Interleukin-1β and IgG subclass concentrations in gingival crevicular fluid from patients with adult periodontitis

Abstract

Interleukin-1β (IL-1β) and the four IgG subclasses were measured in gingival crevicular fluid (GCF) at 35 sites in 19 patients with adult periodontitis. Serum concentrations of the IgG subclasses were assayed in 16 patients. IL-1β was detected in GCF at 88.6% of sites at concentrations ranging from 12.38–420.90 pg/μl (mean 138.35 ± 112.61 pg/μl). IgG1 was detected at 81.2% sites, IgG2 at 93.6%, IgG3 at 71% and IgG4 at 71%. Absolute concentrations in GCF were: IgG1–2.419 g/l ± (SD) 3.389; IgG2-2.945 ± 6.434; IgG3 − 0.118 ± 0.144; IgG4 0.864 ± 1.336. There were no significant correlations between IL-1β concentrations, GCF volume or the clinical status of the sample site. IL-1β was not correlated with any of the IgG subclasses. The absolute concentrations of all subclasses in GCF were significantly negatively correlated with GCF volume and positively correlated with the Bleeding Index. Only IgG4 was significantly negatively correlated with the probeable crevice depth index. The concentration of each IgG subclass was positively correlated with the other three IgG subclasses. Subclass concentrations in GCF, relative to serum concentrations, were not correlated with GCF volume or clinical status. Relative concentrations of IgG1, IgG2 and IgG3 showed significant positive correlation with each absolute concentration of the other subclasses but IgG4 did not show this relation. It was concluded that IL-1β is not related to clinical measurements of inflammation or previous attachment loss. The data suggest that IgG in GCF is largely derived from plasma but that some IgG4 may be locally synthesized.