title: Frequent reduction or absence of detection of the JAK2-mutated clone in JAK2V617F-positive patients within the first years of hydroxyurea therapy.
abstract: We analyzed the effect of hydroxyurea on the JAK2V617F allelic ratio (%JAK2V617F), measured in purified blood granulocytes, of patients with polycythemia vera and essential thrombocythemia. Thirty-six patients were examined sequentially prior to and after start of hydroxy-urea therapy (8 polycythemia vera, 17 essential thrombocythemia), or while remaining untreated (2 polycythemia vera, 9 essential thrombocythemia). Hydroxyurea therapy (median duration: 15 months) reduced the %JAK2V617F by >30% in 13/25 patients (4 polycythemia vera, 9 essential thrombocythemia). For 3 patients, JAK2V617F remained undetectable for 3-27 months. In addition, a single time point study of two large cohorts of patients, examined either at the time of diagnosis (99 polycythemia vera, 178 essential thrombocythemia) or while receiving hydroxyurea (36 polycythemia vera, 98 essential thrombocythemia; median length of therapy: 32 months), confirmed reduction of %JAK2V617F in the hydroxyurea-treated group (24% vs. 33% JAK2V617F at diagnosis, p<0.01). Prospective studies are needed to determine the prognostic value of reduced JAK2V617F allele burden under cytoreductive therapy.
authors: Laboratoire d'Hématologie, Hôpital du Bocage, CHU de Dijon, Dijon, France. francois.girodon@chu-dijon
authors: François
authors: F
authors: Girodon
authors: Céline
authors: C
authors: Schaeffer
authors: Cédric
authors: C
authors: Cleyrat
authors: Morgane
authors: M
authors: Mounier
authors: Ingrid
authors: I
authors: Lafont
authors: Frédéric Dos
authors: FD
authors: Santos
authors: Aurélie
authors: A
authors: Duval
authors: Aurélie
authors: A
authors: Vidal
authors: Marc
authors: M
authors: Maynadié
authors: Sylvie
authors: S
authors: Hermouet
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019943:Amino Acid Substitution; D000986:Antisickling Agents / Q000627:therapeutic use; D015331:Cohort Studies; D017931:DNA Primers; D005260:Female; D006098:Granulocytes / Q000502:physiology; D006801:Humans; D006918:Hydroxyurea / Q000627:therapeutic use*; D053614:Janus Kinase 2 / Q000097:blood / Q000172:deficiency / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011087:Polycythemia Vera / Q000188:drug therapy* / Q000235:genetics; D012189:Retrospective Studies; D013920:Thrombocythemia, Essential / Q000188:drug therapy* / Q000235:genetics
chemical_list: D000986:Antisickling Agents; D017931:DNA Primers; C507924:JAK2 protein, human; D053614:Janus Kinase 2; D006918:Hydroxyurea