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

Figure 2

Algorithm for H. pylori CagA typing by IHC using gastric biopsy samples. The number of samples with positive or negative results by IHC with each of the H. pylori mAb (specific to species-specific LPS), the CagA mAb (specific to a common CagA motif), and the EPIYA-C/D mAbs (specific to either an EPIYA-C or EPIYA-D motif) are shown in the algorithm for CagA status determination. The detection status was positive (+) or negative (−) by IHC with the EPIYA-C mAb (C) or the EPIYA-D mAb (D). According to the algorithm, the CagA status of the 69 H. pylori-infected patients was determined as either the Western type, East Asian type, or CagA-negative H. pylori, excluding 2 patients with undetermined results.