title: Flow cytometric immunophenotypic analysis of systemic mastocytosis involving bone marrow.
abstract: BACKGROUND
  Mast cells of systemic mastocytosis (SM) have aberrant immunophenotypes that are useful for their detection by flow cytometry immunophenotyping.
  
  
  OBJECTIVE
  To assess the usefulness of CD2, CD25, and other antigens for establishing the diagnosis of SM in bone marrow using flow cytometry immunophenotyping.
  
  
  METHODS
  We studied 50 bone marrow aspirates of patients with SM using flow cytometry immunophenotyping. The bone marrow aspirates were stained with antibodies specific for CD2, CD25, CD35, CD59, CD63, and CD69. For the detection of CD2 and CD25, antibodies conjugated with phycoerythrin (PE) or fluorescein isothiocyanate (FITC) were compared. CD45-PerCP and CD117-APC were used for gating. Data were acquired on FACS Calibur cytometers and analyzed using CellQuest software.
  
  
  RESULTS
  CD2 and CD25 were positive in 41 of 50 (82%) and 45 of 50 (90%) SM cases, respectively. For CD2, the PE-conjugated antibody yielded better sensitivity than the FITC-conjugated antibody (31 of 40 [78%] versus 28 of 40 [70%]). For CD25, PE-conjugated and FITC-conjugated antibodies showed similar detection sensitivity, although the intensity of expression was brighter with CD25-PE. Compared with immunohistochemistry, flow cytometry immunophenotyping was superior for detecting CD2 (14 of 23 [61%] versus 9 of 23 [39%]). Other antigens frequently overexpressed in SM were CD35 (43 of 50 [86%]), CD59 (46 of 50 [92%]), CD63 (43 of 49 [88%]), and CD69 (39 of 48 [81%]).
  
  
  CONCLUSIONS
  Flow cytometry immunophenotyping is a rapid and sensitive technique for characterizing mast cells in bone marrow aspirate specimens. The use of PE-conjugated antibodies for CD2 and CD25 improves the detection rate (CD2) or facilitates analysis (CD25); therefore, PE-conjugated antibodies are suggested. Antibodies reactive with CD35, CD59, CD63, and CD69 are also helpful in detecting SM in bone marrow.
authors.affiliation: From the Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Kausar J
authors.initials: KJ
authors.lastname: Jabbar
authors.forename: L Jeffrey
authors.initials: LJ
authors.lastname: Medeiros
authors.forename: Sa A
authors.initials: SA
authors.lastname: Wang
authors.forename: Roberto N
authors.initials: RN
authors.lastname: Miranda
authors.forename: Malisha R
authors.initials: MR
authors.lastname: Johnson
authors.forename: Srdan
authors.initials: S
authors.lastname: Verstovsek
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Jorgensen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000378:metabolism; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism; D001853:Bone Marrow / Q000276:immunology / Q000473:pathology*; D018801:CD2 Antigens / Q000378:metabolism; D018957:CD59 Antigens / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D016650:Fluorescein-5-isothiocyanate; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping / Q000379:methods*; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D037181:Lectins, C-Type / Q000378:metabolism; D008297:Male; D008407:Mast Cells / Q000276:immunology / Q000473:pathology*; D034721:Mastocytosis, Systemic / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology*; D008875:Middle Aged; D010799:Phycoerythrin; D017463:Receptors, Complement 3b / Q000378:metabolism; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D060149:Tetraspanin 30 / Q000378:metabolism; D000099192:CD69 Antigens
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D018801:CD2 Antigens; D018957:CD59 Antigens; D016650:Fluorescein-5-isothiocyanate; D053645:Interleukin-2 Receptor alpha Subunit; D037181:Lectins, C-Type; D010799:Phycoerythrin; D017463:Receptors, Complement 3b; D060149:Tetraspanin 30; D000099192:CD69 Antigens