M1120 Helicobacter pylori Breath Test in an Open Access System Has a High Rate of Potentially False Negative Results. Negative Result Should Be Considered False Negative Until Proven Otherwise

2010 ◽  
Vol 138 (5) ◽  
pp. S-336
Author(s):  
Jin Cai ◽  
Snorri Olafsson
2006 ◽  
Vol 20 (12) ◽  
pp. 770-774 ◽  
Author(s):  
Marina Mauro ◽  
Vladimir Radovic ◽  
Pengfei Zhou ◽  
Melanie Wolfe ◽  
Markad Kamath ◽  
...  

AIM: To determine the test characteristics and the optimal cut-off point for the 13C urea breath test (13C UBT) in a Canadian community laboratory setting.METHODS: Of 2232 patients (mean age ± SD: 51±21 years, 56% female) who completed a 13C UBT, 1209 were tested to evaluate the primary diagnosis of Helicobacter pylori infection and 1023 were tested for confirmation of eradication following treatment. Cluster analysis was performed on the 13C UBT data to determine the optimal cut-off point and the risk of false-positive and false-negative results. Additionally, 176 patients underwent endoscopic biopsy to allow validation of the sensitivity and specificity of the 13C UBT against histology and microbiology using the calculated cut-off point.RESULTS: The calculated cut-off points were 3.09 δ‰ for the whole study population (n=2232), 3.09 δ‰ for the diagnosis group (n=1209) and 2.88 δ‰ for the post-treatment group (n=1023). When replacing the calculated cut-off points by a practical cut-off point of 3.0 δ‰, the risk of false-positive and false-negative results was lower than 2.3%. The 13C UBT showed 100% sensitivity and 98.5% specificity compared with histology and microbiology (n=176) for the diagnosis of active H pylori infection.CONCLUSIONS: The 13C UBT is an accurate, noninvasive test for the diagnosis of H pylori infection and for confirmation of cure after eradication therapy. The present study confirms the validity of a cutoff point of 3.0 δ‰ for the 13C UBT when used in a large Canadian community population according to a standard protocol.


1996 ◽  
Vol 10 (3) ◽  
pp. 167-172
Author(s):  
ABR Thomson

Over 380 abstracts, presentations and posters of recent advances were highlighted at the European and InternationalHelicobacter pylorimeeting held July 7 to 9, 1995 in Edinburgh, Scotland. New advances abound, with major interest focusing on the simple, safe, inexpensive new `gold standard’ forH pylorieradication therapy: a single week of tid omeprazole 20 mg, metronidazole 400 mg and clarithromycin 250 mg, or omeprazole 20 mg, amoxicillin 1000 mg and clarithromycin 500 mg. To avoid false negative results, two biopsies must be taken from the antrum and two from the gastric body at least four weeks after completion of eradication therapy, and ideally should be supplemented with at least one furtherH pyloritest such as a biopsy for urease activity or culture, or a urea breath test. While most patients with a gastric or duodenal ulcer (DU) who do not consume nonsteroidal anti-inflammatory drugs are infected withH pylori, the association is much less apparent in those with a DU who present with an upper gastrointestinal hemorrhage.H pylorieradication for nonulcer dyspepsia is not widely recommended, and the patient with a DU given effectiveH pylorieradication who presents with dyspepsia likely has erosive esophagitis rather than recurrent DU orH pylori. Gastroenterologists are at increased risk ofH pyloriinfection, particularly older gastroenterologists who are very busy endoscopists.


1992 ◽  
Vol 38 (3) ◽  
pp. 426-431 ◽  
Author(s):  
M L Brigden ◽  
D Edgell ◽  
M McPherson ◽  
A Leadbeater ◽  
G Hoag

Abstract Examination of 4379 routine urinalysis specimens with dipsticks sensitive to ascorbic acid showed that 22.8% were positive specimens. The mean urinary vitamin C concentration in this population was 2120 mumol/L. There was a high rate of false-negative dipstick results for hemoglobin in patients with vitamin C in the urine. The highest false-negative rates were observed in urine samples containing less than 50 erythrocytes per high-power field. In further experiments when volunteers consumed supplemental oral USP vitamin C at doses of 100, 250, 500, and 1000 mg or vitamin C-containing fruit juices, even the lowest doses of oral vitamin C or juice resulted in sufficient urinary vitamin C to produce false-negative dipstick results in hemoglobin and glucose testing. To prevent potentially dangerous false-negative results, screening urinalysis protocols relying only on dipstick testing should include a check for urinary vitamin C or use a dipstick that is not subject to vitamin C interference.


2019 ◽  
Vol 3 (1) ◽  
pp. 1-4
Author(s):  
Hui Xu ◽  
Nirmal Lamichhane

Prostate cancer is the most common cancer in males in the western world and is an emerging malignancy in eastern world as well. It is less invasive and easily curable in early stages. It requires efficient and accurate diagnosis strategy to detect it early. To date, the standard diagnosis procedure involves a blind biopsy with a high rate of false negative results. Trans-perineal prostate biopsy is re-emerging after decades of being an underused alternative to trans-rectal biopsy guided by trans-rectal ultrasonography. In order to overcome these limitations, the paper proposes the method and advantages of trans-perineal prostate biopsy.  


PEDIATRICS ◽  
1992 ◽  
Vol 90 (4) ◽  
pp. 608-611 ◽  
Author(s):  
Y. Vandenplas ◽  
U. Blecker ◽  
T. Devreker ◽  
E. Keppens ◽  
J. Nijs ◽  
...  

Serology, 13C-urea breath test, histology, Campylobacter-like organism testing, and culture were performed in 95 consecutive children to evaluate the contribution of these tests to the detection of Helicobacter pylori infection. In analyses considering any combination of three positive tests as "gold standard" for diagnosing H pylori infection, 26 children were Helicobacter positive (27%), which is only one patient more than the number of children with only a positive culture. The accuracy of culture was excellent when "any combination of three positive tests" was used as the gold standard (sensitivity 96%, specificity 100%, positive predictive value 100% [false positivity 0%], negative predictive value 99% [false-negative results 1%]). The results of invasive and noninvasive tests were comparable. When culture was considered as "gold standard," the sensitivity of serology and 13C-urea breath test was 96%; the specificity was 96% and 93%, respectively; the positive predictive value was 89% and 83% (false-positive results in 11% and 17%); and the negative predictive value for both was 99% (false-negative results in 1%). It is concluded that culture can be used as gold standard, but that noninvasive tests such as serology and/or 13C-urea breath test can be used to diagnose H pylori infection in children, since each has at least 95% sensitivity and 92% specificity.


2000 ◽  
Vol 118 (4) ◽  
pp. A504
Author(s):  
Krishna Chathadi ◽  
Uma Murthy ◽  
Jarrod Montague ◽  
Mimi Jones ◽  
William D. Chey

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