The expression of the multidrug resistance related glycoprotein in adult acute lymphoblastic leukemia.
BACKGROUND
More than 50% of adults with acute lymphoblastic leukemia (ALL) actually die with resistant leukemia. The multidrug resistance (MDR) related P170 glycoprotein may be involved in treatment failure.


METHODS
P170 content of leukemic cells was assayed by immunocytochemistry with the MRK-16 monoclonal antibody in 41 consecutive cases of adult ALL (27 at onset and 14 at relapse).


RESULTS
Positive cells were found in 11/14 cases at relapse and in 18/27 cases at onset. All cases with a high WBC, FAB L3, B-mature phenotype, and t(9; 22) were positive. In the 27 patients who were studied at onset and were treated with the same protocol, the overall failure rate was 44% in negative cases and 83% in positive cases.


CONCLUSIONS
P170 overexpression may contribute to drug resistance and to chemotherapy failure in adult ALL.
Savignano
C
C
Division and Chair of Hematology, Udine University Hospital, Italy.
Geromin
A
A
Michieli
M
M
Damiani
D
D
Michelutti
A
A
Melli
C
C
Fanin
R
R
Baccarani
M
M
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000293:Adolescent; D000328:Adult; D000368:Aged; D002352:Carrier Proteins / Q000032:analysis*; D004351:Drug Resistance / Q000502:physiology; D006801:Humans; D008562:Membrane Glycoproteins / Q000032:analysis*; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000378:metabolism*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins