title: P-glycoprotein activity predicts outcome in childhood acute lymphoblastic leukemia.
abstract: Treatment of children with acute lymphoblastic leukemia (ALL) is based on P-glycoprotein (P-gp)-dependent cytostatics. We assessed the P-gp function in blast cells as a possible prognostic factor and its influence on the overall survival. P-gp function was measured using the verapamil-sensitive Rhodamine efflux. Cell samples from 7 of 45 (16%) patients revealed rhodamine-efflux positive blasts. There were no relations between the presence of P-gp, clinical characteristics (age, sex, hepatomegaly, and splenomegaly) and initial laboratory parameters (immunophenotype, white blood cells count, and serum lactate dehydrogenase) in ALL. P-gp activity plays a negative role, both for a remission achieved on day 33 and for susceptibility to steroid therapy. Children bearing rhodamine-efflux positive blasts had a significantly shorter 5-year overall survival of 35%, as compared with 74% in those negative for P-gp function. Lack of any association with clinical characteristic and initial laboratory parameters suggests that presence of P-gp is an independent prognostic factor.
authors: Departments of Pathophysiology, Medical University of Gdańsk, Gdańsk, Poland.
authors: Jacek
authors: J
authors: Brozek
authors: Ewa
authors: E
authors: Bryl
authors: Anna
authors: A
authors: Płoszyńska
authors: Anna
authors: A
authors: Balcerska
authors: Jacek M
authors: JM
authors: Witkowski
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism*; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007223:Infant; D053208:Kaplan-Meier Estimate; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000378:metabolism* / Q000401:mortality; D011379:Prognosis; D012307:Risk Factors; D012737:Sex Factors; D016896:Treatment Outcome
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents