The accuracy of the Helicobacter pylori stool antigen test in diagnosing H. pylori in treated and untreated patients

OBJECTIVE AND DESIGN: To evaluate the performance of the Helicobacter pylori stool antigen test (HpSA test) in detecting H. pylori infection and monitoring the effect of treatment. This was done in two separate studies using either a biopsy or the 13C-urea breath test based 'gold standard' (in untreated and treated patients, respectively). SETTING: Endoscopy units of two general hospitals. PATIENTS: One hundred and twenty-eight dyspeptic patients undergoing endoscopy in the first study. Sixty-five patients receiving anti-H. pylori treatment in the second study. RESULTS: Sensitivity and specificity in untreated patients were 96.3% and 81.8%, respectively. Seven days after treatment, these figures were 20% and 95%, and 4 weeks after treatment they were 40% and 95%. CONCLUSION: The HpSA test is accurate in untreated patients but fails in monitoring treatment success.     

Clinical value of stool Helicobacter pylori antigen test in patients with gastrointestinal diseases

正Objective To investigate the value of stool Helicobacter pylori antigen test(Hp SA)in the diagnosis of Hp in patients with gastrointestinal diseases.Methods The totals of 142 patients who came to our hospital due to gastrointestinal symptoms were selected as the subjects from April 2015 to May 2016.Everyone accepted the     

Usefulness of the Helicobacter pylori stool antigen test for detection Helicobacter pylori infection

Several diagnostic tests are available for evaluating Helicobacter pylori (H. pylori) infection: histological examination, culture of gastric biopsy specimens, rapid urease test, urea breath test and serology. In this study, we assessed the reliability of a newly developed enzyme immunoassay HpSA (H. pylori Stool Antigen) kit for detecting H. pylori antigen in stool. Eighty-five patients (50 males, 35 females; mean age 41.6 +/- 9.8 years) with dyspeptic symptoms who were examined by upper gastrointestinal endoscopy. The patients with a history of previous treatment with proton pump inhibitors, bismuth compounds or antibiotics were excluded. During the endoscopic examination biopsies were taken from antrum and corpus for rapid urease test and histological examination. Stool specimens were submitted to the laboratory and HpSA test was performed. H. pylori was considered in condition with rapid urease test and histopathological examination for H. pylori positive. Forty-six of 85 patients were positive and remaining 39 patients were negative for H. pylori with the rapid urease test and pathologic evaluation. When 0.160 was adopted as the cut-off value, in accordance with the manufacturer's recommendations; stool antigen has been detected in 45 of the 46 H. pylori positive patients. The sensitivity and specificity of HpSA test were 97.8%, 94.9% respectively. These results indicate that HpSA is a highly reliable diagnostic method for H. pylori infection.     

Intravenous eradication therapy for bleeding gastroduodenal ulcer associated with Helicobacter pylori infection.

OBJECTIVE: To evaluate the efficacy of an ultrashort intravenous triple therapy against Helicobacter pylori infection in patients with bleeding peptic ulcer. METHODS: Thirty patients with bleeding peptic ulcer were studied prospectively. At endoscopy, two corpus and antrum biopsies were obtained for urease testing and culture. If H. pylori infection was found (positive urease test), the patient was treated with omeprazole 40 mg bid, metronidazole 500 mg tid and ampicillin 2000 mg fid for three days and then with ranitidine 150 mg bid for 2 months until eradication. In all patients a [13C]urea breath test was done at 2-month intervals, and in patients with gastric ulcer an endoscopy was also done and biopsies for culture and urease testing were obtained. RESULTS: Eradication efficacy (intention-to-treat) was 86.6% (26 out of 30). All schedules were administered in full and no patient had any adverse reactions. No patients had rebleeding. CONCLUSIONS: Ultrashort three-day triple therapy can achieve an eradication rate greater than 80%, with good acceptance and compliance, and without adverse events.     

Helicobacter pylori antigen stool test and 13C-urea breath test in patients after eradication treatments

