Open AccessDetection of autoantibodies to nucleolar transcription factor NOR 90/hubf in sera of patients with rheumatic diseases, by recombinant autoantigen–based assays
Author(s) -
Fujii Takao,
Mimori Tsuneyo,
Akizuki Masashi
Publication year - 1996
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/art.1780390808
Subject(s) - autoantibody , recombinant dna , autoimmunity , fusion protein , antibody , complementary dna , epitope , rheumatoid factor , immunology , biology , microbiology and biotechnology , medicine , gene , genetics
Abstract Objective . We attempted to clarify the clinical characteristics of Japanese patients with autoantibodies to nucleolar transcription factor NOR 90/hUBF (anti‐NOR 90) and to analyze the autoantigenic epitopes recognized by anti‐NOR 90. Methods . Ninety‐one patient sera containing anti‐nucleolar antibodies (ANoA) by indirect immunofluorescence were collected. Immunoblottings were performed using recombinant fusion proteins expressed from several cloned complementary DNA (cDNA) encoding the NOR 90/hUBF autoantigen. Results . Anti‐NOR 90 were detected in sera from 9 (9.9%) of 91 patients with ANoA. Seven of these patients were diagnosed as having Sjögren's syndrome, 4 had concomitant rheumatoid arthritis, I had concomitant systemic sclerosis (SSc), and 2 had SSc alone. All 9 sera were reactive with more than 2 recombinant fusion proteins from cDNA encoding separate regions on the hUBF polypeptide. Conclusion . The results suggest that while anti–NOR 90 antibodies are rare, they are associated with Sjögren's syndrome in Japanese patients, and that autoimmunity is targeted toward at least 2 separate regions (amino acids 89–310 and 310–633) of the hUBF polypeptide.