TY - JOUR
T1 - Genomic quantitative real-time PCR proves residual disease positivity in more than 30% samples with negative mRNA-based qRT-PCR in Chronic Myeloid Leukemia
AU - Pagani, Ilaria Stefania
AU - Spinelli, Orietta
AU - Mattarucchi, Elia
AU - Pirrone, Cristina
AU - Pigni, Diana
AU - Amelotti, Elisabetta
AU - Lilliu, Silvia
AU - Boroni, Chiara
AU - Intermesoli, Tamara
AU - Giussani, Ursula
AU - Caimi, Luigi
AU - Bolda, Federica
AU - Baffelli, Renata
AU - Candi, Eleonora
AU - Pasquali, Francesco
AU - Lo Curto, Francesco
AU - Lanfranchi, Arnalda
AU - Porta, Fulvio
AU - Rambaldi, Alessandro
AU - Porta, Giovanni
PY - 2014
Y1 - 2014
N2 - Imatinib mesylate (IM) is the first line therapy against Chronic Myeloid Leukemia, effectively prolonging overall survival. Because discontinuation of treatment is associated with relapse, IM is required indefinitely to maintain operational cure. To assess minimal residual disease, cytogenetic analysis is insensitive in a high background of normal lymphocytes. The qRT-PCR provides highly sensitive detection of BCR-ABL1 transcripts, but mRNA levels are not directly related to the number of leukemic cells, and undetectable results are difficult to interpret. We developed a sensitive approach to detect the number of leukemic cells by a genomic DNA (gDNA) Q-PCR assay based on the break-point sequence, with a formula to calculate the number of Ph-positive cells. We monitored 8 CML patients treated with IM for more than 8 years. We tested each samples by patient specific gDNA Q-PCR in parallel by the conventional techniques. In all samples positive for chimeric transcripts we showed corresponding chimeric gDNA by Q-PCR, and in 32.8% (42/128) of samples with undetectable levels of mRNA we detected the persistence of leukemic cells. The gDNA Q-PCR assay could be a new diagnostic tool used in parallel to conventional techniques to support the clinician's decision to vary or to STOP IM therapy.
AB - Imatinib mesylate (IM) is the first line therapy against Chronic Myeloid Leukemia, effectively prolonging overall survival. Because discontinuation of treatment is associated with relapse, IM is required indefinitely to maintain operational cure. To assess minimal residual disease, cytogenetic analysis is insensitive in a high background of normal lymphocytes. The qRT-PCR provides highly sensitive detection of BCR-ABL1 transcripts, but mRNA levels are not directly related to the number of leukemic cells, and undetectable results are difficult to interpret. We developed a sensitive approach to detect the number of leukemic cells by a genomic DNA (gDNA) Q-PCR assay based on the break-point sequence, with a formula to calculate the number of Ph-positive cells. We monitored 8 CML patients treated with IM for more than 8 years. We tested each samples by patient specific gDNA Q-PCR in parallel by the conventional techniques. In all samples positive for chimeric transcripts we showed corresponding chimeric gDNA by Q-PCR, and in 32.8% (42/128) of samples with undetectable levels of mRNA we detected the persistence of leukemic cells. The gDNA Q-PCR assay could be a new diagnostic tool used in parallel to conventional techniques to support the clinician's decision to vary or to STOP IM therapy.
KW - Chronic myeloid leukemia
KW - DNA Q-PCR
KW - Leukemic stem cells
KW - Minimal residual disease
KW - Stop imatinib
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U2 - 10.18632/oncoscience.65
DO - 10.18632/oncoscience.65
M3 - Article
AN - SCOPUS:84927912595
VL - 1
SP - 510
EP - 521
JO - Oncoscience
JF - Oncoscience
SN - 2331-4737
IS - 7
ER -