Showing papers on "Breath test published in 2008"

High Prevalence of Small Intestinal Bacterial Overgrowth in Patients with Morbid Obesity: A Contributor to Severe Hepatic Steatosis

Abstract: With the increasing prevalence of obesity, non-alcoholic fatty liver disease (NAFLD) has become a major cause of liver diseases. Small intestinal bacterial overgrowth (SIBO) could be related to NAFLD. Our aim was to determine the prevalence of SIBO and its relationship with liver lesions in morbidly obese patients. A glucose hydrogen (H2) breath test (positive if fasting breath H2 concentration > 20 ppm and/or an increase of > 10 ppm over baseline within the first 2 h) was performed in obese patients referred for bariatric surgery (body mass index [BMI] > 40 kg/m2 or > 35 in association with comorbidities) and in healthy non-obese subjects. In obese patients, a surgical liver biopsy was performed. One hundred and forty-six patients (129 women, age [mean±SE]: 40.7 ± 11.4 years) were prospectively included in the study. The mean BMI was 46.1±6.4 kg/m2. A liver biopsy was available in 137 patients and a breath test in 136. The frequency of positive breath tests was higher in obese patients (24/136, 17.1%) than in healthy subjects (1/40, 2.5%; P=0.031). In the univariate analysis, SIBO was not associated with clinical variables, but tended to be associated with more frequent severe hepatic steatosis (26.3 vs. 10.3%, P=0.127), whereas the frequency of sinusoidal or portal fibrosis, lobular necrosis and non-alcoholic steatohepatitis (NASH) were not different. In the multivariate analysis, SIBO (P=0.005) and the presence of a metabolic syndrome (P=0.006) were independent factors of severe hepatic steatosis. In morbidly obese patients, bacterial overgrowth prevalence is higher than in healthy subjects and is associated with severe hepatic steatosis.

Inhibition of Helicobacter pylori infection in humans by Lactobacillus reuteri ATCC 55730 and effect on eradication therapy: a pilot study.

Abstract: Background: Several studies report an inhibitory effect of probiotics on Helicobacter pylori. Aim: To test whether Lactobacillus reuteri ATCC 55730 reduces H. pylori intragastric load in vivo, decreases dyspeptic symptoms, and affects eradication rates after conventional treatment. Materials and Methods: In a double-blind placebo-controlled study, 40 H. pylori-positive subjects were given L. reuteri once a day for 4 weeks or placebo. All underwent upper endoscopy, 13C-urea breath test, and H. pylori stool antigen determination at entry and 13C-urea breath test and H. pylori stool antigen (used as both qualitative and semiquantitative markers) after 4 weeks of treatment. Sequential treatment was administered subsequently to all. Results: In vivo, L. reuteri reduces H. pylori load as semiquantitatively assessed by both 13C-urea breath test δ-value and H. pylori stool antigen quantification after 4 weeks of treatment (p < .05). No change was shown in patients receiving placebo. L. reuteri administration was followed by a significant decrease in the Gastrointestinal Symptom Rating Scale as compared to pretreatment value (p < .05) that was not present in those receiving placebo (p = not significant). No difference in eradication rates was observed. Conclusions: L. reuteri effectively suppresses H. pylori infection in humans and decreases the occurrence of dyspeptic symptoms. Nevertheless, it does not seem to affect antibiotic therapy outcome.

Small intestinal bacterial overgrowth.

