Fig. 1.

Lane 1 Normal bone marrow. Heterogenous pattern of CD33 expression in CD34+CD38−, CD34+CD38+, CD34−CD38+ and CD34−CD38−, Lane 2 Case 1, A, B, C: AML M4 pre-treatment peripheral blood. Homogenous CD33 expression in CD34+CD38− cells, Case 1, D, E, F: Post-induction bone marrow. Blasts 69 % on morphology. Persistent aberrant CD33 expression in CD34+CD38− and CD34+CD38+cells, Lane 3 Case 2, A, B, C: AML M6 pre-treatment peripheral blood. Single cluster of cells in CD34+CD38− and CD34+CD38+ subsets with homogenous CD33 expression, Case 2, D, E, F: Post-induction bone marrow. Blasts 14 % on morphology. Homogenous CD33 expression in CD34+CD38+ cells subset, Lane 4 Case 3, A, B, C: AML M4 pre-treatment peripheral blood. Single cluster with homogenous CD33 expression in CD34+CD38− and CD34−CD38− cell subset, Case 3, D, E, F: Post-induction bone marrow. Blasts <5 % on morphology. Aberrant CD33 expression in CD34+CD38− cells, Lane 5 Case 4, A, B, C: AML M2 peripheral blood at diagnosis. Heterogenous CD33 expression in CD34+CD38− cells and a more homogenous cluster in CD34+CD38+ cell subset, Case 4, D, E, F: Post-induction bone marrow, blasts <5 % on morphology, showing single homogenous CD33+ cluster in CD34−CD38+ cell subset