Detection of Helicobacter hepaticus in Human Bile Samples of Patients with Biliary Disease

Background:  Since the discovery of Helicobacter pylori , various enterohepatic Helicobacter spices have been detected in the guts of humans and animals. Some enterohepatic Helicobacters have been associated with inflammatory bowel disease or liver disease in mice. However the association of these bacteria with human diseases remains unknown.
Materials and Methods:  We collected 126 bile samples from patients with cholelithiasis, cholecystitis, gallbladder polyp, and other nonbiliary diseases. Samples were screened for the presence of enterohepatic Helicobacter spp. using cultures, nested PCR, or in situ hybridization. We tested for antibodies to H. pylori and H. hepaticus by Western blot analysis.
Results:  Attempts at cultivation were unsuccessful. However, H. hepaticus was detected in bile samples with nested PCR whereas H. bilis was not. Helicobacter hepaticus in the bile was confirmed by in situ hybridization, but H. hepaticus from bile samples was coccoid in appearance. We detected immunoglobulin G antibodies to H. hepaticus in bile samples by Western blotting. Helicobacter hepaticus was detected in 40 (32%) of total 126 samples as H. hepaticus positive if at least one of the three methods with nested PCR, in situ, or Western blotting. Patients with cholelithiasis (41%) and cholecystitis with gastric cancer (36%) had significantly higher ( p  = .029) prevalence of H. hepaticus infection than samples from patients with other diseases.
Conclusion:  Helicobacter hepaticus may closely associate with diseases of the liver and biliary tract in humans.     

Immunoblot Analysis as an Alternative Method to Diagnose Enterohepatic Helicobacter Infections

Introduction: Enterohepatic Helicobacter species have been associated with chronic infections of the hepatobiliary tract and lower bowel in naturally and experimentally infected mice, Helicobacter -infected animals should thus not be used in studies of diseases associated with chronic inflammation. Helicobacter species induce inflammation and modulate host immune responses, thus emphasizing the need to diagnose these infections in laboratory animals.
Materials and Methods: An immunoblot assay was developed to analyze antibodies to enterohepatic Helicobacter species in naturally colonized laboratory mouse colonies. We evaluated the serum antibody responses to cell surface proteins of H. bilis, H. hepaticus , and H. ganmani in 188 mouse sera from four different university animal facilities. Lower bowel tissue specimens from 56 of these animals were available and analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and the results compared with matched immunoblot patterns.
Results: Specific antibody reactivity to H. bilis was detected in 8 of 186 (4.3%) sera, to H. hepaticus in 45 of 184 (24%) sera, and to H. ganmani in 51 of 188 (27%) of tested sera. These results were compared with PCR-DGGE analyses of tissue samples of corresponding animals, and concordance between the two diagnostic tests was found in 96% for H . bilis , in 91% for H. hepaticus, and in 82% for H. ganmani . The PCR-DGGE also detected DNA of H. typhlonius, H. sp. flexispira, and H. rodentium .
Conclusions: Infection with enterohepatic species was common in the laboratory mouse colonies tested, independent of strain and stock. Immunoblot analysis seems to be a promising diagnostic tool to monitor enterohepatic Helicobacter species infections of laboratory rodents.     

Human serum antibody response to Helicobacter pylori whole cell antigen in an institutionalized Bangladeshi population

J. NESSA, H. CHART, R.J. OWEN AND B. DRASAR. 2001 .
Aims: To use a commercial ELISA kit and an immunoblot assay to investigate the antibody levels of selected members of the Bangladeshi population to Helicobacter pylori protein antigens.
Methods and Results: Using immunoblotting, high seroprevalence rates were observed in all age groups, although the subjects within the 1–9 years age group had the highest seroprevalence of antibodies to H. pylori antigens. By ELISA, the highest level of seroprevalence was observed in those over the age of 20 years.
Conclusions: On the basis of these results the overall prevalence rate of H. pylori infection for the whole population was 77·4%; 77·9% for orphan boys and 76% for carers. CagA antibodies were detected in 86% of those with high levels of antibodies to H. pylori antigens.
Significance and Impact of the Study: A combination of immunoblotting and ELISA was the most efficient means of detecting serum antibodies to H. pylori antigens and could be applied to the screening of human sera for H. pylori -specific antibodies.     

