孕妇外周血中胎儿DNA水平检测在子痫前期诊断中的应用

目的探讨孕妇外周血中胎儿DNA水平检测在子痫前期诊断中的应用价值。方法选择30例子痫前期孕妇为子痫前期组(其中轻度18例,重度12例),另选择30例正常孕妇作为对照组,两组孕妇分别于孕20周、孕晚期(子痫前期组孕33周+3、对照组孕34周+3)、分娩后1、3、6 h取外周血,采用荧光定量PCR检测外周血中Y染色体上的性别决定基因(SRY基因)胎儿DNA水平(B超确定两组孕妇所妊娠的胎儿均为男性);放射免疫法检测两组孕妇孕晚期内皮素水平。结果(1)子痫前期组孕20周时的胎儿DNA水平为(316±61)copy/m l,其中轻度、重度患者分别为(266±79)、(396±91)copy/m l;对照组孕妇为(165±43)copy/m l,子痫前期组及轻度、重度患者明显高于对照组,两组比较,差异有统计学意义(P<0.01)。(2)子痫前期组孕晚期胎儿DNA水平为(970±413)copy/m l,其中轻度、重度患者分别为(758±357)、(1285±573)copy/m l,对照组孕妇为(319±99)copy/m l,子痫前期组及轻度、重度患者明显高于对照组,两组比较,差异有统计学意义(P<0.01)。(3)子痫前期组产后1、3、6 h胎儿DNA水平分别为(139±45)、(76±31)、(44±13)copy/m l,其中轻度患者分别为(102±42)、(57±25)、(36±12)copy/m l,重度患者分别为(209±51)、(97±40)、(52±17)copy/m l;对照组分别为(33±13)、(9±5)、0 copy/m l。子痫前期组及轻度、重度患者明显高于对照组,两组比较,差异有统计学意义(P<0.01)。(4)子痫前期组内皮素水平为(80±18)ng/L,其中轻度患者为(74±14)ng/L,重度患者为(89±32)ng/L;对照组为(50±11)ng/L,子痫前期组及轻度、重度患者明显高于对照组,两组比较,差异有统计学意义(P<0.01)。(5)子痫前期组胎儿DNA水平与内皮素水平呈正相关关系(r=0.748,P<0.01)。结论孕妇外周血胎儿DNA水平变化可以作为预测和诊断子痫前期发病与疾病程度的一个指标。

Study on the relation between concentration of circulating non-host fetal DNA in pregnant women and pre-eclampsia

OBJECTIVE: To explore the diagnostic value of plasma fetal DNA level in preeclampsia. METHODS: Thirty cases of pregnant women with preeclampsia (at 33 weeks and 3 days) and 30 cases of normal pregnant women (at 34 weeks and 3 days) were selected. All the pregnant women carried a male fetus by B-ultrasound, and were sampled at gestational 20 weeks, third trimester and at 1 hour, 3 hours, 6 hours after delivery. SRY levels in maternal blood were quantitated by polymerase chain reaction (QF-PCR). The endotheliotoxin (ET) level was measured with RIA. RESULTS: (1) Mean fetal DNA level of patients with preeclampsia at 20 weeks of gestation was (316 +/- 61) copy/ml. They were (266 +/- 79) copy/ml, (396 +/- 91) copy/ml, (165 +/- 43) copy/ml for light and severe preeclampsia women and normal pregnant women, respectively. Maternal blood fetal DNA levels in pregnant women with preeclampsia at 20-weeks of gestation were significantly higher than those normal pregnant women (P < 0.01). (2) Mean fetal DNA level of patients with preeclampsia in third trimester was (970 +/- 413) copy/ml. They were (758 +/- 357) copy/ml, (1285 +/- 573) copy/ml, (319 +/- 99) copy/ml for light and severe preeclampsia and normal pregnant women, respectively. Maternal blood fetal DNA levels in pregnant women with preeclampsia in third trimester were significantly higher than those normal pregnant women (P < 0.01). (3) Maternal blood mean fetal DNA level of patients with preeclampsia were (139 +/- 45) copy/ml, (76 +/- 31) copy/ml, (44 +/- 13) copy/ml at 1 hour, 3 hours, and 6 hours after delivery, respectively. Mean fetal DNA level was (102 +/- 42) copy/ml, (57 +/- 25) copy/ml, (36 +/- 12) copy/ml for patients with light preeclampsia, (209 +/- 51) copy/ml, (97 +/- 40) copy/ml, (52 +/- 17) copy/ml for patients with severe preeclampsia, and (33 +/- 13) copy/ml, (9 +/- 5) copy/ml, 0 copy/ml for normal pregnant women. Significant difference was found between preeclampsia and control groups (P < 0.01). (4) The mean endotheliotoxin level for preeclampsia women was (80 +/- 18) ng/L. For light preeclampsia, severe preeclampsia and normal pregnant women ET levels were (74 +/- 14) ng/L, (89 +/- 32) ng/L, (50 +/- 11) ng/L, respectively. ET levels in pregnant women with preeclampsia were significantly higher than those normal pregnant women (P < 0.01). (5) A positive correlation was found between fetal DNA levels and ET levels in preeclampsia group (r = 0.748, P < 0.01). CONCLUSION: The fetal DNA determination may help diagnose preeclampsia.