Serology and C14-UBT are the most commonly used non-invasive tests of H. pylori infection. The diagnostic characteristics of the tests depend also on the prevalence of H. pylori infection in the population tested. The diagnostic characteristics of the tests depend also on the prevalence of H. pylori infection in the population tested. Higher prevalences would imply higher sensitivity and lower specificity. There are reports suggesting that there is an association between the level of H. pylori IgG antibodies and the severity of inflammation of the gastric mucosa and also between antibody level and a current peptic ulcer. If so, the level, not only positively or not, of H. pylori IgG antibody tests might be of clinical importance.
A research article to be published on August 28, 2008 in the World Journal of Gastroenterology addresses this question. The research team was led by Dr. Rolv-Ole Lindsetmo and his colleagues in the University of Tromsø in Norway.
They showed by comparing H. pylori IgG antibodies from two peptic ulcer populations that coming from a background population with a high H. pylori prevalence, that the level of IgG antibodies could not be used to predict active peptic ulcer disease and did not show any association with gastric mucosal morphology.
Uncritical use of H. pylori serology will represent a considerable overestimation of H. pylori prevalence in the population tested. A negative H. pylori serology test result is on the other hand very reliable to exclude H. pylori infection and thereby useful in screening purposes.
Dr. Lindsetmo believes that H. pylori serology should be limited to screening and research purposes and that H. pylori serology has limited value in daily clinical practice.