title: Autoantibodies specific to hnRNP K: a new diagnostic marker for immune pathophysiology in aplastic anemia.
abstract: To identify a new diagnostic marker for the immune pathophysiology of aplastic anemia (AA), we screened sera of immune-mediated AA patients for the presence of antibodies (Abs) specific to proteins derived from a leukemia cell line UT-7 using two-dimensional electrophoresis followed by immunoblotting. The target proteins were identified by peptide mass fingerprinting. Heterogeneous nuclear ribonucleoprotein (hnRNP) K was identified as a novel autoantigen. An enzyme-linked immunosorbent assay revealed high titers of anti-hnRNP K Abs in 85 (31%) of 273 patients with AA. Sixty-four patients received antithymocyte globulin and cyclosporine after undergoing screening for anti-hnRNP K Ab, anti-DRS-1 Ab, anti-moesin Ab, and paroxysmal nocturnal hemoglobinuria (PNH)-type cells. Twenty (87%) of 23 patients with the presence of anti-hnRNP K Abs responded to the immunosuppressive therapy (IST), while 19 (46%) of 41 patients without the presence of anti-hnRNP K Abs responded. A multivariate analysis showed only PNH-type cells and anti-hnRNP K Abs to be significant factors for the prediction of a good response to IST. The detection of anti-hnRNP K Abs as well as PNH-type cells may therefore be useful for diagnosing the immune pathophysiology of AA.
authors.affiliation: Cellular Transplantation Biology, Kanazawa University Graduate School of Medical Science, 13-1 Takaramachi, Kanazawa, 920-8641, Japan.
authors.forename: Zhirong
authors.initials: Z
authors.lastname: Qi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takamatsu
authors.forename: J Luis
authors.initials: JL
authors.lastname: Espinoza
authors.forename: Xuzhang
authors.initials: X
authors.lastname: Lu
authors.forename: Naomi
authors.initials: N
authors.lastname: Sugimori
authors.forename: Hirohito
authors.initials: H
authors.lastname: Yamazaki
authors.forename: Katsuya
authors.initials: K
authors.lastname: Okawa
authors.forename: Shinji
authors.initials: S
authors.lastname: Nakao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000741:Anemia, Aplastic / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D015415:Biomarkers / Q000097:blood*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D015180:Electrophoresis, Gel, Two-Dimensional; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D018922:HL-60 Cells; D034641:Heterogeneous-Nuclear Ribonucleoprotein K / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D020014:K562 Cells; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D034641:Heterogeneous-Nuclear Ribonucleoprotein K