Elimian A, Figueroa R, Canterino J, Verma U, Aguero-Rosenfeld M, Tejani N
Department of Obstetrics and Gynecology, New York Medical College, Valhalla, USA.
Obstet Gynecol. 1998 Jul;92(1):72-6. doi: 10.1016/s0029-7844(98)00123-9.
To determine the value of amniotic fluid (AF) complement C3 as a marker of intra-amniotic infection and to compare complement C3 with other rapid markers of intra-amniotic infection.
One hundred four women with singleton gestations, in preterm labor with intact membranes, at 23-35 weeks' gestation underwent transabdominal amniocentesis. Amniotic fluid was analyzed for white blood cell (WBC) count, lactate dehydrogenase (LDH), glucose, Gram stain, and complement C3. Cultures for aerobes, anaerobes, and mycoplasma species also were performed. The median values of complement C3, WBC, LDH, and glucose were compared between the culture-positive and -negative groups. Complement C3 was compared with WBC count, LDH, glucose, and Gram stain for sensitivity, specificity, positive and negative predictive values, and accuracy in the prediction of a positive AF culture. Descriptive statistics, receiver operating characteristic curve, Fisher exact test, and Wilcoxon rank-sum test were used for analysis.
The prevalence of positive cultures was 11.5% (12 of 104). The culture-positive group had a significantly higher median C3 (7.0 mg/dL) than the median C3 (3.0 mg/dL) of the culture-negative group (P < .001). Also, the median values of WBC (1120.5 cells/mm3) and LDH (2697 U/L) were significantly higher and the median glucose (6.5 mg/dL) was significantly lower among women with positive AF cultures than among women with negative AF cultures (WBC=1 cell/mm3; LDH=165 U/L; glucose=45 mg/dL; P < .001). Eleven of the 12 culture-positive cases had a C3 of 5 mg/dL or more, whereas four of the 92 culture-negative cases had a C3 of 5 mg/dL (P < .001). Nine of the 12 culture-positive cases but none of the 92 culture-negative cases had a C3 of 6 mg/dL or more (P < .001). The relative risks of a positive AF culture were 65.27 (95% confidence interval [CI] 9.08, 469.27) and 31.67 (95% CI 10.40, 96.43) times greater among women with AF complement C3 levels of 5 and 6 mg/dL or more, respectively. Depending on the cutoff point used, complement C3 had similar or higher sensitivity, specificity, positive predictive value, and negative predictive value for intra-amniotic infection when compared with WBC count, LDH, glucose and Gram stain.
Amniotic fluid complement C3 has value in the diagnosis of intra-amniotic infection in preterm labor with intact membranes. Complement C3 is available readily and compares favorably with other rapid markers of AF infection. This study supports the general concept of fetal inflammatory response to microbial invasion of AF.
确定羊水补体C3作为羊膜腔内感染标志物的价值，并将补体C3与羊膜腔内感染的其他快速标志物进行比较。
104例单胎妊娠、胎膜完整、妊娠23 - 35周的早产妇女接受经腹羊膜腔穿刺术。对羊水进行白细胞（WBC）计数、乳酸脱氢酶（LDH）、葡萄糖、革兰氏染色及补体C3分析。同时进行需氧菌、厌氧菌及支原体培养。比较培养阳性组和阴性组补体C3、WBC、LDH及葡萄糖的中位数。比较补体C3与WBC计数、LDH、葡萄糖及革兰氏染色在预测羊水培养阳性方面的敏感性、特异性、阳性和阴性预测值及准确性。采用描述性统计、受试者操作特征曲线、Fisher确切检验及Wilcoxon秩和检验进行分析。
培养阳性率为11.5%（104例中的12例）。培养阳性组的补体C3中位数（7.0mg/dL）显著高于培养阴性组的中位数（3.0mg/dL）（P <.001）。此外，羊水培养阳性的妇女中，WBC中位数（1120.5个细胞/mm³）和LDH中位数（2697U/L）显著更高，葡萄糖中位数（6.5mg/dL）显著更低，而羊水培养阴性的妇女中WBC = 1个细胞/mm³；LDH =165U/L；葡萄糖 = 45mg/dL；P <.001。12例培养阳性病例中有11例补体C3为5mg/dL或更高，而92例培养阴性病例中有4例补体C3为5mg/dL（P <.001）。12例培养阳性病例中有9例补体C3为6mg/dL或更高，而92例培养阴性病例中无1例如此（P <.001）。羊水补体C3水平分别为5mg/dL及6mg/dL或更高的妇女中，羊水培养阳性的相对风险分别高65.27倍（95%置信区间[CI]9.08, 469.27）和31.67倍（95%CI 10.40, 96.43）。与WBC计数、LDH、葡萄糖及革兰氏染色相比，根据所采用的临界值，补体C3对羊膜腔内感染具有相似或更高的敏感性、特异性、阳性预测值及阴性预测值。
羊水补体C3在胎膜完整的早产羊膜腔内感染诊断中具有价值。补体C3易于获得，与羊水感染的其他快速标志物相比具有优势。本研究支持胎儿对羊水中微生物侵袭产生炎症反应的总体概念。
