Comparison of enzyme immunoassays detecting Helicobacter pylori specific IgG in serum and saliva with endoscopic and biopsy findings in patients with dyspepsia

Purpose: To compare the performance of two indirect enzyme-linked immunosorbent assays (ELISA) detecting Helicobacter pylori (HP)-specific IgG antibodies in serum and saliva with endoscopic observations and histologic findings of biopsies from dyspeptic patients, in an area of high HP prevalence.
Materials and Methods : Sera, saliva and antral biopsies were obtained from 55 dyspeptic patients. IgG antibodies against HP were assayed in sera and saliva utilizing two indirect ELISAs. Biopsies were processed according to standard procedures in order to detect histological changes and the presence or absence of Helicobacter pylori. Laboratory data thus obtained were compared and statistically analyzed.
Results: Forty-two (76.36%) biopsies were positive for HP. The organisms were detected in 4 of 16 (25%) cases with normal endoscopic findings, in all 16 cases of gastritis and in 22 of the 23 (95.6%) cases of duodenal ulcers (DU). Serum and saliva HP-specific IgG antibodies were detected in 4 normal cases with positive biopsies, in 12 and 14 cases of gastritis, respectively, and in all 22 (100%) biopsy positive cases of DU. The sensitivities of the serum and saliva tests were 90.5% and 95%, respectively, while the specificities were 84.5% and 70%, respectively.
Conclusion: Due to their high sensitivity and specificity in diagnosing HP-associated DU and gastritis, serum and saliva antibody testing seems to offer a valuable alternative to invasive procedures especially in areas of high HP prevalence such as ours; saliva antibody testing is simple and practical especially in children and in difficult patients who resent venipuncture.