Serum interleukin-6 level as a diagnostic test in children with sepsis.

BACKGROUND

This study was performed to determine the serum concentrations of interleukin-6 (IL-6) during the early course of bacterial infections disease in children, and to evaluate the usefulness of IL-6 as a diagnostic test alone and in combination with C-reactive protein (CRP).

METHODS

We measured serum IL-6 values in 3 groups of children on their first day of admission, from January 2001 to December 2001: group 1, patients with clinical and microbiological evidence of sepsis (n = 13); group 2, patients with clinical and chest radiographical evidence of pneumonia (n = 18); and group 3, patients with no signs of infection (control group) (n = 16). Kruskal-Wallis tests were used to compare the difference of IL-6 values between groups and control subjects.

RESULTS

IL-6 values were significantly higher in groups 1 and 2 compared with those in the control group (p < 0.001). No significant differences were found between the groups 1 and 2. As a diagnostic test, IL-6 (> or = 20 pg/mL) alone yielded a sensitivity of 68%, a specificity of 88%, a positive predictive value of 71%, and a negative predictive value of 58%. A combined parameter of IL-6 (> or = 20 pg/mL) and CRP (> or = 1 mg/dL) yielded a sensitivity of 94%, a specificity of 63%, a positive predictive value of 79%, and a negative predictive value of 87%.

CONCLUSION

IL-6 levels increase in children with sepsis. In combination with CRP, IL-6 seems to be a valuable parameter in the early diagnosis of pediatric infections.