Acute myeloid leukemia with T-lymphoid features: a distinct biologic and clinical entity.
We studied the clinical and biologic features of 10 cases of acute leukemia that met standard French-American-British (FAB) criteria for acute myeloid leukemia (AML) but in which the blast cells also expressed the T-cell-associated CD2 surface antigen. All cases had greater than 3% myeloperoxidase and Sudan black B-positive leukemic blasts, and blasts from seven cases contained Auer rods. Reactivity of the cells with a panel of monoclonal antibodies (MAbs) indicated that leukemic cells in all cases expressed myeloid-associated (CD11b, CD13) surface antigens, further supporting the diagnosis of AML. However, blasts from every patient coexpressed the T-cell-associated surface CD2 and CD7 as well as cytoplasmic CD3 antigens. Blasts from five patients expressed surface CD25, whereas blasts from only one expressed surface CD3. Five patients had rearranged T-cell receptor beta-chain genes, whereas only three had rearranged T-cell receptor gamma-chain genes. This pattern of lineage-related gene expression appears to define a distinct subtype of AML with T-lymphoid features (CD2+ AML) and could reflect either aberrant gene expression in leukemic blasts or transformation of a pluripotent stem cell having a flexible pattern of gene expression. Clinically, these 10 patients presented at an older age with a higher leukocyte count and a higher frequency of lymphadenopathy than did children whose blast cells were characteristic of myeloid leukemia. Patients with CD2+ AML also had poorer responses to remission induction therapy (50% v 80% entered complete remission, P = .05). However, each of the five children who failed induction chemotherapy on AML protocols had a striking response to drug combinations usually reserved for lymphoid leukemia. We conclude that this leukemia with mixed lymphoid and myeloid characteristics is a distinct biologic and clinical entity.
Cross
A H
AH
Department of Virology and Molecular Biology, St Jude Children's Research Hospital, Memphis, TN 38101.
Goorha
R M
RM
Nuss
R
R
Behm
F G
FG
Murphy
S B
SB
Kalwinsky
D K
DK
Raimondi
S
S
Kitchingman
G R
GR
Mirro
J
J
D000293:Adolescent; D000328:Adult; D000954:Antigens, Surface / Q000032:analysis; D001853:Bone Marrow / Q000473:pathology; D002648:Child; D005260:Female; D006801:Humans; D007621:Karyotyping; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology; D008297:Male; D010641:Phenotype; D011948:Receptors, Antigen, T-Cell / Q000235:genetics; D011995:Recombination, Genetic; D013601:T-Lymphocytes / Q000276:immunology*
D000954:Antigens, Surface; D011948:Receptors, Antigen, T-Cell