Most pediatric patients with essential thrombocythemia show hypersensitivity to erythropoietin in vitro, with rare JAK2 V617F-positive erythroid colonies.
Essential thrombocythemia (ET), a Philadelphia (Ph) chromosome negative chronic myeloproliferative disorder, is usually a disease of middle age and it is extremely rare in pediatric patients. In this report we studied 12 children diagnosed with ET and one child with thrombocytosis and family history of ET. We failed to detect JAK2 V617F mutation either in peripheral blood leukocytes or in separated platelets and granulocytes. Monoclonal hematopoiesis was noted in only one female patient. Erythroid progenitors of most of the patients displayed hypersensitivity to erythropoietin (Epo) in vitro; Epo-independent erythroid colonies (EECs) were detected in seven patients. Among EECs of three patients we observed rare colonies heterozygous or homozygous for the JAK2 V617F mutation. Our data suggest that childhood ET patients could bear minor JAK2 V617F-positive subclones.
Veselovska
Jitka
J
Department of Biology, Faculty of Medicine, Palacky University, Olomouc, Czech Republic.
Pospisilova
Dagmar
D
Pekova
Sona
S
Horvathova
Monika
M
Solna
Renata
R
Cmejlova
Jana
J
Cmejla
Radek
R
Belickova
Monika
M
Mihal
Vladimir
V
Stary
Jan
J
Divoky
Vladimir
V
D000293:Adolescent; D002648:Child; D002999:Clone Cells; D015672:Erythroid Precursor Cells / Q000187:drug effects; D004920:Erythropoiesis; D004921:Erythropoietin / Q000097:blood / Q000494:pharmacology*; D005260:Female; D005838:Genotype; D006412:Hematopoietic Stem Cells; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics*; D008297:Male; D009154:Mutation; D013920:Thrombocythemia, Essential / Q000235:genetics*; D013922:Thrombocytosis / Q000235:genetics
D004921:Erythropoietin; D053614:Janus Kinase 2