title: Impact of very early CD4(+) /CD8(+) T cell counts on the occurrence of acute graft-versus-host disease and NK cell counts on outcome after pediatric allogeneic hematopoietic stem cell transplantation.
abstract: BACKGROUND
  Increasing evidence suggests that early and rapid lymphocyte recovery following allogeneic hematopoietic stem cell transplantation (HSCT) is associated with better survival.
  
  
  METHODS
  We retrospectively analyzed very early lymphocyte subset counts following transplantation from our 5-year pediatric allogeneic HSCT material to find clinically relevant associations with post transplant outcome, and the major complication of HSCT, acute graft-versus-host disease (aGVHD). We analyzed HSCTs performed due to acute leukemias and lymphomas from matched unrelated donors (MUD, n = 33), unrelated cord blood (UCB, n = 9) and matched sibling donors (MSD, n = 17).
  
  
  RESULTS
  Patients with grafts from MUDs and grade II-IV aGVHD) had higher (median 2.1 compared to 0.3, P<0.0001) and earlier (at day +18 post transplant vs. day +25, P = 0.004) first measurable CD4(+) /CD8(+) T cell ratio, compared to patients with no or grade I aGVHD, respectively. At day +32 after HSCT patients with MUDs and significant aGVHD had higher levels of both CD4(+) and CD8(+) T cell subsets. Low (below median 120/µL) versus high natural killer (NK) cell counts at day +32 were associated with 3-year event-free survival of 27.4 +/- 9.0% versus 82.4 +/- 6.4% (P < 0.0001), cumulative transplant-related mortality of 44.7 +/- 12.2% versus 3.0 +/- 3.0% (P < 0.001) and cumulative relapse incidence of 50.4 +/- 12.2% versus 15.0 +/- 6.2% (P = 0.019), respectively.
  
  
  CONCLUSIONS
  We conclude that early lymphocyte subset counts following allogeneic HSCT have an association with aGVHD and post transplant outcome.
authors.affiliation: Division of Hematology-Oncology and Stem Cell Transplantation, Children's Hospital, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Pasi
authors.initials: P
authors.lastname: Huttunen
authors.forename: Mervi
authors.initials: M
authors.lastname: Taskinen
authors.forename: Sanna
authors.initials: S
authors.lastname: Siitonen
authors.forename: Ulla M
authors.initials: UM
authors.lastname: Saarinen-Pihkala
mesh_terms: D000208:Acute Disease; D064591:Allografts; D018791:CD4 Lymphocyte Count; D002648:Child; D002675:Child, Preschool; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006086:Graft vs Host Disease / Q000097:blood / Q000276:immunology* / Q000401:mortality* / Q000473:pathology; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007223:Infant; D007694:Killer Cells, Natural / Q000276:immunology*; D007938:Leukemia / Q000097:blood / Q000276:immunology / Q000401:mortality / Q000473:pathology / Q000628:therapy; D008223:Lymphoma / Q000097:blood / Q000276:immunology / Q000401:mortality / Q000628:therapy; D008297:Male; D012189:Retrospective Studies; D015996:Survival Rate
keywords: allogeneic stem cell transplantation; graft-versus-host disease; lymphocyte reconstitution; lymphocyte subsets