Stability of leukemia-associated aberrant immunophenotypes in patients with acute myeloid leukemia between diagnosis and relapse: comparison with cytomorphologic, cytogenetic, and molecular genetic findings.
BACKGROUND
Multiparameter flow cytometry is increasingly used to monitor minimal residual disease in patients with acute myeloid leukemia to identify leukemic cells by leukemia-associated aberrant immunophenotypes (LAIPs). Changes in LAIPs during the course of the disease may be a limitation for this approach.


METHODS
We analyzed 49 patients at diagnosis and relapse by flow cytometry, cytomorphology, cytogenetics, and molecular genetics.


RESULTS
In 37 patients (76%), at least one LAIP detectable at diagnosis was present at relapse; in 12 patients (24%), none of the original LAIPs were present in at least 1% of bone marrow cells. Three groups were identified: no change in LAIPs, partial changes in LAIPs, and complete change in LAIPs. There were significant differences across these groups with regard to changes in cytomorphology (11%, 40%, and 58% of all cases, respectively; P = 0.007), cytogenetics (15%, 20%, and 25%; not significant), and molecular genetics (18%, 0, and 86%; P = 0.002).


CONCLUSIONS
These data indicate that, in a subset of patients with acute myeloid leukemia, the disease is biologically different at relapse; therefore, monitoring of minimal residual disease is difficult to accomplish. In most patients with acute myeloid leukemia, multiparameter flow cytometry may be used to monitor minimal residual disease.
Laboratory for Leukemia Diagnostics, Department of Internal Medicine III, University Hospital Grosshadern, Ludwig-Maximilians-University, Munich, Germany.
Daniela
D
Voskova
Claudia
C
Schoch
Susanne
S
Schnittger
Wolfgang
W
Hiddemann
Torsten
T
Haferlach
Wolfgang
W
Kern
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001854:Bone Marrow Cells / Q000145:classification / Q000276:immunology / Q000473:pathology; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007124:Immunoenzyme Techniques; D016130:Immunophenotyping / Q000379:methods*; D007621:Karyotyping; D015470:Leukemia, Myeloid, Acute / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D018365:Neoplasm, Residual / Q000235:genetics / Q000276:immunology* / Q000473:pathology