title: Low frequency of anti-SLA/LP autoantibody in Japanese adult patients with autoimmune liver diseases: analysis with recombinant antigen assay.
abstract: Anti-soluble liver antigen/liver pancreas (SLA/LP) autoantibody has been proposed to be one of the autoantibodies characterizing autoimmune hepatitis (AIH). Recently, one of the autoantigens to anti-SLA/LP was identified as a UGA suppressor tRNA-associated protein. Although the function of this protein remains unknown, the recombinant protein has been prokaryotically expressed. Using this protein as an antigen, a recombinant immunoassay for anti-SLA/LP autoantibody has been established and the frequency and significance of this autoantibody have been discussed in European countries. So, in the present study, we investigated anti-SLA/LP autoantibodies in Japanese patients with autoimmune liver diseases using the recombinant antigen ELISA and Western blot assay. Seventy-five patients with AIH type 1, 5 with AIH type 2, 46 with primary biliary cirrhosis, 10 with primary sclerosing cholangitis, 47 with chronic hepatitis C, 48 with systemic lupus erythematosus, 3 with cryptogenic hepatitis, and 40 normal controls were the subjects of the present study. Anti-SLA/LP autoantibodies were detected in only 5 of 75 (6.7%) patients with AIH type 1, but in none of the other 159 patients or 40 normal controls. The clinicopathologic features of anti-SLA/LP-positive AIH type 1, including carriers of HLA DR locus variations, were not significantly different from anti-SLA/LP-negative patients except for the mortality rate. Anti-SLA/LP autoantibody was detected at a low frequency in Japanese patients with AIH type 1 and did not significantly influence clinical features. However, since it has high disease-specificity to AIH type 1, further analysis of SLA/LP may contribute to help clarify the pathogenesis of AIH type 1.
authors.affiliation: Fourth Department of Internal Medicine, Teikyo University School of Medicine, 3-8-3, Mizonokuchi, Takatsu-ku, Kawasaki-shi, Kanagawa 2138507, Japan. naiken@med.teikyo-u.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyakawa
authors.forename: Yumi
authors.initials: Y
authors.lastname: Kawashima
authors.forename: Eriko
authors.initials: E
authors.lastname: Kitazawa
authors.forename: Naomi
authors.initials: N
authors.lastname: Kawaguchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Kato
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kikuchi
authors.forename: Erika
authors.initials: E
authors.lastname: Imai
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Fujikawa
authors.forename: Etsuko
authors.initials: E
authors.lastname: Hashimoto
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schlumberger
mesh_terms: D001323:Autoantibodies / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology* / Q000503:physiopathology; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007564:Japan; D008107:Liver Diseases / Q000276:immunology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; C046431:liver antigen LA-1