Gravett Michael G, Novy Miles J, Rosenfeld Ron G, Reddy Ashok P, Jacob Thomas, Turner Mark, McCormack Ashley, Lapidus Jodi A, Hitti Jane, Eschenbach David A, Roberts Charles T, Nagalla Srinivasa R
Division of Reproductive Sciences, Oregon National Primate Research Center, Beaverton, Ore, USA.
JAMA. 2004 Jul 28;292(4):462-9. doi: 10.1001/jama.292.4.462.
Intra-amniotic infection (IAI) is commonly associated with preterm birth and adverse neonatal sequelae. Early diagnosis of IAI, however, has been hindered by insensitive or nonspecific tests.
To identify unique protein signatures in rhesus monkeys with experimental IAI, a proteomics-based analysis of amniotic fluid was used to develop diagnostic biomarkers for subclinical IAI in amniotic fluid and blood of women with preterm labor.
DESIGN, SETTING, AND PARTICIPANTS: Surface-enhanced laser desorption-ionization/time-of-flight mass spectrometry, gel electrophoresis, and tandem mass spectrometry were used to characterize amniotic fluid peptides in 19 chronically instrumented pregnant rhesus monkeys before and after experimental IAI. Candidate biomarkers were determined by liquid chromatography-tandem mass spectrometry. Polyclonal antibodies were generated from synthetic peptides for validation of biomarkers of IAI. Amniotic fluid peptide profiles identified in experimental IAI were subsequently tested in a cohort of 33 women admitted to Seattle, Wash, hospitals between June 25, 1991, and June 30, 1997, with preterm delivery at 35 weeks or earlier associated with subclinical IAI (n = 11), preterm delivery at 35 weeks or earlier without IAI (n = 11), and preterm contractions with subsequent term delivery at later than 35 weeks (n = 11).
Identification of peptide biomarkers for occult IAI.
Protein expression profiles in amniotic fluid showed unique signatures of overexpression of polypeptides in the 3- to 5-kDa and 10- to 12-kDa molecular weight ranges in all animals after infection and in no animal prior to infection. In women, the 10- to 12-kDa signature was identified in all 11 patients with subclinical IAI, in 2 of 11 with preterm delivery without IAI, and in 0 of 11 with preterm labor and term delivery without infection (P<.001). Peptide fragment analysis of the diagnostic peak in amniotic fluid identified calgranulin B and a unique fragment of insulinlike growth factor binding protein 1, which were also expressed in maternal serum. Mapping of other amniotic fluid proteins differentially expressed in IAI identified several immunoregulators not previously described in amniotic fluid.
This proteomics-based characterization of the differential expression of amniotic fluid proteins in IAI identified a distinct proteomic profile in an experimental primate chorioamnionitis model that detected subclinical IAI in a human cohort with preterm labor. These diagnostic protein expression signatures, complemented by immunodetection of specific biomarkers in amniotic fluid and in maternal serum, might have application in the early detection of IAI.
羊膜腔内感染（IAI）通常与早产及不良新生儿后遗症相关。然而，IAI的早期诊断一直受到检测不敏感或非特异性的阻碍。
为了识别实验性IAI恒河猴独特的蛋白质特征，采用基于蛋白质组学的羊水分析方法来开发用于诊断早产女性羊水和血液中亚临床IAI的生物标志物。
设计、场所和参与者：利用表面增强激光解吸电离飞行时间质谱、凝胶电泳和串联质谱对19只长期植入仪器的怀孕恒河猴在实验性IAI前后的羊水肽进行表征。候选生物标志物通过液相色谱-串联质谱法确定。从合成肽产生多克隆抗体以验证IAI的生物标志物。随后在1991年6月25日至1997年6月30日期间入住华盛顿州西雅图医院的33名女性队列中测试在实验性IAI中鉴定出的羊水肽谱，这些女性包括35周或更早发生早产且伴有亚临床IAI的（n = 11）、35周或更早发生早产但无IAI的（n = 11）以及有早产宫缩随后在35周以后足月分娩的（n = 11）。
鉴定隐匿性IAI的肽生物标志物。
羊水蛋白质表达谱显示，感染后所有动物中分子量在3至5 kDa和10至12 kDa范围内的多肽均有独特的过表达特征，而感染前无动物出现此特征。在女性中，10至12 kDa特征在所有11例亚临床IAI患者中均被鉴定出，在11例无IAI的早产患者中有2例出现，在11例有早产宫缩随后足月分娩且无感染的患者中未出现（P<0.001）。羊水诊断峰的肽片段分析鉴定出钙粒蛋白B和胰岛素样生长因子结合蛋白1的一个独特片段，它们也在母体血清中表达。对IAI中差异表达的其他羊水蛋白进行图谱分析，鉴定出了几种先前未在羊水中描述的免疫调节因子。
基于蛋白质组学对IAI中羊水蛋白差异表达的表征在实验性灵长类绒毛膜羊膜炎模型中确定了一种独特的蛋白质组学特征，该特征在一个有早产的人类队列中检测到了亚临床IAI。这些诊断性蛋白质表达特征，辅以对羊水和母体血清中特定生物标志物的免疫检测，可能在IAI的早期检测中具有应用价值。
