Salivary-Specific Immunoglobulin G in the Diagnosis of Helicobacter pylori Infection in Dyspeptic Patients

Objectives: Helicobacter pylori infection is arguably the most common chronic bacterial infection in humans. The high prevalence and the association with peptic ulceration and gastric cancer indicate that simple, non-invasive methods for diagnosis of the infection are needed. In this study, the accuracy of salivary diagnosis for H. pylori infection was assessed.
Methods: Saliva and serum samples of 152 dyspeptic patients were tested for H. pylori IgG and IgA by an in-house ELISA All patients underwent gastroscopy with biopsy.
Results: One hundred thirty-one patients (86%) were found to be H . pylori positive on histology. Duodenal ulcer was found in 67 patients; 85 had no macroscopic lesion. Salivary and serum H. pylori IgG as well as serum H . pylori IgA titers were significantly higher in H . positive- -positive than in H. pylori-negative patients. The sensitivity and specificity of salivary H. pylori IgG were 82% and 71 %, respectively; the positive and negative predictive values were 95% and 40%, respectively; and the accuracy 81%. The corresponding figures for serum H. pylori IgG were 97% and 91 %; 98% and 83%; and 96%. Those for serum H. pylori IgA were80% and52%;91% and30%;and76%. The sensitivity of salivary H. pylori IgG in detecting duodenal ulcer was 83% (56/67) that of serum H. pylori IgG was 97% (65/67) (odds ratio = 0.15; confidence interval = 0.02–0.8; p = 0.02).
Conclusions: Salivary H. pylori IgG was a fairly sensitive and accurate indicator of gastric H. pylori colonization, with a high positive predictive value in our population. Data, however, suggest that salivary H . pylori IgG measurements do not compare favorably with serology.