Evaluation of the two immunochromatographic methods for detecting urine and serum IgG antibodies to Helicobacter pylori and comparison of accuracy and clinical utility.
OBJECTIVE
To evaluate the accuracy and clinical utility of two immunochromatographic methods, the STAT-PAK and RAPIRUN tests, in detecting H. pylori antibodies in serum and in urine separately.


METHODS
130 patients undergoing gastroendoscopy (70 men and 60 women; mean age, 50.6 years) were enrolled in this study. Their H. pylori status was determined based on 4 tests: CLO test, culture, histology and UBT test. The H. pylori positive status was confirmed when the culture was positive, or 2 of the other 3 tests were positive. Serum samples and urine samples were collected. We used the STAT-PAK test for detecting H. pylori antibodies in serum, and read the results 24 hours later. Antibodies were also detected in urine by the RAPIRUN test, with a reading time of 25 minutes. 3 doctors read the results of both tests separately, and a positive result was determined when at least 2 of the doctors read a positive result.


RESULTS
In the STAT-PAK pretest using serum samples from 21 randomly selected patients (16 patients with H. pylori infection and 5 patients without infection), the sensitivity at 1-hour and 24-hour reading time was 18.7% and 37.5%. Specificity in both reading times was the same at 100%. Of 129 patients, 82 (64%) were H. pylori infected and 47 (36%) were uninfected. The sensitivity, specificity, and positive and negative predictive values were 31.7%, 93.6%, 89.6% and 44.0% in the STAT-PAK test with a 24-hour reading time, and 93.9%, 85.1%, 91.6%, 88.8% in the RAPIRUN test. One female was excluded because of an invalid urine test.


CONCLUSIONS
The urine RAPIRUN test is a faster and more accurate office-based test than the serum STAT-PAK test for detecting the H. pylori infection in untreated patients in Taiwan. The non-invasive urine RAPIRUN test can be used as a large scale screening test for H. pylori status, particularly in children, uncooperative patients, those who have a family history of gastric cancer, or patients who can not tolerate the suffering of endoscopic examination.
Hu
Huang-Ming
HM
Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan.
Kuo
Chao-Hung
CH
Lo
Yi-Ching
YC
Wu
Ming-Tsang
MT
Wu
I-Chen
IC
Lu
Chien-Yu
CY
Su
Yu-Chung
YC
Yu
Fang-Jong
FJ
Lee
Yi-Chen
YC
Lin
Shiu-Ru
SR
Liu
Chiang-Shin
CS
Jan
Chang-Ming
CM
Wang
Wen-ming
WM
Wu
Deng-Chyang
DC
D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000032:analysis* / Q000097:blood / Q000652:urine; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods*; D007074:Immunoglobulin G / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D011933:Reagent Kits, Diagnostic