Quantitative follow-up of lymphocyte clone with individual ASO primers. Patient-specific primers were designed to recognize clonal TCR γ and TCR δ gene rearrangements and were used to estimate the amount of clone in various time points before and during dasatinib therapy. The estimation of the amount of the existing clone was determined by designating one follow-up sample with a reference value of 1, and calculating other follow-up samples in relation to this reference sample. Figures on the left side show the estimated amount of clone in the blood at different time points (reference level 1 is marked with dashed black line). The figure on the right side presents the absolute lymphocyte counts at the same time points (upper limit of normal lymphocyte count is marked with dashed black line). (A) Patient 1 (Tables 1,4). This patient had a clonal rearrangement in TCR γ gene that was detected in CD8⁺αβ⁺ T cells, whereas the clonal rearrangement in TCR δ gene was found in NK cells. Follow-up of these 2 clones was done before (day −103, on imatinib) and after start of dasatinib therapy (days 56, 117, and 138). (B) Patient 5 (Tables 1,4). This patient had a clonal rearrangement in TCR γ gene detected in CD4⁺αβ⁺ T cells, whereas the clonal rearrangement in TCR δ gene was found in CD4⁺γδ⁺ T cells. Follow-up samples were available from the time of diagnosis (day −739) and during imatinib (day −187) and dasatinib (days 29, 239, 336, and 351) therapy.