Interleukin-8 as a predictor of the severity of bacteremia and infectious disease

The relationship between cytokines and sepsis has been studied frequently i n the intensive care unit (ICU). However, the determination of cytokines in patients as they enter the emergency department (ED) would be more meaning ful in predicting the outcome of infection. This study investigated plasma interleukin-8 in the ED as the predictor of bacteremia and sepsis. One hund red patients admitted through the ED with signs of systemic inflammatory re sponse syndrome were studied. Plasma IL-8, IL-6, and tumor necrosis factor (TN Fl were assayed by enzyme-linked immunosorbent assay. Patient's data we re evaluated using the APACHE II scoring system as predictive factors of mo rbidity and mortality. Plasma IL-8 (149 pg/mL) detected bacteremia with a p ositive predictive value of 90.9% and a specificity of 98.7%. Results indic ated that the odds ratios (ORs) of bacteremia were 24.78 (P < 0.01, CI = 2. 27-270.8), 5.42 (P< 0.05, CI = 1.37-21.4), and 6.05 (P< 0.05, Cl = 1.36-26. 8) for IL-8, IL-6, and APACHE II, respectively. Occurrence of bacteremia wa s highly correlated with increases in plasma IL-8 (P < 0.01). IL-8 (OR = 8. 25, CI = 1.03-65.9) and APACHE II scores (OR = 12.6, CI = 2.24-70.4) were f ound to be significantly better predictive factors of mortality (P< 0.01) t han IL-6 (OR = 3.60, CI = 0.57-22.7), TNF (OR = 0.24, CI = 0.01-11.0) and a ge (OR = 1.02, CI = 0.98-1.06). During bacteremia, IL-8 also correlated wel l with patient use of a ventilator (P < 0.01, OR = 2.43, CI = 2.41-311.19), use of vasopressors (P < 0.05, OR = 2.67, CI = 1.79-370.78), length of sta y in the hospital (P < 0.01, OR = 3.14, CI = 1.87-988.31), and stay in the ICU (P < 0.01, OR = 2.51, CI = 2.98-449.80). Measuring IL-8 on patients in the ED with apparent bacterial infections appears to be a reliable predicto r of bacteremia and the severity of disease.