A combined flow cytometry-based method for fetomaternal hemorrhage and maternal D

Area of Science:

• Immunology
• Hematology
• Obstetrics

Background:

• Fetomaternal hemorrhage (FMH) volume is determined by flow cytometry-based fetomaternal bleed assay.
• Current methods require separate tests for fetal bleed volume and maternal RhD status.
• Rh immune globulin (RhIG) administration is crucial for RhD-negative pregnancies.

Purpose of the Study:

• To enhance the fetomaternal bleed assay by integrating maternal RhD typing.
• To simultaneously quantify fetal hemoglobin (Hb F)-containing cells and determine maternal D antigen status.
• To streamline RhIG dose calculation for RhD-negative pregnant individuals.

Main Methods:

• Developed a novel flow cytometry assay combining anti-Hb F and anti-D antibodies in a single tube.
• Compared the performance of the enhanced assay (FMB/D assay) against standard Kleihauer-Betke (KB) and tube methods.
• Analyzed peripheral blood cells from pregnant women using flow cytometry.

Main Results:

• The FMB/D assay demonstrated excellent agreement with standard methods for both D typing and FMH quantitation.
• RhIG dose calculations based on the FMB/D assay showed high concordance (97%) with the KB method.
• The enhanced assay identified maternal D status accurately, matching tube method results.

Conclusions:

• The integrated anti-Hb F and anti-D flow cytometric assay provides a precise and efficient method for FMH assessment and RhD typing.
• This combined approach eliminates the need for separate tests, saving time and resources.
• The assay correlates well with established methods, ensuring reliable clinical information for managing RhD-negative pregnancies.