Comparative chemical and biological characterization of the lipopolysaccharides of gastric and enterohepatic helicobacters

BACKGROUND: The lipopolysaccharide of Helicobacter pylori plays an important role in colonization and pathogenicity. The present study sought to compare structural and biological features of lipopolysaccharides from gastric and enterohepatic Helicobacter spp. not previously characterized. MATERIALS AND METHODS: Purified lipopolysaccharides from four gastric Helicobacter spp. (H. pylori, Helicobacter felis, Helicobacter bizzozeronii and Helicobacter mustelae) and four enterohepatic Helicobacter spp. (Helicobacter hepaticus, Helicobacter bilis, 'Helicobacter sp. flexispira' and Helicobacter pullorum) were structurally characterized using electrophoretic, serological and chemical methods. RESULTS: Structural insights into all three moieties of the lipopolysaccharides, i.e. lipid A, core and O-polysaccharide chains, were gained. All species expressed lipopolysaccharides bearing an O-polysaccharide chain, but H. mustelae and H. hepaticus produced truncated semirough lipopolysaccharides. However, in contrast to lipopolysaccharides of H. pylori and H. mustelae, no blood group mimicry was detected in the other Helicobacter spp. examined. Intra-species, but not interspecies, fatty acid profiles of lipopolysaccharides were identical within the genus. Although shared lipopolysaccharide-core epitopes with H. pylori occurred, differing structural characteristics were noted in this lipopolysaccharide region of some Helicobacter spp. The lipopolysaccharides of the gastric helicobacters, H. bizzozeronii and H. mustelae, had relative Limulus amoebocyte lysate activities which clustered around that of H. pylori lipopolysaccharide, whereas H. bilis, 'Helicobacter sp. flexispira' and H. hepaticus formed a cluster with approximately 1000-10,000-fold lower activities. H. pullorum lipopolysaccharide had the highest relative Limulus amoebocyte lysate activity of all the helicobacter lipopolysaccharides (10-fold higher than that of H. pylori lipopolysaccharide), and all the lipopolysaccharides of enterohepatic Helicobacter spp. were capable of inducing nuclear factor-Kappa B(NF-kappaB) activation. CONCLUSIONS: The collective results demonstrate the structural heterogeneity and pathogenic potential of lipopolysaccharides of the Helicobacter genus as a group and these differences in lipopolysaccharides may be indicative of adaptation of the bacteria to different ecological niches.     

Evaluation of a novel monoclonal-based antigen-in-stool enzyme immunoassay (Premier Platinum HpSA PLUS) for diagnosis of Helicobacter pylori infection in Vietnamese children

Background: Helicobacter pylori infection is difficult to diagnose in children, especially in developing countries where noninvasive methods such as urea breath test are often not available. We evaluate the sensitivity and specificity of a new monoclonal antibody-based antigen-in-stool enzyme immunoassay (Premier Platinum HpSA PLUS) for diagnosis of H. pylori infection in Vietnamese children.
Materials and Methods: Sensitivity of the antigen-in-stool test was evaluated in 232 children, 3–15 years of age, who were positive for H. pylori infection by culture from biopsies. For evaluation of the specificity 98 children of similar age with nongastrointestinal conditions and who were negative for H. pylori infection by serologic assays were included with blood and stool samples.
Results: Of the 232 culture-positive children, 224 were also positive by Premier Platinum HpSA PLUS. Of the 98 control children, 93 were H. pylori negative also in the stool test. The sensitivity of Premier Platinum HpSA PLUS was thus 96.6% (95% CI 93.3–98.5) and the specificity was 94.9% (95% CI 88.5–98.3).
Conclusions: The findings have demonstrated Premium Platinum HpSA PLUS to be a reliable method for detection of H. pylori infection also in children in our area.     

Helicobacter pylori Multiplex Serology

Background:  Helicobacter pylori infection is associated with severe gastrointestinal disease including cancer. It induces complex antibody responses that might vary depending on disease state but currently cannot be assessed adequately. The objective of this work was the development of a sensitive and specific H. pylori multiplex serology assay with high-throughput capability that allows simultaneous detection of antibodies to a protein array.
Methods:  Seventeen proteins of up to three H. pylori strains (26695, G27, 151), including CagA, VacA, UreA, Catalase, Omp, and GroEL, were recombinantly expressed as glutathione- S -transferase fusion proteins, affinity-purified, and used as antigens in a fluorescent bead-based antibody-binding assay. Reference sera (n   =   317) characterized by commercial assays (screening ELISA with Western blot confirmation) were used for validation.
Results:  H. pylori seropositivity by multiplex serology defined as reactivity with at least four proteins showed good agreement (kappa: 0.70) with commercial serologic assay classification, and a sensitivity of 89% and specificity of 82%. For individual antigens, agreement with Western blot was good for CagA (kappa: 0.77), moderate for UreA (kappa: 0.53), and weak for VacA (kappa: 0.12). Of the 13 proteins expressed from two strains, only VacA showed serologic strain differences. High antibody reactivity to CagA (Type I infection) was negatively associated with antibodies to GroEL, Cad, CagM, catalase, HcpC, NapA, and UreA, suggesting type-specific differences in protein expression patterns and/or immune response.
Conclusion:  With its high-throughput and simultaneous detection abilities, H. pylori multiplex serology appears suited as tool for large seroepidemiologic studies assessing H. pylori prevalence, antibody patterns, and associations with specific diseases.     

Genomic characterization of Helicobacter hepaticus: ordered cosmid library and comparative sequence analysis

Helicobacter hepaticus is an important pathogen in laboratory mice and induces the development of liver tumors and gastrointestinal disease in susceptible strains of mice. In this study, a miniset of 36 cosmid clones from a genomic library of H. hepaticus was ordered and grouped into four large contigs representing approximately 1 Mb of the H. hepaticus genome using PCR, DNA sequencing, Southern and dot-blot hybridization and pulsed-field gel electrophoresis. From the 200-300 terminal nucleotide sequences of 38 cosmid clones, 56 coding regions were predicted, of which 51 were found to have orthologs in the public databases and five appeared to be unique to H. hepaticus. Of these 51 genes, 36 have orthologs in Helicobacter pylori and 25 display the highest sequence similarity to H. pylori. However, chromosomal positions of these genes are not conserved between these two helicobacters. In addition, 10 H. hepaticus genes had the highest sequence similarity to orthologs in Campylobacter jejuni. The GC content in a randomly selected 21-kb H. hepaticus genomic sequence was 35.8%, which approximates the average between H. pylori (39%) and C. jejuni (30.6%). These results demonstrate that: (1) H. hepaticus is more closely related to H. pylori than C. jejuni; (2) significant genomic alterations exist between H. hepaticus and H. pylori, including gene organization, protein sequences and GC content, probably in part due to specific adaptation to distinct ecological niches.     

Guidelines for the Management of Helicobacter pylori Infection in Japan: 2009 Revised Edition

Background:  Over the past few years, the profile of Helicobacter pylori infection has changed in Japan. In particular, the relationship between H. pylori and gastric cancer has been demonstrated more clearly. Accordingly, the committee of the Japanese Society for Helicobacter Research has revised the guidelines for diagnosis and treatment of H. pylori infection in Japan.
Materials and Methods:  Four meetings of guidelines preparation committee were held from July 2007 to December 2008. In the new guidelines, recommendations for treatment have been classified into five grades according to the Minds Recommendation Grades, while the level of evidence has been classified into six grades. The Japanese national health insurance system was not taken into consideration when preparing these guidelines.
Results:  Helicobacter pylori eradication therapy achieved a Grade A recommendation, being useful for the treatment of gastric or duodenal ulcer, for the treatment and prevention of H. pylori -associated diseases such as gastric cancer, and for inhibiting the spread of H. pylori infection. Levels of evidence were determined for each disease associated with H. pylori infection. For the diagnosis of H. pylori infection, measurement of H. pylori antigen in the feces was added to the tests not requiring biopsy. One week of proton-pump inhibitor-based triple therapy (including amoxicillin and metronidazole) was recommended as second-line therapy after failure of first-line eradication therapy.
Conclusion:  The revised Japanese guidelines for H. pylori are based on scientific evidence and avoid the administrative restraints that applied to earlier versions .     

Salivary specific IgG is a sensitive indicator of the humoral immune response to Helicobacter pylori

Abstract In humans, salivary antibodies are secreted during humoral immune response. Helicobacter pylori infection is associated with systemic humoral immune response reflected by raised serum levels of specific IgG. The present study was aimed at exploring whether salivary concentrations of specific H. pylori IgG are a reliable indicator of H. pylori infection. Serum and salivary samples were obtained from 291 subjects attending the GI clinic and tested for H. pylori -specific IgG by a direct ELISA (94% sensitivity, 95% specificity for serum determinations) using a crude H. pylori sonicate as antigen. Data are given as optical density (mean±S.D.). Levels of salivary H. pylori IgG paralleled those of circulating specific IgG in the 291 subjects studied (0.981±0.431 vs. 0.777±0.682, respectively). A significant positive correlation was found between specific H. pylori IgG in sera and saliva samples (r = 0.981, P < 0.0001). An overall concordance between circulating and salivary H. pylori IgG was observed in 238 out of the 291 (81.7%) subjects. Salivary H. pylori IgG represent a sensitive marker of specific humoral immune response and they may substitute circulating H. pylori IgG measurement when sera samples are not available.     