Abstract: Small intestinal bacterial overgrowth (SIBO) syndrome is characterized in its florid form by diarrhoea and weight loss The most common underlying factors are dysmotility, small intestinal obstruction, blind or afferent loops Small intestinal bacterial overgrowth can be diagnosed by: 1) culture of jejunum aspirate for bacterial counts, 2) 14C-D-xylose breath testing, 3) non-invasive hydrogen breath testing using glucose or lactulose or 4) 14C-glycocholic acid breath testing The treatment usually consists of the eradication of bacterial overgrowth with repeated course of antimicrobials, correction of associated nutritional deficiencies and, when possible, correction of the underlying predisposing conditions

Dose-Response Effect of Arabinoxylooligosaccharides on Gastrointestinal Motility and on Colonic Bacterial Metabolism in Healthy Volunteers

Abstract: Objective: Arabinoxylooligosaccharides (AXOS) are non-digestible in the upper gastrointestinal tract and have been shown to exert prebiotic effects in animals. The aim of this study was to characterize the influence of AXOS with an average degree of polymerization of 15 and an average degree of arabinose substitution of 0.26 (AXOS-15-0.26) on gastrointestinal motility and colonic bacterial metabolism in healthy human volunteers.Methods: Twelve healthy volunteers received five test meals, containing different amounts of AXOS-15-0.26, with one week intervals between each test meal. Breath tests were used to measure gastric emptying rate, oro-cecal transit time (OCTT) and hydrogen excretion. Colonic bacterial metabolism was estimated using the biomarkers lactose-[15N, 15N′]-ureide (15N-LU) and p-cresol.Results: Gastric emptying and OCTT were not influenced by addition of varying amounts of AXOS-15-0.26. Administration of 2.2g or 4.9g AXOS-15-0.26 significantly decreased the urinary 15N-excretion (respectivel...

A continuous 13C methacetin breath test for noninvasive assessment of intrahepatic inflammation and fibrosis in patients with chronic HCV infection and normal ALT

Abstract: Summary. Up to 30% of patients with hepatitis C virus (HCV) infection and normal serum alanine aminotransferase (NALT) have significant liver disease. Currently, many of these patients undergo a liver biopsy to guide therapeutic decisions. The BreathID® continuous online 13C-methacetin breath test (MBT) reflects hepatic microsomal function and correlates with hepatic fibrosis. To assess its role in identifying intrahepatic inflammation and fibrosis in NALT patients, we tested 100 patients with untreated chronic HCV infection, and 100 age- and sex-matched healthy volunteers using 13C MBT following ingestion of 75 mg methacetin. All HCV patients had undergone a liver biopsy within 12 months of performing the MBT. Patients with a necroinflammatory grade ≤4 or >4, based on Ishak (modified HAI) score, HAIa + HAIb + HAIc + HAId, were defined as having low or high inflammation, respectively. Patients with a histological activity fibrosis stage ≤2 or >2, were defined as having nonsignificant or significant fibrosis, respectively. A proprietary algorithm to differentiate intrahepatic inflammation within chronic HCV patients with NALT achieved an area under the curve (AUC) of 0.90. Setting a threshold on the point of best agreement (at 83%) results in 82% sensitivity and 84% specificity. With application of another proprietary algorithm to differentiate patients with nonsignificant or significant fibrosis, 67% of liver biopsies performed in the patient group could have been avoided. This algorithm achieved an AUC of 0.92, with a sensitivity of 91% and a specificity of 88%. There was no correlation between body mass index (BMI) and MBT scores for patients with the same histological score. The continuous BreathID®13C MBT is an accurate tool for measuring the degree of inflammation and fibrosis in patients with chronic HCV infection and NALT. As such, it may prove to be a powerful, noninvasive alternative to liver biopsy in the management of this patient population.

Concordance of Genetic and Breath Tests for Lactose Intolerance in a Tertiary Referral Centre

