Increased interleukin-8 expression in inflamed human dental pulps

Objective, Elevated levels of interleukin-8, a potent chemoattractant and a ctivator of neutrophils, are associated with infectious and inflammatory di seases. However, little is known about interleukin-8 expression in human de ntal pulp. The purpose of this study was to determine whether tissue levels of interleukin-8 are elevated in irreversibly inflamed human pulps. Study design. Experimental samples were from teeth clinically diagnosed wit h irreversible pulpitis (diseased pulps). Controls were from freshly extrac ted, caries-free third molars (normal pulps). Samples were subjected to enz yme-linked immunosorbent assay and/or immunohistochemical analysis with spe cific antibodies to interleukin-8. Results. The enzyme-linked immunosorbent assay studies showed elevated leve ls of interleukin-8 in diseased pulps (mean, 1.82 +/- 0.79 pg/mL/mu g prote in), as compared to detectable interleukin-8 levels in samples from normal pulps (mean, 0.08 +/- 0.04 pg/mL/mu g protein; P<.05). Immunohistochemical analyses demonstrated that diseased samples exhibited a higher density of l ocalized interleukin-8 staining in areas with heavy infiltration of inflamm atory cells. In contrast, normal pulps showed negative or weak interleukin- 8 staining. Conclusions. Interleukin-8 concentration was higher in pulps diagnosed with irreversible pulpitis; only negligible amounts of interleukin-8 were prese nt in normal pulps.