Efficacy of sonicated and acid-extractable antigens in the serodiagnosis of H. pylori infection in peptic ulcer patients.

ABSTRACT

Helicobacter pylori is implicated in causation of peptic ulcers and gastric cancer and plays a pivotal role in gastric pathophysiology. In the present study we evaluated the relative efficacy of sonicated and acid-extractable antigens in the serodiagnosis of H. pylori infection in peptic ulcer patients by ELISA. In the present study we evaluated the relative efficacy of sonicated and acid-extractable antigens in the serodiagnosis of H. pylori infection in peptic ulcer patients by ELISA. The two types of antigens mentioned above were prepared from H. pylori subcultures following appropriate procedures. Sera were collected from 13 subjects of whom eight were diagnosed to be suffering from duodenal ulcer (DU) and five from non-ulcer dyspepsia (NUD) and screened for the presence of anti H. pylori antibodies by ELISA. A case was considered seropositive, if the OD value was more than or equivalent to twice the mean OD value of blank. Analysis of our results showed that, with acid extractable antigen at a concentration of 2 mg/mL, 12 cases were seropositive. Contrastingly, with sonicated antigen, at a concentration of 2 mg/mL only eight cases were positive. It is concluded from this study, that the use of relatively purified antigens like acid extractable antigens enhances the sensitivity and specificity of this serodiagnostic test, indicative of its relatively higher efficacy over sonicated lysate containing multiple antigens.