Figure 5. Detection of the changes in the composition of the total CD4⁺CD127^low+/−FoxP3⁺-Treg cell pool with four different Treg subsets during the time after transplantation.

The percentage of the DR^high+CD45RA⁻- (A), the DR^low+CD45RA⁻- (B), the DR⁻CD45RA⁺- (C), and the DR⁻CD45RA⁻- (D) Treg subset within the total Treg cell pool was estimated in healthy non-transplanted volunteers (▴) and in non-rejecting (♦) and rejecting kidney transplant patients (•) at different time points after transplantation. In addition the HLA-DR MFI of the DR⁺CD45RA⁻-Treg subset was determined for all participants in all patient groups (E). Monitoring the HLA-DR MFI allowed a significant discrimination between rejecting and non-rejecting patients, due to a significantly reduced percentage of the DR^high+CD45RA⁻-Treg subset within the total Treg pool. MFI = mean fluorescence intensity.