Clinical significance of low levels of myeloperoxidase positivity in
childhood acute nonlymphoblastic leukemia
CH Pui, FG Behm, DK Kalwinsky, SB Murphy, DL Butler, GV Dahl and J Mirro
The clinical significance of a low percentage of myeloperoxidase- positive
blast cells in childhood acute nonlymphoblastic leukemia was determined. Of
155 consecutive cases studied by cytochemical staining methods, 14 were
characterized by 4% to 15% (median 6%) myeloperoxidase- positive blasts.
All 14 cases showed reactivity to Sudan black B stain, and 7 had Auer rods.
The morphological subtypes of leukemia were M1 (8 cases), M2 (3), M4 (1),
and M5 (2). Immunological marker studies disclosed the lymphoid-associated
T11 antigen on cells from 8 of the 11 cases tested. Other lymphoid-related
findings in these 8 cases included the T3 antigen and E rosette formation
in 1 case each. Among cases that were prospectively studied for the
expression of lymphoid-associated markers, 6 of 8 with low levels of
myeloperoxidase positivity compared with only 1 of 44 with higher levels
(greater than 15%) possessed such features (P less than 0.001). We conclude
that low levels of myeloperoxidase reactivity distinguish cases of acute
leukemia in which the blast cells coexpress lymphoid (T11 antigen) and
myeloid markers.
Volume 70,
Issue 1,
pp. 51-54,
07/01/1987
Copyright © 1987 by The American Society of Hematology
