Evaluation of CLO test and polymerase chain reaction for biopsy-dependent diagnosis of Helicobacter pylori infection

Helicobacter pylori is now recognized as possibly playing an etiologic role on the development of chronic gastritis, peptic ulcers and adenocarcinoma of the distal stomach. CLO test and polymerase chain reaction (PCR) assay are rapid, biopsy-dependent diagnostic tests for H. pylori identification. In this study, we assessed four diagnostic methods (CLO test, PCR assay, culture and histological examination) for H. pylori detection in biopsy specimens from 78 patients with gastroduodenal diseases and investigating the efficiency of CLO test and PCR assay for the diagnosis of H. pylori infection. H. pylori was identified in 75.6%, 75.6%, 64.1%, 69.2% of patients by CLO test, PCR assay, culture and histological examination, respectively. Compared with the detection of H. pylori by culture and/or histological examination, the sensitivity and specificity of the CLO test were 98.2% and 81.8%, respectively, whereas the sensitivity and specificity of PCR assay were 96.4% and 77.3%, respectively. According to the H. pylori infection state as determined from the results of three concordant tests, the sensitivities of culture, CLO test, histological examination, and PCR assay were 90.9%, 96.4%, 98.2% and 100%, respectively. Whereas, the specificity was 100%, 95%, 95% and 90% for culture, CLO test, histological examination, and PCR assay, respectively. We found that both CLO test and PCR assay were highly sensitive and specific for H. pylori identification; however, PCR assay was more sensitive than other methods for detecting the specimens after patients received treatment. The results of this study suggest that CLO test is a rapid and sensitive method of screening for H. pylori infection and that PCR assay could provide an accurate indication of the state of infection both during treatment for eradication of H. pylori and at follow-up.     

Use of serum-specific immunoglobulins A and G for detection of Helicobacter pylori infection in patients with chronic gastritis by immunoblot analysis.

Multiple invasive and noninvasive tests for detecting Helicobacter pylori infection are available. The current "gold standard" for the diagnosis of H. pylori infection requires histology and the rapid urease test. Our aim was to test the performance of immunoglobulin A (IgA) and IgG immunoblot assays in comparison with that of the gold standard tests for the diagnosis of H. pylori infection. Ninety patients who underwent gastroscopy were analyzed in a prospective study. Fifty-nine of them were defined to be H. pylori positive by the gold standard tests. The IgA and IgG immunoblot assays correctly identified H. pylori infection in 17 and 58 of these patients, respectively, indicating that determination of IgA antibodies seems to be of low diagnostic value for H. pylori infection. In contrast, the sensitivity and specificity of the IgG immunoblot assay were 98 and 71%, respectively, with positive and negative predictive values of 87 and 96%, respectively. Therefore, the IgG immunoblot assay proved to be a sensitive and useful, noninvasive test for the diagnosis of H. pylori infection.     

Rapid detection of gastric Campylobacter pylori colonization by a simple biochemical test.

A simple and rapid urease test to detect Campylobacter pylori infection was evaluated with bacterial culture as the "gold standard." The test was compared with the Gram stain and the conventional Christensen urease test. The culture method detected C. pylori in 29 of 49 gastric biopsy specimens. The rapid urease test showed 27 positive samples within 1 h at 55 degrees C (specificity, 100%; sensitivity, 93%) and 18 at room temperature (specificity, 100%; sensitivity, 62%). The Gram stain exhibited a sensitivity of 86% and a specificity of 91%. The conventional Christensen urease test detected C. pylori in only 4, 10, and 18 samples after 24, 48, and 72 h, respectively (sensitivities, 12, 36, and 60%, respectively; specificities, 95, 95, and 83%, respectively). We conclude that the rapid urease test is simple and highly specific for the detection of C. pylori and that it can be performed with small amounts of sample.     

The efficacy of laboratory diagnosis of Helicobacter pylori infections in gastric biopsy specimens is related to bacterial density and vacA, cagA, and iceA genotypes

A total of 500 consecutive patients undergoing upper endoscopy were biopsied and tested for H. pylori infection by the Campylobacter-like organism (CLO) test, culture, histology, and PCR. Serum samples were tested by two different serological assays. Patients were considered H. pylori positive if at least two of the four biopsy specimen-based methods yielded positive results. PCR had the highest diagnostic sensitivity (99.4%), followed by histology (92.2%), culture (89.5%), and the CLO test (89.0%). The specificities of all methods were higher than 98%. Of the organisms from the 181 PCR-positive patients, the vacA (s and m regions), cagA, and iceA genotypes were determined by reverse hybridization (line probe assay) or an allele-specific PCR. Organisms that were detected by PCR but that remained undetected by the CLO test were significantly more often vacA s1 (P = 0.006), m1 (P = 0.028), and cagA positive (P = 0.029) than vacA s2, m2, and cagA negative, respectively. Organisms that were detected by PCR but that remained undetected by culture or histology more often contained iceA1 (P = 0. 034 and P = 0.029, respectively) than iceA2. Higher H. pylori density was associated with vacA s2 (P = 0.024), vacA m2 (P = 0.050), and cagA-negative (P = 0.035) genotypes. Also, the diagnostic results of the CLO test (P = 0.001) and culture (P = 0.031) but not those of the PCR (P = 0.130) were significantly associated with the H. pylori density. The rate of detection by the four biopsy specimen-based tests was lower for patients who used proton pump inhibitors, but this was independent of the H. pylori genotypes. These observations may be explained by different bacterial densities, as established by the distinct genotypes of H. pylori, and confirm that the biologies of strains with such genotypes are considerably different.     

UreC PCR based diagnosis of Helicobacter pylori infection and detection of cag A gene in gastric biopsies

Polymerase chain reaction assay using ureC gene specific primers for the detection of Helicobacter pylori in gastric biopsy specimens from 116 dyspeptic patients was compared with other routine invasive diagnostic methods (culture, rapid urease test [RUT] and histology). In parallel, gastric biospy specimens from 54 patients and their corresponding Helicobacter pylori isolates were subjected to PCR with cagA targeting primers using standard protocols. Helicobacter pylori were detected in 53%, 43%, 48% and 50% of patients by PCR, RUT, culture and histological examination respectively. Based on histology and culture positive and at least three test positive result, 44 (37%), 46 (39%) and 26 (22%), and 56 (48%), 52 (44%) and 8 (6%) patients were classified as Helicobacter pylori positive, negative and indeterminate respectively. The sensitivity and specificity of PCR assay was the highest-95% and 100% when compared with both culture and histology positive, and at least any three positive results respectively. The result of cagA positivity in 54 gastric biopsy specimens and their corresponding Helicobacter pylori isolates were identical; 18 of 20 (90%) duodenal ulcer patients and 23 of 28 (82%) patients with chronic gastritis and 2 (40%) of 5 patients with portal hypertension and one gastric biopsy specimens from gastric cancer patients were found to be cagA positive. PCR-based method to detect Helicobacter pylori and the virulence gene cag A directly from gastric biopsy specimens appears to be promising and can curtail the lengthy process of culture-based approaches. The procedure proved to be rapid and reliable and could be utilized for diagnostic purposes.     

Helicobacter pylori infection at a university hospital in Saudi Arabia: prevalence, comparison of diagnostic modalities and endoscopic findings

The presence of Helicobacter pylori (H. pylori) was examined in 491 sequential patients, complaining mainly of epigastric pain, by three biopsy-based methods (rapid urease, histology, and culture), and by a serological test, enzyme immunosorbent assay, (ELISA). H. pylori was detected in 341 (70%) of 491 patients examined by histology, 287 (59%) by rapid urease test, whereas 385 (78%) were seropositive for H. pylori immunoglobulins by ELISA. None of the test methods used was independently sufficient to make an etiologic diagnosis of H. pylori infection. The endoscopic findings revealed that 315 (69%) of 456 patients with non-ulcer dyspepsia, 17 (74%) of 23 patients with duodenal ulcer, 7 (78%) of 9 patients with gastric ulcer, and 2 (67%) of 3 patients with gastric cancer were H. pylori positive. No statistically significant correlation was found between the endoscopic and the histopathological findings. A significant correlation was found between H. pylori infection and the histopathological gradings of gastritis (P < 0.001).     

