Ponnusamy S, Mohammed N, Ho S S Y, Zhang H M, Chan Y H, Ng Y W, Su L L, Mahyuddin A P, Venkat A, Chan J, Rauff M, Biswas A, Choolani M
Diagnostic Biomarker Discovery Laboratory, Division of Maternal and Fetal Medicine, Department of Obstetrics and Gynecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Prenat Diagn. 2008 Jun;28(6):494-502. doi: 10.1002/pd.2009.
To develop an in vivo model to determine fetal-cell enrichment efficiency of novel noninvasive prenatal diagnosis methods.
Efficiency of our three-step enrichment protocol was determined in vitro before fetal nucleated red blood cells (FNRBCs) were enriched from first-trimester maternal blood samples collected from the same patients pre- and postsurgical termination of pregnancy (TOP) (n = 10). FNRBCs enriched were identified using embryonic epsilon-globin immunocytochemistry and chromosomal fluorescence in situ hybridization.
We recovered 37% of spiked FNRBCs (95% confidence interval (CI) 28.5-45.6; n = 8) in in vitro experiments. We show a consistent threefold increase in the number of epsilon + FNRBCs in maternal blood obtained immediately post-TOP (p = 0.005). A mathematical relationship was derived: observed number of pretermination primitive FNRBCs = 0.6 + 0.31 (coefficient between pretermination/post-termination primitive FNRBCs, 95% CI 0.12-0.49; p = 0.005) x observed number of post-termination primitive FNRBCs (R2 = 0.65).
Our data demonstrate that maternal blood obtained immediately post-TOP would be a good in vivo model to determine the enrichment efficiency of novel protocols and methods for noninvasive prenatal diagnosis.
建立一种体内模型，以确定新型非侵入性产前诊断方法的胎儿细胞富集效率。
在从同一患者妊娠终止手术（TOP）前后收集的孕早期母血样本中富集胎儿有核红细胞（FNRBCs）之前，先在体外确定我们三步富集方案的效率（n = 10）。使用胚胎ε-珠蛋白免疫细胞化学和染色体荧光原位杂交鉴定富集的FNRBCs。
在体外实验中，我们回收了37%的加标的FNRBCs（95%置信区间（CI）28.5 - 45.6；n = 8）。我们发现TOP后立即获得的母血中ε + FNRBCs数量一致增加了三倍（p = 0.005）。得出了一种数学关系：终止前原始FNRBCs的观察数量 = 0.6 + 0.31（终止前/终止后原始FNRBCs之间的系数，95% CI 0.12 - 0.49；p = 0.005）×终止后原始FNRBCs的观察数量（R2 = 0.65）。
我们的数据表明，TOP后立即获得的母血将是一种良好的体内模型，可用于确定新型非侵入性产前诊断方案和方法的富集效率。
