity in the GCF and the levels of 7 putative micro‐organisms in the pocket were assessed. The generalized EOP group had the highest βG activity, followed by the localized and incidental EOP groups, and the controls, respectively. There was a significant increase in βG activity with the increase in probing depth. Also, sites with bleeding on probing had a significantly higher βG activity than sites without bleeding. However, the effect of gingival inflammation on βG activity was more evident in the generalized and localized EOP groups. Sites harboring high levels of one or more of the micro‐organisms tended to have high βG activity. There were moderate differences between the organisms with respect to their effect on βG activity, but sites with high numbers of Porphyromonas gingivalis, Prevotella intermedia, or Treponema dentieola also had the highest βG activity. The present findings suggest that βG activity in GCF from patients with EOP can be of value in the early identification of individuals at higher risk of developing EOP, The findings also suggest that host mechanisms leading to higher βG activity in EOP represent systemic responses and are only partly related to the presence of local factors at the site‐level.