OBJECTIVES: Current guidelines recommend either the urea breath test (UBT) or the Helicobacter pylori antigen stool test (HpSA) for monitoring H. pylori infection. The aim of this study was to evaluate the agreement between the two tests in patients after treatment. METHODS: After eradication treatments, patients were tested with both UBT and HpSA. Cut-off values (delta value over baseline at 30') for UBT were positive (> or = 5 per thousand), indeterminate (3.01-4.99 per thousand), and negative (< or = 3 per thousand). Cut-off values (absorbance at 450 nm) for HpSA test were positive (> or = 0.160), indeterminate (0.159-0.140), and negative (< 0.140). Patients with either discordant or indeterminate tests underwent repeat endoscopy with multiple gastric biopsies for rapid urease test (RUT), culture, histology, and immunohistochemistry to detect H. pylori and to assess the ratio between coccoid and bacillary forms. RESULTS: A total of 458 patients were studied. Of these, 422 (92.2%) had concordant tests, three (0.6%) indeterminate tests (one on UBT and two on HpSA), and 33 (7.2%) discordant tests. A total of 28 patients (25 with discordant and three with indeterminate tests) underwent endoscopy. The HpSA was inaccurate in 24 cases (18 false negative, four false positive, and two indeterminate results), whereas the UBT was inaccurate in four cases (two false positive, one false negative, and one indeterminate results). Biopsy-based tests showed no bacillary or coccoid forms in all five endoscoped patients who were negative on UBT and positive on HpSA, but in one in whom the ratio between coccoid and bacillary forms was 3:1 in the antrum and corpus. CONCLUSIONS: UBT and HpSA test give discordant or indeterminate results in nearly 8% of patients after treatment. The HpSA test is less accurate than the UBT. Coccoid forms do not cause false positive HpSA results.     

Genotypes of Helicobacter pylori in patients with peptic ulcer bleeding

AIM: Helicobacter pylori causes chronic gastritis, peptic ulcer, gastric cancer and MALT-lymphoma. Different genotypes of Helicobacter pylori are confirmed from diverse geographic areas. Its association with bleeding peptic ulcer remains controversial. The aim of this study was to investigate the Helicobacter pylori vacA alleles, cagA and iceA in patients with bleeding peptic ulcer. METHODS: We enrolled patients with bleeding, non-bleeding peptic ulcers and chronic gastritis. Biopsy specimens were obtained from the antrum of the stomach for rapid urease test, bacterial culture and PCR assay. DNA extraction and polymerase chain reaction were used to detect the presence or absence of cagA and to assess the polymorphism of vacA and iceA. RESULTS: A total of 168 patients (60.4%) (25 patients with chronic gastritis, 26 patients with bleeding gastric ulcer, 51 patients with non-bleeding gastric ulcer, 26 patients with bleeding duodenal ulcer, and 40 patients with non-bleeding duodenal ulcer) were found to have positive PCR results between January 2001 and December 2002. Concerning genotypes, we found cagA (139/278, 50%), vacA s1a (127/278, 45.7%), and ice A1 (125/278, 45%) predominated in all studied patients. In patients with bleeding peptic ulcers, vacA s1a and m1T were fewer than those in patients with non-bleeding peptic ulcers (37/106 vs 69/135, P=0.017, and 4/106 vs 21/135, P =0.002). CONCLUSION: In patients with peptic ulcers, H pylori vacA s1a and m1T prevent bleeding complication.     

Accuracy of Helicobacter pylori stool antigen for the detection of Helicobacter pylori infection in dyspeptic patients

AIM: The premier platinum Helicobacter pylori (H pylori) stool antigen (HpSA) test is an enzyme immunoassay (EIA) that detects an H pylori antigen present in human stools. However, at present there is no uniformity about the cut off level required to consider the test as positive or negative. So we need the cut off level for our local population. The aim of this study was to evaluate the HpSA for the detection of H pylori infection in dyspeptic patients and to determine the sensitivity, specificity of the HpSA test in the diagnosis of H pylori infection, as compared to other standardized diagnostic techniques. METHODS: Sixty-three dyspeptic patients were selected from patients who came to the Division of Gastrointestinal Clinic in Cipto Mangunkusumo Hospital, Jakarta, Indonesia. H pylori infection was confirmed in all patients by histology and rapid urease test (CLO test). Positive results for H pylori were based on positive results from both rapid urea test and microscopic detection of H pylori. Stool specimens were analyzed for H pylori antigen using HpSA immunoassay. RESULTS: A total 63 patients consisted of 31 (49.2%) males and 32 (50.8%) females ranging in ages between 16 and 73 years with a mean age of 42.4+/-15 years. The mean age of men was 43.2+/-15.7 years and women was 41.6+/-14.4 years. Endoscopic findings in this study included gastric cancer 1.6%, peptic ulcer 4.8%, duodenal ulcer 7.9%, esophagitis 6.3%, gastritis 77.7%, and gastroduodenitis 4.8%. According to the predefined study criteria, 6 (9.5%) of 63 patients were positive for H pylori. In the diagnosis of infection, the area under the receiver operating characteristic (ROC) curve for the HpSA test was 0.722 (95% CI, 0.518-0.927). Using a cut-off value of 0.274 instead of 0.16 (as recommended by the manufacturer) the sensitivity and the specificity were 66.7% and 78.9% respectively. CONCLUSION: The HpSA stool test, using a cut-off value of 0.274, may be useful for the primary diagnosis of H pylori infection, its specificity is similar to other standard tests but its sensitivity was lower.     

