NOVEL ANALYSIS OF MINIMAL RESIDUAL DISEASE IN LEUKEMIA WITH TCR BETA-REARRANGEMENT - DETECTION OF MONOCLONALITY BY SINGLE-STRAND CONFORMATION POLYMORPHISM AND PCR USING A CLONOTYPE PRIMER OF LEUKEMIC T-CELL RECEPTOR BETA-CHAIN RNA

Several means of analyzing minimal residual disease (MRD) in leukemia involving the rearranged T cell receptor (TCR) gene have been describe d. We investigated MRD in leukemia with TCR beta rearrangement by exam ining TCR beta-chain RNA. A complementary DNA (cDNA) corresponding to the variable region of the TCR beta-chains originating from the periph eral blood or bone marrow from four patients was amplified. Single str and conformation polymorphism (SSCP) analysis of amplified cDNA showed that all four patients had monoclonal leukemia with TCR beta rearrang ement; two patients had V beta 2(+) leukemia, another patient had V be ta 14(+) leukemia and the other had V beta 9(+) leukemia. Flow cytomet ry supported this finding. Sequencing of the V beta 2-complementarity determining region 3 (CDR3), V beta 9-CDR3 and V beta 14-CDR3 revealed monoclonality, To investigate MRD using TCR beta-chain RNA, cDNA from each patient was diluted with the cDNA of a healthy person and amplif ied using a specific CDR3 clonotype primer. A band in the ethidium bro mide-stained agarose gel was detected from samples diluted 10 000-fold . SSCP analysis determined which V region gene was utilized in monoclo nal leukemic cells. The leukemic cell specific TCR, determined in such a manner, may be a target for immunotherapy. Because the MRD of T cel l malignancy can be easily examined once the CDR3 clonotype primer is made, this novel analysis is considered to be a useful method. (C) 199 7 Elsevier Science Ltd. All rights reserved.