IMPROVED PCR ASSAY FOR THE DETECTION OF ANTIGEN RECEPTOR GENE REARRANGEMENTS

The detection of small numbers of leukaemia cells in patients with occ ult disease has important clinical implications. Leukaemia is a monocl onal disease which frequently displays clonal rearrangement of the T-c ell receptor gamma (TCR gamma) and/or immunoglobulin heavy chain (IgH) gene. Clone-specific junctional sequences arising as a result of thes e gene rearrangements provide potentially valuable targets for monitor ing residual disease by the polymerase chain reaction (PCR). However, existing strategies for PCR amplification of these clone-specific rear rangements frequently lack the necessary sensitivity or specificity, d ue either to the small size of the target junctional region, or to int erference resulting from polyclonal IgH or TCR gamma rearrangements in normal lymphocytes. We have previously described a novel PCR strategy to overcome these obstacles which is based on the design of two overl apping clone-specific PCR primers which span the junctional region. We now describe a modification to this strategy which employs relatively short clone-specific primers which further increases the level of spe cificity. This new method should improve the detection of residual cel ls, particularly in those cases displaying small junctional regions. U nlike other strategies, specificity is generated from the initial roun d of amplification. This non-radioactive technique should thus prove e ffective in monitoring residual leukaemia in patients. (C) 1997 Elsevi er Science B.V.