title: Restricted killer cell immunoglobulin-like receptor repertoire without T-cell receptor gamma rearrangement supports a true natural killer-cell lineage in a subset of sinonasal lymphomas.
abstract: The cellular lineage of sinonasal T/NK (natural killer) cell lymphoma remains controversial. Lineage assignment is difficult because T cells and NK cells have a similar morphology and surface markers. Consequently, the assignment must depend heavily on the status of T-cell receptor (TCR) rearrangement. A monoclonal TCR rearrangement supports a T lineage; however, a corresponding monoclonality test for NK cells has not yet been established. Each NK cell bears a distinct set of killer cell immunoglobulin (Ig)-like receptors (KIRs) that are randomly distributed over three groups. In principle, restriction of the KIR repertoire signifies a monoclonal or possibly oligoclonal NK-cell proliferation, just as Ig light-chain restriction usually indicates a monoclonal B-cell neoplasm. Using a novel group-specific reverse transcriptase-polymerase chain reaction, we found a restricted KIR repertoire in most sinonasal lymphomas (9 of 10), but only rarely in T-cell lymphomas (2 of 10) or reactive conditions involving T/NK cells (1 of 10). KIR+ sinonasal lymphomas usually lacked a monoclonal TCR-gamma rearrangement pattern, expressed another NK cell receptor, NKG2a, and were usually CD56-positve, cyclin-dependent kinase-6 (CDK6)-positive, CD44-negative, a phenotype already reported to indicate a true NK cell lineage. We conclude that, although sinonasal lymphomas have heterogeneous genotypes and phenotypes, a restricted KIR repertoire without TCR-gamma rearrangement provides preliminary support for the monoclonality hypothesis and can be used for defining a true NK-cell lineage in a subset of sinonasal lymphomas.
authors.affiliation: Department of Pathology, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: C W
authors.initials: CW
authors.lastname: Lin
authors.forename: W H
authors.initials: WH
authors.lastname: Lee
authors.forename: C L
authors.initials: CL
authors.lastname: Chang
authors.forename: J Y
authors.initials: JY
authors.lastname: Yang
authors.forename: S M
authors.initials: SM
authors.lastname: Hsu
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000378:metabolism*; D008223:Lymphoma / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D055654:NK Cell Lectin-Like Receptor Subfamily C; D010255:Paranasal Sinus Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics*; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism*; D055607:Receptors, Natural Killer Cell; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
chemical_list: C527054:KLRC1 protein, human; D055654:NK Cell Lectin-Like Receptor Subfamily C; D016692:Receptors, Antigen, T-Cell, gamma-delta; D011971:Receptors, Immunologic; D055607:Receptors, Natural Killer Cell