PCR of Gene Rearrangements for the Detection of Minimal Residual Disease in Childhood ALL

The study of submicroscopic or minimal residual disease (MRD) in childhood acute lymphoblastic leukemia may eventually lead to stratification of therapy on an individual patient basis (reviewed in ref. 1). PCR of immunoglobulin heavy chain (IgH) and T-cell receptor (TCR) gene rearrangements provides widely informative markers (Table 1), which, in the majority of cases, are stable during the disease course (2). Generation of leukemia-specific probes using this technique allows detection of MRD at levels of one leukemic cell in 10,000 to 100,000 normal bone marrow mononuclear cells (BM MNC). Table 1 Primer Systems ( a ) Locus No( b ) Primer sense (ref) No( b ) Primer antisense (ref) [Mg(2+)] Size, bp +B +T- IgH FR3 1 5'-ACACGGC(C/T)(G/C)TGTATTACTGT-3' (2) 3 5'-GTGACCAGGGT(C/T)C C(C/T)TGGCCCCAG-3' (2) 1.5-30 65-155 75% 8% 4 5'-AACTGCAGAGGAGACGGTGACC-3' (3) 15-30 80-170 2 5'-GACCAGGGT(C/T)C C(C/T)TGGCCCCAG-3'( e ) Vδ2-Dδ3 5 5'-CTTGCACCATCAGAGAGAGA-3' (2) 7 5'-GTTTTTGTACAGGTCTCTGT-3' 10-30 100-150 45% 4% 8 5'-AGGGAAATGCACTTTTGCC-3' (2) 15-30 110-170 6 5'-TTTTGTACAGGTCTCTGT-3' ( c ) Vδ1-Jδ1 5'-GCCTTACAGCTAGAAGATTC-3' 5'-GTTCCTTTTCCAAAGATGAG-3' 15-30 80-150 5% 25% VγI-Jγ1/2( d ) 5'-TG(A/C)(C/T)TCTGG(A/G)GTCTATTACTGT-3' 5'-CGATACTTACCTGTGACAAC(C/A)AG-3' 30 80-160 45% 90%( d ) VγII-Jγ-1/2( d ) 5'-AAACAGGACATAGCTACCTACT-3' 5'-CGATACTTACCTGTGACAAACC/AAG-3' 30 80-160 45% 90%( d ) Lead Vγ2-anti Vγ2 5'-GTCATGTCAGCCATTGAGTT-3' 5'-TCTCTCTCTGATGGTGCAAG-3' 15 220 control control ( a ) The primer shown here use a common buffer and generate products that can easily be resolved on 8% PAGE ( b ) Refers to Fig. 1 ( c ) Sequencing primers ( d ) These primers can be used in a multiplex reaction. The VγI primer is a consensus primer and amplifies all members of this group except Vγ7 + B and +T indicate the percentage of patients by lineage expected to show a clonal rearangement at each locus at diagnosis.