Comparison of Serum IgG and IgA Levels against Helicobacter Pylori in Patients with Gastrointestinal Symptoms

Helicobacter pylori is a pathogen that can be colonized in the stomach. Most laboratories only use IgG and not IgA antibody to diagnose infection. The aim of this study was to compare both IgG and IgA-antibodies level for the detection H. pylori. The presence of IgG and IgA antibodies in the sera of the 517 patients suspected to H. pylori infection was evaluated by Enzyme-Linked Immunoadsordent Assays (ELISA) method. The positive cases of infection on the basis of IgG and IgA titers were 68% and 27%, respectively. Also, 7% of the patients with IgG negative were IgA positive. The comparison of antibody responses in our patients indicate that the sensitivity of IgA level is lower than IgG ELISA and both antibody titers must be evaluated for the identification of infection. In some cases, patients with IgG negative may have IgA positive assays; therefore, in the serological diagnostic process and without endoscopy, IgG results in association with IgA against H. pylori will be completed.