Interleukin-1 alpha, interleukin-8 and interferon-alpha levels in gingival crevicular fluid

Cytokines play an important role in the pathology associated with chronic inflammatory diseases. We measured the total amounts [picograms (pg)] and concentrations.(pg/microliter) of interleukin-1 alpha (IL-1 alpha), interleukin-8 (IL-8) and interferon-alpha (IFN-alpha) in 20 s gingival crevicular fluid (GCF) samples obtained from 2 diseased and 2 healthy sites in 20 subjects with periodontitis, and from 2 healthy sites in 20 subjects without disease. Both the mean amount and concentration of IL-1 alpha were significantly higher (p < 0.001) in diseased sites compared to healthy sites in subjects with disease. The results for IL-8 and IFN-alpha differed depending on the method of reporting. Whereas the amount of IL-8 was significantly higher (p < 0.01) in diseased sites, the mean concentration of IL-8 was lower compared to healthy sites. The mean amount of IFN-alpha was similar in health and disease; however, the concentration of IFN-alpha was significantly lower in diseased sites (p < 0.001) corresponding to the significant increase in crevicular fluid volume (p < 0.001). There were no significant differences in the amount or concentrations of the 3 cytokines between healthy sites from subjects with disease and healthy sites from healthy controls. The total amounts of both IFN-alpha and IL-8 were correlated between healthy and diseased sites in subjects. These data suggest that, while the disease status of a site is the major determinant of the levels of these cytokines locally, subjects with high levels of IL-8 and IFN-alpha in healthy sites also tend to have high levels of these cytokines in diseased sites. Finally, both the concentrations and total amounts of IL-8 and IFN-alpha were significantly correlated in diseased sites, suggesting that levels of these two cytokines rise or fall in tandem. The combination of decreased IL-8 and decreased IFN-alpha concentrations at diseased sites may reflect the reduced anti-bacterial host defense activity at that site.