Serological response to Helicobacter pylori recombinant antigens in Chilean infected patients with duodenal ulcer, non-ulcer dyspepsia and gastric cancer.
We have previously cloned 10 Helicobacter pylori antigen genes from a Chilean strain including: cytotoxin VacA, a truncated region of CagA (called A17), a species-specific protein (Ag26), urease subunits (UreA, UreB), a flagellin, (FlaB), heat shock proteins (HspA and HspB), an adhesin (HpaA) and a lipoprotein (Lpp20). Immunogenicity of these antigens was tested by immunoblot with sera of Chilean infected patients, revealing that HpaA, A17, HspB and VacA were more frequently recognized (86%, 82%, 68% and 68%, respectively). According to the clinical condition, it was determined that Lpp20 was preferentially recognized by sera from non-ulcer dyspepsia patients (80%), A17 and VacA by patients with duodenal ulcer (92% and 83% respectively), and HspB by patients with duodenal ulcer (83%) and gastric cancer (90%). An ELISA was developed with a purified mixture of A17 and VacA antigens to test the different groups of patients. It was found that sera from duodenal ulcer patients showed higher values than those from non-ulcer dyspepsia patients, but this difference was not significant (p<0.2). Moreover, sera from gastric cancer patients showed values lower than those from non-ulcer dyspepsia patients (p<0.019). These results indicate that, in the Chilean population, antibodies raised against VacA and A 7 are not markers either for duodenal ulcer or for gastric cancer.
Opazo
P
P
Unidad de Biología Molecular, BIOS Chile IGSA, Santiago.
Müller
I
I
Rollán
A
A
Valenzuela
P
P
Yudelevich
A
A
García-de la Guarda
R
R
Urra
S
S
Venegas
A
A
D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology; D015415:Biomarkers; D016022:Case-Control Studies; D002677:Chile; D004381:Duodenal Ulcer / Q000150:complications / Q000276:immunology*; D004415:Dyspepsia / Q000150:complications / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D006360:Heat-Shock Proteins / Q000235:genetics / Q000276:immunology; D016481:Helicobacter Infections / Q000150:complications / Q000276:immunology; D016480:Helicobacter pylori / Q000235:genetics / Q000276:immunology*; D006801:Humans; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D013274:Stomach Neoplasms / Q000150:complications / Q000276:immunology*
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D015415:Biomarkers; D006360:Heat-Shock Proteins; C113725:HspA protein, bacteria; C112564:HspB protein, Helicobacter pylori; D011994:Recombinant Proteins; C074689:VacA protein, Helicobacter pylori