Serodiagnosis of Helicobacter pylori infection by enzyme-linked immunoelectrotransfer blot. Gastrointestinal Physiology Working Group of Cayetano Heredia University

Abstract

Immunoreactive bands in sera from 81 Peruvian adults (48 females and 33 males) aged between 18 and 85 years were detected using enzyme-linked immunoelectrotransfer blot with a glycine-extracted Helicobacter pylori antigen. Sensitivity and specificity of bands were determined by comparison with results of H. pylori obtained by culture and silver stain of gastric biopsies. A crude antigen and a commercial enzyme-linked immunosorbent assay (Pylori Stat, Whittaker) were also evaluated for their diagnostic utility. H. pylori was detected in 57/81 (70%) of the subjects. The crude antigen enzyme-linked immunosorbent assay and the commercial enzyme-linked immunosorbent assay kits were, respectively, 84% and 88% sensitive. Specificity of both was 92%. The glycine-extracted antigen produced ten bands. The best single diagnostic band was at 20 kDa (83% sensitive and 96% specific). Three bands (13, 23, 30 kDa) were 100% specific. The combination of two diagnostic bands 20 and 30 kDa was 90% sensitive and 96% specific. Low molecular weight bands could be useful for the diagnosis of H. pylori infection.