Existence of anti-IL-1ra IgG in gingival crevicular fluid

Objectives:In order to investigate whether existence the inhibitors of interlukin-1 receptor antagonist (IL-1ra) in gingival crevicular fluid (GCF). Methods:GCF samples were obtained and pooled from 15 chronical periodontitis (41 teeth). The GCF was absorbed repeatedly by heat killed E.colil. The antibody against E.coli in GCF was completely absorbed by E.coli. Which was confirmed by the indirect immunofluorescence technique. The indirect ELISA was used for measuring IL-1ra IgG antibody (IL-1raAB) in GCF samples. Results:The IL-1raAB mean value in GCF was 0.031±0.003 which was greater than the negative control(0.016±0.004) .When the concentration of the E.coli sonication and the corresponding OD values of IL-1raAB was analysed by linear regression, Y=0.0035X+2.924. The slope almost equated zero. Conclusions:The E.coli antigens did not affect the measurement of IL-1raAB, and GCF from periodontitis sites contain IgG antibody against IL-1ra.