RESUMEN
The urea breath test [UBT] which is carried out with [13]C or [14]C labeled urea is one of the most important non invasive methods for detection of Helicobacter pylori infection. Application of [13]C-UBT is becoming increasingly popular because of its non radioactive nature which makes it suitable for diagnostic purposes in children and women of child bearing ages. While isotope ratio mass spectrometer [IRMS] is generally used to detect [13]C in expired breath, this instrument is expensive and recently non dispersive isotope selective infrared [NDIR] spectroscopy which is a lower cost technique has been employed as a reliable counterpart for IRMS in small clinics. The aim of this study was to assess the validity of NDIR spectroscopy technique in Iranian population in comparison with histological examination, rapid urease test and [14]C-urea breath test as gold standard. Seventy six patients with dyspepsia were underwent [13]CUBT for diagnosis of Helicobacter pylori infection. Good agreements were found between the [13]C-UBT and gold standard methods. The [13]C-UBT showed 100% sensitivity, 97.3% specificity, 97.56% positive predictive value, 100% negative predictive value and 98.65% accuracy. On the basis of these results it could be concluded that [13]C-UBT performed with NDIR spectroscopy is a reliable, accurate and non invasive diagnostic tool for detection of Helicobacter pylori infection in the Iranian population