Commutability assessment of reference materials for the enumeration of lymphocyte subsets

Area of Science:

• Immunology
• Clinical Chemistry
• Biotechnology

Background:

• Accurate enumeration of lymphocyte subsets in peripheral blood is essential for assessing immune status.
• Commutable reference materials (RM) are critical for ensuring consistent and reliable measurement results across different laboratories and over time.
• The commutability of RMs for lymphocyte subset enumeration has not been previously reported.

Purpose of the Study:

• To assess the commutability of reference materials for lymphocyte subset enumeration.
• To compare different approaches for evaluating the commutability of RMs.
• To establish prerequisites for commutability assessment, including RM suitability and measuring system comparability.

Main Methods:

• Lymphocyte subsets were quantified in patient samples and RMs using two common flow cytometry systems (FACS Canto II and Cytomics FC500).
• Suitability of RMs and comparability of the measuring systems were evaluated first.
• Commutability was assessed using both regression and difference in bias approaches.

Main Results:

• Two RMs were not measurable on the FC500 system for specific lymphocyte subsets.
• The two measuring systems demonstrated comparable performance with patient samples.
• Varying numbers of RMs were found to be commutable depending on the specific lymphocyte subset and the assessment approach used.
• Discrepancies were observed between the regression and difference in bias approaches for certain lymphocyte subsets.

Conclusions:

• RM suitability and measuring system comparability are necessary prerequisites for commutability assessment.
• Different commutability assessment approaches can lead to divergent conclusions.
• The difference in bias approach is recommended for commutability assessment, aligning with medical requirements and system performance characteristics.