Neutrophil CD64 expression – comparison of two different flow cytometry protocols on EPICs MCL and the Leuko64^™ assay on a Celldyn Sapphire haematology analyser

Abstract

Objective. To evaluate the Trillium Diagnostics Leuko64^™ assay on Abbott Celldyn Sapphire haematology analyser compared to two flow cytometry protocols on Beckman Coulter EPICS MCL flow cytometer. Materials and methods. CD64 expression on neutrophils was determined by two flow cytometry protocols and by a commercial assay on an automatic haematology analyser. The inclusion of study subjects was based on elevated procalcitonin (PCT) values, identifying patients where a systemic infection was suspected. Healthy blood donors were used as a reference group. Results. Statistically significant correlations between the Trillium Diagnostics Leuko64^™ assay and the flow cytometry methods were found when measuring neutrophil CD64 expression. Conclusions. The good correlation between a reference method and an automated haematology analyser method for CD64 expression on neutrophils supports introduction of the latter assay for routine use as an independent biomarker of bacterial infection and inflammation.

Key Words::

• CD64
• flow cytometry
• neutrophils
• method comparison

Declaration of interest: The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.