Lymphocyte subset recovery and outcome after T-cell replete allogeneic hematopoietic SCT.
Rapid recovery of lymphocytes after T-cell depleted hematopoietic SCT (HSCT) protects from relapse of myeloid malignancies. Whether lymphocyte reconstitution has a similar role after non-manipulated transplantation is controversial. We assessed numbers of CD4 and CD8 T-cells, natural killer (NK) cells and B-cells, before and 1, 3, 6, 12 and 24 months after T-cell replete transplantation in 345 patients. Lymphocyte subset counts up to 6 months post transplant had no effect on relapse. Elevated number of NK cells 12 months post transplant protected from relapse. As a novel finding, early recovery of NK cells was associated with significant protection from TRM already at the 3 and 6 months time points (P=0.03, P=0.02). In Cox multivariable models, patients with NK cells above 150/μL were significantly protected from TRM (hazard ratio (HR) 0.45, 95% confidence interval (95% CI) 0.21-0.95, P=0.03), an effect comparable in magnitude with that of carrying >200 CD4 T-cells/μL (HR 0.37, 95% CI 0.19-0.74, P=0.005). CD8 T-cell and B-cell recovery did not affect the rates of relapse or TRM. Early reconstitution of NK cells and CD4 T-cells in patients undergoing T-cell replete HSCT independently protected from TRM. Only a weak protection from disease relapse was noted for patients with high numbers of NK cells, and this occurred only late after transplantation.
Stem Cell Transplant Team, Division of Hematology, Department of Internal Medicine, University Hospital, Basel, Switzerland.
L
L
Bühlmann
A S
AS
Buser
N
N
Cantoni
S
S
Gerull
A
A
Tichelli
A
A
Gratwohl
M
M
Stern
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D016131:Lymphocyte Subsets / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013601:T-Lymphocytes / Q000276:immunology*; D019172:Transplantation Conditioning / Q000379:methods*; D014184:Transplantation, Homologous; D016896:Treatment Outcome; D055815:Young Adult