Autoantibody detection in type 2 autoimmune hepatitis using a chimera recombinant protein.
Autoantibodies against cytochrome P450 2D6 (CYP2D6), known as anti-liver/kidney microsome type 1 (LKM1) and/or anti-human formiminotransferase cyclodeaminase, formally known as anti-liver cytosol type 1 (LC1) define type 2 autoimmune hepatitis (AIH). The aims of this work are to develop a sensitive and specific test to detect anti-LKM1 and/or anti-LC1 autoantibodies and to establish the prevalence of anti-LC1. Sera from children with type 2 AIH (n=48) and those from a control group (n=100) were evaluated for anti-LKM1 and anti-LC1 by Enzyme-Linked Immunosorbent Assay (ELISA) and Western blotting. Each serum sample was assayed for reactivity against formiminotransferase cyclodeaminase and CYP2D6 alone or as part of a recombinant chimera protein. By ELISA with recombinant chimera protein, 50 serum samples were positive, 48 from patients with type 2 AIH and 2 from patients with chronic hepatitis C. Twenty-five of 48 (52%) patients studied were positive for both CYP2D6 and LC1 autoantibodies. Anti-LC1, either as the only marker or associated with anti-LKM1, was positive in 34/48 (71%). By Western blotting, anti-LC1 was found in 27/48 (56%) patients. This ELISA technique has proven to be antigen-specific and more sensitive than Western blot for the detection of anti-LC1 and anti-LKM1 autoantibodies. The prevalence of anti-LC1 (71%) confirms it as an important immunomarker in type 2 AIH.
Vitozzi
Susana
S
Service de gastroénterologie. Hôpital Sainte-Justine, 3175 Côte Ste-Catherine, Montréal, Québec, Canada H36 1C5.
Lapierre
Pascal
P
Djilali-Saiah
Idriss
I
Alvarez
Fernando
F
D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D019693:Hepatitis, Autoimmune / Q000097:blood / Q000175:diagnosis* / Q000276:immunology*; D006801:Humans; D011993:Recombinant Fusion Proteins / Q000276:immunology; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods
D001323:Autoantibodies; D011993:Recombinant Fusion Proteins; C094307:anti-liver cytosolic protein 1; C060729:anti-liver kidney microsome antibody