Correlation of serum antibody titres with invasive methods for rapid detection of Helicobacter pylori infections in symptomatic children

Helicobacter pylori (H. pylori) is causally associated with peptic ulcer disease and gastric carcinoma. Typically, children get infected during the first decade of life, but diseases associated with H. pylori are seen mainly in adults. Multiple diagnostic methods are available for the detection of H. pylori infection. The aim of this study was to evaluate the correlation and diagnostic accuracy of three invasive methods [rapid urease test (RUT), histology and bacterial culture] and one non-invasive method (IgG serology) for diagnosis of H. pylori infection in a prospective cohort study conducted on 50 symptomatic children between two and eighteen years of age. Endoscopies with gastric biopsies were performed for RUT, culture and histopathological examination, respectively. IgG antibodies were measured in patient sera using a commercially available enzyme-linked immunosorbent assay (ELISA). RUT and positive H. pylori IgG antibodies were concordant in 88% (44/50) of patients. Both tests were negative in 32% (16/50), and both were positive in 56% (28/50). Disagreement occurred in 12% (6/50) of the patients: three of them (6%) had positive RUT and negative H. pylori IgG, and another three (6%) had negative RUT and positive H. pylori IgG. A combination of RUT with non-invasive serology constituted the optimum approach to the diagnosis of H. pylori infection in symptomatic children. The non-invasive serological test (ELISA) could not be used alone as the gold standard because it cannot distinguish between active and recently treated infection; and bacterial culture could not be used alone because of its low sensitivity.     

Evaluation of a Western blot technique (Helicoblot 2.1) for the diagnosis of Helicobacter pylori infection in children

AIM: We evaluated the performance of Helicoblot 2.1 which differentiates the reactivity to each of the various Helicobacter pylori antigens, and compared the results with those obtained by standard techniques (rapid urease test and histological examination of gastric biopsy) in symptomatic children of different ages living in Antalya, Turkey. METHODS: Eighty-eight children (mean age, 9.15 years) were divided into two groups. The first group included 66 children who were found to be infected with H. pylori. The second group included 22 children who were negative for H. pylori. Serum samples collected from all patients were tested for H. pylori IgG antibodies by immunoblot assay (Helicoblot 2.1). RESULTS: The sensitivity, specificity, positive and negative predictive values for detection of H. pylori infection were 80%, 100%, 100% and 85%, respectively. In children under 7 years of age, the sensitivity of the test was found to be lower than other age groups (P<0.05). No relationship was found between peptic ulcer and cagA antibody positivity (P>0.05). CONCLUSION: Helicoblot 2.1 is a useful non-invasive diagnostic tool for H. pylori infection in children over 6 years of age.     

Detection of Helicobacter pylori antigen in faeces by enzyme immunoassay

The detection of Helicobacter pylori antigen directly in faecal specimens may offer an alternative non-invasive method for determining the presence of H. pylori infection. This study compared the performance of the Premier Platinum HpSA enzyme immunoassay (HpSA) with histology and CLOtest, a rapid urease test. Of 134 patients undergoing upper gastrointestinal endoscopy, 37 (28%) were H. pylori-positive by histology and CLOtest. Using the HpSA test, H. pylori was detected in 35 H. pylori-positive patients (95% sensitivity) and one H. pylori-negative patient (99% specificity). The positive and negative predictive values for HpSA were 97 and 98%, respectively. HpSA is a rapid, easily performed, non-invasive method for detecting H. pylori.     

Diagnosis of Helicobacter pylori infection in a colony of rhesus monkeys (Macaca mulatta).

Twenty-three young adult rhesus monkeys from China were evaluated for the presence of Helicobacter pylori. Gastric body and antral biopsy samples were tested for H. pylori by PCR analysis, culture, rapid urease testing, and histologic evaluation. Serologic testing to detect H. pylori immunoglobulin G (IgG) antibodies was performed by using a commercially available human-based enzyme-linked immunosorbent assay (ELISA) test and an ELISA test which utilized homologous H. pylori antigens and an anti-rhesus IgG conjugate. PCR analysis with H. pylori-specific 26-kDa protein primers detected H. pylori in 21 of the 23 rhesus monkeys (91%). Culture testing identified the organism in 12 of the 23 animals (52%). Rapid urease tests were positive for all animals. H. pylori was diagnosed by histological examination in 11 of 23 monkeys (48%). Of the 21 monkeys positive for H. pylori by PCR, only 3 (14%) had positive results by the commercial ELISA test, yielding a sensitivity of 14%, a specificity of 100%, and an accuracy of 22%. However, 19 of the 21 PCR-positive animals (90%) had positive results by the ELISA test with homologous rhesus H. pylori antigen and anti-monkey conjugate, with predicted index values greater than or equal to 0.7 considered positive and values between 0.5 and 0.7 considered equivocal. This test had a sensitivity of 90%, a specificity of 100%, and an accuracy of 91%. Therefore, the ELISA test with rhesus monkey origin components was more accurate for detecting infected animals than the human-based ELISA.     

