Flow cytometric detection of CD79a expression in T-cell acute lymphoblastic leukemias.
We evaluated the lineage specificity of CD79a in acute leukemias using 3-color flow cytometry in 58 consecutive cases. A panel of cell-surface antigens, including myeloid-associated markers, B-cell-associated markers, and T-cell-associated markers, was used. All cases of acute myeloid leukemia were CD79a-, whereas all cases of B-lineage acute lymphoblastic leukemia (ALL) were CD79a+. Three of 8 cases of T-cell ALL showed variable CD79a expression, indicating the presence of a blast subset expressing a relatively high level of CD79a. We investigated the clinical and pathologic characteristics of these 3 cases. All 3 cases had L1 or L2 morphology and expressed surface CD3. None of the other B-cell-associated markers were positive, although 1 case expressed CD13 and CD33. Uncommon random karyotypic abnormalities were identified in all 3 cases. Molecular studies demonstrated monoclonal gene rearrangement of T-cell receptor gamma in 2 of 3 cases. All 3 patients were 18 years old or younger; 1 patient did not enter remission, and 1 had disease relapse in 8 months. Our findings provide further support for the existence of a subset of T-cell ALL coexpressing CD3 and CD79a. Further study of the clinical and biologic significance of this subset may be warranted.
Lai
R
R
Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton.
Juco
J
J
Lee
S F
SF
Nahirniak
S
S
Etches
W S
WS
D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000378:metabolism*; D000954:Antigens, Surface / Q000378:metabolism; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001402:B-Lymphocytes / Q000378:metabolism / Q000473:pathology; D051925:CD79 Antigens; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D025063:Chromosome Disorders; D003582:Cytogenetics; D005260:Female; D005434:Flow Cytometry; D015321:Gene Rearrangement; D019675:Genes, T-Cell Receptor gamma / Q000235:genetics; D006801:Humans; D007223:Infant; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism*; D013601:T-Lymphocytes / Q000378:metabolism / Q000473:pathology
D015703:Antigens, CD; D000954:Antigens, Surface; D051925:CD79 Antigens; C497881:CD79A protein, human; D011947:Receptors, Antigen, B-Cell