Reactive Nitrogen Species Mediate DNA Damage in Helicobacter pylori-Infected Gastric Mucosa

Background:  Reactive oxygen species (ROS) and reactive nitrogen species (RNS) can play an important role in cellular injury and carcinogenesis of gastric epithelial cells infected with Helicobacter pylori . 8-OH-deoxy guanosine (8-OHdG) and 8-nitroguanine (8-NG) are markers for ROS- and RNS-mediated DNA oxidation, respectively. In this study, RNS-mediated DNA damage in gastric mucosa was observed directly using a newly developed antibody to 8-NG to clarify how H. pylori infection causes nitrative DNA damage to gastric epithelial cells.
Methods:  Immunohistochemistry with anti-8-OHdG and anti-8-NG antibodies was performed on gastric tissue samples from 45 patients (25 men and 20 women) with H. pylori -positive gastritis and 19 patients (11 men and 8 women) exhibiting successful H. pylori eradication. Histologic factors for gastric mucosal inflammation were graded according to the guidelines of the Updated Sydney system.
Results:  In corpus mucosa, 8-OHdG and 8-NG production were significantly associated with the degree of glandular atrophy, infiltration of chronic inflammatory cells and intestinal metaplasia in the glandular epithelial cells. Successful H. pylori eradication resulted in a significant reduction of chronic inflammatory cell infiltration and neutrophilic activity. Mean 8-OHdG production was lower after H. pylori eradication in both corpus and antral mucosa ( p  = .022 and .049, respectively). However, the reduction in 8-NG exhibited was more pronounced than the reduction of 8-OhdG ( p  = .004 and .007, respectively).
Conclusions:  Helicobacter pylori infection can induce inflammatory cells infiltration, which evokes DNA damage of gastric epithelial cells through ROS and RNS production. 8-NG might be a more sensitive biomarker than 8-OHdG for H. pylori -induced DNA damage in gastric mucosa.     

Validation of Diagnostic Tests for Helicobacter pylori with Regard to Grade of Atrophic Gastritis and/or Intestinal Metaplasia

Background and Aims:  To evaluate the validity of the biopsy-based tests (histology, culture, and urease test) and serology in detecting current Helicobacter pylori infection against a background of atrophic gastritis (AG) or intestinal metaplasia (IM).
Methods:  Helicobacter pylori infection was diagnosed in 651 subjects, using the predefined gold standard for H. pylori tests. The sensitivity, specificity, and positive and negative predictive values of culture, CLOtest, histology (Giemsa stain), and serology were calculated with regard to the histological grade of AG and IM. The level of serum pepsinogen (PG) I and II was also measured as a marker for the presence of AG.
Results:  In the study population (n = 651), sensitivity and specificity, respectively, were as follows: culture, 56.2 and 100%; histology, 93.0 and 94.0%; CLOtest, 80.4 and 96.7%; serology, 96.0 and 67.5%. If the analysis is limited to those without AG or IM (n = 158) or to those younger than 40 years (n = 69), all tests, except for culture, had a sensitivity and specificity >90%. The sensitivity of CLOtest and the specificity of serology markedly decreased with progression of AG and IM, and serology was less specific in the presence of AG, as determined by a PG I/II ratio ≤4.1 (specificity, 83.7% vs 40.7% in PG I/II >4.1 and ≤4.1, respectively).
Conclusions:  Any one of biopsy-based tests or serology was found to be excellent for identifying current H. pylori infection among individuals without AG or IM and/or younger patients (<40 years). However, a combination of at least two tests is necessary in the clinical setting of AG or IM.     

