Spontaneous improvement of hematologic abnormalities in patients having juvenile myelomonocytic leukemia with specific RAS mutations.
Of 11 children with juvenile myelomonocytic leukemia (JMML) carrying RAS mutations (8 with NRAS mutations, 3 with KRAS2 mutations), 5 had a profound elevation in either or both the white blood cells and spleen size at diagnosis. Three patients had no or modest hepatosplenomegaly and mild leukocytosis at presentation but subsequently showed a marked increase in spleen size with or without hematologic exacerbation, for which nonintensive chemotherapy was initiated. The other three patients with NRAS or KRAS2 glycine to serine substitution received no chemotherapy, but hematologic improvement has been observed during a 2- to 4-year follow up. In the third group, all hematopoietic cell lineages analyzed had the RAS mutations at the time of hematologic improvement, whereas DNA obtained from the nails had the wild type. Additionally, numbers of circulating granulocyte-macrophage progenitors were significantly reduced during the clinical course. Thus, some patients with JMML with specific RAS mutations may have spontaneously improving disease.
Matsuda
Kazuyuki
K
Department of Laboratory Medicine, Shinshu University Hospital, Matsumoto, Japan.
Shimada
Akira
A
Yoshida
Nao
N
Ogawa
Atsushi
A
Watanabe
Akihiro
A
Yajima
Shuhei
S
Iizuka
Susumu
S
Koike
Kazutoshi
K
Yanai
Fumio
F
Kawasaki
Keiichiro
K
Yanagimachi
Masakatsu
M
Kikuchi
Akira
A
Ohtsuka
Yoshitoshi
Y
Hidaka
Eiko
E
Yamauchi
Kazuyoshi
K
Tanaka
Miyuki
M
Yanagisawa
Ryu
R
Nakazawa
Yozo
Y
Shiohara
Masaaki
M
Manabe
Atsushi
A
Kojima
Seiji
S
Koike
Kenichi
K
D019943:Amino Acid Substitution; D001773:Blood Cells / Q000473:pathology*; D005260:Female; D042381:Granulocyte Precursor Cells; D006801:Humans; D007223:Infant; D015477:Leukemia, Myelomonocytic, Chronic / Q000175:diagnosis / Q000235:genetics*; D008297:Male; D009154:Mutation / Q000502:physiology*; D009365:Neoplasm Regression, Spontaneous / Q000235:genetics*; D018631:ras Proteins / Q000235:genetics* / Q000502:physiology
D018631:ras Proteins