Comparison of biopsy-based methods for the detection of Helicobacter pylori infection

Various biopsy-based methods for the detection of Helicobacter pylori are evaluated to determine their sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), followed by polymerase chain reaction (PCR) for the 16S ribosomal RNA (rRNA) gene of H. pylori (16S PCR) to confirm the results. Seventyfive patients (65% [49] males, age range: 17-77 years, mean 42+/-14.6 years) with dyspeptic symptoms are included in the study. Gastric antrum biopsy specimens collected during endoscopy are tested using a urea agar base enriched with 40% urea solution (eUAB, Oxoid)), a commercial rapid urease test (Pronto Dry, Medical Instrument Corp, Switzerland), histopathology and 16S PCR. The eUAB test showed 97% sensitivity, 86% specificity, 84% PPV, 97% NPV and 91% accuracy when the diagnosis of H. pylori infection was made with positive Pronto Dry and histopathology. Pronto Dry showed 100% sensitivity, 82% specificity, 80% PPV, 100% NPV and 89% accuracy when the diagnosis of H. pylori infection was made on positive histopathology and eUAB. Thus, the eUAB can be used as a rapid urease test. It is economical and has a sensitivity and specificity comparable to a commercially available rapid urease test to detect urease activity of H. pylori in gastric biopsy.     

Evaluation of diagnostic methods for Helicobacter pylori gastritis

The authors evaluated the use of direct Gram-stained smears, 1- and 24-hour urease broth tests, histologic examination, and culture to detect Helicobacter pylori in 100 gastric biopsy specimens from 97 patients with epigastric symptoms. Twenty-six patients had positive cultures and 27 had H. pylori identifiable in hematoxylin and eosin-stained sections. The gastric biopsy specimens from the 29 patients with culture and/or histologic findings positive for H. pylori showed active gastritis in 27 cases (93%), compared with 26 cases (37%) without H. pylori (P less than 0.0001). Chronic gastritis was present in 25 cases (86%) with H. pylori and 40 cases (56%) without H. pylori (P less than 0.01). Twenty patients had positive Gram-stained smears. Fifteen patients had positive 1-hour urease tests, and 3 had delayed positive 24-hour urease tests. There were no false-positive Gram's stain results, three false-positive 24-hour urease tests, two false-negative histologic results, and three false-negative cultures (one inadvertently incubated anaerobically). The sensitivities of the methods were as follows: 62% for the 24-hour urease test, 69% for direct Gram's stain, 90% for culture, and 93% for histologic examination. The authors conclude that the urease test used in this study has low sensitivity and limited specificity; that the direct Gram-stained smear is a useful, highly specific, rapid screening test; and that the lengthier methods of culture and histologic examination have comparably high sensitivity for the definitive diagnosis of H. pylori gastritis.     

Evaluation of a rapid urease test to detect Campylobacter pylori infection.

Seventy-five consecutive patients referred for upper gastrointestinal tract endoscopy were evaluated for Campylobacter pylori infection by pathology, culture, and a biochemical test to detect bacterial urease. Forty-eight patients (64%) had C. pylori present based on pathology or culture or both. Thirty-two urease tests were positive after 1 h, all in patients with C. pylori detected by the two other methods (specificity, 100%; sensitivity, 67%). After 24 h, 47 urease tests were positive, but only 40 had C. pylori present (specificity, 74%; sensitivity, 83%). When read after 1 h, the urease test was highly specific and led to rapid presumptive diagnosis.     

A practical single sample dry latex agglutination test for Helicobacter pylori antibody detection.

Assessment of a single serum sample for Helicobacter pylori antibodies is frequently requested in routine diagnostic laboratories. Current enzyme linked immunosorbent assay (ELISA) kits are not ideal for testing small numbers of serum samples and some have low sensitivities, specificities or large grey zones. A panel of 90 serum samples from patients who had presented for routine upper endoscopy was used to compare three kits for the detection of H pylori antibodies: (1) Pyloriset Dry, total antibody latex agglutination, Orion Diagnostica, Espoo, Finland; (2) Pyloriset enzyme immunoassay (EIA), IgG ELISA, Orion; and (3) Hel-p, IgG ELISA, Amrad, Kew, Victoria, Australia. Diagnosis of H pylori positivity was made if culture results and either rapid urease test or histopathology were positive. The sensitivity, specificity, positive, and negative predictive value for each test was as follows: Orion: latex 93.3%, 95.6%, 95.5%, 93.3%, respectively; Orion: EIA-G 84.4%, 97.8%, 97.4%, 84.4%, respectively; and Amrad: EIA-G 100%, 88.9%, 90%, 100%, respectively. The latex test performed better than the EIAs with respect to sensitivity and specificity.     

