ACCURACY OF IGG SEROLOGY AND OTHER TESTS IN CONFIRMING HELICOBACTER-PYLORI ERADICATION

Background: In this study we assessed the accuracy of IgG serology and other tests in confirming Helicobacter pylori eradication. Methods: T he outcome of anti-H. pylori therapy was established by at least two o f the following tests: rapid urease test (RUT), culture, C-14 urea bre ath test (non-capsule or capsule UBT), and IgG serology (Orion Diagnos tica Pyloriset New EIA-G). Results: Successful H. pylori eradication w as confirmed in 698 of 794 patients (88%). The percentage decrease in Ige antibody titre was related to the patients' pre-treatment IgG titr e and rime interval after treatment. A decrease in IgG titres of 40% o r more confirmed H. pylori eradication with 100% specificity, whereas the sensitivity was 82%, 90%, 98%, and 98% 3, 4, 5, and 6 months after therapy, respectively. The 40% cut-off confirmed eradication 3 to 6 m onths after therapy in 328 of 339 patients (97%) with pre-treatment Ig e titres of >700, in 36 of 45 patients (80%) with pre-treatment titres of 300-700, and in 5 of 12 patients (41%) with pretreatment titres of <300. The sensitivity and specificity of the other tests 2 months aft er treatment were as follows: RUT, 84% and 100%; culture. 88% and 100% ; non-capsule UBT, 100% and 89%; and capsule UBT, 100% and 97%. Conclu sion: A decrease in IgG antibody titre of 40% or more 3 to 6 months af ter therapy and the capsule C-14 UBT at the 2-month follow-up were bot h highly accurate in confirming H. pylori eradication.