Skip to main content

Clinical usefulness of measuring endotoxin activity on ICU admission


According to the Surviving Sepsis Campaign, diagnosis of sepsis and infection is urgent, therefore rapid diagnostic tools play a major role in the management of septic patients. The endotoxin activity (EA) assay (EAA) is one of those tools based on the ability of antigen-antibody complexes to prime neutrophils for an augmented respiratory burst response [1]. EAA has been used widely in patients who had suspected infection in the emergency room and ICU, but the clinical usefulness of measuring EAA in the diagnosis of sepsis in critically ill patients is not yet clear.


We performed an observational cohort study in critically ill patients in the ICU of a tertiary care hospital. We investigated the correlation between EA levels and blood concentration of endotoxin measured by the chromogenic limulus amoebocyte lysate (LAL) assay, causative microorganism identified in laboratory culture, procalcitonin (PCT), soluble CD14 subtype (named presepsin), IL-6, antithrombin, protein C, thrombomodulin, lactate, disseminated intravascular coagulation scores in both the Japanese Ministry of Health and Welfare and the Japanese Association for Acute Medicine, and severity of illness at ICU admission.


We enrolled 49 subjects. There was no significant correlation between EA levels and endotoxin concentration measured by LAL assay. There were no significant difference in the EA levels of the Gram-negative infection patients and the others. The diagnostic value of EA levels was investigated using ROC curve analysis. For the diagnosis of sepsis, area under the curve of EA levels, PCT, presepsin, IL-6 and CRP were calculated as 0.76, 0.83, 0.89, 0.88 and 0.72, respectively. Both the EA levels and ICU mortalities of the patients who met the criteria for severe sepsis were significantly higher than those of the patients who did not have sepsis (0.44 ± 0.21 vs. 0.22 ± 0.17, P = 0.0004; EA levels, 33% vs. 5%, P = 0.022; ICU mortalities). There was a positive relationship between EA levels and thrombomodulin (r = 0.30, P = 0.049), EA levels and lactate (r = 0.31, P = 0.028), and EA levels and SOFA score (r = 0.34, P = 0.02). There was a negative relationship between EA levels and platelet counts (r = -0.34, P = 0.018), EA levels and antithrombin (r = - 0.41, P = 0.004), and EA levels and protein C (r = -0.38, P = 0.010).


EA levels in the patients on ICU admission correlated with disease severity. Moreover, we strongly suggested that EAA may have the potential to assess organ dysfunction with sepsis, especially coagulopathy.


  1. 1.

    Marshall JC, et al.: J Infect Dis. 2004, 190: 527-534. 10.1086/422254

    CAS  Article  PubMed  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to A Murai.

Rights and permissions

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and Permissions

About this article

Cite this article

Murai, A., Ishikura, H., Nishida, T. et al. Clinical usefulness of measuring endotoxin activity on ICU admission. Crit Care 16, P34 (2012).

Download citation

  • Published:

  • DOI:


  • Antithrombin
  • Procalcitonin
  • Disseminate Intravascular Coagulation
  • Survive Sepsis Campaign
  • Endotoxin Concentration