Estimation of prevalence of Helicobacter pylori infection in an asymptomatic elderly population comparing [14C] urea breath test and serology.

A non-invasive serological assay devised in this laboratory had a sensitivity and specificity of 100% as determined by culture and confirmed by histology in a group of 47 patients who had undergone endoscopy. The correlation between serology and the non-invasive [14C] breath test was very good. Only one of 24 culture positive patients was, while all 23 culture negative patients were, breath test negative. In a group of 46 healthy elderly persons, however, significant anomalies between serology and breath test were observed. Only 83% of the breath test negative persons were seronegative, while only 68% of the breath test positive persons were seropositive. These results can be explained in terms of age related atrophic gastritis and immune incompetence, causing reduced colonisation and decreased antibody production, respectively. These investigations suggest that non-invasive tests for H pylori infection may not be reliable in the elderly.     

Oral fluid antibody detection in the diagnosis of Helicobacter pylori infection.

The aim of this study was to evaluate an enzyme-linked immunosorbent assay (ELISA) for the detection of anti-Helicobacter pylori specific IgG antibodies in specimens of oral fluid. Antral biopsy specimens, serum and oral fluid samples were collected from 81 patients attending for upper gastrointestinal endoscopy. The presence or absence of current H. pylori infection was determined by culture, histology and urease detection. Anti-H. Pylori specific IgG was detected in serum by an established in-house ELISA and in oral fluid by an ELISA developed for this study. In all, 34 (42%) of 81 patients were positive for H. pylori by one or more of the 'gold standard' tests (culture, histology and urease detection). The oral fluid ELISA had a sensitivity of 94% and specificity of 85% with regard to current H. pylori infection. The serum ELISA had a sensitivity and specificity of 91%. There was an overall agreement of 88% between serum and oral fluid antibody detection. The detection of anti-H. pylori specific IgG in oral fluid by ELISA is comparable in sensitivity and specificity with serum-based methods. Oral fluid-based ELISA could provide a reliable, non-invasive method for the diagnosis of H. pylori infection, and may be of particular benefit for population surveys.     

Serodiagnosis of Helicobacter pylori infection: comparison and correlation between enzyme-linked immunosorbent assay and rapid serological test results.

CLOser is a new, one-step, qualitative anti-Helicobacter pylori immunoglobulin G test having the advantage of convenience and simplicity. We aimed to evaluate its diagnostic accuracy and to compare it with a quantitative enzyme-linked immunosorbent assay (ELISA) (HEL-pTEST II) in a study of 86 adult dyspeptic patients by using the results from histology and urease testing of gastric biopsies as a "gold standard." Forty-six patients were H. pylori positive. The sensitivities, specificities, and positive and negative predictive values were 95.7, 72.5, 80.0, and 93.5%, respectively, for CLOser and 93.5, 92.5, 93.5, and 92.5%, respectively, for HEL-pTEST II. The grade of the colored test bands in CLOser was correlated with antibody titers in HEL-pTEST II (r = 0.71; p < 0.001). The mean antibody titers were 13, 74, 186, and 328 U/ml for the negative, faint, thin, and thick bands, respectively, of CLOser. We concluded that the CLOser rapid serological test yielded sensitivity similar to that of the conventional ELISA. Although CLOser is not suitable for epidemiologic screening for H. pylori infection on account of lower specificity, it is particularly convenient and very easy to perform. Therefore, it may eventually become widely used in the office-based care of patients and lead to more cost-effective patient management decisions.     

Rapid colorimetric hybridization assay for detecting amplified Helicobacter pylori DNA in gastric biopsy specimens.

