IS SALIVA SEROLOGY USEFUL FOR THE DIAGNOSIS OF HELICOBACTER-PYLORI

Background-The Cortecs Diagnostics Helisal Assay test is a quantitativ e immunoassay for salivary IgG antibodies against Helicobacter pylori. Saliva can be obtained simply with the kit in the general practitione rs surgery. Aims-To compare the new saliva serological test for H pylo ri with 'gold standard' evidence of H pylori infection (antral biopsy specimens fbr histology, culture, and urease test) and a new serum ser ological test. Patients-Eighty six unselected dyspeptic patients under going endoscopy. Methods-Each patient provided saliva and serum before endoscopy for H pylori serology, which was compared against 'gold sta ndard' evidence of infection. Results-Thirty two patients were H pylor i positive by the 'gold standard' tests. At a cut off value of 0.15 EU /ml the saliva test had a sensitivity of 88% and a specificity of 71%, with a negative predictive value of 90%. If patients who were taking omeprazole or had recent antibiotics are excluded, the sensitivity is unchanged but the specificity increases to 79%. The serum test had a s imilar sensitivity of 85% but better specificity of 78%. Conclusion-Se rum testing remains the best serological test for H pylori in the hosp ital setting. Saliva testing may have a role in epidemiological studie s and in screening dyspeptic patients in general practice, especially in children in whom venesection is more difficult.