Role of circulating soluble chemokines in septic shock.

PURPOSE: Chemokines are a large superfamily of small proteins that function not only in leukocyte trafficking, but are also necessary for linkage between innate and adaptive immunity. Little is known about their role in septic shock. We hypothesized that serum levels of the most important chemokines are related to organ failure, disease severity and outcome.

DESIGN: A prospective observational study was carried out.

SETTING: Surgical-clinical Intensive Care Unit.

PATIENTS: Ninety-two patients diagnosed with septic shock using international criteria. Forty patients were excluded due to acquired immunity disturbances. Samples from 36 healthy controls were also analyzed.

INTERVENTIONS: None.

RESULTS: In 46% of the patients who suffered acute respiratory distress syndrome (ARDS), IL-8 levels were higher than in patients without ARDS (499.9±194.1 vs. 190.8±91.7 pg/ml; P=.039). This molecule was also higher in 36% of the patients with sepsis-induced acute renal failure (ARF) (453.3±181.6 vs. 201.3±95.9 pg/ml; P=.049). Coagulopathy was found in 19% of the septic shock patients with elevated serum IL-8 levels (635.8±292.3 vs. 218.7±87.0 pg/ml; P=.010), elevated MIP-1α (91.4±27.3 vs. 58.8±11.1 pg/ml; P=.044), and low circulating RANTES levels (8162.2±6321.0 vs. 18781.8±11.1 pg/ml; P=.027). No significant differences were found between survivors and non-survivors at any time of follow-up.

CONCLUSIONS: Upon admission to the ICU, IL-8 is a reliable biomarker of sepsis-induced AFR, ARDS and coagulopathy. Altered circulating MIP-1α and RANTES levels are also found in patients with septic shock and coagulopathy. However, chemokines do not appear to be good biomarkers of mortality in septic shock.