Clinical significance of multidrug resistance P-glycoprotein expression on acute nonlymphoblastic leukemia cells at diagnosis.
To evaluate the clinical value of the expression of multidrug resistance P-glycoprotein (P-170) on the surface of acute nonlymphoblastic leukemia (ANLL) cells, we analyzed specimens from 150 newly diagnosed patients for staining with MRK16, a monoclonal antibody (MoAb) that binds to an external epitope of P-170. Other surface markers (CD13, CD14, CD15, and CD34) were studied by the same technique. A marker was considered positive when 20% or more cells were stained. Of 150 samples, 71 were P-170-positive. These cases did not differ from P-170-negative cases with regard to age, sex, initial white blood cell (WBC) counts, or French-American-British (FAB) type (except for M3 ANLL, which were more frequently negative). However, leukemias arising from previous myelodysplastic syndrome (MDS) and therapy-induced leukemias were more frequently P-170-positive. CD34 and P-170 expression were significantly associated. All patients were treated by intensive chemotherapy. Complete remission (CR) rates were significantly lower in P-170-positive (23/71, 32%) than in P-170-negative cases (64/79, 81%) (P less than 10(-5)). CD34 positivity was also associated with a low remission rate (P less than 10(-5)). Survival was shorter for P-170- and CD34-positive patients (P less than 10(-5)). The prognostic value of both markers was confirmed in multivariate analysis. CR duration was also shorter for P-170-positive cases, but the difference is less significant (P = .05). It is concluded that P-170 analysis may be an important tool for predicting the outcome of intensive chemotherapy in ANLL patients.
Campos
L
L
Service de Cryobiologie, Centre de Transfusion Sanguine, Lyon, France.
Guyotat
D
D
Archimbaud
E
E
Calmard-Oriol
P
P
Tsuruo
T
T
Troncy
J
J
Treille
D
D
Fiere
D
D
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D015703:Antigens, CD / Q000032:analysis; D018952:Antigens, CD34; D004351:Drug Resistance; D005455:Fluorescent Antibody Technique; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000276:immunology / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000032:analysis*; D008875:Middle Aged; D011379:Prognosis; D012074:Remission Induction
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D015703:Antigens, CD; D018952:Antigens, CD34; D008562:Membrane Glycoproteins