HpSA试验监测幽门螺杆菌感染根除效果的价值

目的检测粪便幽门螺杆菌抗原(HpSA)水平在根除治疗期间及以后的变化,并评估根除治疗疗效检测的最佳时间。方法受试者为57例Hp阳性的病人,均接受了一周的三联疗法。根除治疗的结果由尿素呼气试验、细菌培养以及治疗结束后6周时的组织检查来判定。HpSA的水平则从治疗前到治疗后的12周,先后共检测9次。结果根除治疗获得成功组病人的HpSA在治疗结束后立即转阴并保持阴性。而治疗失败组的病人HpSA也在治疗结束后立即转阴,但在治疗结束后2周时又转为阳性。治疗失败组在根除治疗开始后第4天HpSA试验的平均吸收值显著高于根治成功组。HpSA试验诊断(根除成功与否)的准确率在治疗2周以后增长到>90%。治疗结束后第2、6、8、12周HpSA的诊断准确率与治疗结束后第4周相比无显著差异。结论根除成功组病人的HpSA水平在治疗后的变化情况同失败组显著不同。HpSA的检测对于评估根治疗效是非常有意义的,且评估治疗效果的适当时机是在根除治疗后2周以后。     

Evaluation of the Helicobacter pylori stool antigen test for monitoring eradication therapy

OBJECTIVE: We aimed to clarify the time course of the Helicobacter pylori stool antigen (HpSA) level during and after eradication therapy and to determine the appropriate time of measurement of HpSA to evaluate eradication. METHODS: The subjects were 47 patients who were positive for H. pylori. The patients underwent a 1-wk regimen of triple therapy. The outcome of the eradication therapy was judged by urea breath test, culture, and histology 6 wk after the end of treatment. The HpSA level was serially measured nine times from before therapy until 12 wk after the end of therapy. RESULTS: In the group with successful eradication, HpSA became negative immediately after the end of therapy and the negativity persisted. In contrast, in the noneradication group HpSA became negative immediately after therapy, but became positive again within 2 wk after the end of therapy. The mean absorbance value of the HpSA test on the 4th day after the initiation of eradication therapy was significantly higher in the noneradication group than in the group with successful eradication. The diagnostic accuracy of the HpSA test increased to > or = 90% 2 wk after therapy and thereafter. Comparison of the diagnostic accuracy at 4 wk after the end of therapy showed no significant differences with that at 2, 6, 8, and 12 wk after the end of therapy. CONCLUSIONS: The course of the HpSA levels during and after eradication therapy in patients with successful eradication was quite different from that in noneradication patients. Measurement of HpSA was useful to evaluate eradication, and the appropriate evaluation of the outcome of treatment could be made as early as 2 wk after the end of therapy.     

Diagnosis of Helicobacter pylori infection by stool antigen test in southern Taiwan

Helicobacter pylori (H. pylori) has been found to be associated with various gastrointestinal diseases. Confirmation of H. pylori infection includes invasive and non-invasive methods. There has been increasing interest in noninvasive tests recently. However, the geographical differences among H. pylori strains have been emphasized recently and the H. pylori strain in Taiwan showed a high cagA positive result and different vacA subtype when compared with those of Western countries. The aim of this study is to access and compare the reliability and the diagnostic accuracy of the stool H. pylori antigen tests by spectrophotometry and by the visual method, especially in Southern Taiwan. Thirty-two patients (18 men and 14 women; age range: 23-91 y/o, mean: 50.5 y/o) who underwent gastroendoscopy at Kaohsiung Medical University Hospital were enrolled in this study. H. pylori infection status was confirmed by culture or two positive test results on CLO test, histology and 13C-urea breath test (13C-UBT). The exclusion criteria included previous gastrointestinal tract surgery, use of antibiotics, proton pump inhibitor or compounds containing bismuth within 1 month of the study. Among them, 14 patients were with duodenal ulcer (DU), 4 with gastric ulcer (GU), 12 with non-ulcer dyspepsia, and 2 with GU and DU. Those patients had their stool collected for ELISA tests of H. pylori stool antigen (HpSA). The HpSA tests were positive in 16 of 18 patients diagnosed as H. pylori positive, and negative in 13 of 14 patients as H. pylori negative. The sensitivity and specificity were 88.9% and 92.9% respectively. The positive and negative predictive values were 94.1% and 86.7% respectively. The concordance of HpSA accessed by spectrophotometry and visual method is 100%, which makes this test even easier and cheaper. We concluded that stool HpSA test is a noninvasive, accurate, reliable, rapid and easy way to diagnose H. pylori infection in Southern Taiwan, either by spectrophotometry or by visual assessment.     

