Du Lillian, Foshaug Rae, Huang Vivian W, Kroeker Karen I, Dieleman Levinus A, Halloran Brendan P, Wong Karen, Fedorak Richard N
Division of Gastroenterology, University of Alberta, Edmonton, AB, Canada.
J Clin Gastroenterol. 2018 Mar;52(3):235-240. doi: 10.1097/MCG.0000000000000776.
The use of fecal calprotectin (FC) as a stool biomarker for differentiating inflammatory bowel disease (IBD) from IBS has been well validated, and there is a strong correlation between FC and the presence of endoscopic inflammatory lesions. However, recent studies have demonstrated intraindividual sample variability in patients with IBD, possibly limiting the reliability of using a single sample for monitoring disease activity. Our aim was to assess the within-stool and within-day sample variability of FC concentrations in patients with IBD.
We examined a cross-sectional cohort of 50 adult IBD patients. Eligible patients were instructed to collect 3 samples from different parts of the stool from their first bowel movement of the day and 3 samples from each of up to 2 additional bowel movements within 24 hours. FC concentrations were measured by a rapid, quantitative point-of-care test using lateral flow technology (Quantum Blue). Descriptive statistics were used to assess FC variability within a single bowel movement and between different movements at different FC positivity cutoffs.
Within a single bowel movement, there was clinically significant sample variability ranging from 8% to 23% depending on the time of the day or on the FC positivity cutoff value. Between bowel movements, there was clinically significant sample variability ranging from 13% to 26% depending on the FC positivity cutoff.
Considering a single FC sample, the first sample of the day with an FC positivity cutoff of 250 μg/g provided the most reliable indication of disease activity.
粪便钙卫蛋白（FC）作为一种粪便生物标志物用于区分炎症性肠病（IBD）和肠易激综合征（IBS）已得到充分验证，且FC与内镜下炎症性病变的存在之间存在很强的相关性。然而，最近的研究表明IBD患者存在个体内样本变异性，这可能会限制使用单个样本监测疾病活动的可靠性。我们的目的是评估IBD患者粪便内及日内样本中FC浓度的变异性。
我们检查了50例成年IBD患者的横断面队列。符合条件的患者被要求在当天第一次排便时从粪便的不同部位采集3份样本，并在24小时内从最多另外2次排便中各采集3份样本。使用侧向流动技术的快速定量即时检测（Quantum Blue）测量FC浓度。描述性统计用于评估在不同FC阳性临界值下单次排便内以及不同排便之间的FC变异性。
在单次排便内，根据一天中的时间或FC阳性临界值，临床显著的样本变异性在8%至23%之间。在不同排便之间，根据FC阳性临界值，临床显著的样本变异性在13%至26%之间。
考虑单个FC样本时，当天第一个FC阳性临界值为250μg/g的样本能最可靠地指示疾病活动。
