Introduction:
The rapid urease test (RUT) is widely known and used for diagnosing H. pylori infection because of its practicality and high accuracy, however its false negative rate is significantly higher in patients with peptic ulcer bleeding. Though there are several tests available, no prior studies have been conducted that showed a head-to-head comparison of these tests. The study aims to evaluate the diagnostic performance of the tests that are available for patients with peptic ulcer bleeding.
Method:
- The study included 135 patients with active peptic ulcer bleeding. Patients who had profound shock or prior gastric/duodenal surgery were excluded.
- After achieving hemostasis seven tissue biopsies were taken: two from the antrum and incisura for Rapid Urease Test (RUT) and Polymerase Chain Reaction (PCR), and five (two antrum, one incisura, two body) for histology with immunohistochemistry. Patients with negative RUT and histology underwent a urea breath test (UBT).
- Blood samples were collected for current immune marker (CIM) and anti-urease antibody testing.
- The diagnostic performance was analysed using any positive result from RUT, histology, PCR, or UBT as the reference standard and logistic regression was used to identify factors associated with RUT false negatives.
Results:
- A total of 135 patients were included in the study with a mean age of 70 years. 62.2% were male patients and the remaining 37.8% were females.
- 1% has Forrest III Ulcers
- Post PCR it was seen that there was a reduction in idiopathic ulcers from 31.85% to 26.67%.
- There were no predictors for RUT false negatives (e.g., blood content, PPI use, high-risk ulcers)
The following table gives a detailed explanation about the sensitivity, specificity and diagnostic yield of various parameters.
|
Test/Parameter |
Sensitivity (%) |
Specificity (%) |
Diagnostic Yield (%) |
Additional Diagnostic Yield (%) |
|
RUT (Rapid Urease Test) |
56 |
100 |
56 |
– |
|
Histology |
48 |
100 |
– |
– |
|
RUT + Histology (combined) |
74 |
100 |
74 |
– |
|
PCR (Polymerase Chain Reaction) |
84 |
100 |
– |
26 |
|
CIM (Culture + Immunostaining Method) |
70 |
82.4 |
– |
12 |
|
Anti-urease antibodies |
80 |
68.2 |
– |
16 |
|
UBT (Urea Breath Test) |
85.7 |
Very high |
– |
12 |
Conclusion:
In bleeding peptic ulcer patients, RUT alone is inadequate for H. pylori diagnosis. Tissue PCR offered the highest accuracy and practicality. Combining RUT with histology improved yield moderately. CIM and anti-urease antibodies added value but lacked specificity. UBT was highly accurate but often impractical due to patient limitations.
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