Aberrant underexpression of CD81 in precursor B-cell acute lymphoblastic leukemia: utility in detection of minimal residual disease by flow cytometry.
We studied CD81 expression by flow cytometry (FC) on benign precursor B cells (hematogones) and leukemic blasts in precursor B-cell acute lymphoblastic leukemia (pre-B-ALL) and established its usefulness in minimal residual disease (MRD) assays. Hematogones showed uniformly bright CD81 expression. In 98 pre-B-ALLs at diagnosis or overt relapse, 80 (82%) showed aberrantly decreased CD81 intensity. We used hematogones in 139 MRD- specimens to set a lower threshold for normal CD81 expression. In 133 specimens positive for residual pre-B-ALL, 87.2% showed increased CD81-dim immature B cells (>10%) and/or a discrete cluster of CD81-dim cells in a background of hematogones. Only 1 of 139 MRD- specimens showed more than 10% CD81-dim cells. Decreased CD81 expression was maintained in 91% of aberrant cases analyzed before and after chemotherapy. Decreased CD81 expression is a sensitive and specific marker for residual pre-B-ALL, even in a background of hematogones, making CD81 a useful addition to a panel for MRD detection by FC.
Dept of Hematopathology, University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA.
Tariq
T
Muzzafar
L Jeffrey
LJ
Medeiros
Sa A
SA
Wang
Archana
A
Brahmandam
Deborah A
DA
Thomas
Jeffrey L
JL
Jorgensen
D015703:Antigens, CD / Q000096:biosynthesis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D015536:Down-Regulation; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D006801:Humans; D018365:Neoplasm, Residual; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000378:metabolism / Q000473:pathology*; D012680:Sensitivity and Specificity; D060225:Tetraspanin 28
D015703:Antigens, CD; D014408:Biomarkers, Tumor; C554798:CD81 protein, human; D060225:Tetraspanin 28