Journal of Clinical Oncology, Vol 16, 1519-1525, Copyright © 1998 by American Society of Clinical Oncology
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
K Laczika, M Novak, B Hilgarth, M Mitterbauer, G Mitterbauer, A Scheidel- Petrovic, C Scholten, R Thalhammer-Scherrer, S Brugger, F Keil, I Schwarzinger, OA Haas, K Lechner and U Jaeger
Department of Medicine I, Clinical Institute of Medical and Chemical Laboratory Diagnosis, University of Vienna, St Anna Children's Hospital, Austria.
PURPOSE: (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. PATIENTS AND 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. CONCLUSION: Competitive RT-PCR is a valuable tool for
molecular monitoring during postremission chemotherapy, as well as after
BMT.