Bieniarz A, Kulaga H, Medearis A L, Nakamura R, Platt L D, Paul R H
Department of Obstetrics and Gynecology, University of Southern California School of Medicine, Los Angeles.
Am J Obstet Gynecol. 1988 Mar;158(3 Pt 1):560-4. doi: 10.1016/0002-9378(88)90025-7.
Deoxythymidine kinase is present in human cells in two forms: the cytosolar form (fetal thymidine kinase) and the mitochondrial form (adult thymidine kinase). The activity of thymidine kinase isozymes in plasma of preterm and term newborns has been previously reported to be related to gestational age, and fetal thymidine kinase activity was reported to be undetectable after the thirty-ninth week of gestation. Our purpose was to determine if similar changes in the activity levels of the thymidine kinase isozymes could be demonstrated in late third trimester maternal plasma. A cross-sectional sample of 35 patients was studied from week 34 of pregnancy to delivery. Significant differences between fetal and adult thymidine kinase activity patterns were observed. Adult thymidine kinase activity remained relatively constant throughout the evaluation interval, while fetal thymidine kinase activity decreased with advancing gestational age. Regression analysis of gestational age by neonatal examination (GAPED) and fetal thymidine kinase revealed a linear relationship (fetal thymidine kinase = 0.380 - 0.00745 GAPED; R2 = 0.2944; standard estimate of error = 0.0350; p less than 0.0008). Comparison of fetal thymidine kinase activity in term and postterm pregnancy plasma revealed a significant difference (p less than 0.0159). Our findings indicate that deoxythymidine kinase activity can be measured in maternal plasma, may relate to the fetoplacental growth rate, and may be useful in differentiating between term and postterm gestations.
胞质形式（胎儿胸苷激酶）和线粒体形式（成人胸苷激酶）。此前有报道称，早产和足月新生儿血浆中胸苷激酶同工酶的活性与胎龄有关，且据报道，妊娠39周后无法检测到胎儿胸苷激酶的活性。我们的目的是确定在妊娠晚期母血中是否能显示出胸苷激酶同工酶活性水平的类似变化。对35名患者从妊娠34周直至分娩进行了横断面样本研究。观察到胎儿和成人胸苷激酶活性模式存在显著差异。在整个评估期间，成人胸苷激酶活性保持相对恒定，而胎儿胸苷激酶活性随胎龄增加而降低。通过新生儿检查的胎龄（GAPED）与胎儿胸苷激酶的回归分析显示出线性关系（胎儿胸苷激酶 = 0.380 - 0.00745 GAPED；R2 = 0.2944；标准误差估计值 = 0.0350；p小于0.0008）。足月和过期妊娠血浆中胎儿胸苷激酶活性的比较显示出显著差异（p小于0.0159）。我们的研究结果表明，脱氧胸苷激酶活性可在母血中测量，可能与胎儿胎盘生长速率有关，并且可能有助于区分足月和过期妊娠。
