Application of isotope-selective non-dispersive infrared spectrometry for the evaluation of the 13C-urea breath test: comparison with three concordant methods

Abstract

The aim of this work was to compare the performance of isotopeselective non-dispersive infrared spectrometry (IRIS) for the 13 C-urea breath test with the combination of the 14 C-urea breath test ( 14 C-UBT), urease test and histologic examination for the diagnosis of H. pylori (HP) infection. Fifty-three duodenal ulcer patients were studied. All patients were submitted to gastroscopy to detect HP by the urease test, histologic examination and 14 C-UBT. To be included in the study the results of the 3 tests had to be concordant. Within one month after admission to the study the patients were submitted to IRIS with breath samples collected before and 30 min after the ingestion of 75 mg 13 Curea dissolved in 200 ml of orange juice. The samples were mailed and analyzed 11.5 (4-21) days after collection. Data were analyzed statistically by the chi-square and Mann-Whitney test and by the Spearman correlation coefficient. Twenty-six patients were HP positive and 27 negative. There was 100% agreement between the IRIS results and the HP status determined by the other three methods. Using a cutoff value of delta-over-baseline (DOB) above 4.0 the IRIS showed a mean value of 19.38 (minimum = 4.2, maximum = 41.3, SD = 10.9) for HPpositive patients and a mean value of 0.88 (minimum = 0.10, maximum = 2.5, SD = 0.71) for negative patients. Using a cutoff value corresponding to 0.800% CO 2 /weight (kg), the 14 C-UBT showed a mean value of 2.78 (minimum = 0.89, maximum = 5.22, SD = 1.18) in HP-positive patients. HP-negative patients showed a mean value of 0.37 (minimum = 0.13, maximum = 0.77, SD = 0.17). IRIS is a lowcost, easy to manage, highly sensitive and specific test for H. pylori detection. Storing and mailing the samples did not interfere with the performance of the test.

3rd BRAZILIAN CONSENSUS ON Helicobacter pylori

“…The test was validated for adults in Brazil on 1999 (26) and for adolescents and children on 2002 (106) . Although highly accurate, simple and relatively cheap, the test has not yet been incorporated into daily gastroenterology practice, its use being restricted to large urban centers and for epidemiological studies.…”

“…The most commonly used serological tests are those performed by ELISA, as previously validated in Brazil (146,169) . To control bacteria eradication in the test-and-treat strategy, only the labeled urea breath test and a fecal antigen survey are recommended, both of which have also been validated in Brazil already (26,189) .…”

Low Dose Capsule Based 13c-Urea Breath Test Compared With the Conventional 13c-Urea Breath Test and Invasive Tests

“…In this report, we showed that 13 C-urea breath test performed with formulated 50 mg hard gelatin capsule with citric acid and taken with orange juice (pH = 3.0) had almost perfect agreement (Kappa Index measure of agreement = 1; P<0.05) with the conventional 13 C-urea breath test in powder dissolved in orange juice. The conventional breath test with 75 mg of 13 C-urea in 200 mL orange juice and considering a cutoff value of DOB≥4‰ was previously validated with 100% sensitivity and specificity (4) , and performed in other publications in Brazil (3,15,16,29,30) . Considering a cutoff value of DOB≥4‰ at 20 minute time collection or a cutoff value of DOB≥2‰ at 10, 20 and 30 minutes, the capsule (50 mg) urea breath test had 100% relative sensitivity and relative specificity.…”

An optimized13C-urea breath test for the diagnosis ofH pyloriinfection

“…Later on, doses of 125 [35,72] and 100 mg [36,40,47,48,51,54,57,60,62,65,[73][74][75][76][77][78][79][80][81][82][83] were validated by several American, European and Asian groups, and more recently 75 mg [32,37,[43][44][45]49,50,55,72,[84][85][86][87][88][89][90][91][92][93] , 50 mg [52,56,58,94,95] , 38 mg [96] , 25 mg and even 10 mg [69] of 13 C-urea have proved to be sufficient.…”

“…Through the years there have been numerous modifications to the test meal, including the use of citric acid alone before administering the urea [37,62,67,79,84,85,97] , or mixed with the 13 C-urea at the time of administration [43][44][45]88,91,98] , or as a presentation in combination with the 13 C-urea [42,61,72,94,99] . Several alternatives to citric acid have also been tested, including orange juice [43,49,67,90,95] and apple juice [100] , as well as other types of food such as milk [48,58,101,102] and a pudding test meal [34,46] , and even water [41,103] . As shown in Table 3, the majority of the test meals have provided reliable results.…”