Comparison of¹³C- urea blood test to¹³C-breath test and rapid urease test for the diagnosis of Helicobacter pylori infection

At present, the available methods to diagnose active H. pylori infection are endoscopy with biopsy for histology, culture, rapid urease tests, ¹³C or ¹⁴C urea breath test, urine antibody and the stool antigen test. The aims of this study were to simplify the ¹³C urea test by measuring ¹³C in blood rather than breath, and to evaluate the usefulness of the ¹³C urea blood test for the diagnosis of H. pylori infection. Patients who underwent upper endoscopy for standard clinical indications (e.g. dyspepsia, abdominal pain) were enrolled. A total of 161 patients (93F, 68M, mean age 47±14.2) were evaluated; 50 (31%) of them were H. pylori positive, and 111(69%) were H. pylori negative. H. pylori infection was diagnosed with a rapid urease test (CLO-test) and ¹³C urea breath test (UBT). Performance characteristics for the ¹³C urea blood test for diagnosis and evaluation of H. pylori eradication were calculated using UBT and CLO as gold standards. The fifty H. pylori-positive patients were treated with triple antibiotic therapy for two weeks. Four weeks after finishing antibiotic therapy patients were retested with a commercial UBT and urea blood test. The ¹³C blood test had sensitivities of 92 and 98% and specificities of 96 and 100% as compared with urea breath test and CLO, respectively. We conclude that the ¹³C urea blood test is highly sensitive and specific for the initial diagnosis and control of eradication of H. pylori infection.