WHO’s QC requirements
Historically, when it comes to the immunohistochemical (IHC) staining process for biopsy sections, it has been virtually impossible for any laboratory in the world to process co-resident control materials and patient sample on a single slide in accordance with the World Health Organization’s (WHO) strict requirements. In addition to the quality control material missing for each test, there has never been a calibrating system available to track and improve the IHC process.
However, this is now all possible with the introduction of the PRS product which provides a cost competitive solution vs. the available IHC compatible adhesive coated only slides.
Our product, the Process Record Slide (PRS) came about due to a book published by the World Health Organization (WHO). If you Google “Laboratory Quality Control”, you will find a copy of a book entitled “Laboratory Quality Control System” . This book provides details of the universal quality control rules for health related laboratories.
In chapter 7.2, WHO provides a clear definition of control materials and calibrators:
Defining control materials
7-2: Control materials
Controls are substances that contain an established amount of the substance being tested -the analyse. Controls are tested at the same time and in the same way as patient samples. The purpose of the sample is to validate the reliability of the test system and evaluate the operator’s performance and environmental conditions that might impact results.
Differentiating controls and calibrators
It is important not to confuse calibrators and control materials. Calibrators are solutions with a specified concentration that are used to set or calibrate an instrument, kit, or system before testing is begun. Calibrators are often provided by the manufacturer of an instrument. They should not be used as controls since they are used to set the instrument. Calibrators are sometimes called standards, but the term calibrator is preferred. They usually do not have the same consistency as patients’ samples.
With this in mind, we have developed the PRS product as a must-have essential device for combining the functions of control material and calibration in strict accordance with the WHO requirements:
Role in quality management system
Quality Control (QC) is a component of process control, and is an essential element of the quality management system. It monitors the process related to the examination phase of testing and allows for detecting errors in the testing system. These errors may be due to test system failure, adverse environmental conditions or operator performance. QC gives the laboratory confidence that test results are accurate and reliable before patient results are reported.
How the PRS helps laboratories
We strongly recommend that all laboratories consider using PRS for their IHC biopsy staining process particularly in view of the fact that WHO states this quality control component is an essential element. By including this, the laboratory can confirm the efficacy of reagents used, tissue handling, and process control of the patient sample through the IHC processing. Thus, the laboratory can document that its processing of the biopsy sample is valid prior to the diagnostic interpretation being performed. Of course, the biopsy may not contain any of the sought for conditions and the outcome would be a true negative result.
WHO also goes on to stress that if QC is missing from the process, then laboratories should not consider reporting the patient results at all:
If QC results are not what are expected, do not report patient results.
If you are a laboratory that wishes to comply with the WHO guidelines, then the Process Record Slide (PRS) product is for you. Contact us now for full details and get your laboratory fully QC compliant and your patient reports fully controlled and recorded.