Abstract: Background and aims Lactase non-persistence causes gastrointestinal symptoms after milk ingestion. Hydrogen breath test (BTH) and genotyping of a single nucleotide polymorphism (SNP) C >T 13,910 base pairs upstream of the lactase gene represent potential methods for diagnosis of this autosomal-recessive trait. The aim of the study was to compare the results of both tests in detecting lactose non-persistence in a tertiary referral centre. Patients A group of 58 patients admitted to a German university hospital for symptoms suggesting lactose intolerance. Methods BTH after lactose ingestion (50 g) and SNP -13,910C>T genotyping using single nucleotide primer extension (SNaPshot) technology (CC genotype--lactase non-persistence; TC/TT genotypes--lactase persistence). Results Overall, 17 (29%) patients had a positive and 41 (71%) had a negative BTH result; 15 (26%) patients were CC-positive and 43 (74%) were CC-negative [28 (48%) TC; 15 (26%) TT]. The genotype frequencies did not deviate from the Hardy-Weinberg equilibrium. In the CC-positive group, concordance between both tests was 100%. In contrast, in the CC-negative group concordance was 95%, and positive BTH results could be attributed to other gastrointestinal pathologies in two patients. BTH had 100% negative predictive value, 88% positive predictive value, 100% sensitivity and 95% specificity, as compared to genetic testing. Conclusions In carriers of the CC-genotype, BTH and genotyping correlate perfectly, and the genetic test provides an unambiguous result. In BTH-positive individuals with a negative genetic test there is good reason to suspect secondary causes of lactase deficiency.

Comparison of breath testing with fructose and high fructose corn syrups in health and IBS

Abstract: Although incomplete fructose absorption has been implicated to cause gastrointestinal symptoms, foods containing high fructose corn syrup (HFCS) contain glucose. Glucose increases fructose absorption in healthy subjects. Our hypothesis was that fructose intolerance is less prevalent after HFCS consumption compared to fructose alone in healthy subjects and irritable bowel syndrome (IBS). Breath hydrogen levels and gastrointestinal symptoms were assessed after 40 g of fructose (12% solution) prepared either in water or as HFCS, administered in double-blind randomized order on 2 days in 20 healthy subjects and 30 patients with IBS. Gastrointestinal symptoms were recorded on 100-mm Visual Analogue Scales. Breath hydrogen excretion was more frequently abnormal (P < 0.01) after fructose (68%) than HFCS (26%) in controls and patients. Fructose intolerance (i.e. abnormal breath test and symptoms) was more prevalent after fructose than HFCS in healthy subjects (25% vs 0%, P = 0.002) and patients (40% vs 7%, P = 0.062). Scores for several symptoms (e.g. bloating r = 0.35) were correlated (P ≤ 0.01) to peak breath hydrogen excretion after fructose but not HFCS; in the fructose group, this association did not differ between healthy subjects and patients. Symptoms were not significantly different after fructose compared to HFCS. Fructose intolerance is more prevalent with fructose alone than with HFCS in health and in IBS. The prevalence of fructose intolerance is not significantly different between health and IBS. Current methods for identifying fructose intolerance should be modified to more closely reproduce fructose ingestion in daily life.

Helicobacter pylori infection detected by 14C-urea breath test is associated with iron deficiency anemia in pregnant women.

Abstract: Aims: To determine whether there is a relationship between Helicobacter pylori (H. pylori) infection, iron deficiency anemia and thrombocytopenia in pregnant women. Methods: Hemoglobin and ferritin levels and platelet counts of pregnant women were measured during the third trimester. H. pylori infection was determined using a 14C-urea breath test (14C-UBT) after delivery. Statistical analyses were determined with a Mann–Whitney U-test and the χ2 test. Statistical significance was determined with a P-value less than .05. Results: Seventy-two of 117 women had positive results on the 14C-UBT. Overall, 27 of 117 pregnant women had anemia (23.1%), and all them were in the H. pylori-positive group; 18 of 27 (66.7%) had iron deficiency anemia. Median hemoglobin levels and neonatal body weights were 12.0 g/dL vs 12.0 g/dL and 3320.0 grams vs 3520.0 grams in the H. pylori-positive and negative groups, respectively. Serum hemoglobin and ferritin levels and neonatal body weight were found to be lower in the anemic group compared with the non-anemic group among H. pylori-infected women (P = 0.0001, P = 0.02, P = 0.008, respectively). There were no statistically significant differences with regard to gestational thrombocytopenia between the H. pylori-positive and H. pylori-negative groups (P = 0.532). Conclusions: Our study indicates that there is a strong relationship between H. pylori infection and iron deficiency anemia in women with uncomplicated pregnancy. However, an association between H. pylori infection and thrombocytopenia was not found.

