Evaluation of the anti-East Asian CagA-specific antibody for CagA phenotyping.
The determination of the cagA genotype is generally based on sequencing the variable 3' region of the cagA gene. In a previous study, we successfully generated an anti-East Asian CagA-specific antibody (anti-EAS Ab) immunoreactive only with the East Asian CagA and not with the Western CagA. In a small number of Japanese patients, anti-EAS Ab appeared to be a useful tool for phenotyping CagA immunohistochemically. The present study was conducted to validate the anti-EAS Ab immunohistochemistry method in a larger number of patients from Vietnam and Thailand. A total of 385 Vietnamese and Thais were recruited. Helicobacter pylori status was determined by a combination of three methods, including culture, histology, and immunohistochemistry with anti-H. pylori antibody. The sensitivity, specificity, and accuracy of the anti-EAS Ab immunohistochemistry method for the diagnosis of CagA phenotype were calculated based on the results of the cagA sequencing as the gold standard. The sensitivity, specificity, and accuracy of our immunohistochemistry method were 96.7%, 97.9%, and 97.1%, respectively. Moreover, anti-EAS Ab was not cross-reactive with noninfected gastric mucosa. In conclusion, immunohistochemistry with anti-EAS Ab appears to be a good method for determination of CagA phenotype.
Nguyen
Lam Tung
LT
Department of Molecular Pathology, Faculty of Medicine, Oita University, Yufu-city, Oita, Japan.
Uchida
Tomohisa
T
Kuroda
Akiko
A
Tsukamoto
Yoshiyuki
Y
Trinh
Tuan Dung
TD
Ta
Long
L
Mai
Hong Bang
HB
Ho
Dang Quy Dung
DQ
Hoang
Hoa Hai
HH
Vilaichone
Ratha-Korn
RK
Mahachai
Varocha
V
Matsuhisa
Takeshi
T
Kudo
Yoko
Y
Okimoto
Tadayoshi
T
Kodama
Masaaki
M
Murakami
Kazunari
K
Fujioka
Toshio
T
Yamaoka
Yoshio
Y
Moriyama
Masatsugu
M
D000328:Adult; D000818:Animals; D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial / Q000032:analysis* / Q000276:immunology; D001426:Bacterial Proteins / Q000032:analysis* / Q000276:immunology; D003429:Cross Reactions; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000382:microbiology; D016480:Helicobacter pylori / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D013785:Thailand; D014744:Vietnam; D037521:Virulence Factors / Q000032:analysis* / Q000276:immunology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D037521:Virulence Factors; C080866:cagA protein, Helicobacter pylori