title: Aberrant expression of napsin A in a subset of malignant lymphomas.
abstract: BACKGROUND
  Napsin A is commonly expressed in pulmonary adenocarcinomas and some renal cell carcinomas. However, napsin A expression in lymphoid neoplasms has never been reported.
  
  
  METHODS
  Glycoproteomic analyses of lymphoma-derived cell lines revealed napsin A expression in anaplastic large cell lymphoma (ALCL) cells. We thus investigated napsin A expression in lymphoid neoplasms. A variety of lymphomas (n=672) and histiocytic tumors (n=55) was immunostained for napsin A using patient tissues.
  
  
  RESULTS
  In reactive lymphoid tissues, only a few histiocytes were positive for napsin A. ALK-positive ALCLs most frequently expressed napsin A (34.4%, 11/32 cases) at a rate that was significantly higher compared with ALK-negative ALCL (8.6%, 3/35; P=0.015). Napsin A expression was also observed in 13.4% (20/149) of diffuse large B-cell lymphomas (DLBCL), 11.1% (15/134) of Hodgkin lymphomas, 4.9% (2/41) of follicular lymphomas, 6% (4/67) of peripheral T-cell lymphomas, and 3.8% (1/26) of plasma cell neoplasms. Otherwise, napsin A was not detected in any other types of lymphomas or histiocytic neoplasms. Napsin A expression in systemic ALCL was associated with a higher international prognostic index. ALCL and DLBCL patients with napsin A expression tended to have poor prognosis.
  
  
  CONCLUSIONS
  These results demonstrated that napsin A is aberrantly expressed in a subset of lymphomas. The biological significance of napsin A in lymphomas warrants further study.
authors.affiliation: Department of Pathology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Soo Jeong
authors.initials: SJ
authors.lastname: Nam
authors.affiliation: Department of Pathology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Sehui
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Pathology, Seoul National University Boramae Hospital, Seoul, South Korea.
authors.forename: Ji Eun
authors.initials: JE
authors.lastname: Kim
authors.affiliation: Department of Pathology, University of Michigan School of Medicine, Ann Arbor, MI, USA.
authors.forename: Megan S
authors.initials: MS
authors.lastname: Lim
authors.affiliation: Department of Pathology, University of Michigan School of Medicine, Ann Arbor, MI, USA.
authors.forename: Kojo S J
authors.initials: KS
authors.lastname: Elenitoba-Johnson
authors.affiliation: Department of Pathology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Chul Woo
authors.initials: CW
authors.lastname: Kim
authors.affiliation: Department of Pathology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea. junarplus@chol.com.
authors.forename: Yoon Kyung
authors.initials: YK
authors.lastname: Jeon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016282:Aspartic Acid Endopeptidases / Q000235:genetics / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006023:Glycoproteins / Q000378:metabolism*; D006689:Hodgkin Disease / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D016403:Lymphoma, Large B-Cell, Diffuse / Q000235:genetics / Q000378:metabolism; D017728:Lymphoma, Large-Cell, Anaplastic / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D020543:Proteome / Q000378:metabolism; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D006023:Glycoproteins; D020543:Proteome; D016282:Aspartic Acid Endopeptidases; C498549:NAPSA protein, human