Chapter 22 : Acute Myeloid Leukemia: Diagnosis and Minimal Residual Disease Detection by Flow Cytometry

Example dot plots of normal, early stem cells (purple) and normal CD34-positive blasts (red). Upper left dot plot shows CD45 versus side scatter (blue: lymphocytes; pink: monocytes; green: maturing granulocytes; aqua: hematogones) with circled area defining the blast region. Remaining dot plots are selectively displaying CD34-positive progenitors only. Myeloid progenitors show increasing expression of CD13, CD33, CD117, and HLA-DR.

Example dot plots of acute myeloid leukemia (red). Upper left dot plot shows CD45 versus side scatter with blast population highlighted in red. Remaining dot plots are selectively displaying CD34-positive leukemic blasts only. Notice, compared to normal myeloid blasts in Fig. 1 , these abnormal, leukemic blasts demonstrate lower side scatter, variably increased CD13, early/abnormal expression of CD15, decreased to absent CD33, variably increased CD34, variably decreased CD45, variably increased CD117, and variably decreased HLA-DR.

Example dot plots of minimal residual disease (MRD; purple population visualized on CD34 gating) with associated regenerating normal myeloid blasts (red). Upper left dot plot shows CD45 versus side scatter (blue, lymphocytes; pink, monocytes; green, maturing granulocytes; aqua, hematogones) with circled area defining the blast region. Remaining dot plots are selectively displaying emphasized, CD34-positive progenitors only. The MRD-positive population (purple) shows abnormal expression of CD4, decreased to absent CD13, uniform CD33, increased CD34, absent CD38, increased CD45, and subset CD56 (not shown) with normal expression of CD117 and HLA-DR and normal lack of CD15. Although the total CD34-positive population accounted for 2% of the white cells, the abnormal, MRD-positive population accounted for 0.03% of the white cells.