Accuracy of stool antigen test for the diagnosis of Helicobacter pylori infection in children: A meta-analysis

Summary

Introduction

Helicobacter pylori (H. pylori) is regarded as a major pathogen in gastrointestinal diseases and the infection rate is still at a high level in children. Therefore, the diagnosis is of great clinical importance. The objective was to perform a meta-analysis on H. pylori stool antigen test (SAT) for the diagnosis of the infection in children.

Methods

Published information on the sensitivity and specificity of stool antigen test in each study was collected to assess the accuracy of the test for the diagnosis of H. pylori infection. Forty-five eligible studies were selected for analysis. Data on the publication year, H. pylori prevalence, eradication rate and gold standard of each study were summarized.

Result

Forty-five studies, including 5931 patients, evaluated the accurancy of H. pylori SAT. Pooled sensitivity, specificity, LR+ and LR– were: 92.1%, 94.1%, 17.01, 0.085, respectively. Subgroup analyses were conducted to evaluate the sensitivity and specificity of H. pylori SAT in different situations and found that sensitivity and specificity were significantly higher when monoclonal H. pylori SAT and two or more reference methods were used.

Conclusions

Detection of H. pylori antigen in stools with ELISA monoclonal antibodies is a non-invasive efficient test for the diagnosis of infection in children. However, the available one-step and polyclonal SAT tests are still unreliable.

Introduction

Helicobacter pylori is regarded as a major pathogen in gastritis, gastric and duodenal ulcers, MALT lymphoma and gastric carcinoma. Although the prevalence of H. pylori infection in children is decreasing worldwide recently, the incidence is still at a high level [1] and varies depending on age, geographic region, socioeconomic and hygienic conditions [2]. H. pylori infection could be much easier transmitting among children since their incomplete immunity and this is significantly associated with nausea, vomiting, abdominal pain and diarrhea [3]. In addition, it has been reported that H. pylori infection could lead to growth retardation, iron deficiency anaemia, diarrhoeal disease and recurrent headaches in childhood [4].

Both invasive (e.g., endoscopy with biopsy for histology, culture, and rapid urease test [RUT]) and non-invasive (e.g., urea breath test [13C-UBT], stool antigen test and serology) methods are available to diagnose H. pylori infection. Ideally, a diagnostic test for H. pylori infection in children should be non-invasive, highly sensitive and specific, inexpensive, and easy to perform [5]. The sensitivity of serology is markedly lower in children, particularly in those below 8 years old [6]. UBT is considered the gold standard non-invasive test. However, it is not suitable for infants and toddlers since it demands the children's cooperation and trained technicians [7]. Since SAT does not require expensive chemical agents or specified equipment, it may be the most appreciate means for children.

It has been suggested that the accuracy of H. pylori SAT in pre-treatment and post-treatment conditions were different and the sensitivity and specificity was significantly lower after H. pylori eradication as the H. pylori density grade was reduced after treatment in patients from whom the microorganism has not been eradicated could be accompanied by low H. pylori SA optical densities, leading to an erroneous diagnosis of eradication [8].

Given the diversity of stool-based diagnostic tests for H. pylori infection, a critical appraisal of their performance is needed. Therefore, our objective of this study was to perform a meta-analysis of the experience on H. pylori SAT for the diagnosis of H. pylori infection in children. We not only analyze the diagnostic accuracy of the method, but also systematically assess the different factors that may influence its performance.