Ultrastructural demonstration of peroxidase expression in acute
unclassified leukemias: correlation to immunophenotype and treatment
outcome
G Heil, E Gunsilius, A Raghavachar, CR Bartram, A Ganser, E Kurrle, U Aydemir, H Loffler, D Hoelzer and E Thiel
Department of Internal Medicine III, University of Ulm, FRG.
The lineage affinity of 57 cases of acute unclassified leukemias (AUL) was
reevaluated by ultrastructural analysis of peroxidase expression (POEM) in
combination with immunophenotyping and analysis of immunoglobulin gene
configuration. Twenty-three cases of myeloid and three cases of
megakaryocytic differentiation were identified by detection of
ultrastructural myeloperoxidase (UMPO) and platelet peroxidase (UPPO). No
significant correlation was noted between myeloid marker expression and
POEM positivity, whereas presence of CD 19 or CD 24 antigen significantly
correlated with POEM negativity (P = .001 and .023, respectively). Ig gene
rearrangements including oligoclonal patterns were also recorded in 8 of 14
UMPO+ patients tested. Fourteen UMPO+ patients responded poorly to an
ALL/AUL chemotherapy regimen with a low complete remission (CR) rate of 29%
and a short median remission duration (MRD) of 5 months. The POEM- patients
proved very heterogenous with respect to immunophenotype and Ig gene
rearrangement. Seventeen of 21 patients tested had Ig gene rearrangements,
including oligoclonal patterns. Combined data suggest that a proportion of
these cases probably derive from a very immature lymphoid progenitor cell,
particularly because 15 POEM- AUL patients showed a response to ALL/AUL
chemotherapy comparable to that observed in patients with definitive acute
lymphoblastic leukemia (ALL) (CR rate 80%, MRD 20 months). Thus,
ultrastructural analysis of peroxidase expression can provide decisive
prognostic information in AUL patients.
Volume 77,
Issue 6,
pp. 1305-1312,
03/15/1991
Copyright © 1991 by The American Society of Hematology
