Elevation of serum IL-6 levels in patients with acute bacterial infection

Serum cytokine levels have been reported to elevate in acute bacterial infection, but the relationship of differential elevation in cytokine levels to patients' clinical parameters and prognosis remains controversial. The present study was designed to evaluate whether serum interleukin-1 alpha (IL-1 alpha) and IL-6 levels were raised in patient with acute bacterial infection, and were correlated with patients clinical parameters.

Thirty patients, aged from 20 to 91 years, calling our emergency room with clinical evidence of acute bacterial infection and marked leukocytosis, were enrolled in this study. Sera were collected immediately and analyzed for IL-1 alpha and IL-6 levels with Enzyme-Linked Immunosorbent Assay (ELISA) method.

All patients with acute bacterial infection had measurable higher levels of serum IL-6 than normal volunteers. Patients with higher serum IL-6 level were more likely to have fever, though without statistical significance (p = 0.09). Serum IL-6 levels did not correlate significantly with positive blood culture result, septic shock, or fatal outcome. Serum IL-1 alpha levels were below minimal detectable concentrations in all patients checked.

Serum IL-6 levels were elevated in patients with acute bacterial infection, and were possibly associated with the occurrence of fever. IL-1 alpha played no obvious role as systemic effector molecule in acute bacterial infection in our study.