Accuracy of IgG Serology and Other Tests in Confirming Helicobacter pylori Eradication

• Published in: Scandinavian journal of gastroenterology Vol. 33; no. 7; pp. 710 - 715
• Main Authors: LERANG, F, HAUG, J. B, MOUM, B, MOWINCKEL, P, BERGE, T, RAGNHILDSTVEIT, E, BJØRNEKLETT, A
• Format: Journal Article
• Language: English
• Published: Copenhagen Informa UK Ltd 1998; Oslo Taylor & Francis; Stockholm Scandinavian University Press
• Subjects: Adult; Aged; Aged, 80 and over; Bacterial diseases; Bacterial diseases of the digestive system and abdomen; Biological and medical sciences; Biopsy, Needle; Breath Tests; Chi-Square Distribution; Confidence Intervals; Culture Media; Duodenal Ulcer - blood; Duodenal Ulcer - diagnosis; Female; Follow-Up Studies; Gastric Mucosa - microbiology; Gastroscopy; Helicobacter Infections - blood; Helicobacter Infections - diagnosis; Helicobacter pylori - isolation & purification; Human bacterial diseases; Humans; Immunoglobulin G - blood; Infectious diseases; Male; Medical sciences; Middle Aged; Sensitivity and Specificity; Serologic Tests - methods; Stomach Ulcer - blood; Stomach Ulcer - diagnosis; Urea - analysis; Human; Spirillales; Enzyme; Spirillaceae; IgG; Serology; Urease; Eradication; Infection; Accuracy; Breath test; Helicobacter pylori; Follow up study; Bacteriosis; Bacteria; Hydrolases; Culture
• ISSN: 0036-5521; 1502-7708
• DOI: 10.1080/00365529850171648

Background: In this study we assessed the accuracy of IgG serology and other tests in confirming Helicobacter pylori eradication. Methods: The outcome of anti-H. pylori therapy was established by at least two of the following tests: rapid urease test (RUT), culture, 14C urea breath test (non-capsule or capsule UBT), and IgG serology (Orion Diagnostica Pyloriset New EIA-G). Results: Successful H. pylori eradication was confirmed in 698 of 794 patients (88%). The percentage decrease in IgG antibody titre was related to the patients' pre-treatment IgG titre and time interval after treatment. A decrease in IgG titres of 40% or 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 months after therapy in 328 of 339 patients (97%) with pre-treatment IgG titres of >700, in 36 of 45 patients (80%) with pre-treatment titres of 300-700, and in 5 of 12 patients (42%) with pre-treatment titres of <300. The sensitivity and specificity of the other tests 2 months after treatment were as follows: RUT, 84% and 100%; culture, 88% and 100%; non-capsule UBT, 100% and 89%; and capsule UBT, 100% and 97%. Conclusion: A decrease in IgG antibody titre of 40% or more 3 to 6 months after therapy and the capsule 14C UBT at the 2-month follow-up were both highly accurate in confirming H. pylori eradication.