Pacora P, Maymon E, Gervasi M T, Gomez R, Edwin S S, Yoon B H, Romero R
Perinatology Research Branch, National Institute of Child Health and Human Development, Bethesda, MD, USA.
Am J Obstet Gynecol. 2000 Oct;183(4):904-10. doi: 10.1067/mob.2000.108882.
Lactoferrin is an iron-binding protein with antimicrobial properties. This study was undertaken to determine whether amniotic fluid concentrations of this protein change with gestational age, infection, labor, and rupture of membranes.
This cross-sectional study included women who underwent transabdominal amniocentesis (n = 268) in the following groups: (1) mid trimester of pregnancy; (2) preterm labor who delivered at term, preterm labor who delivered preterm with intra-amniotic infection, and preterm labor who delivered preterm without intra-amniotic infection; (3) preterm premature rupture of membranes in the presence or absence of intra-amniotic infection; (4) term with intact membranes not in labor, in labor, and in labor with intra-amniotic infection; and (5) premature rupture of membranes at term not in labor. In addition, lactoferrin concentrations were determined in maternal plasma and cord blood of patients at term not in labor. Lactoferrin concentration was measured with an immunoassay.
(1) Lactoferrin was detectable in 85.4% (229/268) of amniotic fluid samples, not detectable in all fluid obtained in the mid trimester, and detectable in all maternal and cord plasma samples. (2) The concentration of lactoferrin increased with advancing gestational age (r = 0.68; P <.0001). (3) Intra-amniotic infection was associated with significant increases in amniotic fluid lactoferrin concentrations in patients with preterm labor (no intra-amniotic infection median, 1641.2 ng/mL; range, <1.24-35,090.0 ng/mL; vs intra-amniotic infection median, 3833.6 ng/mL; range, 746.0-47,020.0 ng/mL; P <.001), term labor (no intra-amniotic infection median, 2085.8 ng/mL; range, 425.0-23,230.0 ng/mL; vs intra-amniotic infection median, 5627.0 ng/mL; range, <1.24-19,220.0 ng/mL; P <. 001), and preterm premature rupture of membranes (no intra-amniotic infection median, 2190 ng/mL; range, <1.24-7456.1 ng/mL; vs intra-amniotic infection median, 3449.3 ng/mL; range, <1.24-83,600. 0; P <.01). (4) Spontaneous labor at term but not preterm was associated with a significant decrease in amniotic fluid lactoferrin concentration (P <.05). (5) Spontaneous term parturition was associated with a significant increase in umbilical cord plasma lactoferrin concentration (P <.005).
(1) Intra-amniotic infection was consistently associated with dramatically increased concentrations of lactoferrin in amniotic fluid. (2) Term parturition was associated with a significant increase in lactoferrin concentration in the fetal compartment (umbilical cord blood) and a decrease in the amniotic compartment. We propose that lactoferrin is part of the repertoire of host defense mechanisms against intra-amniotic infection.
乳铁蛋白是一种具有抗菌特性的铁结合蛋白。本研究旨在确定该蛋白的羊水浓度是否会随孕周、感染、分娩及胎膜破裂而变化。
这项横断面研究纳入了接受经腹羊膜腔穿刺术的女性（n = 268），分为以下几组：（1）妊娠中期；（2）足月分娩的早产患者、伴有羊膜腔内感染的早产患者以及无羊膜腔内感染的早产患者；（3）伴有或不伴有羊膜腔内感染的早产胎膜早破患者；（4）胎膜完整未临产、临产以及伴有羊膜腔内感染的足月临产患者；（5）足月未临产的胎膜早破患者。此外，还测定了足月未临产患者的母血和脐血中的乳铁蛋白浓度。采用免疫分析法测定乳铁蛋白浓度。
（1）85.4%（229/268）的羊水样本中可检测到乳铁蛋白，妊娠中期获取的所有羊水样本中均未检测到，而所有母血和脐血样本中均可检测到。（2）乳铁蛋白浓度随孕周增加而升高（r = 0.68；P <.0001）。（3）羊膜腔内感染与早产患者（无羊膜腔内感染时中位数为1641.2 ng/mL；范围为<1.24 - 35,090.0 ng/mL；伴有羊膜腔内感染时中位数为3833.6 ng/mL；范围为746.0 - 47,020.0 ng/mL；P <.001）、足月临产患者（无羊膜腔内感染时中位数为2085.8 ng/mL；范围为425.0 - 23,230.0 ng/mL；伴有羊膜腔内感染时中位数为5627.0 ng/mL；范围为<1.24 - 19,220.0 ng/mL；P <.001）以及早产胎膜早破患者（无羊膜腔内感染时中位数为2190 ng/mL；范围为<1.24 - 7456.1 ng/mL；伴有羊膜腔内感染时中位数为3449.3 ng/mL；范围为<1.24 - 83,600.0；P <.01）的羊水乳铁蛋白浓度显著升高相关。（4）足月自然分娩而非早产与羊水乳铁蛋白浓度显著降低相关（P <.05）。（5）足月自然分娩与脐血血浆乳铁蛋白浓度显著升高相关（P <.005）。
（1）羊膜腔内感染始终与羊水中乳铁蛋白浓度显著升高相关。（2）足月分娩与胎儿部分（脐血）乳铁蛋白浓度显著升高以及羊膜腔部分浓度降低相关。我们认为乳铁蛋白是宿主抵御羊膜腔内感染的防御机制之一。