Diagnostics of Helicobacter pylori infection in patients with peptic ulcer bleeding

BACKGROUND: In peptic ulcer bleeding, the sensitivity of H. pylori tests, in particular of the rapid urease test (RUT), has been reported to be insufficient. AIM: To validate the RUT, serology and the urea breath test were carried out in patients with bleeding peptic ulcers, and to study the influence of H. pylori suppressive treatment (HpSuT), i. e., antibiotics and proton pump inhibitors. PATIENTS AND METHODS: 123 consecutive patients (mean age 65.5 years) with a relevant bleeding from gastric or duodenal ulcers were prospectively tested for H. pylori infection by directs tests (RUT, histology, culture, urea breath test) and by IgG serology as an indirect test. Positive H. pylori status was defined by positive histology or culture. RESULTS: In patients without HpSuT during the preceding four weeks (N = 83), the sensitivity and specificity of RUT was 94 and 84 %, that of serology 83 and 68 % respectively. The sensitivity of urea breath test decreased from 82 to 60 % after even one day of HpSuT. In the overall group, the duration of HpSuT and preceding hospitalization were independent factors linked with negative results of all direct tests. CONCLUSIONS: In peptic ulcer bleeding, RUT combined with histology is an adequate diagnostic approach. However, false negative results have to be considered following even short-term HpSuT or hospitalization. Non-invasive diagnosis based on serology alone is inaccurate and should be complemented by the urea breath test prior to starting HpSuT.     

粪便抗原检测诊断幽门螺杆菌现症感染

目的 评价应用免疫酶联吸附试验(ELISA)检测粪便中幽门螺杆菌(Helicobacter pylori)抗原诊断H.pylori现症感染的敏感性和特异性。方法 应用^14C呼气试验以及幽门螺杆菌粪便抗原(HpSA)试验，对100例因上消化道不适就诊，怀疑有H.pylori感染的患者进行检测，观察两种检查的符合率。结果 ^14C呼气试验和HpSA同时阳性者38例，^14C呼气试验阳性而HpSA阴性者4例；^14C呼气试验和HpSA同时阴性者57例，^14C呼气试验阴性而HpSA阳性1例。以^14C呼气试验作为金标准计算，HpSA检测方法的敏感性为90．48％，特异性为98．28％。结论 幽门螺杆菌抗粪便原检测与^14C呼气试验有较高的符合率，而且简便易行，不需特殊设备，解决了无法进行呼气试验的婴幼儿和有肺部疾患者的非侵人性幽门螺杆菌现症感染诊断问题，是一种非侵入性幽门螺杆菌现症感染诊断的新方法。     

Evaluation of the Helicobacter pylori stool antigen test (HpSA) for detection of Helicobacter pylori infection in children

OBJECTIVE: Helicobacter pylori (H. pylori) infection is usually acquired in early childhood. Noninvasive methods for detection of H. pylori infection are required to study its incidence, transmission, and clearance. They should be easy to perform, inexpensive, and have a high diagnostic accuracy, especially in infants and toddlers. Both serology and the 13C-urea breath test (13C-UBT) do not fulfill all these requirements. The aim of this study was to evaluate a new enzyme immunoassay for detection of H. pylori antigen in stool (Premier Platinum HpSA, Meridian Diagnostics, Cincinnati, OH) in a large cohort of children and to compare it to invasive techniques and the 13C-UBT. METHODS: HpSA was performed in 310 stool samples of 274 children divided into three groups. Group A consisted of 145 children and adolescents (0.5-19.8 yr, 66/145 <6 yr) who underwent upper endoscopy for various gastrointestinal symptoms. H. pylori status was defined by histology, culture, and rapid urease test from biopsies of the antrum and corpus. A 13C-UBT was performed in 133 of 145 children. Group B consisted of 22 patients (5.7-16.1 yr) who were retested with both noninvasive tests 8 wk after anti-H. pylori triple therapy. Group C consisted of 129 healthy infants and toddlers (0.9-3.1 yr) who were tested with the 13C-UBT. Children with discrepant or positive test results were retested after 2 and 12 months. Results of the HpSA were read at 450/620 nm by spectrophotometry. An optical density <0.100 was defined as negative, >0.120 as positive, and values between 0.100 and 0.120 were considered as equivocal. RESULTS: In Group A, the HpSA gave false-negative results in five of 45 infected children and false-positive results in four of 100 noninfected children, whereas four patients (2.8%) showed equivocal results. In both infected and noninfected children, no relation between the optical density values and age was found. The 13C-UBT was correct in 132 of 133 children tested. In Group B, there was complete concordance between the HpSA and 13C-UBT: 19 children tested negative and three positive. In Group C, concordant results between the two noninvasive methods were found in 124 of 129 (96%) toddlers (122 negative and two positive). Retesting of five children with discrepant results revealed that, on initial testing, the HpSA was incorrect in two (one false-positive, one false-negative), and the 13C-UBT was incorrect in three (always false-positive). CONCLUSIONS: In symptomatic children, the HpSA revealed a sensitivity of 88.9% (95% CI 77.3-96.3) and a specificity of 94.0% (88.1-97.7) compared to the 13C-UBT, 100% (94.0-100) and 98.9% (94.7-100), respectively. However, in healthy toddlers, the HpSA performed as well as the 13C-UBT with excellent concordance between the two noninvasive tests. There was no age dependency of the stool test results, and changing the cutoff would not have improved accuracy. Thus, the HpSA test seems suitable to monitor the success of anti-H. pylori therapy.     

