A sensitive quantitative single-platform flow cytometry protocol to measure human platelets in mouse peripheral...

Area of Science:

• Hematology
• Immunology
• Transplantation Science

Background:

• NOD/SCID mice are standard models for human cord blood (CB) transplantation.
• Current engraftment assessments use semiquantitative methods, limiting precise hematopoietic recovery evaluation.
• Quantitative methods are needed to accurately enumerate human cells for improved protocol comparison.

Purpose of the Study:

• To develop and validate a single-platform flow cytometry protocol for enumerating human platelets (hPLTs) in mouse peripheral blood (PB).
• To assess the sensitivity and applicability of this method for monitoring platelet recovery after transfusion and CB transplantation in vivo.

Main Methods:

• Utilized an anti-human CD41 antibody and counting beads for flow cytometric detection of hPLTs.
• Validated sensitivity down to 1 platelet per microliter.
• Monitored platelet recovery and kinetics in NOD/SCID mice following hPLT transfusions and CB CD34+ cell transplantation.

Main Results:

• The single-platform method demonstrated high sensitivity, detecting hPLTs at levels as low as 1 per microliter.
• This approach was at least 10 times more sensitive than traditional dual-platform methods.
• Earlier detection of platelet recovery was achieved in transfusion and transplantation studies.

Conclusions:

• A reproducible single-platform flow cytometry method effectively quantifies low levels of circulating hPLTs in mice.
• This technique can accelerate the development of protocols to enhance platelet recovery after CB transplantation.
• The method holds potential for clinical applications, including monitoring platelet reconstitution post-hematopoietic stem cell transplantation.