RESUMO
This study was conducted in order to compare the performance of the rapid urease test (RUT) with that of the polymerase chain reaction (PCR) for H. pylori diagnosis. Of 536 patients, 81% were concordant between RUT and PCR, 16% were concordant between two PCR assays but not between RUT and PCR, and the remaining 3% showed discrepant results between two PCR assays evaluated. Low bacterial load was shown to be a significant factor associated with false-negative diagnosis by RUT, and non-H. pylori urease activity or bacterial alkaline-generating activity was the cause of false-positive diagnosis. Disagreement between the PCR assays was due to single nucleotide polymorphisms in primers or probes causing decreased amplification efficiency and false-negative diagnosis when the bacterial load in the samples was low.
