Induction failure in de novo acute myelogenous leukemia is associated with expression of high levels of CD34 antigen by the leukemic blasts.
The prognostic significance of CD34 antigen expression in acute myelogenous leukemia (AML) is controversial. Most studies to date have reported on CD34 positivity and not the level of antigen present. In this study of 62 patients with de novo AML, 48 (77%) patients were CD34+ in varying levels (0-85 mean channels of fluorescence (MCF)). Forty seven of 62 were treated with combination chemotherapy and 39 (83%) of them achieved complete remission (CR). Patients with CD34- blasts were more likely to achieve CR; however, this trend was not statistically significant (p = .11). On the other hand, patients with higher levels of CD34 antigen on the blasts were less likely to attain CR (p < 0.001, multivariate analysis). The patients who achieved CR expressed lower levels of CD34 (0-57; median 9 MCF) as compared to those who did not achieve CR (15-85; median 30 MCF). Of the other antigens tested, partial or complete absence of CD33 (CD33 absent in > or =25% blasts) correlated with failure to achieve CR (p = 0.0029). These results are in keeping with the hypothesis that more primitive AML blasts with high levels of CD34 are chemoresistant.
Dalal
B I
BI
Division of Hematopathology, Vancouver Hospital & Health Sciences Center, BC, Canada. dbak@unixg.ubc.ca
Wu
V
V
Barnett
M J
MJ
Horsman
D E
DE
Spinelli
J J
JJ
Naiman
S C
SC
Shepherd
J D
JD
Nantel
S H
SH
Reece
D E
DE
Sutherland
H J
HJ
Klingemann
H G
HG
Phillips
G L
GL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018952:Antigens, CD34 / Q000378:metabolism*; D000951:Antigens, Neoplasm / Q000378:metabolism*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D003561:Cytarabine / Q000008:administration & dosage; D003630:Daunorubicin / Q000008:administration & dosage; D005260:Female; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012074:Remission Induction
D018952:Antigens, CD34; D000951:Antigens, Neoplasm; D003561:Cytarabine; D003630:Daunorubicin