Discrepancy between Helicobacter pylori stool antigen assay and urea breath test in the detection of Helicobacter pylori infection.

BACKGROUND: The reference diagnostic methods available for detection of Helicobacter pylori infection are either invasive (histology) or expensive and highly sophisticated (Urea Breath Test). A new enzyme immunoassay, which can be easily performed in any laboratory, has been developed to detect Helicobacter pylori in stool specimens (HpSA-Meridian Diagnostics, Cincinnati, USA). Aim of the study was to compare HpSA to Urea Breath Test. PATIENTS AND METHODS: A total of 125 patients (52 never treated for Helicobacter pylori infection and 73 after Helicobacter pylori eradication therapy) referring to our Department, underwent both tests within two weeks. RESULTS: Contrasting results between the two tests were found in 30% of cases: in 19% of the untreated patients and in 37% of the treated patients (p<0.001). The main discrepancy consisted in positive HpSA associated with negative Urea Breath Test. Mean HpSA value in such conditions was 0.273 optical density, while in patients with both positive tests, it was 1.192 optical density. In untreated, but not in treated patients, raising the HpSA cut off value significantly decreased the percentage of conflicting results. CONCLUSIONS: Some disagreement was detected between HpSA and Urea Breath Test results, especially in treated patients. Possible explanations for our findings are a low HpSA cut off value together with the identification of Helicobacter pylori coccoid forms by the immunoassay but not by the urease based Urea Breath Test. The higher percentage of discrepancy detected in treated patients might support this hypothesis.     

幽门螺杆菌粪便抗原试验检测幽门螺杆菌感染的临床评价

目的 评价一种新的酶免疫法——幽门螺杆菌(HP)粪便抗原(HPSA)试验检测HP感染和监测HP根除治疗的可靠性。方法 未接受过抗HP治疗的患者分为2组，A组331例，无胃部手术史；B组65例，胃大部切除术后。2组患者因上消化道症状而接受胃镜检查，以胃黏膜活检标本快速尿素酶试验(RUT)和组织学检查(W-S染色)联合检测HP作为“金标准”，对HPSA试验的准确性进行评价，并与另一非侵入性的^13C-尿素呼气试验(^13C-UBT)加以比较。此外，A组中HP阳性的56例患者(C组)给予三联根除治疗1周，分别于停药后第1、7、14、21、28天收集粪便标本进行HPSA测定。于停药后第28天测定^13C-UBT，并以此为标准，评价HPSA试验的准确性。结果 A组患者经“金标准”诊断HP阳性175例，阴性156例。HPSA试验的敏感性为95，4％，特异性为91．0％，与^13C-UBT比较差异无统计学意义。B组患者中，经“金标准”诊断HP阳性30例，阴性35例。月psA试验敏感性为90．0％，^13C-UBT的敏感性为66．7％。HPsA试验的敏感性明显优于^13C-UBT(P＜0．05)。C组患者于停药后第28天经^13C-UBT诊断HP阳性16例，阴性40例。HPSA于停药后第1天54例阴性，此后随时间推移，未成功根除病例陆续转为阳性，而成功根除病例仍大部分保持在阴性范围，仅少数病例出现假阳性。停药后第28天的准确性最高(92．9％)。结论 HPSA试验是一种可靠的非侵入性检测方法，对于抗HP治疗前、后患者HP感染的诊断均有较高的准确性。对于胃大部切除术后的患者亦有较高的诊断价值。