Characterization of Multiple Helicobacter bizzozeronii Isolates From a Finnish Patient With Severe Dyspeptic Symptoms and Chronic Active Gastritis

Background:  Helicobacter pylori is the primary cause of gastritis and peptic ulceration in humans. In a minority of patients with upper gastrointestinal symptoms, long tightly coiled spiral bacteria, provisionally named " Helicobacter heilmannii, " are observed in gastric biopsies. These bacteria are extremely fastidious and only one previous study has succeeded in obtaining an isolate in vitro.
Materials and Methods:  We used two different selective media to isolate " H. heilmannii " from the gastric mucosa of a Finnish patient presenting with severe dyspeptic symptoms. The isolates were characterized by testing for urease and catalase activity, by using light and electron microscopy, and by sequencing of the partial 16S rRNA and ureAB genes. Single-enzyme amplified fragment length polymorphism (sAFLP) was used to analyze the genetic diversity among the isolates.
Results:  We obtained 15 isolates from different gastric biopsies prior and three after unsuccessful treatment of the patient. The isolates were identified as Helicobacter bizzozeronii . Eradication therapy was unsuccessful most probably due to high level of resistance to metronidazole. Persistent colonization by the same H. bizzozeronii clone was confirmed by sAFLP, however, small differences between the profiles suggested long-term colonization of the patient.
Conclusions:  Helicobacter bizzozeronii remains the only " H. heilmannii " species isolated from human gastric mucosa although it has been an infrequent observation among " H. heilmannii "-infected patients in PCR-based screening studies. The relevance of H. bizzozeronii and other potentially zoonotic gastric Helicobacter spp. in human disease remains to be determined.     

Could Helicobacter organisms cause inflammatory bowel disease?

The discovery of Helicobacter pylori sparked a revolution in the understanding and management of peptic ulcer disease and gastric cancer. Other Helicobacter species are recognized as important pathogenic agents in colitic diseases of rodents and primates, in particular Helicobacter bilis, Helicobacter fennelliae, Helicobacter hepaticus and Helicobacter trogontum. Helicobacter bilis and H. hepaticus are now routinely used to initiate rodent models of inflammatory bowel disease (IBD), particularly in immunocompromised hosts. Molecular evidence exists linking various non-pylori Helicobacter spp. with human IBD; however, attempts to culture organisms in this disease cohort have proved unsuccessful to date. Attributing causation has therefore proved elusive. Seven enterohepatic, non-pylori Helicobacter organisms have been successfully cultured from humans, namely Helicobacter canadensis, Helicobacter canis, Helicobacter cinaedi, H. fennelliae, Helicobacter pullorum, Helicobacter winghamensis and Helicobacter sp. flexispira taxon 8 (now classified as H. bilis). Of these, H. cinaedi and H. fennelliae are the closest to fulfilling Koch's postulates as causative agents in homosexual proctitis. The possibility that novel Helicobacter organisms have a role in the initiation of human IBD warrants further consideration and targeted investigations.     

Quantitative detection of Helicobacter pylori in water samples by real-time PCR amplification of the cag pathogenicity island gene, cagE

Aims:  A new real-time PCR assay that simultaneously amplifies a 102-bp fragment of the cagE gene from Helicobacter pylori and a new internal positive control containing a specific sequence of the gyrB gene from Aeromonas hydrophila , was developed and validated for the detection of H. pylori in environmental samples.
Methods and Results:  The specificity, limits of detection and quantification, repeatability, reproducibility, and accuracy of the method were calculated. The resulting values confirmed the applicability of the method for the quantitative detection of H. pylori . The feasibility of the method was also evaluated by testing 13 pyloric antrum-positive biopsies and 69 water samples, including potable (10), surface (19) and wastewater (40) matrices. The results showed that all the biopsies and 3 of the 40 wastewater samples analysed were positive.
Conclusions:  This real-time PCR method provides a sensitive, specific, and accurate method for the rapid quantification of H. pylori in environmental samples.
Significance and Impact of the Study:  The PCR diagnostic system proposed in this work, provides a suitable tool for the quantitative detection of H. pylori in environmental samples and can be useful for verifying the role of water as a potential route of its transmission.     

The Effect of the Human Gut-Signalling Hormone, Norepinephrine, on the Growth of the Gastric Pathogen Helicobacter pylori

Background and Aims: Helicobacter pylori is an important human pathogen, infecting around half the population of the world. It has developed a number of refinements to allow it to persist in the human stomach. Catecholamine hormones have been shown to enhance growth of other bacterial species and are found in the gastric niche. We aimed to study growth enhancement of H. pylori by the human catecholamine hormones epinephrine and norepinephrine.
Methods: Growth studies were carried out in complex and defined media containing the hormones epinephrine, norepinephrine, and normetanephrine, the main host metabolite of norepinephrine. Bacterial density was measured by viable count or optical density. Intracellular ATP was measured using a bioluminescence assay technique.
Results: Both epinephrine and norepinephrine enhanced H. pylori growth in a dose-dependent strain-independent fashion, with norepinephrine being more effective than epinephrine. We showed a rapid (4 hours) dose-dependent effect on metabolic activity, as measured by intracellular ATP levels. We used a chemically defined medium to study mechanisms: chelation of ferric iron blocked H. pylori growth, which could be overcome by addition of norepinephrine. Disruption of the catechol group of norepinephrine abrogated its H. pylori- growth-promoting activity.
Conclusions: Norepinephrine stimulates growth of H. pylori under otherwise growth-restricted conditions, and this effect is related to the ability of norepinephrine to bind ferric iron. This supports the notion that norepinephrine may aid H. pylori persistence in the stomach.     

