幽门螺杆菌粪便抗原检测方法学评价

目的 评价幽门螺杆菌粪便抗原（ HpSA）检测在诊断患者幽门螺杆菌（Hp）感染中的价值.方法 以胃镜病理学诊断结果为金标准,对328例有消化道症状患者粪便,同时应用酶联免疫吸附实验检测幽门螺杆菌粪便抗原,计算HpSA检测诊断Hp感染的特异性、灵敏度和准确性等性能指标.结果 幽门杆菌粪便抗原酶免疫检测法对Hp感染诊断与金标准相比无统计学差异（P＞0.05）,其敏感性为94.6％、特异性为96.9％、准确性为96.3％、阳性预期值为89.7％、阴性预期值为98.4％.结论 幽门螺杆菌粪便抗原酶免疫检测是一种简便、易行、准确性高、便宜、易重复的非侵入性检测方法.     

Evaluation of [13C]urea breath test and Helicobacter pylori stool antigen test for diagnosis of H. pylori infection in children from a developing country

The [(13)C]urea breath test ((13)C-UBT) and Helicobacter pylori stool antigen test (HpSA) for the diagnosis of H. pylori infection in children were validated. The sensitivity, specificity, and positive and negative predictive values were 93.8, 99.1, 97.8, and 98.0%, respectively, for the (13)C-UBT and 96.9, 100, 100, and 98.0%, respectively, for HpSA. Both tests are appropriate for diagnosing H. pylori infection in children.     

Evaluation of a rapid new stool antigen test for diagnosis of Helicobacter pylori infection in adult patients

The evaluation of a new rapid stool antigen test showed different levels of sensitivity for final readings of test results at 20 min (59.1%) and 30 min (76.9%). Significant differences in performance were observed between the two sexes and the various age categories, with higher efficiency in male patients and young adults. Generally, this test is efficient and can be used to detect H. pylori infection in adults. However, further studies are required to confirm its accuracy.     

Posttreatment follow-up of Helicobacter pylori infection using a stool antigen immunoassay.

The Helicobacter pylori stool antigen enzyme immunoassay (HpSA) was evaluated during posttreatment follow-up of patients in a country with a very high prevalence of H. pylori infection. From among 273 dyspeptic individuals (18 to 55 years) initially recruited from a shantytown in Lima, Peru, 238 participants who met the inclusion criteria and were suspected to be H. pylori positive based on (14)C urea breath test (UBT) results underwent endoscopy. Participants with endoscopy-proven infections received standard eradication therapy and were monitored by UBT and HpSA at 1 month following treatment and at 3-month intervals for 9 months posttreatment. A second endoscopy was performed if UBT results showed evidence of treatment failure or H. pylori recurrence. Biopsy results were considered the "gold standard" in all analyses. Among patients who underwent endoscopy, HpSA had a pretreatment sensitivity of 93%. Two-hundred thirty patients completed the treatment regimen, of whom 201 (93%) were considered to have had successful treatment outcomes based on a negative follow-up UBT. Thirty-two patients with UBT-defined treatment failures or H. pylori recurrences at any point during the 9-month follow-up underwent a second endoscopy. In the posttreatment setting, HpSA had an overall sensitivity of 73% and a specificity of 67%. Agreement between UBT and HpSA diminished throughout the follow-up. Among 14 participants in whom HpSA remained positive at 1 month following treatment despite UBT evidence of treatment success, 12 (86%) became HpSA negative within 3 months posttreatment. Although this study confirmed the validity of the HpSA in the initial assessment of dyspeptic patients, the test demonstrated a reduced overall accuracy in the detection of treatment failures and H. pylori recurrences during 9 months of posttreatment follow-up. Furthermore, in some patients it may take up to 3 months after successful eradication for antigen shedding to diminish to levels within the negative HpSA range.     

