High rate of chromosomal abnormalities in HTLV-I-infected T-cell colonies derived from prodromal phase of adult T-cell leukemia: A study of IL-2-stimulated colony formation in methylcellulose

To detect chromosomal abnormalities in prodromal phase of adult T-cell leuk emia IA TLI, we established a clonal culture method for human T-lymphotropi c virus type I (HTLV-I) infected T-cells in methylcellulose containing reco mbinant human interleukin 2 (rhIL-2). We tried to analyze chromosomes of 18 7 colonies (4, 23, 69, 74, and 17, from HTLV-I-uninfected normal T-cells, H TLV-I-Infected normal T-cells, HTLV-I carriers, smoldering ATL, and chronic ATL, respectively), using chromosomal banding methods, In the prodromal gr oup, 53 % of colonies (84/160) (36/69, 37/74, 11/17 in HTLV-I carriers, smo ldering ATLs, and chronic ATL, respectively) had chromosomal abnormal clone s. In HTLV-I carriers, multiple clones with simple chromosomal abnormalitie s tt ere observed. In more progressed chronic ATL, more complex chromosomal abnormalities were detected, and specific colonies were selected. Thus, co lonies in the prodromal phase of ATL are characterized by cytogenetical clo nal evolution and clonal changes. (C) Elsevier Science Inc., 1999. All righ ts reserved.