New sepsis-related marker: endotoxin activity assay

Introduction

The endotoxin activity assay (EAA) is a rapid whole-blood chemiluminescent test for endotoxin that has proven clinical utility in the detection and risk stratification of clinically ill patients with suspicion of sepsis.

Methods

The EAA was studied in a cohort of 153 septic patients admitted to the ICU. At the same time, IL-6 (chemiluminescent enzyme immunoassay), C-reactive protein (CRP), procalcitonin (PCT, chemiluminescent enzyme immunoassay) and plasminogen activator inhibitor-1 (PAI-1, latex photometric immunoassay) were measured within 24 hours after ICU admission. The patients were divided into the following three groups: L group: EAA < 0.4, M group: 0.4 ≤ EAA < 0.6, H group: 0.6 ≤ EAA. Nonrepeated-measures ANOVA was used to compare over three groups or conditions. Statistical significance was assumed for values of P < 0.05. Normally distributed data are presented as mean ± SD, and abnormally distributed data are presented as median values.

Results

Of the 153 patients, the L group contained 61 patients, M group 41 patients, and H group 51 patients, respectively. On the day of ICU admission, the rate of EAA ≥0.4 was 60.1% (MEDIC study: 57.2%). APACHE score in the L group was 21.0 ± 7.9, M group 24.8 ± 8.4, H group 26.4 ± 8.9, and SOFA score in the L group was 8.2 ± 4.3, M group 8.9 ± 4.1, H group 9.5 ± 4.3, respectively. There was no statistically significant difference among the groups. The median value of PCT in the L group was 1.1 ng/ml, M group 5.9 ng/ml, H group 8.5 ng/ml, respectively. PCT values of the M and H groups were significantly higher than those of the L group. Median IL-6 level of the H group was significantly higher than that of the L group (H group: 2,635 pg/ml, L group: 177 pg/ml).

Conclusions

EAA has no significant correlation with other sepsis-related markers, but may be associated with body insults (inflammation or infection).