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Clinical and Vaccine Immunology, November 2009, p. 1687-1692, Vol. 16, No. 11
1071-412X/09/$08.00+0 doi:10.1128/CVI.00200-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.
Evaluation of the Anti-East Asian CagA-Specific Antibody for CagA Phenotyping
Lam Tung Nguyen,1,2,
Tomohisa Uchida,1,3,
Akiko Kuroda,1,2,
Yoshiyuki Tsukamoto,1
Tuan Dung Trinh,4
Long Ta,4
Hong Bang Mai,4
Dang Quy Dung Ho,5
Hoa Hai Hoang,5
Ratha-Korn Vilaichone,6
Varocha Mahachai,7
Takeshi Matsuhisa,8
Yoko Kudo,2
Tadayoshi Okimoto,2
Masaaki Kodama,2
Kazunari Murakami,2
Toshio Fujioka,2
Yoshio Yamaoka,9 and
Masatsugu Moriyama1*
Department of Molecular Pathology,1 Department of Gastroenterology,2 Department of Human Environmental and Social Medicine,3 Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita, Japan,9 108 Hospital, Hanoi, Vietnam,4 Cho Ray Hospital, Ho Chi Minh, Vietnam,5 Gastroenterology Unit, Department of Medicine, Thammasat University Hospital, Pathumthani, Thailand,6 Gastroenterology Unit, Department of Medicine, Chulalongkorn University Hospital, Bangkok, Thailand,7 Department of Gastrointestinal Endoscopy, Tama-Nagayama Hospital, Nippon Medical School, Tokyo, Japan8
Received 12 May 2009/ Returned for modification 13 August 2009/ Accepted 15 September 2009
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.
* Corresponding author. Mailing address: Department of Molecular Pathology, Faculty of Medicine, Oita University, Yufu-city, Oita 879-5593, Japan. Phone: 81-97-586-5690. Fax: 81-97-586-5699. E-mail: mmoriyam{at}med.oita-u.ac.jp
Published ahead of print on 23 September 2009.
L.T.N., T.U., and A.K. contributed equally to this work.
Clinical and Vaccine Immunology, November 2009, p. 1687-1692, Vol. 16, No. 11
1071-412X/09/$08.00+0 doi:10.1128/CVI.00200-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.
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