Meta-analysisindependent cross-checkabstract checked I-SRC-120 standard review
How accurate H. pylori blood and stool tests are
Diagnostic Accuracy of Serum Antibody, Urine Antibody, and Stool Antigen Tests for Helicobacter pylori in Japan: A Systematic Review and Meta-Analysis.
Overview
Ichita C et al.. Helicobacter 2026 · PMID 42604577 · DOI 10.1111/hel.70157
Blood and stool tests were about 92-97% accurate for current infection; blood tests were less specific in people infected before.
Does the study support the specific claim? Partly · Methodological quality: high
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Measure test accuracy
- How was the study done?
Diagnostic meta-analysis
- How many people, animals or samples were studied?
43 studies
- What was actually found?
High accuracy; lower for serology after past infection
- How large was the observed effect?
Serology specificity 0.956 (0.861 with past infection)
- What do the results mean in everyday life?
A positive antibody test can reflect an old infection
- What are the study's limitations?
Japan only
- What does it say about Elawady's specific claim?
Partly fits; does not support 70% false positives
- Do the results apply to Germany and Europe?
Moderate
- What can explicitly not be concluded from this study?
Egyptian kit performance
Scientific in-depth review
1. Full reference
- Authors
- Ichita C et al.
- Journal
- Helicobacter
- Year
- 2026
- Identifier
- PMID 42604577 DOI 10.1111/hel.70157
- Verification
- verified – PubMed efetch 2026-10-26; Crossref works record checked
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
Some authors received lecture honoraria from Fujifilm and Olympus; funded by Japanese Ministry of Health.
2. Research question
How accurate are serum antibody, urine antibody and stool antigen tests for H. pylori in Japanese populations?
3. Study design and population
- Study design
- Meta-analysis – Systematic review and diagnostic test accuracy meta-analysis (bivariate random effects)
- Population
Japanese participants tested for H. pylori
- Country
Japan
- Period
Studies 2005-2024
- Sample size
43 studies (29 serum antibody, 6 urine antibody, 8 stool antigen)
- Inclusion and exclusion criteria
Studies evaluating these tests in Japanese participants
4. Methods and endpoints
- Exposure / intervention
Index tests
- Comparator
Reference standards
- Endpoints
Sensitivity, specificity
- Statistical methods
Bivariate random-effects models; subgroup analyses
5. Actual results
- Results
Current infection: serum antibody sensitivity/specificity 0.922/0.956; urine antibody 0.885/0.970; stool antigen 0.928/0.972. Under clinically relevant conditions serum 0.908/0.968, stool 0.935/0.985. Serum antibody studies including previously infected individuals: 0.876/0.861 vs 0.929/0.967 without.
- Absolute risks
not applicable
- Authors' conclusion
Serum antibody and stool antigen tests are highly accurate for current infection in Japan, but accuracy declines when previously infected individuals are included.
6. Strengths
- Recent, large DTA meta-analysis
- Subgroup on past infection
7. Weaknesses
- Japan-specific test kits and populations
8. Risk of bias
- Orienting tool
- AMSTAR 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- low
- Rationale
Standard DTA methods.
9. Assessment of the statistical interpretation
With specificity 0.861, 70% of positives would be false only at prevalence <=6.4%; at Africa's pooled prevalence (70.1%) about 6% of positives would be false (stats/C-SRC-50_ppv_hpylori.py).
10. Relevance to the specific claim
Supporting side (partly): antibody tests lose specificity after past infection (treated patients), so false positives occur. But false positives are a minority of results in high-prevalence settings such as Egypt.
11. Independent contrary findings
12. Transferability to Germany and Europe
Japan; principles transferable.
13. Overall methodological judgement
Quantifies the kernel of truth.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | low |
| Precision of results | high |
| Directness | direct |
| Reproducibility | replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Egyptian validation data.
15. Linked fact checks
- The common test for H. pylori ('the stomach germ') is the test with the highest rate of false-positive results. – Studies with mixed or unclear results