Autoantibodies to asialoglycoprotein receptor (ASGPR) measured by a novel ELISA--revival of a disease-activity marker in autoimmune hepatitis.
BACKGROUND
The liver-specific ASGPR is an autoantigen in autoimmune hepatitis (AIH) patients. Anti-ASGPR antibody correlates with disease activity, however, only in-house assays have been reported so far.


METHODS
Rabbit ASGPR was purified by affinity chromatography on galactose-Sepharose and used for standardised detection of anti-ASGPR by ELISA. Anti-ASGPR IgG was measured in sera from 45 patients with AIH, PBC (n=43), alcoholic liver disease (n=13), HBV infection (n=35), HCV infection (n=53), and 118 blood donors. Anti-ASGPR was correlated with biochemical parameters of disease activity in 22 AIH patients with consecutive samples.


RESULTS
Twenty-one of 30 untreated (70%) and five of 15 treated AIH patients (30%) showed elevated anti-ASGPR at first presentation. Only one blood donor demonstrated anti-ASGPR. ALD and PBC patients were all negative. ROC curve analysis of AIH and disease-control patients revealed a sensitivity of 77.8% and a specificity of 99.4%. Three (8.6%) of 35 HBV and 7 (13.2%) of 53 HCV patients demonstrated elevated anti-ASGPR. In AIH patients, anti-ASPGR correlated with liver-transaminases levels. In 22 follow-up patients, elevation of anti-ASPGR preceded liver-transaminases increase.


CONCLUSIONS
The novel anti-ASGPR ELISA is a readily available and specific diagnostic tool for anti-ASGPR detection in AIH. Quantification of anti-ASGPR is helpful in monitoring disease activity.
Hausdorf
Gert
G
Department of Rheumatology and Clinical Immunology, Charité Universitätsmedizin Berlin, Berlin, Germany.
Roggenbuck
Dirk
D
Feist
Eugen
E
Büttner
Thomas
T
Jungblut
Peter R
PR
Conrad
Karsten
K
Berg
Christoph
C
Klein
Reinhild
R
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D037263:Asialoglycoprotein Receptor / Q000276:immunology* / Q000302:isolation & purification; D001323:Autoantibodies / Q000032:analysis* / Q000276:immunology; D015415:Biomarkers / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D019693:Hepatitis, Autoimmune / Q000175:diagnosis* / Q000276:immunology* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011817:Rabbits; D051381:Rats; D012680:Sensitivity and Specificity; D055815:Young Adult
D037263:Asialoglycoprotein Receptor; D001323:Autoantibodies; D015415:Biomarkers