H. pylori diagnostic test accuracy Isotope breath test is a sensitive noninvasive method of different disease diagnostics. It can detect disease at early stages when visual symptoms are weak or absent. Sensitivity and specificity for H.pylori diagnostic tests are listed in the table below. It's clear that all tests except polimerase-chain reaction (PCR) can detect the bacterium with the same sensitivity and specificity. PCR is more sensitive but it demands: a. biopsy sample, b. extremely careful treatment of the sample, c. several days to obtain the result. It should be noted that highly skilled staff and careful sample treatment are necessary if histology, cytology or bacterioculture methods are used otherwise the values of sensitivity and specificity will be substantially lower. Comparative table of tests used for H.pylori detection

Methos Sample Active diagnostics Sensitivity, % Specificity, % Histology Biopsy Yes 91-99 95-100 Cytology Biopsy Yes 87-97 92-96 Bacterioculture test Biopsy Yes 70-92 90-100 Serology Serum No 88-99 86-95 Polimerase chain reaction Biopsy Yes 100 100 Breath test Breath sample Yes 89-99 93-100

Invasive character of histology, cytology, bacterioculture test and PCR results in patient discomfort and becomes a great drawback when examination should be made for children or nervous patients. Serology test which detects H.pylori antibodies, is very effective screening test but it can't be used fot therapy monitoring because H.pylori antibodies can be observed in serum for a long time (up to 2 years) after bacterium eradication in the stomach. Isotope breath test has high sensitivity and specificity, it is simple in use and it is the most appropriate test for eradication therapy monitoring.