Competitive CBFbeta/MYH11 reverse-transcriptase polymerase chain reaction for quantitative assessment of minimal residual disease during postremission therapy in acute myeloid leukemia with inversion(16): a pilot study.
OBJECTIVE
(1) Quantification of minimal residual disease (MRD) by competitive CBFbeta/MYH11 reverse-transcriptase polymerase chain reaction (RT-PCR) in patients with acute myeloid leukemia (AML) and inversion(16) [inv(16)] during postremission therapy, (2) comparison of this method with conventional two-step RT-PCR, and (3) evaluation of a potential prognostic value.


METHODS
MRD of six consecutive adult patients with AML and inv(16)(p13;q22) or t(16;16)(p13;q22) who entered complete remission (CR) was monitored by competitive CBFbeta/MYH11 RT-PCR in their bone marrow (BM) during postremission therapy with high-dose cytarabine (HiDAC) or after BM transplantation with a matched unrelated-donor marrow (MUD-BMT) during an observation period of 4.5 to 27 months after initiation of treatment.


RESULTS
Competitive PCR showed a gradual decline by at least 4 orders of magnitude after 7 to 9 months in patients in continuous CR (CCR), while one patient who relapsed after 13.5 months only achieved a reduction by 2 orders of magnitude at the end of consolidation therapy. A rapid decrease below the detection limit was observed within 1 month in two patients after MUD-BMT. A temporary reappearance of molecular MRD was observed in these patients during immunosuppression for graft-versus-host disease (GvHD). After reduction of immunosuppression, the level of MRD dropped again below the PCR detection limit. Molecular monitoring by conventional two-step RT-PCR yielded comparable results only when multiple assays per time point were performed, while single-assay RT-PCR gave misleading results.


CONCLUSIONS
Competitive RT-PCR is a valuable tool for molecular monitoring during postremission chemotherapy, as well as after BMT.
Laczika
K
K
Department of Medicine I, Clinical Institute of Medical and Chemical Laboratory Diagnosis, University of Vienna, St Anna Children's Hospital, Austria.
Novak
M
M
Hilgarth
B
B
Mitterbauer
M
M
Mitterbauer
G
G
Scheidel-Petrovic
A
A
Scholten
C
C
Thalhammer-Scherrer
R
R
Brugger
S
S
Keil
F
F
Schwarzinger
I
I
Haas
O A
OA
Lechner
K
K
Jaeger
U
U
D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001853:Bone Marrow / Q000473:pathology*; D016026:Bone Marrow Transplantation; D007446:Chromosome Inversion; D006801:Humans; D007700:Kinetics; D015470:Leukemia, Myeloid, Acute / Q000175:diagnosis* / Q000235:genetics* / Q000378:metabolism / Q000628:therapy; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism*; D010865:Pilot Projects; D016133:Polymerase Chain Reaction / Q000379:methods*; D012333:RNA, Messenger / Q000378:metabolism; D012074:Remission Induction
C095514:CBFbeta-MYH11 fusion protein; D015514:Oncogene Proteins, Fusion; D012333:RNA, Messenger