Retention, Fixation, and Loss of the [13C] Label: A Review for the Understanding of Gastric Emptying Breath Tests

Abstract: A [13C]-breath test is a promising method for measuring gastric emptying. The methodological relevance is based on a close correspondence between gastric emptying of [13C]-acetate/octanoate (input) and pulmonary excretion of [13CO2] (output). Despite the close input-output correspondence, the pulmonary output is quite remote from the gastric input: the pulmonary output is delayed compared to the gastric input, and the total recovery of [13CO2] in the breath is incomplete. This review focuses on the kinetics of [13C]-acetate/octanoate in the body and suggests that (1) the delayed pulmonary output results from temporal retention of [13CO2] in the well-perfused tissues (heart, brain, etc.), (2) the incomplete recovery results from incorporation of the label into metabolic products (ketone bodies, amino acids, etc.) or from fixation of [13CO2] in the low-perfused tissues (bone, skeletal muscle, etc.), and (3) knowledge on the retention is the key to appropriate interpretations of breath test results. Recognition of these kinetic aspects is essential for appropriate interpretations of these breath test results.

Evaluation of a novel stool native catalase antigen test for Helicobacter pylori infection in asymptomatic North American children.

Abstract: Rapid immunochromatographic tests for Helicobacter pylori infection have been developed to allow "near-patient" testing. We therefore performed a pilot study to test a rapid immunochromatographic stool antigen test for the diagnosis of H. pylori infection in asymptomatic children. We tested stool specimens collected from children participating in a cohort study in the United States and Mexico. H. pylori-positive status was defined by positivity on at least 2 tests: a commercial H. pylori stool antigen enzyme immunoassay, an immunoglobulin G antibody enzyme immunoassay, and the C-urea breath test. Negative H. pylori status was defined by negative findings of all of these tests. Of 52 children (22 girls, 30 boys) 25 were H. pylori-positive, 19 H. pylori-negative, and 8 uncertain (eg, presumably negative; positive findings on 1 of the 3 noninvasive tests). The sensitivity and specificity of the new stool antigen test for those with definite H. pylori status were 100% (exact 95% CI 86.3%-100% and 82.4%-100%, respectively). This rapid stool antigen test may prove useful for point-of-care testing and epidemiological field studies. Larger prospective studies are needed in symptomatic and asymptomatic children for more precise estimates.

Comparison of CO breath testing and women's self-reporting of smoking behaviour for identifying smoking during pregnancy

Abstract: Healthcare services often use a carbon monoxide (CO) breath test to validate self-reported smoking and to assess reductions in smoking habit A cut-off level of ≥ 8 parts per million (ppm) is used to identify smoking This cut-off requires further validation in pregnant women Data on self-reported smoking were assessed in conjunction with breath CO levels Subjects in the study were 2548 women attending antenatal booking during 12 months 546/2584 (214%) women self-reported as current smokers A cut-off of 8 ppm identified only 325/546 self-reported smokers (sensitivity 594%) 27/2002 self-reported non-smokers had levels greater than 8 ppm (specificity 987%) Sensitivity and specificity analysis revealed that CO cut-off levels of 2 or 3 ppm resulted in the best sensitivity and specificity for discriminating apparent smokers and non-smokers A cut-off of 2 ppm would have identified 468/546 of self-reported smokers (sensitivity 86%) 206/2002 self-reported non-smokers had levels > 2 ppm (specificity 90 %) If all these women were 'true' smokers, the real prevalence of smoking in pregnancy was 265% (752/2548) and 27% of true smokers provided false answers to the self-reported question at maternity booking At 8 ppm, many smokers are missed and there may be gross underestimating of levels of smoking in a pregnant population Results emphasise the need to support a lower cut-off level for the breath CO test closer to 2 or 3 ppm These cut-offs may be more appropriate in the antenatal clinic setting, and are in line with recent recommendations in the non-pregnant population

Validation of 13C-acetic acid breath test by measuring effects of loperamide, morphine, mosapride, and itopride on gastric emptying in mice.

