Diagnosis of Helicobacter pylori infection by invasive and noninvasive tests

Abstract

Although several invasive and noninvasive tests have been developed for the diagnosis of Helicobacter pylori infection, all of the tests have their limitations. We conducted a study to investigate and compare the suitability of rapid urease test (RUT), serology, histopathology and stool antigen tests with polymerase chain reaction (PCR) for detection of H. pylori, and correlate the diagnostic methods with PCR. Eighty nine patients (61 adults, 28 children) referred to the Firoozgar Hospital and Children Medical Center Hospital for diagnostic upper gastrointestinal endoscopy entered to the study and noninvasive tests such as immunoassay for serological antibodies against H. pylori and detection of its antigen in feces were measured. The biopsies were utilized for histological examination, RUT and PCR. The H. pylori statuses were evaluated by the positivity of ureC PCR in biopsy specimens and 53 subjects had H. pylori positive result. Histopathology showed high overall performance in adults and children with sensitivity and specificity 100% and 90%, respectively. Sensitivity, specificity, and accuracy for stool antigen test were 87.8%, 75% and 82%, respectively. Correlation of RUT, serology (IgG), histopathology and stool antigen tests with PCR were 0.82, 0.32, 0.91 and 0.63, respectively. In conclusion, the RUT and histopathology are as accurate as the PCR of biopsy and stool antigen test can consider as appropriate noninvasive test for detection of H. pylori infection.

Diagnosis of Helicobacter pylori infection in children and their mothers using some non-invasive techniques

“…Similar findings were reported by Okuda et al (2002) who compared H. pylori IgG and IgA Abs with H. pylori stool Ags (Okuda et al, 2002). Our results were in concordance with that of Pourakbari et al (2013) who found that ELISA-IgG serum tests in children showed high specificity, but low sensitivity. These findings have significant clinical implications, since a negative test would not be reliable for ensuring the absence of H. pylori infection.…”

“…These findings have significant clinical implications, since a negative test would not be reliable for ensuring the absence of H. pylori infection. Low sensitivity may be attributed to the weak or immature immune response observed in young children (Pourakbari et al, 2013). IgG was also much more specific in children than adults, corroborating the fact that adults are more likely to have been frequently exposed to H. pylori in the past so if it is present in a child, it is so specific to the infection (She et al, 2009).…”

“…This is due to its high sensitivity and specificity in children and adult patients and excellent positive and negative predictive values regardless of H. pylori prevalence as reported by Bakri (2012). In addition, Pourakbari et al (2013) has recorded that the performance of stool Ag test in adult patients was excellent, with a sensitivity, specificity, and accuracy of 91, 79 and 85%, respectively. Furthermore in 2014, a review done by Garza-González et al documented that H. pylori stool Ag test seemed to perform well in children with sensitivity of 97%, specificity of 97%, PPV of 88%, and NPV of 99% (Garza-González et al, 2014).…”

Screening for Helicobacter pylori Infection among Asymptomatic University Students in Alexandria, Egypt, Using Non Invasive Laboratory Techniques

“…In the current research, H. pylori stool Ag test was considered the gold standard method for diagnosis of H. pylori infection. This is attributed to its previously reported high sensitivity and specificity (up to 97%) (Bakri 2012, Pourakbari et al, 2013, GarzaGonzález et al, 2014, Jekarl et al, 2013 and its excellent positive and negative predictive values regardless of H. pylori prevalence (Bakri 2012).…”

Correlation Between Chronic Treatment With Proton Pump Inhibitors and Bacterial Overgrowth in the Stomach

“…Diagnostic methods for H. pylori infection are usually classified as invasive and noninvasive. 34 Histopathology can be regarded as accurate as the PCR of biopsy. Gastroscopies were performed at the Gastroenterology Department of Maggiore della Carita`Hospital in Novara.…”