title: Hematopoietic stem cell transplantation in severe congenital neutropenia.
abstract: BACKGROUND
  Severe congenital neutropenia (SCN) is an immunodeficiency characterized by disturbed myelopoiesis and an absolute neutrophil count (ANC) <0.5 × 10(9)/L. SCN is also a premalignant condition; a significant proportion of patients develop myelodysplastic syndrome or leukemia (MDS/L). Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative treatment for SCN.
  
  
  METHODS
  Since 2004, eight HSCT have been performed in seven patients at our center. The indications were transformation to MDS/L (n = 2), granulocyte colony-stimulating factor receptor (CSF3R) mutation(s) (n = 2), granulocyte colony-stimulating factor (G-CSF) resistance (n = 2), and at the patient's own request (n = 1).
  
  
  RESULTS
  The mean age at transplantation was 13 years (2.8-28 years) (mean follow-up 32 months, range 21-60). Three patients harbored ELANE mutations, three HAX1 mutations, and in one patient no causative mutation was identified. Two of the ELANE mutations were novel mutations. Three patients initially received myeloablative conditioning and four had reduced intensity conditioning (RIC). Three grafts were from HLA-identical siblings, three from matched unrelated donors and two were cord blood units. Engraftment occurred in all patients. Two of seven (29%) patients died; both had MDS/L and both were among the three that underwent myeloablative conditioning. One patient has chronic GVHD 2 years post-transplant.
  
  
  CONCLUSIONS
  The role of HSCT should be explored further in patients with SCN. In particular, the influence of the conditioning regime needs to be evaluated in a larger cohort of patients.
authors.affiliation: Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden.
authors.forename: G
authors.initials: G
authors.lastname: Carlsson
authors.forename: J
authors.initials: J
authors.lastname: Winiarski
authors.forename: P
authors.initials: P
authors.lastname: Ljungman
authors.forename: O
authors.initials: O
authors.lastname: Ringdén
authors.forename: J
authors.initials: J
authors.lastname: Mattsson
authors.forename: M
authors.initials: M
authors.lastname: Nordenskjöld
authors.forename: I
authors.initials: I
authors.lastname: Touw
authors.forename: J-I
authors.initials: JI
authors.lastname: Henter
authors.forename: J
authors.initials: J
authors.lastname: Palmblad
authors.forename: B
authors.initials: B
authors.lastname: Fadeel
authors.forename: H
authors.initials: H
authors.lastname: Hägglund
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D000080984:Congenital Bone Marrow Failure Syndromes; D005260:Female; D006086:Graft vs Host Disease / Q000517:prevention & control*; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007938:Leukemia / Q000209:etiology / Q000628:therapy; D008297:Male; D009190:Myelodysplastic Syndromes / Q000209:etiology / Q000628:therapy; D009503:Neutropenia / Q000151:congenital / Q000628:therapy; D015996:Survival Rate; D019172:Transplantation Conditioning; D016896:Treatment Outcome; D055815:Young Adult