Application of a Stool Antigen Test To Evaluate the Incidence of Helicobacter pylori Infection in Children and Adolescents from Tehran, Iran

Helicobacter pylori infection is acquired mainly in childhood, especially in developing countries, where a low-cost, rapid diagnostic technique which is reliable for all age groups may be useful for the management of H. pylori infection. For this purpose, we used an HpSA test (Equipar) to detect H. pylori infection in children and adolescents from Tehran, Iran. Thirty-five children who were positive or negative for H. pylori infection by endoscopy-based tests were used as positive and negative controls for the HpSA test. Stools were collected from 430 randomly selected children and adolescents (4 to 18 years old) from southwest, near the center, and northwest of Tehran. A questionnaire that included presence of recurrent abdominal pain (RAP), family history of infection and/or peptic ulcer disease (PUD), and income of parents was completed. A good agreement was found between the results of endoscopy-based tests and those of the HpSA test; the sensitivity and specificity of the Equipar-HpSA test were 100% and 83.4%, respectively. Among 430 children and adolescents, 47% were positive by the HpSA test, of whom 82% had RAP. No difference in incidence was observed between the two sexes; the various categories of age showed an increasing incidence, ranging from 24% (ages 4 to 6) to 58% (ages 16 to 18). The rate of infection in children and adolescents from the southwest was significantly higher (70%) than the rate in those from the northwest (32%), and a family history of H. pylori infection or PUD was observed in 59% of the HpSA positive subjects. The HpSA test is a useful test to detect H. pylori infection in children and adolescents from developing countries.     

Detection of Helicobacter pylori antigen in stool by enzyme immunoassay

Invasive techniques for diagnosis of Helicobacter pylori (H. pylori) infection require an endoscopic examination which is expensive and inconvenient and may cause complications. Stool cultures for H. pylori or a direct detection of H. pylori antigen in stools by PCR are expensive, tedious, and have a low sensitivity. We recently used an enzyme immunoassay (EIA) to detect H. pylori antigen in stool specimens. A total of 41 patients were seen at Inha University Hospital, Inchon, Korea between September and October 1998. There were 26 men and 15 women who had an average age of 37.6 years which ranged from 5 to 71 years in the present study. All of these patients came to the hospital complaining of an upper abdominal discomfort and were subjected to endoscopy and biopsies. Fifteen had a gastric ulcer, 13 had a duodenal ulcer, 1 had an early gastric cancer, and there were 12 chronic gastritis patients as shown by endoscopy. The biopsy specimens were examined by histology, CLO test, and cultures and these results were used as gold standards. Stool specimens were tested for the H. pylori antigen by EIA. A dual wavelength cut-off of 0.100 that was recommended by the manufacturer gave a good performance (87.1% sensitivity, 100% specificity, 100% positive predictive value, 71.4% negative predictive value, and a 90.2% efficiency). But the adjusted cut-off value using the receiver operating characteristic curve improved the performance of the test (using the cut-off value of 0.024, the sensitivity, specificity, PPV, NPV, and efficiency were 100%, 90.0%, 96.9%, 100%, and 97.6% respectively). Re-evaluation of the cut-off value may be needed for Korean patients. This technique is non-invasive, rapid, easy-to-use, and shows good performance characteristics for diagnosis of H. pylori infections. Therefore, this technique may be a substitute for gastric endoscopy especially in children and some patients who are unable to tolerate an endoscopic examination and it may be substituted for a serologic test in epidemiological research.     

Susceptibilities to different antibiotics of Helicobacter pylori strains isolated from patients at the pediatric medical center of Tehran, Iran

Antibiotic susceptibility testing of 70 pediatric Helicobacter pylori isolates was performed by using screening agar and disk diffusion methods. Resistance to metronidazole and tinidazole was 72 to 79% and 71 to 81% by modified disk diffusion and 77% and 78% by screening agar, respectively. Susceptibilities to amoxicillin, ampicillin, clarithromycin, tetracycline, erythromycin, and ciprofloxacin were 58, 69, 75, 68, 68, and 65%, respectively.     

Evaluation of a novel rapid one-step immunochromatographic assay for detection of monoclonal Helicobacter pylori antigen in stool samples from children

