Summary auto-generated
This study examined the prevalence of serum antibodies to Helicobacter pylori virulence proteins VacA and CagA in 418 Chilean adults, correlating antibody presence with gastric disease severity. Participants included 316 patients with gastroduodenal pathology (152 duodenal ulcers, 14 gastric cancers, 150 gastritis cases) and 102 asymptomatic controls. Using enzyme immunoassay and Western blotting, researchers detected IgG antibodies to both VacA and CagA in 85% of symptomatic patients and 71% of asymptomatic subjects. Notably, duodenal ulcer and gastric cancer patients showed significantly higher prevalence of these antibodies compared to gastritis patients and healthy controls (p<0.0001). While the VacA+/CagA+ phenotype was common in Chilean H. pylori strains, findings differed from Asian studies where these virulence markers showed equally high prevalence across disease categories. The researchers concluded that although antibodies to VacA and CagA associate with severe gastric pathologies in Chile, the high overall prevalence in the population limits their utility as reliable risk markers for identifying individuals at risk of severe disease.
Key findings
- 85% of Chilean patients with gastroduodenal pathology and 71% of asymptomatic subjects carried antibodies to both VacA and CagA virulence proteins
- VacA+/CagA+ H. pylori strain infection was significantly more prevalent in duodenal ulcer and gastric cancer patients than in gastritis patients or asymptomatic controls
- Unlike Asian populations where VacA/CagA prevalence is uniformly high across disease categories, Chilean patients showed significant differences between symptomatic and asymptomatic groups
- The high overall prevalence of VacA/CagA antibodies in Chilean H. pylori-colonized individuals limits their utility as a reliable risk marker for severe gastric pathology
This summary was generated automatically from the article PDF and is not part of the original publication. Refer to the PDF for the authoritative text.
Abstract
The objective of this study was to evaluate the prevalence of antibodies to Helicobacter pylori CagA and VacA proteins and correlate this prevalence with gastric diseases in colonised Chileans. The study was performed in 418 adults colonised with H. pylori: 316 with gastroduodenal pathology (152 duodenal ulcer, 14 gastric cancer and 150 gastritis patients) and 102 asymptomatic subjects. Serum IgG antibodies to H. pylori were determined by enzyme immunoassay (EIA). Antibodies to VacA and CagA proteins were detected by Western blotting. In a subgroup of the patients, the vacuolating activity was determined by HeLa cell assay and the CagA product was confirmed by PCR assay. IgG antibodies to both VacA and CagA proteins of H. pylori were found in 270 (85%) of 316 colonised gastric patients and in 72 (71%) of 102 asymptomatic subjects. Colonisation with virulent strains was significantly higher among duodenal ulcer and gastric cancer patients than in gastritis patients or asymptomatic subjects. Infections with VacA+/CagA+ H. pylori strains is common in Chile but, in contrast to some Asian countries, this phenotype was more prevalent in isolates from patients with more severe gastric pathologies.