Fig. 4.

a PBMCs were measured using two markers for cell populations negative for HLA-DR and positive for CD33. Patients were categorized according to whether they had stable (n = 5) or progressive disease (n = 11). A HLA-DR^negCD33⁺ percentage greater than 2.5 % is suggestive of progressive disease. Of these 16 patients, 1 patient had stage I disease, 2 patients had stage II disease, four patients had stage III disease, and 9 patients had stage IV disease. b Measurement of HLA-DR^negCD33⁺CD14^negCD15^neg in the same patient populations suggests a percentage greater than 0.5 % lineage-negative MDSC is suggestive of progressive disease. c Percentages of HLA-DR^negCD33⁺ cells were measured as a function of ECOG performance status. Worse performance status is associated with increasing numbers of MDSC. Patients with ECOG ≥ 2 (n = 5) tended to have higher levels of MDSC