title: Utility of quantitative flow cytometry immunophenotypic analysis of CD5 expression in small B-cell neoplasms.
abstract: BACKGROUND
  The value of assessing CD5 expression in the differential diagnosis of small B-cell neoplasms is well established. Assessment is usually done qualitatively.
  
  
  OBJECTIVE
  To assess CD5 expression levels by quantitative flow cytometry immunophenotyping and to determine possible differences among various small B-cell neoplasms.
  
  
  METHODS
  We performed 4-color flow cytometry analysis on specimens of peripheral blood and bone marrow aspirate and quantified CD5 expression in various small B-cell lymphomas and leukemias. We also assessed CD5 levels in peripheral blood samples of healthy blood donors.
  
  
  RESULTS
  Cases of chronic lymphocytic leukemia and mantle cell lymphoma had higher levels of CD5 compared with control B cells (P < .001). Cases of marginal zone lymphoma and hairy cell leukemia had CD5 levels similar to control B cells (P = .35 and P = .14, respectively), whereas cases of follicular lymphoma and lymphoplasmacytic lymphoma had significantly lower CD5 levels than control B cells (P < .001 and P = .04, respectively). In B-cell neoplasms, a high level of CD5 expression was correlated with a homogeneous pattern of positive events, whereas lower CD5 levels were correlated with heterogeneous patterns of positive events.
  
  
  CONCLUSIONS
  Using flow cytometric immunophenotypic analysis to quantify CD5 levels can aid in diagnosis. CD5 expression levels are higher in patients with chronic lymphocytic leukemia and mantle cell lymphoma, and expression is observed in a homogeneous pattern, as compared with other B-cell neoplasms that are either negative for CD5 or express CD5 at lower levels with a heterogeneous pattern. However, there is some overlap in CD5 expression levels between a subset of atypical chronic lymphocytic leukemia and marginal zone lymphoma cases.
authors: From the Departments of Hematopathology (Ms Challagundla, Mr Reyes, and Drs Jorgensen, Kanagal-Shamanna, Medeiros, and Miranda) and Leukemia (Dr Ferrajoli), University of Texas MD Anderson Cancer Center, Houston; the Department of Hematopathology, Genoptix Medical Laboratory, Carlsbad, California (Dr Gurevich); and the Department of Hematopathology, King's Daughters Medical Center, Ashland, Kentucky (Dr Pierson).
authors: Pramoda
authors: P
authors: Challagundla
authors: Jeffrey L
authors: JL
authors: Jorgensen
authors: Rashmi
authors: R
authors: Kanagal-Shamanna
authors: Inga
authors: I
authors: Gurevich
authors: Diane M
authors: DM
authors: Pierson
authors: Alessandra
authors: A
authors: Ferrajoli
authors: Steven R
authors: SR
authors: Reyes
authors: L Jeffrey
authors: LJ
authors: Medeiros
authors: Roberto N
authors: RN
authors: Miranda
mesh_terms: D018956:CD5 Antigens / Q000378:metabolism*; D016022:Case-Control Studies; D020732:Cytogenetic Analysis; D003937:Diagnosis, Differential; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D016130:Immunophenotyping / Q000379:methods*; D015448:Leukemia, B-Cell / Q000175:diagnosis / Q000276:immunology*; D007943:Leukemia, Hairy Cell / Q000175:diagnosis / Q000276:immunology; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000175:diagnosis / Q000235:genetics / Q000276:immunology; D016393:Lymphoma, B-Cell / Q000175:diagnosis / Q000276:immunology*; D018442:Lymphoma, B-Cell, Marginal Zone / Q000175:diagnosis / Q000276:immunology; D008224:Lymphoma, Follicular / Q000175:diagnosis / Q000276:immunology; D020522:Lymphoma, Mantle-Cell / Q000175:diagnosis / Q000276:immunology; D008258:Waldenstrom Macroglobulinemia / Q000175:diagnosis / Q000276:immunology
chemical_list: D018956:CD5 Antigens