Vijayvargiya P, Camilleri M, Carlson P, Lueke A, O'Neill J, Burton D, Busciglio I, Donato L
Clinical Enteric Neuroscience Translational and Epidemiological Research (CENTER), Mayo Clinic, Rochester, MN, USA.
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA.
Aliment Pharmacol Ther. 2017 Sep;46(6):581-588. doi: 10.1111/apt.14214. Epub 2017 Jul 10.
The serum biomarkers, elevated 7αC4 (C4) and decreased FGF19, have been proposed as screening tests for bile acid diarrhoea.
To analyse prevalence, specificity and reproducibility of fasting C4 and FGF19 in identifying bile acid diarrhoea in patients with irritable bowel syndrome with predominant diarrhoea or functional diarrhoea (summarised as IBS-D).
We prospectively studied fasting serum C4 and FGF19 in 101 IBS-D patients; we reviewed data from 37 of the 101 patients with prior fasting serum C4 and FGF19 and from 30 of the 101 patients with prior faecal bile acids per 48 hours. We compared results with normal values (C4 ≥52.5 ng/mL [n=184], FGF-19 ≤61.7 pg/mL [n=50]). We used Spearman correlation and Bland-Altman plots to appraise reproducibility.
Among the 101 patients, there was a negative correlation between serum C4 and FGF19 (Rs=-.342, P=.0005). Bile acid diarrhoea was diagnosed in 10 patients based on elevated serum C4 levels (mean 23.5±23.1 [SD] ng/mL) and 21 patients based on decreased FGF19 levels (121.6±84.2 pg/mL). With replicate tests in patients with stable IBS-D, 78% of C4 and 70% of FGF19 measurements remained concordant, with 3% and 11% respectively consistently positive for bile acid diarrhoea in the 101 patients. Compared to 48 hours faecal bile acids, specificity for C4 and FGF19 was 83% and 78%, respectively. Bland-Altman plots demonstrated greater reliability of C4 than FGF19.
Among 101 patents with IBS-D, fasting FGF19 and C4 levels had good specificity and negative predictive value, suggesting utility as screening tests to exclude bile acid diarrhoea.
血清生物标志物7αC4（C4）升高和FGF19降低已被提议作为胆汁酸腹泻的筛查试验。
分析空腹C4和FGF19在鉴别以腹泻为主型肠易激综合征或功能性腹泻（统称为IBS-D）患者胆汁酸腹泻中的患病率、特异性和可重复性。
我们前瞻性研究了101例IBS-D患者的空腹血清C4和FGF19；我们回顾了101例患者中37例之前空腹血清C4和FGF19的数据以及101例患者中30例每48小时粪便胆汁酸的数据。我们将结果与正常值（C4≥52.5 ng/mL [n = 184]，FGF - 19≤61.7 pg/mL [n = 50]）进行比较。我们使用Spearman相关性分析和Bland - Altman图来评估可重复性。
在101例患者中，血清C4和FGF19之间存在负相关（Rs = - 0.342，P = 0.0005）。基于血清C4水平升高（平均23.5±23.1 [标准差] ng/mL）诊断出10例胆汁酸腹泻患者，基于FGF19水平降低（121.6±84.2 pg/mL）诊断出21例。在IBS-D病情稳定的患者中进行重复检测时，101例患者中C4检测结果的78%和FGF19检测结果的70%保持一致，分别有3%和11%持续呈胆汁酸腹泻阳性。与48小时粪便胆汁酸相比，C4和FGF19的特异性分别为83%和78%。Bland - Altman图显示C4比FGF19具有更高的可靠性。
在101例IBS-D患者中，空腹FGF19和C4水平具有良好的特异性和阴性预测价值，提示其作为排除胆汁酸腹泻的筛查试验具有实用性。
