(A,B): Post-transplant persistence of preformed high titer anti-class I DSA in a sensitized multiviceral transplant recipient (A), was associated with early disappearance of T-cell chimerism (B). (C): In this highly sensitized patient (Pt10), post-transplant, but not pre-transplant, donor cells display a lower level of detectable HLA class I, when compared to recipient cells. In contrast, post-transplant donor and recipient cells have comparable HLA class I expression in non-sensitized patients (representative staining from Pt7). (D): Incubation with pre-transplant Pt10 serum decreases the HLA-class I staining on donor, yet not on recipient, pre-transplant cells. (E): The positive anti-human IgG staining on the circulating donor cells showed that they had been bound in vivo by DSA.