Kinetics of recovery of dendritic cell subsets after reduced-intensity conditioning allogeneic stem cell transplantation and clinical outcome.
OBJECTIVE
Dendritic cells (DC) play a critical role in the regulation of alloimmune responses and might influence the outcome of allogeneic stem cell transplantation (allo-SCT). We studied the clinical relevance of early reconstitution of DC after reduced-intensity conditioning allo-SCT (allo-RIC).


METHODS
This study included 79 adult patients undergoing allo-RIC from HLA-identical siblings. Peripheral blood samples were drawn from patients at 1 month (+1m) and 3 months (+3m) after the transplant. DC were identified as positive for HLA-DR and negative for CD3, CD19, CD14 and CD56. The expression of CD33, CD123 and CD16 was used to identify myeloid DC, plasmacytoid DC and CD16(+) DC subpopulations, respectively.


RESULTS
Patients whose DC count at +1m was lower than the median had a higher probability of treatment-related mortality (TRM) (60% vs 12%; p=0.02), poorer overall survival (OS) (15% vs 45%; p=0.002) and worse event-free survival (EFS) (20% vs 38%; p=0.03). A multivariate analysis confirmed that low DC counts had a detrimental effect on OS (RR 3.2; p=0.007), relapse (RR 4.1; p=0.01), and EFS (RR 6; p=0.001). Low CD16(+) DC counts were observed to have a detrimental effect on EFS, which was due to both a higher incidence of deaths caused by infections (50% vs 0%, p=0.05) and a higher incidence of relapse (57% vs 50%; p=0.03). Indeed, the number of CD16(+) DC at +3 m was the most important prognostic factor for EFS (RR 6; p=0.001). Interpretations and Conclusions This study shows the clinical importance of DC recovery, especially of the CD16(+) DC subset, in the outcome of patients treated with allo-RIC.
Institute of Hematology and Oncology, Department of Hematology, H. Clínic, Barcelona , Spain.
Carme
C
Talarn
Alvaro
A
Urbano-Ispizua
Rodrigo
R
Martino
José Antonio
JA
Pérez-Simón
Montserrat
M
Batlle
Concepción
C
Herrera
Miquel
M
Granell
Anna
A
Gaya
Montserrat
M
Torrebadell
Francesc
F
Fernández-Avilés
Marta
M
Aymerich
Pedro
P
Marín
Jorge
J
Sierra
Emili
E
Montserrat
D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000276:immunology; D001772:Blood Cell Count; D003713:Dendritic Cells / Q000276:immunology* / Q000473:pathology; D018572:Disease-Free Survival; D005260:Female; D019337:Hematologic Neoplasms / Q000276:immunology* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D022423:Myeloid Cells / Q000276:immunology / Q000473:pathology; D010950:Plasma Cells / Q000276:immunology* / Q000473:pathology; D020127:Recovery of Function / Q000276:immunology*; D012189:Retrospective Studies; D013030:Spain; D033581:Stem Cell Transplantation; D019172:Transplantation Conditioning; D014184:Transplantation, Homologous
D015703:Antigens, CD