Plasma interleukin-1β, -6, -8 and tumor necrosis factor-α as highly informative markers of pelvic inflammatory disease

Background: The role of proinflammatory cytokines in pelvic inflammatory disease (PID) is unclear. We therefore determined whether plasma proinflammatory cytokines, interleukin-1β (IL-1β), IL-6, IL-8 and tumor necrosis factor-α (TNF-α) were useful plasma markers in PID patients. Methods: Multiplex bead array analysis was used to measure the plasma levels of proinflammatory cytokines in 50 healthy controls as well as in 41 PID patients before and after routine protocol treatments. Results: IL-1β, IL-6, IL-8 and TNF-α were significantly elevated in PID patients before antibiotic treatment than after treatment. However, IL-8 was not significantly different between healthy controls and PID patients. The relative increase in ratio of IL-6 was significantly correlated with white blood cell count (r=0.448, p=0.003), neutrophil count (r=0.472, p=0.002) and C-reactive protein level (r=0.412, p=0.008). Conclusions: IL-1β, IL-6, IL-8 and TNF-α may play an important role in the pathogenesis of PID. These biomarkers, particularly IL-6, could be useful adjuncts for the clinical diagnosis of PID.