Characterization of Immunophenotype Changes in Precursor B-Lymphoblastic Leukemia of Childhood during the Course of Leukemia Progression
F Castro-Silva, J Shao, A McGranahan, X Liang. The Children's Hospital, Aurora; University of Colorado Denver, Aurora
Background: Precursor B-lymphoblastic leukemia (LL) is the most common leukemia in childhood. Although there has been a significant improvement in the treatment of LL, patients with LL relapse remain more difficult to treat, convey a worse prognosis, and require different therapeutic approaches. Immunophenotypic characterization not only plays an important role in diagnosis of LL but also provides important information for the selection of an effective therapy to treat patients with leukemia relapse. It is unclear if immunophenotype changes significantly and what the pattern of change is during the course of precursor B-LL progression. We examined immunophenotype in a series of precursor B-LL at time of diagnosis and subsequent relapses.
Design: 29 cases of precursor B-LL at The Children's Hospital, Colorado from 1998 to 2009 which had immunophenotype available at both diagnosis and relapses were evaluated. Immunophenotype was performed by flow cytometry. We evaluated the frequency of change (“+” to “-” or “-” to “+”) (“+” is defined as expression of a marker in ≥20% of blasts) in each marker between initial diagnosis and relapse, and also between subsequent relapses.
Results: Frequencies of immunophenotype change during the course of leukemia progression in precursor B-LL of childhood.
|# of cases||% of cases with antigen|
|expression change during the|
|Maturation related markers||CD34||29||17.24% (5/29)|
|Pan-B cell markers||CD19||29||0% (0/29)|
|T-cell markers||CD2||29||0% (0/29)|
|Myeloid markers||CD13||29||17.24% (5/29)|
|Other marker||HLA-DR||29||0% (0/29)|