Leguy Marie-Clémence, Tavares Silvina Dos Reis, Tsatsaris Vassili, Lewin Fanny, Clauser Eric, Guibourdenche Jean
Service de biologie hormonale et métabolique, Hôpital Cochin, APHP, Paris.
Ann Biol Clin (Paris). 2011 Jul-Aug;69(4):441-6. doi: 10.1684/abc.2011.0600.
Ultrasound scanning is useful to detect neural tube defect (NTD) but scarcely distinguished between closed NTD and open NTD, which had very different prognosis. An amniotic fluid punction is thus mandatory to search for an increase in alpha foeto protein (AFP) levels and for the presence of acetylcholinesterase which identified open NTD. However, AFP levels fluctuate both with the gestational age and the assay used. Our aim was to establish normative values for AFP in amniotic fluid in the second half of pregnancy using three different immunoassays and to improve their clinical relevance. Amniotic fluid punctions were performed on 527 patients from 9 week of gestation (WG) to 37 WG either for maternal age, Trisomy 21 screening, increase in nucal translucency (control group, n = 527) or for suspicion of neural tube defect or abdominal defect (n = 5). AFP was measured using the immunoassay developed for serum AFP on the Access 2 system, the Immulite 2000 and the Advia Centaur. Results were expressed in ng/ml, multiple of the median (MoM) and percentiles. AFP decrease by 1.5 fold between 9 and 19 WG. When NTD was suspected, an increase in anmniotic AFP was observed (from 2.5 MoM to 9.3 MoM) confirming an open NTD. In conclusion, the assay developed on those 3 automates is suitable for the measurement of AFP in amniotic fluid.
超声扫描有助于检测神经管缺陷（NTD），但很难区分闭合性NTD和开放性NTD，而这两者的预后截然不同。因此，必须进行羊水穿刺以检测甲胎蛋白（AFP）水平的升高以及乙酰胆碱酯酶的存在，后者可识别开放性NTD。然而，AFP水平会随孕周和所使用的检测方法而波动。我们的目的是使用三种不同的免疫测定法建立妊娠后半期羊水中AFP的标准值，并提高其临床相关性。对527例妊娠9周（WG）至37周WG的患者进行了羊水穿刺，穿刺原因包括产妇年龄、21三体筛查、颈部透明带增厚增加（对照组，n = 527）或怀疑神经管缺陷或腹部缺陷（n = 5）。使用Access 2系统、Immulite 2000和Advia Centaur上为血清AFP开发的免疫测定法测量AFP。结果以ng/ml、中位数倍数（MoM）和百分位数表示。AFP在9至19周WG之间下降了1.5倍。当怀疑有NTD时，观察到羊水AFP升高（从2.5 MoM至9.3 MoM），证实为开放性NTD。总之，在这3种自动化仪器上开发的检测方法适用于测量羊水中的AFP。