A new rapid one-step immunochromatographic test using monoclonal antibodies for detection of Helicobacter pylori antigen in stool in children was evaluated on coded stool samples from 159 children (mean age, 9.7 +/- 5.0 years; 118 from Munich, 41 from Vienna): 86 children were H. pylori infected defined by positive culture and/or > or =2 other positive tests ([13C]urea breath test, histology, rapid urease test), and 73 children showed concordant negative results. Seventy-nine patients (12.1 +/- 3.8 years; 42 from Munich; 37 from Vienna) were tested 6 to 8 weeks after anti-Helicobacter pylori therapy with urea breath test and stool test. In Munich, all 160 tests (118 pre- and 42 posttreatment) were independently read by two observers. Equivocal results were excluded for calculation of sensitivity and specificity but were considered as false to assess accuracy. The two observers in Munich agreed in 63 out of 65 positive and 89 out of 95 negative results, while eight times (5.0%) they judged the test as equivocal. Pretreatment and posttreatment results for sensitivity were 88.1% (79.2 to 94.1) and 88.9% (51.8 to 99.7), specificity 88.1% (77.8 to 94.1) and 93.9% (85.2 to 98.3), and accuracy 83.5% and 81.5%, respectively. We conclude that the new monoclonal immunochromatographic quick test shows a good interobserver agreement, but equivocal results occur in 5%. Performance is comparable before and after therapy. The test may become a good alternative in children in settings where a [13C]urea breath test or a reliable enzyme immunoassay stool test are not available.     

Sensitivity of a novel stool antigen test for detection of Helicobacter pylori in adult outpatients before and after eradication therapy

We investigated whether a novel monoclonal stool antigen test for detection of Helicobacter pylori performs with the same accuracy as the (13)C-urea breath test (UBT) for adult outpatients in the setting of a private office. The two tests showed identical levels of sensitivity when used to identify H. pylori-infected patients before and after eradication therapy.     

Evaluation of a monoclonal antibody-based test for detection of Helicobacter pylori-specific antigen in stool samples from mice

A test using monoclonal antibodies for detection of antigen in stool samples was compared with culture and histology for noninfected (n = 25), Helicobacter pylori-infected (n = 25), and Helicobacter felis-infected (n = 6) mice. Sensitivity and specificity were 96%. The monoclonal antibody-based test is therefore a noninvasive technique that is able to diagnose H. pylori infection in mice.     

根除儿童口腔幽门螺杆菌预防胃内幽门螺杆菌感染的多中心研究

目的:探讨根除儿童口腔幽门螺杆菌（Hp）预防胃内Hp感染的可能性。方法:采用多中心前瞻随机研究,选取口腔Hp阳性但胃内Hp阴性的幼儿园儿童共计427例,随机分为使用“无幽梅”牙膏组与普通牙膏组,分别接受“无幽梅”牙膏和普通牙膏。疗程结束后,再次检测口腔Hp,将口腔Hp阳性及阴性患者各分为一组,1年后行C13呼气试验检查,分析两组患者胃内Hp感染情况。口腔Hp检测方法采用特异度及敏感度双高的套式PCR方法。结果:随访1年,口腔Hp阴性组胃内Hp感染率为0.51%,口腔Hp阳性组胃内Hp感染率为6.51%,两组统计差异具有显著性（P<0.01）。结论:儿童根除口腔Hp可以降低胃内Hp感染的发生。     

The Utility of the helicobacter pylori stool antigen test in managing dyspepsia: an experience from a low resource setting

Background

Dyspepsia is defined as a chronic or recurrent pain or discomfort centered in the upper abdomen. Endoscopy is the best strategy for confirming the cause of dyspepsia. Non- invasive strategies would be more appropriate in low resource countries where endoscopy is not readily available. However, there is concern that these strategies may miss serious disease like gastric cancer. One test that needs to be assessed in this regard is the Helicobacter pylori stool antigen test (HPSAT).

Objective

To determine the validity of the stool antigen test in predicting H. pylori associated disease among patients with dyspepsia.

Methods

In this prospective study patients with dyspepsia attending Mulago Hospital were recruited consecutively. Helicobacter pylori was determined using the Rapid Strip HpSA ®, endoscopy and gastric mucosal biopsy were done.

Results

167 patients with dyspepsia were recruited into the study. There were ninety six (57.5%) females and seventy one (42.5%) males with an average age of 48.1(±18.1) years. Patients presenting with dyspepsia in Mulago hospital were more likely to come from the Central 60 (36%) and western tribes 55 (33%). The commonest endoscopic finding was oesophagitis 25 (15%). Peptic ulcer disease was found in 32 (19.2%) and 54 (32.3%) had normal endoscopy findings. H pylori was found in 33.5% and 32.5% using the HPSAT and histology respectively. The validity of the HPSAT in predicting H.pylori associated diseases was generally low with an overall sensitivity of 55.8%, and specificity of 74.2%. However, the validity was higher in predicting the diagnosis of peptic ulcer disease with a sensitivity 59.4% and specificity 72.6%.

