NON-ENDOSCOPIC TESTS IN THE DIAGNOSIS OF HELICOBACTER-PYLORI INFECTION

The urea breath test (UBT) and serological antibody detection are simp ler and less expensive than endoscopic tests for the diagnosis of Heli cobacter pylori. For the UBT, either non-radioactive C-13 or radioacti ve C-14 is used as an isotopic marker. C-14-UBTs are cheaper and are s afe, but licensing regulations may make them inconvenient, Some UBTs h ave been simplified by omitting the normal test meal and encapsulating the urea to avoid metabolism by oral bacteria, These modified tests n eed further validation, especially when used for assessing H. pylori s tatus after treatment, Serological tests detect circulating IgG or IgA . They are of variable accuracy, the best performing as well as UBTs. Paired serum samples pre-treatment and 6 months post-treatment accurat ely assess treatment success, Rapid in-office tests appear less accura te and cannot be used for post-treatment assessment. In practice, for primary diagnosis of H. pylori infection, endoscopic tests are best be cause endoscopy allows assessment of treatment indications, Where indi cations already exist or taking biopsies is dangerous, UBTs or serolog y are suitable, but serology is cheaper and more convenient, After tre atment, endoscopy is usually unnecessary and UBTs accurately assess H. pylori status at 4 weeks. Serology is an alternative only if results are not required before 6 months.