Identification and quantification of fetal red blood cells in maternal blood by a dual‐color flow cytometric method: evaluation of the Fetal Cell Count kit

Abstract

With this new dual-color flow cytometric method, accurate evaluation of fetomaternal hemorrhage was achieved even in the face of HbF of maternal origin.

Evaluation of FMH QuikQuant for the detection and quantification of fetomaternal hemorrhage

“…However, this assay lacks specificity and exhibits a large inter-observer variation resulting in potential overtreatment risks related to plasma-derived products and unnecessary treatment cost (20)(21)(22). In accordance with previous studies, we reported an overestimation of FMH by the KBT (12,15,23). The KBT presents stained maternal F cells that may be counted as fetal RBCs, leading to these false positive results (20,23,24).…”

“…An accurate quantification of FMH is important and defines the right dose of anti-D therapy. The KBT is an efficient screening test, when performed with correct attention in an experienced center (8,15). However, this assay lacks specificity and exhibits a large inter-observer variation resulting in potential overtreatment risks related to plasma-derived products and unnecessary treatment cost (20)(21)(22).…”

“…Anti-human carbonic anhydrase has been used (15). This strategy is based upon the observation that adult RBCs express more carbonic anhydrase than fetal cells, allowing a good separation even if adult cells contained high values of HbF (33).…”

“…However, such strategy is limited to the determination of anti-RhD immunoglobulin dose, as it cannot distinguish fetal RBCs from adult cells in cases of RhD compatibility. In the last decade, FCM approaches using intracellular detection of HbF have been developed (4,(12)(13)(14)(15)(16)(17). Monoclonal anti-HbF antibody allows discrimination of three distinct populations: fetal RBCs, F cells, and adult RBCs (12,14) The quantification of F cells provided by FCM eliminates a major drawback of KBT.…”

Flowcytometric assessment of fetomaternal hemorrhage during external cephalic version at term

“…Concomitant test controls to validate and monitor the quality of flow cytometric procedures were performed using FetalTrol ᮋ test samples (IQ-Products, Groningen, The Netherlands). In concomitant test controls and spiking experiments, we were able to confirm the level of quantification of 0.05% fetal RBC when screening 2=10 6 maternal erythrocytes, as described by Porra et al (2007) w18x.…”