title: Gain of CD26 expression on the malignant T-cells in relapsed erythrodermic leukemic mycosis fungoides.
abstract: Loss of CD26 surface expression on the circulating malignant T-cell is the most widely accepted diagnostic marker in patients with leukemic cutaneous T-cell lymphoma (CTCL). CTCL cases with reemergence of CD7 and/or CD26 surface expression are unusual and of uncertain prognosis. We report the case of an erythrodermic leukemic mycosis fungoides patient who had achieved temporary remission after several months on multimodality immunotherapy and extracorporeal photopheresis, but who relapsed with aggressive disease phenotypically characterized by CD4+ T-cells with high CD26 expression. Polymerase chain reaction studies and high-throughput sequencing analyses from peripheral blood mononuclear cells at presentation and relapse consistently showed an identical clonal T-cell receptor suggesting evolution of her original malignant clone which lacked CD26 expression. Interestingly, quantitative expression of the sialomucin, CD164, mirrored her clinical picture, thus favoring its reliability as a novel biomarker in CTCL.
authors.affiliation: Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Filiberto
authors.initials: F
authors.lastname: Cedeno-Laurent
authors.affiliation: Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Maria
authors.initials: M
authors.lastname: Wysocka
authors.affiliation: Department of Molecular Pathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Amrom E
authors.initials: AE
authors.lastname: Obstfeld
authors.affiliation: Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Roberto A
authors.initials: RA
authors.lastname: Novoa
authors.affiliation: Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Carmela C
authors.initials: CC
authors.lastname: Vittorio
authors.affiliation: Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Ellen J
authors.initials: EJ
authors.lastname: Kim
authors.affiliation: Division of Blood and Marrow Transplantation, Department of Medicine, Stanford University School of Medicine, Stanford, California.
authors.forename: Wen-Kai
authors.initials: WK
authors.lastname: Weng
authors.affiliation: Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Alain H
authors.initials: AH
authors.lastname: Rook
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism / Q000473:pathology; D003873:Dermatitis, Exfoliative / Q000378:metabolism / Q000473:pathology; D018819:Dipeptidyl Peptidase 4 / Q000096:biosynthesis*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D015458:Leukemia, T-Cell / Q000378:metabolism / Q000473:pathology; D009182:Mycosis Fungoides / Q000378:metabolism / Q000473:pathology; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; C042807:DPP4 protein, human; D018819:Dipeptidyl Peptidase 4
keywords: CD164; CD26; CTCL; clonal evolution