Background & Aims

It is not clear how often patients who are on gluten-free diets (GFDs) for treatment of celiac disease still are exposed to gluten. We studied levels of gluten immunogenic peptides (GIP) in fecal and urine samples, collected over 4 weeks, from patients with celiac disease on a long-term GFD.

Methods

We performed a prospective study of 53 adults with celiac disease who had been on a GFD for more than 2 years (median duration, 8 y; interquartile range, 5–12 y) in Argentina. At baseline, symptoms were assessed by the celiac symptom index questionnaire. Patients collected stool each Friday and Saturday and urine samples each Sunday for 4 weeks. We used a commercial enzyme-linked immunosorbent assay to measure GIP in stool and point-of-care tests to measure GIP in urine samples.

Results

Overall, 159 of 420 stool and urine samples (37.9%) were positive for GIP; 88.7% of patients had at least 1 fecal or urine sample that was positive for GIP (median, 3 excretions). On weekends (urine samples), 69.8% of patients excreted GIP at least once, compared with 62.3% during weekdays (stool). The number of patients with a sample that was positive for GIP increased over the 4-week study period (urine samples in week 1 vs week 4: P < .05). Patients with symptoms had more weeks in which GIP was detected in stool than patients without symptoms (P < .05). The number of samples that were positive for GIP correlated with titers of deamidated gliadin peptide IgA in patients’ blood samples, but not with levels of tissue transglutaminase.

Conclusions

Patients with celiac disease on a long-term GFD still frequently are exposed to gluten. Assays to detect GIP in stool and urine might be used to assist dietitians in assessment of GFD compliance.

中文翻译：

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从尿液和粪便样本中的麦胶蛋白免疫原性肽确定无麸质饮食的乳糜泻患者的真实面筋暴露

背景与目标

目前尚不清楚使用无麸质饮食 (GFD) 来治疗乳糜泻的患者仍然暴露于麸质的频率。我们研究了 4 周内收集的来自长期 GFD 的乳糜泻患者的粪便和尿液样本中麸质免疫原性肽 (GIP) 的水平。

方法

我们对阿根廷 53 名接受 GFD 超过 2 年（中位持续时间，8 年；四分位距，5-12 年）的乳糜泻成人进行了前瞻性研究。在基线时，通过腹腔症状指数问卷评估症状。患者每周五和周六收集粪便，每周日收集尿液样本，持续 4 周。我们使用商业酶联免疫吸附测定来测量粪便中的 GIP，并使用即时检验来测量尿液样本中的 GIP。

结果

总体而言，420 份粪便和尿液样本中有 159 份（37.9%）为 GIP 阳性；88.7% 的患者至少有 1 个粪便或尿液样本为 GIP 阳性（中位数，3 次排泄）。在周末（尿液样本），69.8% 的患者至少排泄一次 GIP，而在工作日（粪便）中这一比例为 62.3%。在 4 周的研究期间，具有 GIP 阳性样本的患者数量增加（第 1 周与第 4 周的尿液样本：P < .05）。有症状的患者在粪便中检测到 GIP 的时间比没有症状的患者多 ( P < .05)。GIP 阳性的样本数量与患者血液样本中脱酰胺醇溶蛋白肽 IgA 的滴度相关，但与组织转谷氨酰胺酶水平无关。

结论

长期 GFD 的乳糜泻患者仍然经常接触麸质。检测粪便和尿液中 GIP 的分析可用于帮助营养师评估 GFD 依从性。