Novel CagA ELISA exhibits enhanced sensitivity of Helicobacter pylori CagA antibody

World J Gastroenterol. 2017 Jan 7;23(1):48-59. doi: 10.3748/wjg.v23.i1.48.


Aim: To develop a novel Helicobacter pylori (H. pylori) CagA antibody enzyme-linked immunosorbent assay (ELISA) suitable for detecting serum anti-CagA antibodies with high sensitivity.

Methods: Recombinant East Asian-type CagA protein was purified and immobilized for ELISA. Serum samples from 217 Vietnamese individuals (110 H. pylori-infected and 107 uninfected individuals) were applied. Conventional ELISA from Western-type CagA and our East Asian-type CagA ELISA were evaluated by comparing 38 subjects with the Western-type genotype and 72 subjects with the East Asian-type cagA genotype. Histological scores of the gastric mucosa were determined using the updated Sydney System to examine the relationship with anti-CagA antibody titers.

Results: Recombinant 70-100 kDa fragments were immobilized on the ELISA plate. In ROC analysis, the area under the curve of our East Asian-type CagA ELISA was comparable to that of conventional CagA ELISA. The sensitivity of the two ELISAs differed depending on the cagA genotype. The sensitivity of East Asian-type CagA ELISA was higher for subjects infected with East Asian-type cagA H. pylori (P < 0.001), and the sensitivity of the conventional CagA ELISA tended to be higher for subjects infected with Western cagA H. pylori (P = 0.056). The titer of anti-CagA antibody tended to correlate with monocyte infiltration scores (r = 0.25, P = 0.058) and was inversely correlated with H. pylori density (r = -0.26, P = 0.043).

Conclusion: The novel ELISA is useful to detect anti-CagA antibodies in East Asian countries, and the titer may be a marker for predicting chronic gastritis.

Keywords: Anti-CagA antibody; Enzyme-linked immunosorbent assay; Gastritis; Helicobacter pylori; Inflammation; cagA genotype.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Antigens, Bacterial / blood
  • Antigens, Bacterial / genetics
  • Antigens, Bacterial / immunology*
  • Bacterial Proteins / blood
  • Bacterial Proteins / genetics
  • Bacterial Proteins / immunology*
  • Biopsy
  • Chronic Disease
  • Enzyme-Linked Immunosorbent Assay
  • Gastric Mucosa / microbiology*
  • Gastric Mucosa / pathology
  • Gastritis / blood
  • Gastritis / diagnosis*
  • Gastritis / microbiology
  • Gastroscopy
  • Genotype
  • Helicobacter Infections / blood
  • Helicobacter Infections / diagnosis*
  • Helicobacter Infections / microbiology
  • Helicobacter pylori / genetics
  • Helicobacter pylori / isolation & purification*
  • Humans
  • Recombinant Proteins / immunology
  • Sensitivity and Specificity
  • Vietnam


  • Antigens, Bacterial
  • Bacterial Proteins
  • Recombinant Proteins
  • cagA protein, Helicobacter pylori