Abstract
In childhood acute lymphoblastic leukemia (ALL), early response to treatment is an important prognostic factor and drug resistance is a major cause of poor outcome. One of the most investigated resistance mechanisms is P-glycoprotein (P-gp)-mediated multiple drug resistance (MDR). We analyzed P-gp using flow cytometry with monoclonal antibody JSB1 in a series of 118 children with ALL, 103 at diagnosis and 15 at relapse. Increased P-gp expression was found in 55 (53%) patients at diagnosis and in 11 (73%) at relapse. We also analyzed the bone marrow aspirate slides for early response to treatment in a central review. No correlation was found between P-gp and early response. Patients with T-ALL had higher P-gp levels than the others, 5.3% versus 1.0% (P = .002). We conclude that P-gp-mediated multiple drug resistance is not a factor in a slow response to ALL induction therapy.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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ATP Binding Cassette Transporter, Subfamily B, Member 1 / biosynthesis*
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Adolescent
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Antineoplastic Combined Chemotherapy Protocols / therapeutic use*
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Asparaginase / administration & dosage
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Blast Crisis
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Bone Marrow / pathology
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Burkitt Lymphoma / drug therapy*
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Burkitt Lymphoma / pathology
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Burkitt Lymphoma / physiopathology*
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Child
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Child, Preschool
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Cyclophosphamide / administration & dosage
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Cytarabine / administration & dosage
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Doxorubicin / administration & dosage
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Drug Resistance, Multiple*
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Finland
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Follow-Up Studies
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Humans
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Infant
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Leukemia-Lymphoma, Adult T-Cell / drug therapy*
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Leukemia-Lymphoma, Adult T-Cell / pathology
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Leukemia-Lymphoma, Adult T-Cell / physiopathology
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Mercaptopurine / administration & dosage
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Methotrexate / administration & dosage
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Predictive Value of Tests
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Prednisone / administration & dosage
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Prognosis
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Recurrence
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Remission Induction
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Vincristine / administration & dosage
Substances
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ATP Binding Cassette Transporter, Subfamily B, Member 1
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Cytarabine
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Vincristine
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Doxorubicin
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Cyclophosphamide
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Mercaptopurine
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Asparaginase
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Prednisone
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Methotrexate