title: Immune reconstitution after anti-thymocyte globulin-conditioned hematopoietic cell transplantation.
abstract: OBJECTIVE
  Anti-thymocyte globulin (ATG) is being used increasingly to prevent graft-versus-host disease (GvHD); however, its impact on immune reconstitution is relatively unknown. We (i) studied immune reconstitution after ATG-conditioned hematopoietic cell transplantation (HCT), (ii) determined the factors influencing the reconstitution, and (iii) compared it with non-ATG-conditioned HCT.
  
  
  METHODS
  Immune cell subset counts were determined at 1-24 months post-transplant in 125 HCT recipients who received ATG during conditioning. Subset counts were also determined in 46 non-ATG-conditioned patients (similarly treated).
  
  
  RESULTS
  (i) Reconstitution after ATG-conditioned HCT was fast for innate immune cells, intermediate for B cells and CD8 T cells, and very slow for CD4 T cells and invariant natural killer T (iNKT) (iNKT) cells. (ii) Faster reconstitution after ATG-conditioned HCT was associated with a higher number of cells of the same subset transferred with the graft in the case of memory B cells, naive CD4 T cells, naive CD8 T cells, iNKT cells and myeloid dendritic cells; lower recipient age in the case of naive CD4 T cells and naive CD8 T cells; cytomegalovirus recipient seropositivity in the case of memory/effector T cells; an absence of GvHD in the case of naive B cells; lower ATG serum levels in the case of most T-cell subsets, including iNKT cells; and higher ATG levels in the case of NK cells and B cells. (iii) Compared with non-ATG-conditioned HCT, reconstitution after ATG-conditioned HCT was slower for CD4 T cells, and faster for NK cells and B cells.
  
  
  CONCLUSIONS
  ATG worsens the reconstitution of CD4 T cells but improves the reconstitution of NK and B cells.
authors.affiliation: University of Calgary/Alberta Health Services, Calgary, Alberta, Canada. mbosch@ucalgary.ca
authors.forename: Mark
authors.initials: M
authors.lastname: Bosch
authors.forename: Manveer
authors.initials: M
authors.lastname: Dhadda
authors.forename: Mette
authors.initials: M
authors.lastname: Hoegh-Petersen
authors.forename: Yiping
authors.initials: Y
authors.lastname: Liu
authors.forename: Laura M
authors.initials: LM
authors.lastname: Hagel
authors.forename: Peter
authors.initials: P
authors.lastname: Podgorny
authors.forename: Alejandra
authors.initials: A
authors.lastname: Ugarte-Torres
authors.forename: Faisal M
authors.initials: FM
authors.lastname: Khan
authors.forename: Joanne
authors.initials: J
authors.lastname: Luider
authors.forename: Iwona
authors.initials: I
authors.lastname: Auer-Grzesiak
authors.forename: Adnan
authors.initials: A
authors.lastname: Mansoor
authors.forename: James A
authors.initials: JA
authors.lastname: Russell
authors.forename: Andrew
authors.initials: A
authors.lastname: Daly
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Stewart
authors.forename: David
authors.initials: D
authors.lastname: Maloney
authors.forename: Michael
authors.initials: M
authors.lastname: Boeckh
authors.forename: Jan
authors.initials: J
authors.lastname: Storek
mesh_terms: D000293:Adolescent; D000328:Adult; D000961:Antilymphocyte Serum / Q000097:blood / Q000276:immunology*; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D003586:Cytomegalovirus Infections / Q000097:blood / Q000276:immunology; D005260:Female; D006086:Graft vs Host Disease / Q000276:immunology; D018380:Hematopoietic Stem Cell Transplantation; D006650:Histocompatibility Testing; D006801:Humans; D008297:Male; D008875:Middle Aged; D035781:Siblings; D019172:Transplantation Conditioning; D055815:Young Adult
chemical_list: D000961:Antilymphocyte Serum