Variability in engraftment profiles and impact of prior chemotherapy on chimerism and GVHD. (A) The engraftment kinetics of donor T cells (▪) and myeloid cells (♦) are shown in patients 10, 11, 16, and 36. The PCR products of a single informative STR in T-cell and myeloid lineages from day-30 blood samples in the same patients are shown. The informative donor band(s) is shown in red and the informative patient band(s) is shown in blue. (B) Regression equation predicting donor myeloid chimerism on day-45 after HCT. CD14⁺/15⁺ is the % donor myeloid chimerism on day 45. CHEMO = 0 if no prior chemotherapy; and CHEMO = 1 if prior chemotherapy and log₁₀ CD34⁺ dose is the logarithm (base 10) of the CD34⁺ dose. The interaction between the 2 independent variables was tested and found not to be significant (P > .5). The F value for the model was 14.59, 2, and 29 degrees of freedom; P < .0001. (C) The percentage donor myeloid chimerism on days 15, 30, 45, 60, and 100 in individual patients who had received prior chemotherapy (blue lines) versus those who were chemotherapy naive (red lines). On day 30 (D) and day 45 (E), patients who had received prior chemotherapy had more rapid donor myeloid and T-cell engraftment compared with patients who were chemotherapy naive. Individual (•) and median (—) values of the 18 patients in each cohort are shown. (F) Time to acute grades II to IV GVHD in patients who had received prior chemotherapy compared with chemotherapy naive patients.