*Inflammatory Bowel Disease Center, Division of Gastroenterology, Department of Medicine, University of California San Diego, La Jolla, California; †San Diego Digestive Disease Research Center, University of California San Diego, La Jolla, California; ‡Department of Medicine, Division of Gastroenterology, University of California San Diego, La Jolla, California; §Clinical and Translational Research Institute, University of California San Diego, La Jolla, California; ‖Department of Medicine, Division of Rheumatology, University of California San Diego, La Jolla, California; ¶Department of Pathology, University of California San Diego, La Jolla, California; **Division of Gastroenterology & Hepatology, Kaiser Permanente, San Diego, California; and ††Department of Epidemiology and Biostatistics, Western University, London, ON, Canada.
Inflamm Bowel Dis. 2015 Feb;21(2):323-30. doi: 10.1097/MIB.0000000000000264.
The ability to measure the expression of proinflammatory cytokines from intestinal biopsies in patients with Crohn's disease in an accurate and reproducible way is critical for proof-of-concept and mechanism-of-action trials; however, the number of biopsies from a segment of the ileum or colon required to yield reproducible results has not been rigorously evaluated. We examined intestinal biopsies from patients with Crohn's disease to validate methods for detecting changes in inflammatory gene expression.
To evaluate the reproducibility of gene expression measurements, intestinal biopsies were obtained from designated segments from 6 healthy controls, 6 patients with active Crohn's disease, and 6 patients with inactive Crohn's disease. Disease activity was based on the simple endoscopic score for Crohn's disease. Expression of 7 proinflammatory genes was measured from each biopsy using quantitative polymerase chain reaction. Using a linear mixed effects model, the power to detect transcriptional changes corresponding to active and inactive Crohn's disease was calculated.
Total simple endoscopic score for Crohn's disease score corresponds with expression of most inflammatory biomarkers. For most genes, 2 to 5 biopsies are needed to reduce sampling error to <25% for most genes. To measure changes in mRNA expression corresponding to active versus inactive Crohn's disease, 1 to 2 intestinal biopsies from 3 patients before and after treatment are needed to yield power of at least 80%.
Measuring proinflammatory gene expression from mucosal biopsies from patients with Crohn's disease is practicable and provides objective biomarkers that can be used in proof-of-concept and mechanism-of-action trials to assess response to therapy.
以准确和可重复的方式测量克罗恩病患者肠道活检中促炎细胞因子的表达能力，对于概念验证和作用机制试验至关重要；然而，为了获得可重复的结果，从回肠或结肠的一段获得足够数量的活检尚未得到严格评估。我们检查了克罗恩病患者的肠道活检，以验证检测炎症基因表达变化的方法。
为了评估基因表达测量的可重复性，从 6 名健康对照者、6 名活动性克罗恩病患者和 6 名非活动性克罗恩病患者的指定部位获得肠道活检。疾病活动度基于克罗恩病简单内镜评分。使用定量聚合酶链反应从每个活检中测量 7 种促炎基因的表达。使用线性混合效应模型，计算检测与活动性和非活动性克罗恩病相对应的转录变化的能力。
克罗恩病简单内镜总评分与大多数炎症生物标志物的表达相对应。对于大多数基因，需要 2 到 5 个活检以将采样误差降低到<25%，对于大多数基因而言。为了测量与活动性与非活动性克罗恩病相对应的 mRNA 表达变化，在治疗前后需要来自 3 名患者的 1 到 2 个肠道活检，以产生至少 80%的功效。
从克罗恩病患者的黏膜活检中测量促炎基因表达是可行的，并提供了客观的生物标志物，可用于概念验证和作用机制试验，以评估对治疗的反应。
