Hiele M, Ghoos Y, Rutgeerts P, Vantrappen G, Carchon H, Eggermont E
Department of Internal Medicine, University Hospital St.-Raphaël Gasthuisberg, University of Leuven, Belgium.
J Lab Clin Med. 1988 Aug;112(2):193-200.
A 13CO2 breath test using naturally enriched 13C-lactose as a substrate was performed in 47 patients with chronic abdominal pain or chronic diarrhea, taken from a population with a low prevalence of primary acquired lactase deficiency. The cumulative 13CO2 excretion 4 hours after 13C-lactose intake was compared with the H2 breath excretion and with jejunal lactase activity. A physiologically significant relation was found between the cumulative 13CO2 excretion (at 4 hours) and lactase activity, 14.5% 13CO2 excretion being the best cutoff point for discrimination between patients with low and normal lactase activity. The 13CO2 breath test was found to be more sensitive (0.84 versus 0.68) and more specific (0.96 versus 0.89) than the H2 breath test in detecting low jejunal lactase activity. Concordant results of both breath tests performed simultaneously give a reliable picture of the lactose absorption status of the patient. Discordance in results of 13CO2 and H2 lactose breath tests, if not explained by history, indicates in which patients a jejunal biopsy should be performed. If lactase activity and morphology of the biopsy are normal, other causes of discordance must be investigated.
对47例慢性腹痛或慢性腹泻患者进行了以天然富集的13C-乳糖为底物的13CO2呼气试验，这些患者来自原发性获得性乳糖酶缺乏患病率较低的人群。将摄入13C-乳糖后4小时的累积13CO2排泄量与H2呼气排泄量以及空肠乳糖酶活性进行比较。发现（4小时时的）累积13CO2排泄量与乳糖酶活性之间存在具有生理意义的关系，14.5%的13CO2排泄量是区分乳糖酶活性低和正常患者的最佳临界点。发现在检测空肠乳糖酶活性低时，13CO2呼气试验比H2呼气试验更敏感（0.84对0.68）和更具特异性（0.96对0.89）。同时进行的两种呼气试验结果一致能可靠地反映患者的乳糖吸收状况。如果13CO2和H2乳糖呼气试验结果不一致且无法用病史解释，则表明哪些患者应进行空肠活检。如果活检的乳糖酶活性和形态正常，则必须调查其他导致结果不一致的原因。
