The prevalence of an elevated F cell population in a maternal and gynaecology cohort

• Published in: Transfusion medicine (Oxford, England) Vol. 29; no. 5; pp. 369 - 373
• Main Authors: Cormack, O. M., Guilfoyle, F., Flynn, C. M.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-10-2019
• Subjects: Adult; anti‐D flow cytometry; anti‐D prophylaxis; anti‐HbF flow cytometry; F cells; Female; Fetomaternal haemorrhage; Fetomaternal Transfusion - blood; Fetomaternal Transfusion - epidemiology; Flow Cytometry; Humans; Kleihauer–Betke test; maternity; Pregnancy; Pregnancy Complications, Hematologic - blood; Pregnancy Complications, Hematologic - epidemiology; Prevalence; Rh-Hr Blood-Group System - blood; anti-HbF flow cytometry; F cells; maternity; Fetomaternal haemorrhage; anti-D flow cytometry; anti-D prophylaxis; Kleihauer-Betke test
• ISSN: 0958-7578; 1365-3148
• DOI: 10.1111/tme.12625

SUMMARY
Objectives
This study aimed to determine F cell prevalence in a cohort of maternal and gynaecology specimens using QuikQuant anti‐HbF flow cytometry (FC) kit and to investigate if the presence of maternal F cells can lead to fetomaternal haemorrhage (FMH) overestimation.
Background
The gold standard to estimate FMH is the Kleihauer–Betke test (KBT). The KBT has proved to be insufficiently sensitive to detect low numbers of circulating fetal cells due to the presence of maternal F cells. At present, the prevalence of false positive KBT results due to raised maternal F cell population, defined as >5%, is poorly characterised.
Methods
A total of 120 specimens were tested for the presence of F cells and fetal cells by KBT and anti‐HbF FC. The results calculated were compared to determine FMH overestimation.
Results
Of our cohort, 32% showed an elevated F cell population, of which 69% (27 of 39) were clinically significant according to KBT (>2 mL FMH). The mean FMH volumes by KBT and anti‐HbF FC were 3·90 mL (0·20–35·40 mL) and 4·09 mL (0·20–9·70 mL), respectively.
Conclusion
The study highlighted that an elevated F cell level could be found in the cohort tested, with an F cell level of >10% causing significant FMH overestimation by KBT.