Elecsys® IL-6

Early marker in acute inflammation

Elecsys IL-6
Early marker in acute inflammation

Elecsys® IL-6 is an immunoassay for the in vitro quantitative determination of Interleukin‑6 (IL‑6) in serum and plasma. This assay can be used to aid in the management of critically ill patients as early indicator for acute inflammation.

Diagnosis of sepsis - Time matters

Clinical signs suggestive of sepsis are non-specific, making diagnosis of sepsis difficult.1 Blood cultures remain the gold standard for diagnosis of patients with suspected sepsis, however, they have several limitations.2,3


Limitations of blood cultures in sepsis diagnosis:2,3

  • Require up to 5 days to obtain the results
  • Lack sensitivity
  • Easy to contaminate
  • Cannot assist in early sepsis management decisions
Elecsys IL-6
Biomarkers in sepsis

There is considerable unmet medical need in sepsis, and biomarkers may have an important clinical role to play.

Biomarkers can indicate the presence of sepsis, differentiate bacterial from viral or fungal infection, differentiate local from systemic infection, stratify severity of sepsis, may help to guide antibiotic therapy, provide prognostic information, evaluate response to therapy, predict septic complications and predict the development of organ dysfunction. However, the exact role of biomarkers is yet to be defined.1

Unmet medical needs in the management of sepsis and suspected sepsis:


  • Diagnosis and differential diagnosis of infection1
  • Recognition and stratification of severity of sepsis1
  • Early and appropriate decision regarding antibiotic therapy decisions5,8

Interleukin-6 (IL-6) is an early marker for inflammation in sepsis


Il-6, a key mediator for inflammation and an early alarm signal of infection that becomes elevated as part of the inflammatory response, has emerged as a valuable biomarker in the management of sepsis.9

IL-6 levels predict development of septic complications


IL‑6 concentrations in trauma patients may predict later complications from additional surgical stress or indicate missed injuries or complications.10,11

IL-6 levels predict severity of sepsis


Sequential measurements of IL‑6 in serum or plasma of patients admitted to the ICU (intensive care unit) showed to be useful in evaluating the severity of sepsis and to predict the outcome of these patients.12,13,14



  • Aid in the management of critically ill patients
  • Optimized laboratory workflow
  • Available on a fully automated platform
  • Small sample volume

Elecsys® IL-6

  • Assay time

    18 minutes

  • Sample material

    Serum, Li-heparin and K2- and K3-EDTA plasma

  • Sample volume

    30 µL

  • Measuring range

    1.5 – 5,000 pg/mL

  • Analytical sensitivity

    1.5 pg/mL

  • Functional sensitivity

    5 pg/mL

  • Traceability

    WHO Standard NIBSC 1st IS 89/548


  1. Pierrakos, C., & Vincent, J. (2010). Sepsis biomarkers: a review. Crit Care, 14(R15).
  2. Dark, P., Wilson, C., Blackwood, B., McAuley, D., Perkins, G., et al. (2012). Accuracy of LightCycler SeptiFast for the detection and identification of pathogens in the blood of patients with suspected sepsis: a systematic review protocol. BMJ Open, e000392.
  3. Schuetz, P., Christ-Crain, M. & Mueller, B. (2008). Procalcitonin and other biomarkers for the assessment of disease severity and guidance of treatment in bacterial infections. Adv Sepsis, 6(3), 82-89.
  4. Kumar, A., Roberts, D., Wood, K., Light, B., Parrillo, J., et al. (2006). Duration of hypotension before initiation of effective antimicrobial therapy is the critical determinant of survival in hu septic shock. Crit Care Med, 34(6), 1589-1596.
  5. Nobre, V., Harbarth, S., Graf, J., Rohner, P. & Pugin, J. (2008). Use of procalcitonin to shorten antibiotic treatment duration in septic patients. Am J Respir Crit Care Med, 177, 498-505.
  6. Schuetz, P., Briel, M., Christ-Crain, M., Stolz, D., Bouadma, L., et al. (2012). Procalcitonin to guide initiation and duration of antibiotic treatment in acute respiratory infections: an individual patient data meta-analysis. Clin Infect Dis, 55(5), 651-662.
  7. Silva, E., de Almeida Pedro, M., Beltrami Sogayar, A., Mohovic, T., de Oliveira Silva, C., et al. (2004). Brazilian Sepsis Epidemiological Study (BASES study). Crit Care, 8(4), R251-260.
  8. Schuetz, P., Albrich, W. & Mueller, B. (2011). Procalcitonin for diagnosis of infection and guide to antibiotic decisions: past, present and future. BMC Med, 9(107).
  9. Ventetuolo, C., & Levy, M. (2008). Biomarkers: Diagnosis and risk assessment in sepsis. Clin Chest Med, 29, 591-603.
  10. GiannoudisPV,HarwoodPJ,LoughenburyP, et al. Correlation between IL-6 levels and the systemic Inflammatory response score:Can an IL-6 cut off predict a SIRS state?JTrauma2008;65:646-652.
  11. TschoekeSK, HellmuthM, HostmannA,et al.  The early second hit in trauma management augments the proinflammatory immune response to multiple injuries. JTrauma2007;62:1396-1404
  12. Jekarl DW, Lee SY, Lee J, et al. Procalcitonin as a diagnostic marker and IL-6 as a prognostic marker for sepsis. Diagn Microbiol Infect Dis 2013;75(4):342-347. 
  13. Oda S, Hirasawa H, Shiga H, et al. Sequential measurement of IL-6 blood levels in patients with systemic inflammatory response syndrome (SIRS)/sepsis. Cytokine 2005;29:169-175. 
  14. Jawa RS, Anillo S, Huntoon K, et al. Interleukin-6 in Surgery, Trauma, and Critical Care Part II: Clinical Implications. J Intensive Care Med 2011;26(2):73-87.