Conclusion and recommendations

The HPSAT may be used in the test and treat strategy for young patients with dyspepsia without alarm signs and symptoms in low resource settings. However, because of its low validity in predicting H.pylori associated disease, it is important to follow up patients so that if symptoms persist or recur endoscopy is performed     

Diagnosis of Helicobacter pylori infection in adults and children by using the Malakit Helicobacter pylori, a commercially available enzyme-linked immunosorbent assay.

Malakit Helicobacter pylori (Biolab, Limal, Belgium) is a second-generation enzyme-linked immunosorbent assay (ELISA) for the detection of Helicobacter pylori infection. We evaluated its ability to diagnose H. pylori infection in 489 asymptomatic pregnant women, 427 asymptomatic children, and 95 symptomatic children. 87 asymptomatic adults (17.8%), 31 asymptomatic children (7.3%), and 27 symptomatic children (28.4%) were seropositive. We observed an increase in H. pylori infection with age. 13C-urea breath tests were performed for all seropositive and 100 randomly selected seronegative asymptomatic adults. They were also performed for all seropositive and 65 randomly chosen seronegative asymptomatic children. Breath tests were positive for 86 of 87 (98.9%) seropositive adults, 30 of 31 seropositive children (96.8%), and no seronegative individual. Compared with those of culture, the sensitivity and specificity of the Malakit Helicobacter pylori were both 96%. We conclude that the Malakit Helicobacter pylori is equally suitable for adults and children. Therefore, this ELISA can be proposed as an important alternative to other more time-consuming and/or more expensive diagnostic tests for the detection of H. pylori.     

Significance of transiently positive enzyme-linked immunosorbent assay results in detection of Helicobacter pylori in stool samples from children

In young children, the significance of stool samples transiently positive for Helicobacter pylori antigen is unknown. As part of a larger prospective study on enteric infections, stool samples were obtained from 323 children at two time points 3 months apart and tested for H. pylori antigen using a commercially available enzyme-linked immunosorbent assay (ELISA) test. Seminested PCR for a Helicobacter-specific 16S rRNA gene was performed on all 26 pairs reverting from positive to negative (transient positives), all 4 persistent antigen-positive pairs, and 10 randomly selected persistent antigen-negative pairs. Helicobacter species were amplified from the first stool samples of 15/26 (58%) of the transient positives and 1 (25%) of 4 persistent positives. No Helicobacter species were amplified from the 10 persistent negatives. Among the 15 amplicons from transient-positive stool, H. pylori was sequenced and identified from 12 (80%; 95% confidence interval, 52% to 96%) and other Helicobacter spp. were identified from three (Helicobacter canis, Helicobacter winghamensis, and MIT 99-5504). Four of the 15 remained positive by PCR for the second (antigen-negative) stool sample, including all 3 initially identified as non-H. pylori. Helicobacter bilis was amplified from the second sample of a persistent positive. Two of eight transient positives from whom serum was available had accompanying transient elevations in anti-H. pylori antibodies. Transiently positive stool ELISAs for H. pylori are common and represent H. pylori in the majority of cases where sequences can be obtained. A not-insignificant percentage of antigen-positive stools, however, may represent other Helicobacter species.     

Salivary immunoglobulin G assay to diagnose Helicobacter pylori infection in children.

An in-house enzyme-linked immunosorbent assay (ELISA) for measurement of Helicobacter pylori-specific immunoglobulin G (IgG) and IgA in saliva was evaluated by comparison with histopathologic (Giemsa staining) and biochemical (urease quick test) examination of gastric biopsy specimens obtained from 112 children referred for diagnostic gastroscopy. Serum H. pylori IgG was also measured in a subgroup of 50 children by the same ELISA. Salivary H. pylori IgG levels were significantly higher in H. pylori-positive (n = 57) than in H. pylori-negative (n = 55) children (P < 0.001). The sensitivity and specificity of the salivary IgG test were 93 and 82%, respectively; the positive and negative predictive values were 84 and 92%, respectively; and the accuracy was 87.5%. Salivary H. pylori IgA did not distinguish H. pylori-positive from H. pylori-negative children. The performance of serum H. pylori IgG was slightly (3 to 6%) better than that of salivary H. pylori IgG. The salivary IgG test can be considered a useful tool for the screening of H. pylori infection in children.     

