Mooiweer Erik, Fidder Herma H, Siersema Peter D, Laheij Robert J F, Oldenburg Bas
Department of Gastroenterology and Hepatology, University Medical Center Utrecht, Utrecht, The Netherlands.
Inflamm Bowel Dis. 2014 Feb;20(2):307-14. doi: 10.1097/01.MIB.0000438428.30800.a6.
Fecal calprotectin can be used as a noninvasive tool to assess inflammation in patients with inflammatory bowel disease (IBD). However, the diagnostic accuracy of calprotectin is modest, and therefore additional markers are needed. We compared the efficacy of fecal hemoglobin and calprotectin as markers for endoscopic inflammation in patients with IBD.
Consecutive patients with Crohn's disease or ulcerative colitis scheduled for surveillance colonoscopy collected a stool sample before bowel preparation. Experienced endoscopists assessed the presence of inflammation in each colonic segment. Fecal calprotectin and hemoglobin were analyzed with an enzyme-linked immunosorbent assay. Receiver operator characteristic statistics were used to determine cutoff values for calprotectin and hemoglobin.
A total of 176 surveillance colonoscopies were performed in 164 patients, of which 83 patients had Crohn's disease, 74 had ulcerative colitis, and 7 IBD-unclassified. Median (interquartile range) calprotectin and hemoglobin concentrations were 137 mg/kg (interquartile range, 33-494) and 0.51 μg/g (interquartile range, 0.18-8.50), respectively. For calprotectin, a cutoff value of 140 mg/kg predicted endoscopic inflammation with 86% sensitivity, 72% specificity, 64% positive predictive value, 90% negative predictive value, and an area under the curve of 0.87. For hemoglobin, a cutoff value of 1.51 μg/g indicated endoscopic inflammation with 74% sensitivity, 84% specificity, 72% positive predictive value, 84% negative predictive value, and an area under the curve of 0.81. Combining both tests did not increase the predictive accuracy substantially compared with calprotectin or hemoglobin alone (area under the curve, 0.88).
Fecal hemoglobin can identify patients with IBD with active inflammation with a predictive accuracy similar to calprotectin.
粪便钙卫蛋白可作为评估炎症性肠病（IBD）患者炎症的一种非侵入性工具。然而，钙卫蛋白的诊断准确性一般，因此需要其他标志物。我们比较了粪便血红蛋白和钙卫蛋白作为IBD患者内镜下炎症标志物的效能。
连续的克罗恩病或溃疡性结肠炎患者计划接受监测结肠镜检查，在肠道准备前采集粪便样本。经验丰富的内镜医师评估每个结肠段的炎症情况。采用酶联免疫吸附测定法分析粪便钙卫蛋白和血红蛋白。使用受试者工作特征统计来确定钙卫蛋白和血红蛋白的临界值。
164例患者共进行了176次监测结肠镜检查，其中83例为克罗恩病，74例为溃疡性结肠炎，7例为未分类的IBD。钙卫蛋白和血红蛋白浓度的中位数（四分位间距）分别为137 mg/kg（四分位间距，33 - 494）和0.51 μg/g（四分位间距，0.18 - 8.50）。对于钙卫蛋白，临界值为140 mg/kg时预测内镜下炎症的灵敏度为86%，特异度为72%，阳性预测值为64%，阴性预测值为90%，曲线下面积为0.87。对于血红蛋白，临界值为1.51 μg/g时提示内镜下炎症的灵敏度为74%，特异度为84%，阳性预测值为72%，阴性预测值为84%，曲线下面积为0.81。与单独使用钙卫蛋白或血红蛋白相比，联合两种检测方法并未显著提高预测准确性（曲线下面积，0.88）。
粪便血红蛋白可识别有活动性炎症的IBD患者，其预测准确性与钙卫蛋白相似。
