Is the Remarkable Contradiction between Histology and 14 C Urea Breath Test in the Detection of Helicobacter pylori due to False-negative Histology or False-positive 14 C Urea Breath Test?

We assessed the diagnostic value of the 14 C urea breath test (UBT) in the detection of Helicobacter pylori compared with histology and the rapid urease test (RUT). The study included 68 patients (22 men and 46 women) with dyspeptic symptoms. H. pylori status was evaluated by 14 C UBT, RUT and histology. Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy were determined for 14 C UBT and for RUT. Histology revealed dense yeast-like micro-organisms in the biopsy specimens in all patients with false-positive results by 14 C UBT (n = 8), a significantly higher proportion than in patients with negative 14 C UBT (five of 31). The low specificity of the H. pylori 14 C UBT should not be neglected by accepting histology results as false-negative. Gastric mucosal colonization by yeast-like micro-organisms with urease activity can account for the high frequency of false-positive results for 14 C UBT.