title: Applicability of IG/TCR gene rearrangements as targets for minimal residual disease assessment in a population-based cohort of Swedish childhood acute lymphoblastic leukaemia diagnosed 2002-2006.
abstract: Minimal residual disease (MRD) detection during the early treatment phase has become an important stratification parameter in many childhood acute lymphoblastic leukaemia (ALL) treatment protocols. Here, we aimed to address the applicability of rearranged antigen-receptor genes as potential MRD markers using real-time quantitative polymerase chain reaction (RQ-PCR) in a Swedish population-based cohort. From 334 childhood ALL cases diagnosed during 2002-2006, we analysed 279 diagnostic samples (84%) by screening for rearranged immunoglobulin (IG) and T-cell receptor (TCR) genes. Allele-specific oligonucleotides were designed, and the sensitivity and quantitative level was determined for each target. Overall, clonal IG/TCR rearrangements were detected in 97% (236/244) of B-cell precursor ALL (BCP ALL) and 94% (33/35) of T-ALL. A sensitive RQ-PCR analysis (< or = 10(-4)) was obtained in 89% (216/244) of BCP ALL and in 74% (26/35) of T-ALL, whereas two sensitive targets were only available in 47% (115/244) of BCP ALL and 29% (10/35) of T-ALL cases. With the stratification threshold of > or = 10(-3), which is applied in the current Nordic treatment protocol (NOPHO-ALL 2008) for the identification of high-risk patients, 93% of BCP ALL and 86% of T-ALL reached this quantitative range by at least one target gene. Taken together, this national retrospective study demonstrates that an IG/TCR target for MRD monitoring can be identified in the majority of childhood ALL cases, whereas identification of a second sensitive target gene needs to be improved.
authors.affiliation: Department of Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Thörn
authors.forename: Erik
authors.initials: E
authors.lastname: Forestier
authors.forename: Britt
authors.initials: B
authors.lastname: Thuresson
authors.forename: Carina
authors.initials: C
authors.lastname: Wasslavik
authors.forename: Maria
authors.initials: M
authors.lastname: Malec
authors.forename: Aihong
authors.initials: A
authors.lastname: Li
authors.forename: Elenor
authors.initials: E
authors.lastname: Lindström-Eriksson
authors.forename: Johan
authors.initials: J
authors.lastname: Botling
authors.forename: Gisela
authors.initials: G
authors.lastname: Barbany
authors.forename: Stefan
authors.initials: S
authors.lastname: Jacobsson
authors.forename: Tor
authors.initials: T
authors.lastname: Olofsson
authors.forename: Anna
authors.initials: A
authors.lastname: Porwit
authors.forename: Christer
authors.initials: C
authors.lastname: Sundström
authors.forename: Richard
authors.initials: R
authors.lastname: Rosenquist
mesh_terms: D000293:Adolescent; D000483:Alleles; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage; D002648:Child; D002675:Child, Preschool; D005260:Female; D015322:Gene Rearrangement, B-Lymphocyte; D015329:Gene Rearrangement, T-Lymphocyte; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods*; D018365:Neoplasm, Residual; D016133:Polymerase Chain Reaction; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000378:metabolism*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013548:Sweden