We conclude that AML with t(8;21) is better identified by a combination of markers than by a single antigen pattern, the absence of CD34+, HLA-DR+ or MPO+ would preclude and the expression of the pattern CD34+/CD19+/CD56+ is highly predictive and could serve as a screening criteria for the t(8;21).
Following evaluation by the Mann-Whitney test, we found that t(8;21) AMLs showed a significantly higher expression of CD19, CD34, CD56, CD45RA and CD54.
AML with t(8;21) has a distinctive immunophenotype, characterized by expression of the myeloid and stem cell antigens CD13, CD15, CD34, and HLADr, and frequent expression of the B-cell antigen CD19 and the neural cell adhesion molecule CD56, a natural killer cell/stem cell antigen.
Among the patients with AML not expressing SCL, a high percentage of patients with CD7+ AML and CD19+ AML had detectable GATA-1, while patients with GATA-1-negative AML had the best CR rate (87.5%).
Leukemic cells from an 8-year-old girl with ANLL-M2 expressed precursor B-cell antigen CD19, but none of the myeloid antigens CD11b, CD13, CD14 and CD33.
The acute biphenotypic leukaemia cases consisted of four major immunophenotypic subgroups: CD2+ AML (11), CD19+ AML (8), CD13 and/or CD33+ ALL (24), CD11b+ ALL (5) and others (4).
We herein describe an unusual case of acute myeloid leukaemia (AML) showing strong cytochemical reactivity for myeloperoxidase (MPO) but surprisingly no reactivity using flow cytometry for any of the lineage-specific cell surface markers, i.e. myelomonocytic antigens CD13, CD14 and CD33; or B-lymphoid antigens CD19, CD20 and immunoglobulins; or T-lymphoid antigens CD2, CD3 and CD5.
Frequent expression of CD19 was found in the blastic population of t(8;21) AML (18 of 23 cases) without other B-cell antigens and Ig gene rearrangements.
We studied the S-phase DNA content of immunophenotypically defined BM subpopulations (CD2+; CD19+; CD2/CD19+; glycophorin-A+; CD14+; CD13+; CD33+ and CD13/CD33+) in 18 patients with acute myeloid leukemia (AML), including three patients with M6 AML.
We conclude that IG-h gene is rearranged in a substantial proportion of AML, strongly associated with a specific immunophenotype (TdT+, CD19+, CD34+), whereas TCR-b gene rearrangement appears more rarely.