Detection of anti-HAV antibody with dot immunogold filtration assay.
OBJECTIVE
To establish a rapid, sensitive and specific immunogold assay for detection of hepatitis A virus infection.


METHODS
Rabbit monoclonal antibodies to anti-human IgM and IgG (Dako) were dotted on a nitrocellulose membrane (NCM) respectively to capture the human sera IgM and IgG. Then the captured antibodies would conjugate to HAV antigen, which was revealed by mouse anti-HAV IgG conjugated to gold particles. Final results were assessed by blind method.


RESULTS
Sera from 96 patients with acute hepatitis were used for our study. Compared with well-recognized standard (Abbott Laboratory, USA), the sensitivity and specificity of IgM-DIGFA (self-made) were 91.3 % (42/46) and 96.0 % (48/50), and those of IgM-ELISA (Kehua, Shanghai) were 97.8 % (45/46) and 100.0 % (50/50). The identical results were produced from the study with reagents at different conditions, and the study was repeated in 15 negative sera and 10 positive sera. The serum anti-HAV IgG was tested with DIGFA at the same time. In comparison with ELISA, the sensitivity and specificity of DIGFA for IgG anti-HAV were 87.2 % (41/47) and 91.8 % (45/49), respectively.


CONCLUSIONS
This assay can detect anti-HAV IgM and IgG simultaneously, and be done within 3 minutes. The simplicity, rapidity and specificity of the assay were useful for screening and epidemiological study.
Shao
Zhong-Jun
ZJ
Department of Epidemiology, Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China.
Xu
De-Zhong
DZ
Yan
Yong-Ping
YP
Li
Jing-Hua
JH
Zhang
Jing-Xia
JX
Zhang
Zhi-Ying
ZY
Pan
Bo-Rong
BR
D004797:Enzyme-Linked Immunosorbent Assay; D006506:Hepatitis A / Q000175:diagnosis* / Q000276:immunology*; D035922:Hepatitis A Antibodies / Q000032:analysis*; D006801:Humans; D015151:Immunoblotting / Q000379:methods*; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007150:Immunohistochemistry; D012680:Sensitivity and Specificity
D035922:Hepatitis A Antibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M