An office-based serological test for detection of current Helicobacter pylori infection: is it useful?

Diagnostic Validity of a Serological Test with the Current Infection Marker in Thai Adults before and after Helicobacter pylori Eradication Therapy

Helicobacter pylori infection poses significant health risks, such as gastric adenocarcinoma, necessitating accurate diagnosis and effective treatment in primary care. This study evaluated the diagnostic efficacy of the serological current infection marker (CIM) test in identifying current H. pylori infection. The CIM test samples from 159 participants undergoing gastroscopy were collected, and H. pylori-positive outpatients received triple therapy based on histology or rapid urease test results. Following treatment, 45 patients underwent a 13C-urea breath test and the CIM test for eradication assessment. For pre-eradication, the CIM test demonstrated 89.6% sensitivity, 95.7% specificity, 93.8% positive predictive value, 92.6% negative predictive value, and 93.1% accuracy. Following post-eradication, the CIM test exhibited sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 71.4%, 92.1%, 62.5%, 94.6%, and 88.9%, respectively, using the 13C-urea breath test as the reference standard. The CIM test showcased commendable diagnostic performance, emphasizing its efficacy in both pre- and post-eradication scenarios. Notably, the accuracy, non-invasiveness, user-friendliness, and cost-effectiveness of the CIM test advocate for its recommendation as a preferred diagnostic tool in primary care settings for H. pylori infection detection.

Ectopic expression of guanylyl cyclase C and endogenous ligand guanylin correlates significantly with Helicobacter pylori infection in gastric carcinogenesis

The molecular mechanisms leading to gastric carcinogenesis still remain unclear. Recently, several studies demonstrated that over-expression of guanylyl cyclase C (GCC) has been detected in intestinal-type gastric cancer (GC) and precursor lesions. Our objective was to explore the expression levels of GCC and endogenous ligands guanylin (GN) and uroguanylin (UGN) and the correlation between Helicobacter pylori (H. pylori) and GCC, GN, and UGN expressions in patients at different stages from normal mucosa to superficial gastritis, atrophic gastritis, intestinal metaplasia (IM), dysplasia, and finally adenocarcinoma. The expression of GCC and GN was absent in the distal normal gastric tissues and superficial gastritis in all cases, whereas they were measured in IM, dysplasia, and GC. The expression of GCC and GN was closely related to intestinal-type GC. From superficial gastritis to gastric carcinomas, the H. pylori positive rate was 19.7, 33.3, 69.6, 80.0, and 82.1%, respectively. The positive correlation was found between GCC and GN in IM, dysplasia, and GC. Also, the positive correlation was found between GCC, GN, and H. pylori infection in them. These results demonstrate that the detection of GCC and GN will be beneficial to diagnosis human gastric carcinoma and precancerous lesions. Ectopic expression of GCC and GN in human gastric mucosa and H. pylori infection may play an important role in the carcinogenesis of the intestinal-type GC.

Distribution of Helicobacter pylori virulence markers in patients with gastroduodenal diseases in Pakistan

BACKGROUND

Helicobacter pylori (H. pylori) infection is known to be associated with a spectrum of gastroduodenal diseases. We studied the association of H. pylori virulence markers cytotoxin-associated gene (cagA) and vacuolating associated cytotoxin gene (vacA) alleles in patients with non ulcer dyspepsia (NUD), gastric ulcer (GU), gastric carcinoma (GC) and duodenal ulcer (DU).

METHODS

H. pylori infection established by both rapid urease test and histology were studied. The cagA and vacA allelic status was determined by polymerase chain reaction (PCR). Sequencing of vacA i1 and i2 PCR product was carried out.

RESULTS

Two hundred and twenty-four patients were included, 141 (63%) were males with a mean age of 45 +/- 16, range 16-83 years. The virulence marker cagA was associated with GU in 20(63%) (p = 0.04), DU in 23(72%) (p = 0.003) and GC in 29(73%) (p = 0.001) compared to NUD in 51(42%). VacA s1am1 was associated with GU in 23(72%) (p = 0.001), DU in 17(53%) (p < 0.001) and GC in 23(58%) (p = 0.003) compared to NUD in 38(32%) while vacA s1bm1 was also associated with GU in 9(28%) (p = 0.001), DU in 12(37%) (p < 0.001) and GC 11(28%) (p < 0.001) compared to NUD in 13(11%), respectively. The diagnoses of GU in 21(66%), DU in 16(50%), GC in 20(50%) and NUD in 50(42%) were associated with moderately active chronic inflammation. CagA in 55(45%) (p = 0.037), vacA s1am1 in 51(51%) (P < 0.001), s1bm1 in 25(56%) (p = 0.002), s1am2 32(30%) (p < 0.001) and s1bm2 29(69%) (p = 0.004) were also associated with moderately active chronic inflammation.

CONCLUSION

CagA was negative in majority of NUD patients with H. pylori infection. However, cagA was associated with peptic ulcer and GC. VacA allele's s1am1 and s1bm1 were associated with H. pylori associated diseases and inflammation.

An evaluation of a serologic test with a current infection marker of Helicobacter pylori before and after eradication therapy in Chinese

BACKGROUND AND AIMS

Development of an accurate and less cumbersome noninvasive method to detect current Helicobacter pylori infection is essential in clinic. The aim of this study was to evaluate the performance of the CIM test, also known as the Assure H. pylori Rapid Test (Genelabs Diagnostics Pty. Ltd., Singapore), for the diagnosis of current H. pylori infection before and after eradication therapy in Chinese population.

METHODS

A total of 452 eligible people were recruited for this study in Jiangsu Province, China. Each individual underwent a 13C urea breath test (13C-UBT). For the evaluation of CIM test after eradication, 115 H. pylori-positive outpatients were treated with 1-week triple therapy. One month after the end of therapy, the patients underwent 13C-UBT again, and the CIM-test was performed 1, 3, and 6 months after the end of therapy. Its performance (sensitivity, specificity, positive and negative predictive values, and accuracy) were determined using the 13C-UBT as a gold standard for H. pylori diagnosis.

RESULTS

H. pylori was detected in 221 (65.6%) of the 337 people by 13C-UBT. The sensitivity, specificity, positive and negative predictive values, and accuracy of the CIM test were 93.2%, 90.5%, 94.9%, 87.5%, and 92.3%, respectively, using 13C-UBT as a gold standard. One month after eradication therapy, the sensitivity, specificity of CIM test were only 50% and 66.7%, 66.7% and 84.6% 3-month after eradication therapy and the sensitivity, specificity increased to 85.7% and 96.9%, respectively, when CIM test was used 6 months after the end of anti-H. pylori therapy.

CONCLUSIONS

The CIM test is a simple, rapid, accurate, cheap, and near-people test. It may be satisfactory for detecting H. pylori infection in cases without eradication therapy, but it could not differentiate the past or current infection correctly within 6 months after anti-H. pylori therapy.