VJ REARRANGEMENTS OF THE TCR-GAMMA LOCUS IN PERIPHERAL T-CELL LYMPHOMAS - ANALYSIS BY POLYMERASE CHAIN-REACTION AND DENATURING GRADIENT GEL-ELECTROPHORESIS

Using Southern blotting for the diagnosis of clonality in peripheral T -cell lymphomas (PTCLs), analysis of the T-cell receptor (TCR) gamma g ene rearrangement was shown to be more informative than that of the TC R beta gene rearrangement, In order to amplify every VJ gamma rearrang ement, a polymerase chain reaction (PCR) procedure using newly designe d GC-clamp primers has been developed, All primers can be mixed in a s ingle multiplex PCR. PCR products are analysed by denaturing gradient gel electrophoresis (DGGE), providing tumour-specific imprints inasmuc h as the procedure characterizes N sequence polymorphism at the VJ jun ctions, In a series of 30 PTCL cases, the PCR procedure demonstrated 2 7 cases to be clonally rearranged and failed in three cases, PCR,vas m ore accurate than Southern blotting, showing 47 rearranged gamma allel es, four of which were undetectable on the Southern blot, When lymphom as were studied at different sites and at relapse, the DGGE pattern re mained unchanged, In PTCL, the proposed PCR is helpful for the diagnos is and staging of the disease and should improve the follow-up monitor ing. The undetectability of clonal rearrangements in a few cases is di scussed in the light of concepts of lymphomagenesis and T-cell differe ntiation.