Rapid detection of clonality in patients with acute lymphoblastic leukemia

Abstract

BACKGROUND AND OBJECTIVES: Polymerase chain reaction (PCR) detection of clonal T-cell receptor (TCR) gamma and delta gene rearrangements is widely used in clonality assessment of lymphoid leukemias and lymphomas and for detection of minimal residual disease of acute lymphoblastic leukemia (ALL). Standard analyses for clonality assessment include Southern blotting or PCR-based detection of clonal TCR gene rearrangements. The latter consist of heteroduplex PCR analysis by separation of PCR products on non-denaturing polyacrylamide gel (PAGE). We describe a rapid and sensitive method to identify specific clonal rearrangements in PCR fragments obtained by amplification of TCRgamma and TCRdelta genes. DESIGN AND METHODS: We applied a semi-automated electrophoretic technique (PhastSystem , Amersham Pharmacia Biotech) and compared it with standard homo-heteroduplex analysis in 21 cases of childhood acute lymphoblastic leukemia (ALL). RESULTS: The results obtained for each sample analyzed by standard homo-heteroduplex detection were completely reproduced by the PhastSystem approach. INTERPRETATION AND CONCLUSIONS: We conclude that heteroduplex analysis of TCR gene rearrangements using the semi-automated PhastSystem is a simple, rapid, cheap and highly reproducible method which can be used as an alternative to traditional analysis for detection of clonality.