title: Post-Transplantation Natural Killer Cell Count: A Predictor of Acute Graft-Versus-Host Disease and Survival Outcomes After Allogeneic Hematopoietic Stem Cell Transplantation.
abstract: Reconstitution of the immune system after allogeneic hematopoietic stem cell transplantation (allo-HSCT) plays an important role in post-transplant outcomes. However, the clinical relevance of the lymphocyte subset (LST) counts to transplant-related complications and survival outcomes after allo-HSCT has not been fully elucidated.
  
  
  
  A total of 70 patients who had undergone allo-HSCT from 2007 to 2013, with LST results both 7 days before conditioning and 30 or 90 days after allo-HSCT were included. The LST counts in the peripheral blood were determined using 6-color flow cytometry. Clinical information, including transplant-related events during the first 100 days after allo-HSCT, was reviewed, and any association between these events and LST was analyzed.
  
  
  
  At 30 days after allo-HSCT, the CD4+T-cell (P = .009) and B-cell (P = .035) counts were lower and the natural killer (NK) cell count was greater (P < .001) than before conditioning. The CD8+T-cell (P = .001) and NK cell (P < .001) counts were high 90 days after transplantation. The hazard ratios for a low NK cell count on days 30 and 90 for acute graft-versus-host disease were 6.22 and 14.67, respectively. Patients with low NK cell counts at 30 and 90 days after allo-HSCT had poorer overall survival (P = .043 and P = .028, respectively) and greater nonrelapse mortality (P = .036 and P = .033, respectively). A low NK cell count on day 30 was still prognostic for overall survival (P = .039) on multivariable analysis.
  
  
  
  NK cell counts after allo-HSCT, especially on day 30, were predictive of acute graft-versus-host disease, nonrelapse mortality, and survival. Serial lymphocyte subset analysis can be used to identify and treat patients at risk during the early period after allo-HSCT.
authors.affiliation: Department of Laboratory Medicine, Center for Diagnostic Oncology, Hospital and Research Institute, National Cancer Center, Korea, Goyang, Republic of Korea.
authors.forename: Seo Yeon
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Hematology-Oncology, Center for Hematologic Malignancy, Hospital and Research Institute, National Cancer Center, Korea, Goyang, Republic of Korea.
authors.forename: Hyewon
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, Center for Diagnostic Oncology, Hospital and Research Institute, National Cancer Center, Korea, Goyang, Republic of Korea.
authors.forename: Mi-Soon
authors.initials: MS
authors.lastname: Han
authors.affiliation: Department of Laboratory Medicine, Center for Diagnostic Oncology, Hospital and Research Institute, National Cancer Center, Korea, Goyang, Republic of Korea.
authors.forename: Hyoeun
authors.initials: H
authors.lastname: Shim
authors.affiliation: Department of Hematology-Oncology, Center for Hematologic Malignancy, Hospital and Research Institute, National Cancer Center, Korea, Goyang, Republic of Korea.
authors.forename: Hyeon-Seok
authors.initials: HS
authors.lastname: Eom
authors.affiliation: Biometric Research Branch, Hospital and Research Institute, National Cancer Center, Korea, Goyang, Republic of Korea.
authors.forename: Boram
authors.initials: B
authors.lastname: Park
authors.affiliation: Department of Laboratory Medicine, Center for Diagnostic Oncology, Hospital and Research Institute, National Cancer Center, Korea, Goyang, Republic of Korea; Division of Cancer Epidemiology and Prevention, Hospital and Research Institute, National Cancer Center, Korea, Goyang, Republic of Korea. Electronic address: ksy@ncc.re.kr.
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Kong
mesh_terms: D000328:Adult; D015415:Biomarkers; D005260:Female; D005500:Follow-Up Studies; D006086:Graft vs Host Disease / Q000175:diagnosis / Q000209:etiology; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects / Q000379:methods; D006801:Humans; D016130:Immunophenotyping; D053208:Kaplan-Meier Estimate; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism*; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009026:Mortality; D016017:Odds Ratio; D063868:Patient Outcome Assessment; D011184:Postoperative Period; D011379:Prognosis; D016016:Proportional Hazards Models; D012372:ROC Curve; D019172:Transplantation Conditioning / Q000009:adverse effects / Q000379:methods; D014184:Transplantation, Homologous; D055815:Young Adult
chemical_list: D015415:Biomarkers
keywords: Acute GVHD; Flow cytometry; HSCT; Lymphocyte subsets; NK cell