[The significance of antimitochondrial IgA and IgG in the diagnosis of primary biliary cirrhosis].
OBJECTIVE
To evaluate the sensitivity and the specificity of Anti-M2-3E ELISA for the detection of IgG- and IgA-specific isotypes of antimitochondrial antibody (AMA), and to investigate the significance of antimitochondrial IgA and IgG in the diagnosis of primary biliary cirrhosis (PBC).


METHODS
Sera were collected from 107 PBC patients, 87 disease controls and 26 healthy controls, and the antimitochondrial antibodies (IgG and IgA) were detected using indirect immunofluorescence (IFL), Anti-PDC ELISA and Anti-M2-3E ELISA.


RESULTS
The AMA IgG positive rate in PBC patients was 90.6% detected by Anti-M2-3E ELISA, which is significantly higher than that (81.3%) detected by IFL(t = 4.32, P < 0.05) and that (72.9%) detected by Anti- PDC ELISA (t = 6.03, P < 0.05). The AMA IgA was positive in 59 of the 107 PBC patients, and 99 of the 107 patients were positive for AMA IgG or/and IgA. 9 of the 20 IFL-negative patients were positive for AMA IgG as indicated by Anti-M2-3E ELISA, 11 of the 20 IFL-negative patients were positive for AMA IgG or/and IgA as indicated Anti-M2-3E ELISA. Compared to patients negative for IgG AMA, patients positive for IgG AMA had more severe histopathology and higher levels of ALP, IgG, and IgM.


CONCLUSIONS
The IgG and IgA Anti- M2-3E ELISAs are more sensitive for the AMA detection than IFN and the Anti-PDC ELISA. The presence of AMA IgG is the characteristics of severe PBC.
Lu
Jian-xi
JX
Vaccine Research Institute, the Third Affiliated Hospital, Sun Yat-sen University, Guangzhou 510630, China.
Qian
Shi-yu
SY
Shu
Xin
X
Li
Gang
G
D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D001707:Biopsy, Needle; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D019693:Hepatitis, Autoimmune / Q000097:blood / Q000175:diagnosis / Q000276:immunology; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D007074:Immunoglobulin G / Q000097:blood*; D008105:Liver Cirrhosis, Biliary / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D008930:Mitochondria, Liver / Q000276:immunology*; D012680:Sensitivity and Specificity
D001323:Autoantibodies; D015415:Biomarkers; D007070:Immunoglobulin A; D007074:Immunoglobulin G