Effectiveness of Alpha-Fetoprotein Variants L2 and L3 as Substitutes of Alpha-Fetoprotein in Screening for Fetal Trisomy 18
作者单位：Department of Prenatal diagnosis and screening center Hangzhou Women's Hospital (Hangzhou Maternity and Child Health Care Hospital) Department of Cell Biology and Medical GeneticsSchool of Medicine Zhejiang University
会议名称：《2019长三角围产医学学术会议暨浙江省围产医学学术大会》
会议日期：2019年
学科分类：1002[医学-临床医学] 100211[医学-妇产科学] 10[医学]
关 键 词：pregnant women mid-pregnancy prenatal screening fetoprotein variant AFP-L2/AFP-L3 Trisomy 18. case-controlled study
摘 要：Objectives To evaluate the effectiveness of alpha-fetoprotein variants(AFP-L2, AFP-L3) for fetal screening of Trisomy 18 in place of alpha fetoprotein(AFP).Methods A case-control study, per the presence or absence of fetal Trisomy 18, was conducted. The case group included 39 pregnant women diagnosed by karyotype analysis of amniotic fluid cells as bearing Trisomy 18 fetuses. The control group was randomly selected and included 48 pregnant women with clinically normal and healthy fetal development. The serum AFP-L2 and AFP-L3 concentrations for the two groups of pregnant women were detected by enzyme-linked immunosorbent assays. Receiver operating characteristic(ROC) curves were used to determine the optimal cutoff value, area under the curve(AUC), and assess the screening performance of AFP-L2 and *** The AFP-L2 and AFP-L3 concentrations in pregnant women with Trisomy 18 fetuses were 7.95±3.57 ng/mL(6.79 ～ 9.10 ng/mL), and 2.53±1.80 ng/mL(1.94 ～ 3.11 ng/mL), respectively, which was significantly higher than those of the control group(3.73±1.63 ng/mL [3.26 ～ 4.20], t=6.820, P0.001, and 0.84±0.60 ng/mL [0.66 ～ 1.01], t=5. 588, P0.001, respectively). The AUC for AFP-L2 and AFP-L3 in screened Trisomy 18 fetuses was 0.848(95% CI: 0.767-0.930, P 0.001) and 0.806(95% CI: 0.707-0.905, P 0.001), respectively. The optimal cutoff values of AFP-L2 and AFP-L3 for Trisomy 18 fetuses were determined to be 6.340 ng/mL and 1.705 ng/mL, respectively. The corresponding sensitivity, specificity, and Youden index values were 0.615, 1.000, 0.615;0.6410, 0.958, and 0.599, respectively. Comparisons across multiple modeling methods showed that the highest AUC of screened Trisomy 18 fetuses(0.992 and 0.986) was yielded by AFP-L2 + AFP-L3 + free β-HCG, and AFP-L2 + free β-HCG, with 1.000 sensitivity indicated in both instances. By comparing the results of the two combined tests, it was shown that, when performed in parallel, the sensitivities of the four Trisomy 18 screening