Relevance of CagA positivity to clinical course of Helicobacter pylori infection in children

A potential virulence determinant of Helicobacter pylori is the cagA gene product. To determine the relevance of the expression of CagA to the clinical picture and outcome of H. pylori infection in children, we examined 104 consecutive children diagnosed with H. pylori infection. Serum samples were collected to test for the presence of immunoglobulin G (IgG) anti-CagA antibodies. Forty-five patients (43%) had antibodies to the CagA protein (group I), and 59 did not (group II). Seropositive patients had a longer prediagnostic history of abdominal pain (P = 0.02), more severe abdominal pain (defined as ulcer pain) (P = 0.05), a higher prevalence of duodenal ulcer (38 versus 7%; P<0.01), more active chronic gastritis (82 versus 32%; P<0.001), and a higher titer of serum IgG anti-H. pylori antibodies (P<0.001). Ninety percent of the patients were monitored for 27+/-18 months. On multivariate analysis, CagA-negative patients had a 3.8-fold-higher chance of achieving a disease-free state than CagA-positive patients (95% confidence interval, 1.5- to 9.5-fold). We conclude that infection with CagA-producing strains of H. pylori is a risk factor for severe clinical disease and ongoing infection.     

Distribution of Helicobacter pylori organisms in the stomachs of children with H. pylori infection

Histology has been recognized as the gold standard for the diagnosis of Helicobacter pylori (Hp) infection in children. For ethical reasons, the number of mucosal biopsies obtained during endoscopic procedures is limited in the pediatric population. The aim of this study was to identify the optimal location where Hp organisms are colonized. Children who were scheduled for upper endoscopic procedures were prospectively recruited for the study. At least 2 mucosal biopsy samples were obtained from the following anatomic locations: greater curvature (mid-fundus [B3], mid-body [B1], and mid-antrum [A1] and lesser curvature mid-body [B2], incisura angularis [A3], and mid-antrum [A2]). In addition, a biopsy sample for a rapid urease test was obtained. The biopsy samples were stained with hematoxylin and eosin and Giemsa for the detection of inflammation and Hp colonization. The degree of mucosal inflammation and Hp colonization was assessed. The study group comprised 206 children, of whom 16 (8%) were positive for Hp infection. Hp colonization was significantly greater in the antral locations (A1, A2, and A3) than the body locations (B1, B2, and B3) (P <.001). The degree of mucosal inflammation correlated with the presence of Hp organisms, Hp density, and antral location. The mid-antrum location (A2) was superior for the detection of Hp organisms. The antrum, especially mid-antrum, at the lesser curvature is the best location in which to detect Hp organisms in children who have not recently used antibiotics or proton pump inhibitor medications.     

Study of diagnostic modalities and pathology of Helicobacter pylori infection in children

To evaluate various diagnostic tests for Helicobacter pylori (Hp) in children, and to study the spectrum of endoscopic and histological changes in the stomach and duodenum of children with gastroduodenal disorders, associated with Hp infection Children below 12 years of age with various gastroduodenal disorders requiring upper gastrointestinal endoscopy were studied. Endoscopic biopsy specimens were collected from duodenum and antrum. Apart from histopathological examination of biopsy material, rapid urease test (RUT) of the antral biopsy specimen and blood examination to estimate specific IgG antibodies to Hp by Indirect Solid Phase Enzyme Immunoassay was performed. Forty seven children were included. Nine (19.1%) of them were positive both by serology and RUT. Seven (14.9%) were positive by histology. A significant correlation of Hp was noticed with chronic antral gastritis (p = 0.002) and chronic duodenitis (p = 0.006). Age equal to or more than 10 years was found to be significant risk factor for acquiring Hp infection. Prevalence of Hp in children with gastroduodenal complaints was found to be 19%. Both RUT and serology were found to be reliable diagnostic tests for Hp as compared with histology. Antral gastritis and chronic duodenitis had a significant correlation with Hp colonization.