Immunohistochemical Differentiation between Western and East Asian Types of CagA-Positive Helicobacter pylori in Gastric Biopsy Samples

Figure 3

IHC features of H. pylori with different CagA status in the gastric mucosa. Representative pictures of IHC with the H. pylori mAb (1), the CagA mAb (2), the EPIYA-C mAb (3), and the EPIYA-D mAb (4) are shown pairwise for each identical gastric biopsy sample with the Western type (a), East Asian type (b), or CagA-negative (c) H. pylori infection confirmed by PCR afterward. The novel EPIYA-C and EPIYA-D mAbs showed a prominent contrast in the presence (a3/b4) or absence (a4/b3) of signals on the surface of gastric foveolar epithelium in the CagA-positive (a2/b2) samples with H. pylori infection (a1/b1). A sample with many H. pylori (c1) and minimum inflammation was CagA negative (c2) with no reactivity by the novel EPIYA-C/D mAbs (c3/c4). Bars: 50 µm.