title: The diagnosis of Sézary syndrome on peripheral blood by flow cytometry requires the use of multiple markers.
abstract: BACKGROUND
  Diagnosis of Sézary syndrome (SS)-defining blood involvement is hampered by the lack of Sézary cell-specific markers and nonspecific morphology of the tumour cells.
  
  
  OBJECTIVE
  To identify the most reliable and easy to use markers for the diagnosis of SS-defining blood involvement.
  
  
  METHODS
  We studied 17 patients with SS and 11 control patients. We used flow cytometry for the detection of T-cell antigens (CD3, CD4, CD7 and CD8), expression of the Sézary cell-associated marker CD158k and T-cell receptor (TCR)-Vbeta chain. Additionally, Sézary cells were identified by peripheral blood smear for lymphocytes with cerebriform nuclei.
  
  
  RESULTS
  It was not possible to diagnose blood involvement in all patients with SS by a single marker or method, although none of the markers was increased in the control population. Sézary cells were detected by blood smears in 13 of 17 (76%), by flow cytometry by their CD4+ CD7- CD3(dim) phenotype (> 1000 cells microL(-1)) in 13 of 17 (76%) and by expression of CD158k in 11 of 17 (65%) patients with SS. A specific T-cell clone was identified by identical TCR-Vbeta chain expression in 12 of 17 (71%) patients with SS. The identification of Sézary cells in individual patients varied for the different markers investigated.
  
  
  CONCLUSIONS
  The combination of identifying CD4+ CD7- CD3(dim) cells, TCR-Vbeta chain and CD158k expression allowed a definite identification of SS-defining blood involvement in every individual patient. All of these markers can be measured by flow cytometry which would avoid time-consuming analysis of blood smears. These markers would also be suitable to monitor tumour cell load during therapy.
authors.affiliation: Department of Dermatology, Venereology and Allergology, University Medical Centre Mannheim, Ruprecht-Karls-University of Heidelberg, 68135 Mannheim, Germany. claus-detlev.klemke@haut.ma.uni-heidelberg.de
authors.forename: C-D
authors.initials: CD
authors.lastname: Klemke
authors.forename: J
authors.initials: J
authors.lastname: Brade
authors.forename: S
authors.initials: S
authors.lastname: Weckesser
authors.forename: M M
authors.initials: MM
authors.lastname: Sachse
authors.forename: N
authors.initials: N
authors.lastname: Booken
authors.forename: M
authors.initials: M
authors.lastname: Neumaier
authors.forename: S
authors.initials: S
authors.lastname: Goerdt
authors.forename: T C
authors.initials: TC
authors.lastname: Nebe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood*; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D012751:Sezary Syndrome / Q000175:diagnosis* / Q000378:metabolism; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D013601:T-Lymphocytes / Q000473:pathology*
chemical_list: D015703:Antigens, CD; D014408:Biomarkers, Tumor