[Development of a new strategy for minimal residual disease monitoring in children with B-precursor acute lymphoblastic leukemia].
Despite modern regimen of chemotherapy, one-third of children with acute lymphoblastic leukaemia relapse. Recent studies have shown that a high level of minimal residual disease (MRD) at the end of induction is associated with an increased risk of relapse. We have developed and validated a real-time PCR method (RQ-PCR) to quantify MRD. We monitored 57 patients using IgH and TCR (Vdelta2Ddelta3) genes rearrangements as PCR targets. RQ-PCR was performed with a primer and a TaqMan probe designed to consensus sequences in VH segments in combination with one allele specific oligonucleotide primer complementary to the junctionnal region. A sensitivity of 10(-4) was reached for 72% of the IgH alleles (n = 50) and for 54,5% of the Vdelta2Ddelta3 alleles (n = 22). We compared the results with those obtained by competitive PCR in 53 patients: no discordance between the two methods was observed. Seventeen patients were found positive (32%) and 27 negative (51%) with both techniques and 9 children (17%) were positive only with TaqMan technology. RQ-PCR is more sensitive and more specific than competitive PCR. We thus propose that RQ-PCR might be used in first intention for MRD analysis.
Laboiratoire central d'hématologie, Hôpital Saint Louis, Paris.
B
B
Bonjean
L
L
Grollet
E
E
Visentin
F
F
Sigaux
J-M
JM
Cayuela
D000293:Adolescent; D000359:Aftercare / Q000379:methods* / Q000592:standards; D002648:Child; D002675:Child, Preschool; D004273:DNA, Neoplasm / Q000032:analysis / Q000235:genetics; D016903:Drug Monitoring / Q000379:methods* / Q000592:standards; D005260:Female; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain / Q000187:drug effects / Q000235:genetics; D006801:Humans; D007223:Infant; D018365:Neoplasm, Residual; D018579:Patient Selection; D016133:Polymerase Chain Reaction / Q000379:methods* / Q000592:standards; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy; D011379:Prognosis; D012074:Remission Induction; D012307:Risk Factors; D012680:Sensitivity and Specificity; D019914:Taq Polymerase
D004273:DNA, Neoplasm; D019914:Taq Polymerase