Abstract: Several methods are used to evaluate gastric motility in rodents, but they all have technical limitations. Recent technical developments enable a convenient method to evaluate gastric motility. The (13)C-acetic acid breath test in rodents is a non-invasive and repeatable method that can be used without physical restraints. The present study aimed to validate the (13)C-acetic acid breath test by measuring the effects of loperamide, morphine, mosapride, and itopride on gastric emptying in mice. Loperamide (1-10 mg/kg) and morphine (1.25-10 mg/kg) slowed gastric emptying and decreased the maximum concentration (C(max)) and area under the curve (AUC(90 min)) value in a dose-dependent manner. Mosapride (0.2-5 mg/kg) accelerated gastric emptying and increased C(max) value. Mosapride (20 mg/kg) did not accelerate gastric emptying on the (13)C-breath test. Itopride (30 mg/kg, per os) significantly accelerated gastric emptying compared with the vehicle group. In a comparison with the conventional phenol red test, there was a correlation between the C(max) value of breath test and gastric emptying (%) of phenol red tests in treatment with loperamide or mosapride. These results indicate that the (13)C-acetic acid breath test is an accurate, noninvasive, and simple method for monitoring gastric emptying in mice. This method is useful to assess the effect of drugs and gut function pharmacologically.

13C-Methacetin-Atemtest zur quantitativen nicht-invasiven Leberfunktionsanalyse mittels eines isotopenselektiven nicht-dispersiven Infrarotspektrometers bei Leberzirrhose*

Abstract: BACKGROUND AND OBJECTIVE Cytochrome-P450-dependent liver function can be measured with the 13C-methacetin breath test (MBT). This has heretofore been done with the use of a mass-spectrometer. This study was undertaken to evaluate the MBT (NDIRS) done with the isotope-selective nondispersive infrared spectrometer. PATIENTS AND METHODS 20 healthy volunteers (ten women, ten men, aged 22-76 years) and 16 patients (ten women, six men, aged 48-71 years) with histologically confirmed liver cirrhosis (Child-Pugh stage A [n = 7], B [n = 5] or C [n = 4]) were given 13C-methacetin in 100 ml of tea after a 12-hour fasting period. Breath tests were performed before the test drink and 5, 10, 15, 20, 30, 40, 50, 60, 80, 100, 120, 150 and 180 min thereafter. The ratio of 13C to 12C was determined, as delta (/1000), and from it the maximal percentage rate (PDRmax) calculated, as well as the cumulative rate (cPDRmax) after 30, 60, 120 and 180 min (Median and 5th and 95th percentiles). RESULTS For patients with liver cirrhosis there were significantly lower values for cPDRmax and cPDR after 30, 60, 120 and 180 min than in the healthy subjects (P < 0.002): PDR [%]/h: 3.9 (0.7-15.9) vs. 36.5 (23.1-50.0); cDPR 30 min [%]: 1.1 (-0.2-6.0) vs. 12.4 (7.6-17.1); cDPR 3 h [%]: 9.8 (-2.3-27.5) vs. 36.0 (29.9-45.1). There were significant differences among the patients, depending on their Child-Pugh staging. CONCLUSION The MBT with the cost-effective NDIRS can reliably and noninvasively distinguish between healthy subjects and patients with liver cirrhosis. The test is therefore suitable for the quantitative analysis of liver functions.

The 13C-caffeine breath test detects significant fibrosis in patients with nonalcoholic steatohepatitis.

