Detection of abnormalities in B-cell differentiation pattern is a useful tool to predict relapse in precursor-B-ALL.
Immunophenotypic investigation of minimal residual disease (MRD) has traditionally been based on the investigation of phenotypic aberrants at diagnosis to be used later as a target for MRD detection. This approach has several shortcomings (it is only applicable to patients with aberrant phenotypes, requires a diagnostic sample, and is patient-specific) and therefore a search for simpler alternatives is warranted. The present study is based on the hypothesis that in precursor-B-ALL patients the persistence of residual leukaemic cells may induce abnormalities in the precursor-B-cell compartment in bone marrow (BM) and these could be used as a criteria to predict relapse. These abnormalities may include: (1) the presence of an increase in the frequencies of immature B cells (CD34+/CD19+ or CD20-/CD19+) or (2) the existence of an altered B-cell differentiation pathway due to a blockade or to the presence of B cells outside the normal pathway. A total of 180 BM samples from 45 consecutive precursor-B-ALL patients who achieved morphological complete remission (CR) were analysed by multiparametric flow cytometry. Our results show that a significant increase in immature B-cell subsets or an altered B-cell differentiation predicts a high relapse rate (P<0.01) and a shorter disease-free survival (P<0.01). Moreover, abnormalities in either of these two criteria detected at specific time points during follow-up (end of induction, maintenance, or after treatment) were associated with a significantly shorter disease-free survival (P<0.01). In summary, the investigation of abnormalities in B-cell differentiation is a relatively simple and cheap approach for predicting relapse in precursor-B-ALL patients.
Ciudad
J
J
Servicio General de Citometría, Universidad de Salamanca, Spain.
San Miguel
J F
JF
López-Berges
M C
MC
García Marcos
M A
MA
González
M
M
Vázquez
L
L
del Cañizo
M C
MC
López
A
A
Van Dongen
J J
JJ
Orfao
A
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism; D002471:Cell Transformation, Neoplastic; D002648:Child; D002675:Child, Preschool; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000473:pathology; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000473:pathology*; D012008:Recurrence
D015703:Antigens, CD