A Population-Based Epidemiologic Study of Helicobacter Pylori Infection and its Association with Systemic Inflammation

Background:  Infection with Helicobacter pylori is associated with a variety of non-gastrointestinal sequelae. These may be mediated by an increase in systemic inflammation. We assessed if serologic evidence of infection with H. pylori is associated with increased serum C-reactive protein (CRP) levels.
Methods:  The study design consisted of a randomly selected, cross-sectional population-based study of 2633 individuals phenotyped in 1991, of whom 2361 participants provided serum samples to permit measurement of H. pylori 's serologic status and CRP levels.
Results:  Male gender (odds ratio (OR): 1.65; 95% confidence interval (CI): 1.23–2.21), age (OR per year: 1.05; 95% CI: 1.04–1.06), height (OR per meter: 0.05; 95% CI: 0.01–0.24), current smoking habit (compared with never smokers, OR: 1.46; 95% CI: 1.13–1.88), and less affluent socioeconomic status were associated with increased odds of being seropositive for H. pylori . Helicobacter pylori infection was associated with increased risk of having an elevated serum CRP (above 3 mg/L) after adjustment for gender, age, height, smoking status, and socioeconomic status (OR: 1.32; 95% CI: 1.05–1.67). Similar associations were seen using a threshold for elevated serum CRP of greater than 1 mg/L.
Conclusions:  Our data suggest that infection with H. pylori is associated with increased systemic inflammation. This suggests one potential mechanism to explain the extra-gastrointestinal conditions associated with H. pylori infection.     

Anti-Lewis X IgM and IgG in H. pylori infections in children and adults

A role of autoimmune processes in the pathology of Helicobacter pylori infections has been suggested. The Lewis determinants present in LPS molecule of H. pylori bacteria have been indicated as the cause of antigenic mimicry. In this study, the prevalence of IgM and IgG antibodies to Lewis X antigen in the sera from children and adults, with or without dyspepsia, infected or not infected with H. pylori, seropositive and seronegative for anti-H. pylori IgG were determined immuno-enzymatically (ELISA). Our results revealed that humans may produce anti-Lewis X antibodies, particularly of IgM class, in the absence of H. pylori infection or H. pylori independent dyspepsia. The production of such antibodies, by healthy children who had never been infected with H. pylori suggested that anti-Lewis X antibodies may occur naturally.     

Urea Breath Test in Children: The United States Prospective, Multicenter Study

Background: The urea breath test (UBT) is generally considered the gold standard for the diagnosis of Helicobacter pylori infections in adults.
Goals: To investigate the utility and accuracy of urea breath testing in children from the United States.
Methods: Children scheduled to undergo upper gastrointestinal endoscopy for various clinical symptoms underwent a ¹³C-UBT using the US standard protocol for adults. Results were compared with rapid urease testing (RUT), culture, and histology. H. pylori positivity was defined according to the FDA, Division of Anti-Infective Drug Products criteria, i.e. positive culture and/or positive RUT and histology. H. pylori negativity was defined as all tests negative. Results were evaluated by delta over baseline (DOB) and urea hydrolysis rate (UHR).
Results: A total of 176 children from five centers were evaluated; 48 were infected. Compared to the defined standard, the results with the UBT based on delta over baseline (DOB) cut-off value (positive: ≥ 2.4‰) showed that the sensitivity and specificity of the UBT were 97.9% and 96.1%, respectively. Based on the UHR cut-off value (positive: ≥ 10.0 µg/min), the sensitivity and specificity were 95.8% and 99.2%. In young children (2- to 5-year olds), sensitivity and specificity of UHR method were higher than the DOB method (100% and 100% vs 100% and 82.4%, respectively).
Conclusion: The US standard ¹³C-UBT proved to be both simple and accurate for the diagnosis of H. pylori infections in children. The UHR method to calculate of ¹³C-UBT result provided excellent results for children of all ages.