title: Outcomes of immunological interventions for mixed chimerism following allogeneic stem cell transplantation in children with juvenile myelomonocytic leukemia.
abstract: BACKGROUND
  For children with juvenile myelomonocytic leukemia (JMML) who undergo stem cell transplantation (SCT), the role of immunological interventions including withdrawal of immunosuppressive therapy (IST) and donor lymphocyte infusion (DLI) for treatment of disease recurrence remains uncertain.
  
  
  METHODS
  We analyzed serial chimerism status following SCT and evaluated the efficacy of immunological interventions for the management of mixed chimerism (MC) in children with JMML.
  
  
  RESULTS
  Chimerism analysis was available in 26 SCT cases following the first and second SCT. MC was observed in 16 cases and withdrawal of IST was performed in 14 cases immediately after identification of MC. Donor lymphocyte infusion (DLI) was performed in five MC cases. Eight MC cases were observed at the time of neutrophil recovery. Following withdrawal of IST, three cases achieved complete chimerism (CC) while the proportion of autologous cells increased rapidly in the remaining five cases. Six MC cases were observed after achievement of hematological remission (HR) and responses to withdrawal of IST were observed in two cases. In the remaining four cases, despite withdrawal of IST, the proportion of autologous cells increased. Five cases received DLI but only one case responded.
  
  
  CONCLUSIONS
  Although the benefits of immunological interventions for MC after SCT in JMML were limited, some patients did achieve HR as a result of these treatment modalities without a second SCT. Close monitoring of donor chimerism and early detection of MC is helpful in guiding treatment after SCT in children with JMML.
authors: Department of Pediatrics, National Kyushu Cancer Center, Fukuoka, Japan. inagakij@nk-cc.go.jp
authors: Jiro
authors: J
authors: Inagaki
authors: Reiji
authors: R
authors: Fukano
authors: Takuro
authors: T
authors: Nishikawa
authors: Kentaro
authors: K
authors: Nakashima
authors: Daisuke
authors: D
authors: Sawa
authors: Nobuhiro
authors: N
authors: Ito
authors: Jun
authors: J
authors: Okamura
mesh_terms: D002675:Child, Preschool; D046528:Chimerism; D005260:Female; D006086:Graft vs Host Disease / Q000209:etiology; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects; D006801:Humans; D007223:Infant; D054429:Leukemia, Myelomonocytic, Juvenile / Q000276:immunology / Q000628:therapy*; D017710:Lymphocyte Transfusion; D008297:Male; D012189:Retrospective Studies; D014184:Transplantation, Homologous; D016896:Treatment Outcome