Abstract: BACKGROUND: The C-caffeine breath test (CBT) is a noninvasive tool for the evaluation of the cytochrome P450 system, implicated in the development of nonalcoholic steatohepatitis. GOAL: To apply the CBT to assess the extent of hepatic fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). METHODS: Twenty-six consecutive patients (mean age 56.1+/-6.85 y, 69.2% women) with NAFLD underwent the CBT, in addition to the clinical and laboratory evaluations and liver biopsy. Ten healthy individuals matched for age served as controls. RESULTS: Mean delta over baseline values differed significantly between patients and controls (1.51+/-0.9 vs. 2.37+/-0.8 Delta per thousand/mg, respectively) (P=0.01) and were significantly higher in patients with fibrosis stage or =2, P=0.05). Mean delta over baseline values correlated highly with fibrosis stage (P=0.01), albumin (P=0.007), international normalized ratio (P=0.04), bilirubin (P=0.0008), and platelet count (P=0.0001). On multivariate stepwise logistic regression analysis, CBT was the best predictor of severe fibrosis (stage > or =2) (odds ratio 0.274, 95% confidence interval 0.086-0.872, P=0.028), with an area under the curve of 0.788. CONCLUSIONS: The CBT is safe and easy to perform. It can reliably predict severe hepatic fibrosis in patients with NAFLD. Further large-scale studies are still needed.

H pylori eradication: A randomized prospective study of triple therapy with or without ecabet sodium

Abstract: AIM: To investigate whether adding ecabet sodium to the standard triple therapy for H pylori infection improve eradication rate. METHODS: Two hundred and fifty-seven H pylori-infected patients were randomly assigned to standard triple therapy (group A, n = 129) or triple therapy plus ecabet sodium (group B, n = 128). Successful eradication was defined as a negative 13C-urea breath test 6-8 wk after completion of treatment. RESULTS: After completion of therapy, 194/257 patients showed negative 13C-urea breath test results. According to intention-to-treat analysis, the infection was eradicated in 93/129 (72.1%) patients in group A and 101/128 (78.9%) in group B (P = 0.204). Per-protocol analysis showed successful eradication in 93/118 (78.8%) patients from group A and 101/114 (88.6%) from group B (P = 0.044). There were no significant differences in the side effects experienced by the patients in the two treatment groups. CONCLUSION: Our results suggest that the addition of ecabet sodium improves the efficacy of the standard triple therapy for H pylori.

Orocecal Transit Time in Patients in the Chronic Phase of Corrosive Injury

Abstract: Accidental/suicidal ingestion of corrosive substances is common in North India. Decreased gastric secretion and delayed gastric emptying in the chronic phase of corrosive injury has been documented at our center. We hypothesize that patients in the chronic phase of corrosive injury may have delayed orocecal transit time (OCTT). Objective To measure the orocecal transit time (using the noninvasive method of lactulose hydrogen breath test) in patients in the chronic phase of corrosive injury. Methods Thirty patients with corrosive injury to their gastrointestinal tract with its sequelae and attending the gastroenterology services of PGIMER, Chandigarh for endoscopic dilatation of strictures were enrolled in this study. Patients with age >60 years, vagotomy, prior gastric surgery, peptic ulcer disease, systemic sclerosis, history of diabetes, hypothyroidism or intestinal pseudo-obstruction were excluded. Orocecal transit time was measured by using a 15 mL lactulose hydrogen breath test. End expiratory breath was taken every 10 min until there was a rise >10 ppm over the fasting value in two consecutive readings. Results Thirty patients (11 females and 19 males) with a median age of 32 years, 27 with acid ingestion and 3 with alkali ingestion, were studied. None had symptoms of gastric outlet obstruction or gastroparesis. OCTT was significantly prolonged in the study group as compared to the control group (135.4 ± 15.8 versus 90.6 ± 10.4 min). No significant difference was observed between different age groups, gender, and type of caustic agent consumed. OCTT was maximally prolonged in patients with involvement of lower oesophagus, whereas patients without lower oesophagus involvement did not show significantly altered OCTT. Conclusion Our results show that patients with corrosive injury have prolonged OCTT even in the absence of any gastric symptoms. OCTT was prolonged maximally in patients with lower-third oesophageal cicatrization. This may a result of autovagotomy due to vagal entrapment in the cicatrization process involving the lower third of oesophagus.

