Characterization of dendritic cell subsets in patients undergoing renal transplantation.

Dendritic cells (DCs) play a key role in transplantation tolerance and immune reactions to transplants. In order to ascertain whether DC levels are predictive for rejection, we examined the levels and expression patterns of DCs of renal transplant patients following immunosuppressive and/or surgical interventions. Myeloid (HLA-DR+/CD11c+) and plasmacytoid (HLA-DR+/CD123+) DCs were characterized by flow cytometry over 28 days. We demonstrated that myeloid DCs and plasmacytoid DCs in peripheral blood were discernable and dramatically decreased following renal transplantation and immunosuppression. Furthermore, the expression of CD62L was significantly up-regulated (P=.032), while CD86 was significantly down-regulated (P=.008) on myeloid but not plasmacytoid DCs. Although DC levels alone were not predictive for the occurrence of a rejection episode, in combination with other factors they may be indicative of rejection, thereby sparing the patient a biopsy.