A very simple, practical, sensitive, and specific colorimetric hybridization assay for detecting amplified Helicobacter pylori DNA is described. This assay, which combines a sensitive sandwich DNA hybridization reaction and a colorimetric protocol similar to those used in conventional enzyme immunoassays, was shown to be suitable for detecting H. pylori-infected gastric biopsy specimens and for monitoring the eradication of the pathogen after treatment. The specificity and sensitivity of the colorimetric hybridization assay were tested by assaying 27 H. pylori strains (4 reference and 23 clinical isolates), 9 strains of other Helicobacter spp. or Campylobacter spp., and 11 clinical isolates of other urease-positive bacteria. The likelihood of H. pylori detection in gastric biopsy specimens by the colorimetric hybridization assay was evaluated with 23 H. pylori-positive and 41 H. pylori-negative biopsy specimens on the basis of positive and negative results, respectively, of culture, rapid urease test, histological examination, and PCR. Biopsy specimens from 33 treated patients, endoscopied 4 to 8 weeks after the end of treatment, were also tested. All H. pylori strains showed positive results in the colorimetric hybridization assay, presenting optical densities at 450 nm (OD450S) of > or = 3.0. None of the other Helicobacter spp., Campylobacter spp., or the clinical isolates of other urease-positive bacteria showed OD450S equal to or greater than the cutoff (mean OD450 cutoff, 0.208). The colorimetric hybridization assay detected all 23 H. pylori-positive biopsy specimens (mean OD450, 2.910 +/- 0.295), while none of the H. pylori-negative biopsy specimens was shown to be positive in the assay (mean OD450, 0.108 +/- 0.025). H. pylori was considered to be not eradicated from three of the posttreatment biopsy specimens by culture, rapid urease test, histological examination, and PCR. They were all positive by the colorimetric hybridization assay, and their OD450S were > or = 3.0. The colorimetric hybridization assay also detected two other H. pylori-positive patients. Specimens from these two patients had negative culture, rapid urease test, and histology results, and a specimen from one of them also tested negative by PCR. These results indicate that the colorimetric hybridization assay is a suitable method both for the diagnosis of H. pylori in biopsy specimens and for the follow-up of patients after the end of treatment.     

Characteristics of Helicobacter pylori infection in Jamaican adults with gastrointestinal symptoms

Helicobacter pylori infection is common in Jamaica. Describing its epidemiology in a population-based study depends largely on serology, but serologic assays have not been validated in this population. To address this issue, we examined the presence of H. pylori infection in 30 sequential adult patients with gastroduodenal symptoms by three biopsy-based methods (rapid urease test, histology, and culture) as well as by one research and two commercial enzyme-linked immunosorbent assays (ELISAs). A patient was considered H. pylori positive if the organism was detected by at least one biopsy-based method. Eighteen (60%) of the 30 patients were H. pylori positive by these criteria, whereas 21 (70%) were seropositive for H. pylori immunoglobulin G by our research ELISA. The presence of H. pylori infection in patients with gastric cancer and those with chronic gastritis was missed by biopsy-based methods but was detected by serologic assays. This observation indicates that serologic assays may be better suited for the detection of this infection in a population in which H. pylori-associated pathology is prevalent. The performance of our research ELISA in detecting biopsy-based H. pylori-positive cases was excellent, with a sensitivity and specificity of 100% and 75%, respectively. Molecular genotyping of the isolates revealed that the predominant H. pylori genotypes in this cohort of Jamaicans were cagA(+) vacA slb-m1, and iceA2. The validated serologic assay enables us to interpret epidemiologic data from population-based studies in Jamaica by comparison to those from other populations.     

Serologic Diagnosis of Helicobacter pylori Infection in Outpatients Aged 45 Years or Less

The diagnostic accuracy of serological tests for Helicobacter pylori was studied in 145 consecutive outpatients aged 45 years or less referred for gastroscopy. Helicobacter pylori infection can be detected by serological tests, including rapid whole-blood tests. The low prevalence of the disease in young people may have a negative effect on the positive predictive value of a test. In this study, the presence of Helicobacter pylori was assessed by a biopsy urease test and histological examination, and by several serological tests: a rapid whole-blood test on fingerstick blood, a latex agglutination serum test, a commercial enzyme immunoassay (EIA) test, and an in-house EIA for detection of antibodies of both the IgG and IgA classes. Helicobacter pylori infection was diagnosed with invasive tests in 21 (14.5%) patients. The sensitivity, specificity, and positive and negative predictive values of the EIA-based tests, compared to histological examination, were 100%, 96-97%, 81-84%, and 100%, respectively. The positive predictive value of the latex agglutination test was 78%, whereas it was only 47% for the whole-blood rapid test used. Although the results of the whole-blood rapid test were unsatisfactory, the quantitative EIA-based tests could reliably detect Helicobacter pylori among young patients, in whom the prevalence of the infection is low.