Lactulose breath test results in patients with persistent abdominal symptoms following Giardia lamblia infection

Abstract: Objective. Bacterial overgrowth has been implicated in the pathogenesis of irritable bowel syndrome (IBS). The objective of this study was to investigate whether post-infectious IBS following Giardia lamblia infection is related to intestinal bacterial overgrowth, as diagnosed by the lactulose breath test (LBT). Material and methods. Seventy-seven patients with persistent gastrointestinal complaints related to a recent outbreak of G. lamblia infection were included in the study. Despite one or several courses of treatment with metronidazole during the previous months, 23 of the patients were still stool positive for G. lamblia, whereas the remaining 54 patients had cleared the infection. All patients and 42 healthy volunteers underwent a LBT with 10 g lactulose, and their customary and post-LBT abdominal symptoms were scored. Results. Ninety-five percent of the patients had IBS. Lactulose-induced hydrogen breath excretion was not significantly different in patients and controls. Customary and post-LBT sym...

Clinical aspects of Helicobacter pylori infection.

Abstract: The Helicobacter pylori (Hp) infection is common. However, only 10-20% of infected individuals require antibacterial treatment. The main indications to such treatment are peptic ulcer disease, atrophic gastritis, dyspeptic symptoms, previous surgical procedure for gastric cancer, family history of gastric cancer and low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma. The treatment may also be undertaken at the patient's request. To detect the infection the urease test (when the patient has indications for gastroscopy), the urea breath test or serologic test are most commonly used. A standard treatment of Hp infection consists of a 7-day administration of one of the proton pump inhibitors and 2 out of 3 antibiotics such as amoxicillin, clarithromycin and metronidazole. After failure of the first-line treatment, the recommended second choice treatment is a quadruple treatment regimen consisting of bismuth salts, tetracycline, metronidazole and proton pump inhibitor. European guidelines (Maastricht III) allow the use of the quadruple treatment regimen already as the first choice treatment and therapy prolongation up to 14 days. Ineffectiveness of the second-line treatment is an indication for antimicrobial susceptibility testing. New antibiotics used for Hp eradication are levofloxacin and rifabutin. Eradication treatment should be obligatorily assessed with the use of the urease or breath test only in patients with peptic ulcer bleeding. The current guidelines do not envisage an active search for Hp infection in an asymptomatic population and treating people infected with this bacterium, for gastric cancer prevention.

Genetic testing for adult-type hypolactasia in Italian families

Abstract: Background: Adult-type hypolactasia is characterized by the inability to digest lactose during adulthood, due to lactase (LCT) deficiency. It is usually diagnosed by the measurement of breath hydrogen increase after a lactose load (breath hydrogen test, BHT). A substitution of C to T at position –13910 bp upstream the LCT gene (rs4988235), in a regulatory region, was found to be strongly associated with the lactase persistence phenotype in North-European populations. Methods: We investigated the –13910 C/T polymorphism to determine LCT genotype distribution and to validate genetic testing for adult-type hypolactasia in a Southern European population. A total of 43 children referred for suspected lactose malabsorption were enrolled in the study, their parents and siblings (whole samples112 individuals) also took the breath test, and all were enrolled for clinical monitoring and genotype determination. In addition, 125 unrelated blood donors from the same geographic area were genotyped for the calculation of allelic frequencies. The frequency of C/C genotypes was 70%. Results: The correlation between the C/C genotype (which should correspond to lactose non-digesters) and positive BHT in unrelated family founders was significant (x 2 s16.7, p-0.002). The genetic test compared to the BHT had a sensitivity of 95% and 91% and a specificity of 48% and 55% in adults and children, respectively. Conclusions: Low specificity might be due to intrinsic limitations of the standard BHT or to other possible mutations, although no sequence variation was found upon sequencing a 253 bp fragment of the LCT regulatory region in asymptomatic individuals. Clin Chem Lab Med 2008;46:980–4.