Real-time quantitative PCR chimerism determination.

(A) Recipient genotype percentages assessed from 10 post–allo-BMT DNA samples (vertical axis) are plotted against time after allo-BMT (horizontal axis) for clinical case 1 (see text). Complete donor chimerism (day 108) followed decrease of recipient genotype percentage (day 0 to day 93) after allo-BMT. (B) Recipient genotype percentages assessed from 12 post–allo-BMT DNA samples (vertical axis) are plotted against time after allo-BMT (horizontal axis) for clinical case 2 (see text). Decrease of recipient genotype percentage (day 35) is followed by stable mixed chimerism until day 235. (C) Recipient genotype percentages assessed from 10 post–allo-BMT DNA samples are plotted against time centered around DLI date for clinical case 3 (see text). Mixed chimerism associated with the relapse (day 210 and day 15) is followed 2 months after DLI by a decrease (day 60 and day 75) and a disappearance of recipient genotype fraction (days 90, 204, and 300). (D) Recipient genotype percentages assessed from 9 post–allo-BMT DNA samples are plotted against time centered around the allogenic peripheral blood stem cell (allo-PBSC) infusion date for clinical case 4 (see text). Mixed chimerism associated with first relapse (day 5) is followed after chemotherapy and allo-PBSC infusion by recipient genotype percentage decrease and disappearance (day 57). Reappearance of recipient genotype fraction is observed in 2 DNA samples (day 112 and day 151) before diagnosis of second relapse.