Di Leo Vincenza, D'Incà Renata, Diaz-Granado Natalia, Fries Walter, Venturi Carla, D'Odorico Anna, Martines Diego, Sturniolo Giacomo C
Department of Surgical and Gastroenterological Sciences, University of Padova, Padova, Italy.
Am J Gastroenterol. 2003 Oct;98(10):2245-52. doi: 10.1111/j.1572-0241.2003.07697.x.
Diagnosis in chronic diarrhea in the absence of a distinctive clinical pattern is often challenging, as biochemical tests prescribed at the first evaluation do not show enough sensitivity and specificity to tailor further investigation. Intestinal permeability to sugars is an accurate test for detecting intestinal damage. The aim of this study was to evaluate the diagnostic value of the lactulose/mannitol (L/M) test in patients with chronic diarrhea.
We conducted a prospective cohort study to evaluate the diagnostic value of the L/M test in chronic diarrhea. The test was administered to 261 consecutive patients presenting with three or more bowel movements daily for at least 3 wk. Biochemical tests including complete blood cell count, acute phase reactive proteins, serum albumin and iron, and stool cultures for bacteria, ova, and parasites were assessed at the same time. Additional diagnostic investigations were directed by clinical features as well as first-line test results.
Over 3 yr, 120 (46%) of our patients were found to have an organic cause for chronic diarrhea, whereas in 141 (54%) a functional condition was diagnosed. Multivariate logistic regression analysis revealed that the L/M test and C-reactive protein were independent predictors for the final diagnosis of organic cause of chronic diarrhea, with odds ratios of 1.5 (95% CI = 1.29-1.78) and 5.2 (95% CI = 1.90-14.12), respectively. The area under the receiver operating characteristic (ROC) curve of the adjusted model was 0.82, with positive predictive value of 80.4% and negative predictive value of 77.7%.
The L/M test is a powerful tool for workup in patients with chronic diarrhea. Introducing the L/M test as first-level test effectively improves the selection of patients who need further evaluation.
在缺乏典型临床症状的慢性腹泻病例中，诊断往往具有挑战性，因为初次评估时所采用的生化检测在敏感性和特异性方面不足以指导进一步的检查。肠道对糖类的通透性检测是一种检测肠道损伤的准确方法。本研究旨在评估乳果糖/甘露醇（L/M）检测在慢性腹泻患者中的诊断价值。
我们进行了一项前瞻性队列研究，以评估L/M检测在慢性腹泻中的诊断价值。对连续261例每日排便3次及以上且持续至少3周的患者进行了该检测。同时评估了包括全血细胞计数、急性期反应蛋白、血清白蛋白和铁在内的生化检测，以及细菌、虫卵和寄生虫的粪便培养。根据临床特征和一线检测结果进行进一步的诊断性检查。
在3年多的时间里，我们发现120例（46%）患者的慢性腹泻存在器质性病因，而141例（54%）被诊断为功能性疾病。多因素逻辑回归分析显示，L/M检测和C反应蛋白是慢性腹泻器质性病因最终诊断的独立预测因素，优势比分别为1.5（95%CI = 1.29 - 1.78）和5.2（95%CI = 1.90 - 14.12）。调整后模型的受试者操作特征（ROC）曲线下面积为0.82，阳性预测值为80.4%，阴性预测值为77.7%。
L/M检测是慢性腹泻患者检查的有力工具。将L/M检测作为一级检测可有效改善对需要进一步评估患者的筛选。
