A rare-event analysis model for quantifying white cells in white cell-depleted blood

Area of Science:

• Biomedical Engineering
• Hematology
• Analytical Chemistry

Background:

• Accurate quantification of residual white blood cells (WBCs) in red blood cell concentrates (RBCC) is crucial for transfusion safety.
• Existing methods for WBC detection in RBCC have limitations in sensitivity, efficiency, and sample preservation.

Purpose of the Study:

• To develop and validate a novel analysis model for precise detection and quantification of WBCs in highly WBC-depleted RBCC.
• To establish a sensitive and efficient method for monitoring WBC depletion processes.

Main Methods:

• Fluorescence analysis of propidium iodide-labeled RBCC (50 microL) for WBC detection.
• Quantification using regression analysis of standard dilutions in a novel, substantially WBC-free red cell diluent.
• WBC-free diluent prepared by filtration of blood through a new medium.

Main Results:

• The developed method demonstrates high precision (CV = 7%) and linearity (r = 0.99) for WBC depletion up to 6 log10.
• The method is efficient, with an analysis time of approximately 30 minutes per aliquot.
• Achieved superior signal-to-noise discrimination for monitoring extremely low WBC concentrations compared to previous techniques.

Conclusions:

• The novel fluorescence analysis model provides a precise, efficient, and sensitive method for quantifying WBCs in RBCC.
• This technique surpasses previous methods like ficoll concentration and earlier fluorescence analyses by preserving the blood unit and improving low-concentration detection.
• The enhanced sensitivity allows for more effective monitoring of WBC depletion procedures, exceeding current commercial capabilities.