Intensive Care Infection Score (ICIS RUO)*
- A weighted RUO* score derived from parameters in the CBC, DIFF, and RET channels
- Reflects the strength of immune cell activation
- Studies [1 -5] show the potential of ICIS RUO* to support the interpretation of infectious and non-infectious immune response in patients with an underlying condition of acute inflammation
- Available as a research use-only (RUO*) add-on
- This add-on requires validation by the user before implementing it in routine clinical work
Accurately distinguishing between infectious and non-infectious inflammation is a critical challenge in managing acutely ill patients, particularly in intensive care settings. The ICIS RUO is a weighted RUO score integrated into the Extended IPU based on the differential count of white blood cells and red blood cell parameters from a routine blood count using the CBC, DIFF and RET channels. Studies have demonstrated it can potentially differentiate inflammation from infection in such patient cohorts, as it measures immune cell activation [1 – 5]. Expanding on this, Nacke et al. presented three clinical cases that further illustrate the potential of ICIS RUO* to support antimicrobial stewardship (AMS) [6]. Sysmex Extended Inflammation Parameters (EIP) from a CBC and DIFF allow assessment of the activation status of immune cells such as lymphocytes and neutrophilic granulocytes. Together with information on the quality of haemoglobinisation of the reticulocytes via parameters from the RET channel, this enables the differentiation of an infectious versus inflammatory immune response. The combination of parameters balances inter-individual variation and considers the immune response's kinetics. Besides these, further information from the analyser and the blood count is used for algorithm validation steps to ensure the biological and technical validity of ICIS RUO.
* RUO is the abbreviation for ‘Research Use Only’, which indicates that an in vitro diagnostic medical purpose has not been validated by the manufacturer. Health institutions that intend to use RUO product results for diagnostic purposes do so under their own responsibility and must observe the rules and regulations applicable in their region, such as Regulation (EU) 2017/746 (IVD-R) for the EU. Sysmex cannot support such diagnostic use.
ICIS RUO is currently provided as a licence-protected RUO add-on in the Extended IPU work area manager.
References
[1] Nierhaus A et al. (2012): Use of a Weighted, Automated Analysis of the Differential Blood Count to Differentiate Sepsis from Non-Infectious Systemic Inflammation: The Intensive Care Infection Score (ICIS). Inflamm. Allergy Drug Targets 11(2):109-15.
[2] Weimann K et al. (2015): Intensive Care Infection Score--A new approach to distinguish between infectious and noninfectious processes in intensive care and medicosurgical patients. J. Int. Med. Res. 43(3):435-51.
[3] Van der Geest PJ et al. (2016): The intensive care infection score - a novel marker for the prediction of infection and its severity. Crit. Care 20(1):180.
[4] Vrbacký F et al. (2025): Intensive Care Infection Score (ICIS) is an Early Marker for Infection in Time of Admission to Intensive Care Units. Int J Lab Hematol. 47(4):707-712.
[5] Deniz E et al. (2025): Intensive care infection score: ICIS discriminates between infected and uninfected critically ill patients in routine intensive care unit practice. Intensive Care Med Exp 13(1): 58.
[6] Nacke N et al. (2025): Exploring The Potential of The Intensive Care Infection Score in Antimicrobial Stewardship: A Case Report. A A Pract. 19(7):e02004.
