title: Prognostic significance of CD38 and CD20 expression as assessed by quantitative flow cytometry in chronic lymphocytic leukaemia.
abstract: CD38 expression on chronic lymphocytic leukaemia (CLL) cells is a poor prognostic factor, however, methods for measuring this vary. The QuantiBRITETM flow cytometry (FC) system yields an absolute antigen expression value (antibodies bound/cell, ABC) and may be useful in standardizing CD38 expression analysis. We evaluated cryopreserved pretreatment CLL cells for CD20 ABC, CD38 ABC, and percentage of CD38+ B cells from 131 patients requiring therapy. The 92 patients (70%) with >/= 100 CD38 ABC had worse overall survival (OS; 34% at 5 years) compared with those with < 100 CD38 ABC (70% at 5 years, mortality hazard ratio 2.30, 95% confidence interval 1.28-4.12; two-tailed P = 0.003). Among the 64 patients with < 30% CD38+ cells, OS of the 25 with >/= 100 ABC was worse than that of the 39 with < 100 ABC (P = 0.018). OS of patients with < 30% CD38+ cells and >/= 100 ABC was actually similar to that of patients with >/= 30% CD38+ cells. BrightCD20 expression (>/= 20 000 ABC) was not associated with a worse OS (P = 0.10). The presence of >/= 100 CD38 ABC in CLL patients requiring therapy is an unfavourable prognostic factor for OS and quantitative FC may be superior to percentage CD38+ cell assessment. Prospective trials are required to determine more precisely the prognostic significance of absolute expression levels in fresh CLL cells.
authors.affiliation: Department of Clinical Pathology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA. hsie@ccf.org
authors.forename: Eric D
authors.initials: ED
authors.lastname: Hsi
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Kopecky
authors.forename: Frederick R
authors.initials: FR
authors.lastname: Appelbaum
authors.forename: David
authors.initials: D
authors.lastname: Boldt
authors.forename: Tom
authors.initials: T
authors.lastname: Frey
authors.forename: Margaret
authors.initials: M
authors.lastname: Loftus
authors.forename: Mohamad A
authors.initials: MA
authors.lastname: Hussein
mesh_terms: D036541:ADP-ribosyl Cyclase / Q000032:analysis*; D051997:ADP-ribosyl Cyclase 1; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000032:analysis*; D018951:Antigens, CD20 / Q000032:analysis*; D001402:B-Lymphocytes / Q000276:immunology; D015415:Biomarkers / Q000032:analysis; D002478:Cells, Cultured; D015925:Cryopreservation; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000276:immunology* / Q000401:mortality; D018655:Lymphocyte Count; D008297:Male; D008562:Membrane Glycoproteins; D008875:Middle Aged; D011379:Prognosis; D015996:Survival Rate
chemical_list: D015703:Antigens, CD; D018951:Antigens, CD20; D015415:Biomarkers; D008562:Membrane Glycoproteins; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1