The release of the new version of ISO 15189 (2022), introduced increased focus on risk stratification and mitigation for patients and laboratory stakeholders as well as more emphasis on quality control to improve accuracy and validity of results. Interference caused by hemolysis, icterus and lipemia is responsible for many rejected results and incorrect diagnosis. It is therefore of the upmost importance to accurately capture the presence of interfering substances in samples before quantitative analysis is carried out.
Historically, HIL levels were determined by a visual examination. However, this method is unreliable and subject to interpretation. The internationally recognized standard, C56-A Hemolysis, Icterus and Lipemia/Turbidity Indices as Indicators of Interference in Clinical Laboratory Analysis; Approved Guidelines advises that "visual inspection does not accurately capture the possible presence of interfering substances".
Today, most clinical chemistry analyzers on the market can detect HIL status and calculate an HIL alert index. C56-A states7, "HIL indices should be measured on all samples which analytes are sensitive to hemolysis, icterus and lipemia/ turbidity." Due to the wide variety of wavelengths affected by these forms of interference, this statement encompasses a large variety of laboratory tests.
Before results of any HIL detection method are used for patient samples, the specificity and sensitivity should be assessed at a minimum of two clinical decision concentrations. This evaluation should include the sensitivity of the icterus index to hemoglobin and lipids, the hemolysis index to bilirubin and lipids and the lipemic index to hemoglobin and bilirubin7.
C56-A states that laboratories should consider verification and quality control of expected performance to assess the following implications:
- HIL parameters, like all spectrophotometric measurements, are subject to drift and failure
- Failure to maintain consistent measurements may lead to changes in effective criteria for acceptance/rejection of specimens
- Inter-analyzer variability can result in inconsistent acceptance/rejection criteria
To combat these implications, Randox Laboratories introduces the Serum indices Control and Serum Indices EQA.
Randox Serum Indices Control
The Randox Acusera Serum Indices (SI) control is designed to be used to monitor an IVD instrument's response in the detection of hemolyzed, icteric and lipemic (HIL) samples. This control can be utilized in laboratory interference testing to assist in improving error detection of pre-analytical errors affecting clinical chemistry testing. This control provides a full range of clinically relevant testing levels, including a negative (-) and three positives (+, ++ & +++).
Control Features & Benefits
- Lyophilized for enhanced stability
- Manufactured using human serum, ensuring commutable sample matrix
- 2-year shelf life from date of manufacture
- True third party control providing unbiased assessment of performance
- Reconstituted stability of 14 days at 2°C – 8°C
- 4 separate levels available including -, +, ++ & +++
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