title: Immunoglobulin kappa deleting element rearrangements in precursor-B acute lymphoblastic leukemia are stable targets for detection of minimal residual disease by real-time quantitative PCR.
abstract: Immunoglobulin gene rearrangements are used as PCR targets for detection of minimal residual disease (MRD) in acute lymphoblastic leukemia (ALL). We investigated the occurrence of monoclonal immunoglobulin kappa-deleting element (IGK-Kde) rearrangements by Southern blotting and PCR/heteroduplex analysis at diagnosis, their stability at relapse, and their applicability in real-time quantitative PCR (RQ-PCR) analysis. In 77 selected children with precursor-B-ALL, Southern blotting detected 122 IGK-Kde rearrangements, 12 of which were derived from subclones in six patients (8%). PCR/heteroduplex analysis with BIOMED-1 Concerted Action primers identified 100 of the 110 major IGK-Kde rearrangements (91%). Comparison between diagnosis and relapse samples from 21 patients with PCR-detectable IGK-Kde rearrangements (using Southern blotting, PCR/heteroduplex analysis, and sequencing) demonstrated that 27 of the 32 rearrangements remained stable at relapse. When patients with oligoclonal IGK-Kde rearrangements were excluded, 25 of the 27 rearrangements remained stable at relapse and at least one stable rearrangement was present in 17 of the 18 patients. Subsequently, RQ-PCR analysis with allele-specific forward primers, a germline Kde TaqMan-probe, and a germline Kde reverse primer was evaluated for 18 IGK-Kde rearrangements. In 16 of the 18 targets (89%) a sensitivity of < or =10(-4) was reached. Analysis of MRD during follow-up of eight patients with IGK-Kde rearrangements showed comparable results between RQ-PCR data and classical dot-blot data. We conclude that the frequently occurring IGK-Kde rearrangements are generally detectable by PCR (90%) and are highly stable MRD-PCR targets, particularly where monoclonal rearrangements at diagnosis (95%) are concerned. Furthermore, most IGK-Kde rearrangements (90%) can be used for sensitive detection of MRD (< or =10(-4)) by RQ-PCR analysis.
authors: Department of Immunology, University Hospital, Erasmus University Rotterdam, 3000 DR Rotterdam, The Netherlands.
authors: V H J
authors: VH
authors: van der Velden
authors: M J
authors: MJ
authors: Willemse
authors: C E
authors: CE
authors: van der Schoot
authors: K
authors: K
authors: Hählen
authors: E R
authors: ER
authors: van Wering
authors: J J M
authors: JJ
authors: van Dongen
mesh_terms: D000293:Adolescent; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D015321:Gene Rearrangement / Q000235:genetics*; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D007223:Infant; D007231:Infant, Newborn; D018365:Neoplasm, Residual / Q000175:diagnosis / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods / Q000592:standards; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis* / Q000235:genetics; D012008:Recurrence; D012680:Sensitivity and Specificity
chemical_list: D007145:Immunoglobulin kappa-Chains