Enzyme-Linked Immunosorbent Assay forHelicobacter pyloriNeeds Adjustment for the Population Investigated

Abstract

Helicobacter pylori infection and peptic ulcer disease are common in developing countries, e.g., Vietnam. An enzyme-linked immunosorbent assay (ELISA) for screening of patients and for seroepidemiology is a useful tool but needs to be validated in the population studied. We used in-house ELISA with sonicated Swedish and Vietnamese strains as antigens to measure immunoglobulin G antibodies after absorption with sonicated Campylobacter jejuni in sera from 270 H. pylori culture-confirmed peptic ulcer patients, 128 Swedish ureabreath test and immunoblot-positive healthy controls, and 432 Vietnamese immunoblot-positive population controls. Sonicated whole-cell antigen based on the local strains showed a significantly better performance. Immunoblot-positive peptic ulcer patients had significantly higher antibody concentrations than immunoblotpositive population controls, necessitating a lower cutoff level if serology is used for screening or epidemiological purposes. The study shows that the parameters of ELISA for H. pylori need to be adjusted for the population being investigated.

Prevalence and Risk Factors of Helicobacter pylori Infection in Muong Children in Vietnam

“…Nguyen et al reported an increase of H. pylori seroprevalence from 30.9% in children under 3% to 53.1% in 15-18 year group (OR: 1.59; 95% CI: 1.1-2.32) in a study population of 476 children [13]. Our results are comparable with some other findings [13,16,20,21].…”

“…The method had been established and evaluated previously, giving with a cut-off level of OD 0.22 a sensitivity of 93.9% to 99.6% and a specificity of 90.7%. [16]. Since this type of assay can have ±10% variability around the established cut-off level, we used the lower cut-off of 0.2 in order to ensure a high sensitivity in the assay.…”

“…Blood samples (5 mL) were obtained from each subject by peripheral venipuncture under aseptic conditions and were immediately centrifuged. Sera were separated and preserved in vaccine thermos, then sent to the reference laboratory (Microbiology Division of Digestive Diseases, National Institute of Epidemiology and Hygiene) on the same day where sera were stored at -20°C and processed as previously described [16].…”

vacA genotypes in oral cavity and Helicobacter pylori seropositivity among adults without dyspepsia

“…The difference might be due to several factors: genetic, geographic and socio-economic proper to each population plus to differences in the bacterial strains that originated the antigens used in antibody detection (15). More than 70% of the seropositive subjects used to drink alcohol, sodas and coffee, so this group might have a greater probability to develop gastric pathology.…”

Intestinal Helminthiasis in Colombian Children Promotes a Th2 Response to Helicobacter pylori: Possible Implications for Gastric Carcinogenesis

“…To test the association between parasites in children and potential polarization of the host immune response to H. pylori, we assayed feces for parasites and serum for IgG responses to H. pylori as noninvasive and sensitive methods to screen for parasitic and H. pylori infections. These assays have been used to estimate prevalence of H. pylori in defined populations (40), and as others have reported (19,22,41), we developed an antigen-specific ELISA for H. pylori because the accuracy of commercial kits for serologic screening for H. pylori infection in children has been questioned (42). Furthermore, commercial kits for measurement of IgG subclass responses to H. pylori are not available.…”