The origin of neoplastic mast cells in systemic mastocytosis with AML1/ETO-positive acute myeloid leukemia.
OBJECTIVE
Systemic mastocytosis with associated clonal hematological non-mast cell lineage disease (SM-AHNMD) is a distinct entity that was defined by World Health Organization. Systemic mastocytosis with acute myeloid leukemia (AML) is frequently seen among SM-AHNMD. However, the pathogenesis or origin of neoplastic mast cells has not been fully elucidated in this category of diseases.


METHODS
We examined KIT mutation, chimeric status, and AML1/ETO mRNA concerning mast cells and immature hematopoietic cells of the bone marrow in a patient with systemic mastocytosis with AML1/ETO-positive AML following allogeneic hematopoietic stem cell transplantation (HSCT).


RESULTS
Mast cells of the patient displayed KIT D816Y mutation, and were derived from the recipient. In contrast, immature hematopoietic cells as defined by CD34+ CD117+ were derived from the donor, which did not possess detectable KIT D816Y mutation. The ratio of AML1/ETO to 18S rRNA of the mast cells was 7.53, whereas that of immature hematopoietic cells was 1.67.


CONCLUSIONS
In a patient with SM-AHNMD who underwent allogeneic HSCT, the major source of the detectable AML1/ETO mRNA of the bone marrow after transplantation was neoplastic mast cells with KIT mutation, which were thought to be derived from CD34+ CD117+ immature leukemic cells of the recipient.
Nagai
Sumimasa
S
Department of Hematology and Oncology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
Ichikawa
Motoshi
M
Takahashi
Tsuyoshi
T
Sato
Hiroyuki
H
Yokota
Hiromitsu
H
Oshima
Kumi
K
Izutsu
Koji
K
Hangaishi
Akira
A
Kanda
Yoshinobu
Y
Motokura
Toru
T
Chiba
Shigeru
S
Yatomi
Yutaka
Y
Kurokawa
Mineo
M
D000328:Adult; D018952:Antigens, CD34; D019070:Cell Lineage; D050676:Core Binding Factor Alpha 2 Subunit; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D015470:Leukemia, Myeloid, Acute / Q000209:etiology* / Q000473:pathology; D008407:Mast Cells / Q000473:pathology*; D034721:Mastocytosis, Systemic / Q000145:classification / Q000150:complications / Q000473:pathology*; D009154:Mutation; D015514:Oncogene Proteins, Fusion; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics; D000075142:RUNX1 Translocation Partner 1 Protein; D014184:Transplantation, Homologous
C107844:AML1-ETO fusion protein, human; D018952:Antigens, CD34; D050676:Core Binding Factor Alpha 2 Subunit; D015514:Oncogene Proteins, Fusion; D000075142:RUNX1 Translocation Partner 1 Protein; D019009:Proto-Oncogene Proteins c-kit