Salivary IgG assay to detect Helicobacter pylori infection in an Indian adult population

Abstract

Helicobacter pylori infection, the commonest chronic bacterial infection in humans, causes chronic gastritis, peptic ulcer, and possibly gastric carcinoma and lymphoma. Recently, investigators have focused on its role in the development of extra-gastrointestinal diseases with oral manifestations. H. pylori infection can be diagnosed by various methods. Of late, H. pylori IgG antibodies have been detected in saliva using enzyme-linked immunosorbent assay (ELISA). However, local validation of serological test is needed before implementing a test in different populations. To detect anti H. pylori specific immunoglobulin G (IgG) antibodies in saliva of adult patients with gastrointestinal symptoms by ELISA, to diagnose H. pylori infection in such patients by histopathology, and to evaluate the diagnostic accuracy of the immunoassay as compared to histopathologic diagnosis. The study included 40 adult patients with gastrointestinal symptoms suggestive of peptic ulcer disease. Saliva samples were analyzed for anti H. pylori IgG using EIAgen H. pylori IgG kit. Histopathologic diagnosis using gastric biopsy samples was the gold standard. The sensitivity and specificity of the test were 79.31% and 63.64%, respectively. The positive and negative predictive values were 85.19% and 53.85%, respectively. The accuracy of EIAgen H. pylori IgG kit for salivary detection of anti H. pylori IgG antibodies was found to be 75%. EIAgen H. pylori IgG assay is a noninvasive, moderately accurate, and sensitive method for the detection of H. pylori infection in saliva. Salivary anti H. pylori IgG test prior to endoscopy is a useful screening test for seroepidemiological studies.