Biomaterial Database

A comparison between lactose breath test and quick test on duodenal biopsies for diagnosing lactase deficiency in patients with self-reported lactose intolerance. 2013

Manuele Furnari, and Daria Bonfanti, and Andrea Parodi, and Jolanda Franzè, and Edoardo Savarino, and Luca Bruzzone, and Alessandro Moscatelli, and Francesco Di Mario, and Pietro Dulbecco, and Vincenzo Savarino

Department of Internal Medicine, Gatroenterology Unit, University of Genoa, Genoa, Italy.

BACKGROUND A lactose breath test (LBT) is usually used to diagnose lactase deficiency, and a lactose quick test (LQT) has been proposed as a new test on duodenal biopsies to detect this disorder. OBJECTIVE We aimed to assess the diagnostic accuracy of LBT and LQT and their ability to predict the clinical response to a lactose-free diet in patients with self-reported lactose intolerance. METHODS Fifty-five patients (age 47 ± 14 y; M/F 15/36) underwent upper gastrointestinal endoscopy and 25g-LBT. Two duodenal biopsies were taken to determine lactase deficiency (normal, mild, or severe) by LQT and to rule out other causes of secondary lactose malabsorption. Patients with a positive LBT and normal LQT also underwent a glucose breath test to exclude small intestinal bacterial overgrowth as a cause of the former result. The severity of gastrointestinal symptoms was measured with a GSS questionnaire, under basal condition and 1 month after a lactose-free diet. RESULTS Lactose malabsorption was detected in 31/51 patients with LBT and in 37/51 patients with LQT (P = NS). Celiac disease was found in 2 patients. Two LBT+ patients showed a positive glucose breath test for small intestinal bacterial overgrowth. Eight patients had a mild hypolactasia by LQT and a negative LBT, but they had a significant improvement of symptoms after diet. LQT and LBT were concordant in 83% of cases and predicted the response to a lactose-free diet in 98% and 81% of the cases, respectively (P = 0.03). CONCLUSIONS LQT is as sensitive as LBT in detecting lactase deficiency; however, it seems to be more accurate than LBT in predicting the clinical response to a lactose-free diet.

UI	MeSH Term	Description	Entries
D007785	Lactose	A disaccharide of GLUCOSE and GALACTOSE in human and cow milk. It is used in pharmacy for tablets, in medicine as a nutrient, and in industry.	Anhydrous Lactose,Lactose, Anhydrous
D007787	Lactose Intolerance	The condition resulting from the absence or deficiency of LACTASE in the MUCOSA cells of the GASTROINTESTINAL TRACT, and the inability to break down LACTOSE in milk for ABSORPTION. Bacterial fermentation of the unabsorbed lactose leads to symptoms that range from a mild indigestion (DYSPEPSIA) to severe DIARRHEA. Lactose intolerance may be an inborn error or acquired.	Lactose Malabsorption,Alactasia,Dairy Product Intolerance,Hypolactasia,Milk Sugar Intolerance,Intolerance, Lactose,Malabsorption, Lactose
D007789	Lactose Tolerance Test	A measure of a patient's ability to break down lactose.	Lactose Tolerance Tests,Test, Lactose Tolerance,Tests, Lactose Tolerance,Tolerance Test, Lactose,Tolerance Tests, Lactose
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D011237	Predictive Value of Tests	In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.	Negative Predictive Value,Positive Predictive Value,Predictive Value Of Test,Predictive Values Of Tests,Negative Predictive Values,Positive Predictive Values,Predictive Value, Negative,Predictive Value, Positive
D011446	Prospective Studies	Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.	Prospective Study,Studies, Prospective,Study, Prospective
D011795	Surveys and Questionnaires	Collections of data obtained from voluntary subjects. The information usually takes the form of answers to questions, or suggestions.	Community Survey,Nonrespondent,Questionnaire,Questionnaires,Respondent,Survey,Survey Method,Survey Methods,Surveys,Baseline Survey,Community Surveys,Methodology, Survey,Nonrespondents,Questionnaire Design,Randomized Response Technique,Repeated Rounds of Survey,Respondents,Survey Methodology,Baseline Surveys,Design, Questionnaire,Designs, Questionnaire,Methods, Survey,Questionnaire Designs,Questionnaires and Surveys,Randomized Response Techniques,Response Technique, Randomized,Response Techniques, Randomized,Survey, Baseline,Survey, Community,Surveys, Baseline,Surveys, Community,Techniques, Randomized Response
D001944	Breath Tests	Any tests done on exhaled air.	Breathalyzer Tests,Breath Test,Breathalyzer Test,Test, Breath,Test, Breathalyzer,Tests, Breath,Tests, Breathalyzer
D004386	Duodenum	The shortest and widest portion of the SMALL INTESTINE adjacent to the PYLORUS of the STOMACH. It is named for having the length equal to about the width of 12 fingers.	Duodenums