BillionToOne, Inc, Menlo Park, and the Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, San Francisco, California; Obstetrix Maternal-Fetal Medicine Specialists, Houston, Grifols Laboratory Solutions Inc, San Marcos, and the Department of Women's Health, Dell Medical School, University of Texas at Austin, and the Comprehensive Fetal Care Center, Dell Children's Medical Center, Austin, Texas; and the Division of Maternal-Fetal Medicine, Department of Women's and Infant's Services, MedStar Washington Hospital Center, Washington, DC.
Obstet Gynecol. 2024 Oct 1;144(4):436-443. doi: 10.1097/AOG.0000000000005692. Epub 2024 Jul 25.
To evaluate the accuracy of next-generation sequencing-based quantitative cell-free DNA analysis for fetal antigen genotyping in individuals with alloimmunized pregnancies undergoing clinical testing in practices across the United States as early as 10 weeks of gestation, with the objective of identifying individuals with pregnancies at risk for hemolytic disease of the fetus and newborn and guiding management.
This prospective cohort study included patients with alloimmunized pregnancies undergoing clinical fetal antigen cell-free DNA analysis between 10 0/7 and 37 0/7 weeks of gestation at 120 clinical sites. Both the pregnant person with the alloimmunized pregnancy and the neonates resulting from the pregnancies were included. The laboratory issued the cell-free DNA results prospectively as a part of clinical care. After delivery, neonatal buccal swabs collected between 0 and 270 days of life were sent to an outside independent laboratory for antigen genotyping. The outside laboratory was blinded to the fetal cell-free DNA results, and the results were compared. Concordance was reported for the fetal antigen cell-free DNA analysis for antigens to which the pregnant person was alloimmunized and for all antigens for which the pregnant person was genotype negative.
A total of 156 pregnant people who received clinically ordered cell-free DNA fetal antigen testing provided neonatal buccal swabs for genotyping after delivery. Overall, 15.4% of participants were Hispanic, 9.0% were non-Hispanic Black, 65.4% were non-Hispanic White, 4.5% were Asian, 1.3% were more than one race or ethnicity, and 4.5% were unknown. The median gestational age at the time of testing was 16.4 weeks with a median fetal fraction of 11.1%. Concordance between cell-free DNA analysis results and neonatal genotype was determined for 465 antigen calls for the following antigens: K1 (n=143), E (124), C (60), Fy a (50), c (47), and D(RhD) (41). These 465 calls included 145 in which the fetus was antigen positive and 320 in which the fetus was antigen negative. We observed complete concordance between prenatal fetal antigen cell-free DNA analysis results and neonatal genotypes for the 465 calls, resulting in 100% sensitivity, specificity, and accuracy.
In a diverse multicenter cohort, cell-free DNA analysis was highly sensitive and specific for determining fetal antigen genotype as early as 10 weeks of gestation in individuals with alloimmunized pregnancies. Taken together with previously published evidence, this study supports the implementation of cell-free DNA testing to manage individuals with alloimmunized pregnancies in the United States.
评估基于下一代测序的定量游离胎儿 DNA 分析在全美各地临床实践中对 10 周龄起的同种免疫孕妇胎儿抗原基因分型的准确性，以识别有患胎儿和新生儿溶血病风险的孕妇，并指导管理。
这项前瞻性队列研究纳入了在 120 个临床站点接受 10 0/7 至 37 0/7 周龄的同种免疫孕妇进行临床游离胎儿抗原细胞 DNA 分析的患者。研究对象包括患有同种免疫性妊娠的孕妇和由此产生的新生儿。实验室作为临床护理的一部分，前瞻性地出具游离 DNA 结果。分娩后，在新生儿出生后 0 至 270 天期间采集的口腔拭子被送到一个外部独立实验室进行抗原基因分型。外部实验室对胎儿游离 DNA 结果不知情，然后对结果进行比较。报告了胎儿抗原游离 DNA 分析对孕妇同种免疫抗原的一致性，以及对孕妇基因型阴性的所有抗原的一致性。
共有 156 名接受临床下单细胞游离 DNA 胎儿抗原检测的孕妇在分娩后提供了新生儿口腔拭子进行基因分型。总体而言，15.4%的参与者为西班牙裔，9.0%为非西班牙裔黑人，65.4%为非西班牙裔白人，4.5%为亚洲人，1.3%为多种族或族裔，4.5%为未知。检测时的中位孕龄为 16.4 周，中位胎儿分数为 11.1%。对 465 种抗原的游离 DNA 分析结果与新生儿基因型进行了一致性评估，包括 K1（n=143）、E（124）、C（60）、Fya（50）、c（47）和 D（RhD）（41）。这 465 次检测中，145 次胎儿抗原阳性，320 次胎儿抗原阴性。我们观察到，在 465 次检测中，产前胎儿抗原游离 DNA 分析结果与新生儿基因型完全一致，具有 100%的敏感性、特异性和准确性。
在一个多样化的多中心队列中，游离 DNA 分析在 10 周龄的同种免疫孕妇中，对确定胎儿抗原基因型具有高度的敏感性和特异性。结合之前发表的证据，这项研究支持在美国实施游离 DNA 检测来管理同种免疫孕妇。
