Proposals and rationale for revision of the World Health Organization diagnostic criteria for polycythemia vera, essential thrombocythemia, and primary myelofibrosis: recommendations from an ad hoc international expert panel.
The Janus kinase 2 mutation, JAK2617V>F, is myeloid neoplasm-specific; its presence excludes secondary polycythemia, thrombocytosis, or bone marrow fibrosis from other causes. Furthermore, JAK2617V>F or a JAK2 exon 12 mutation is present in virtually all patients with polycythemia vera (PV), whereas JAK2617V>F also occurs in approximately half of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF). Therefore, JAK2 mutation screening holds the promise of a decisive diagnostic test in PV while being complementary to histology for the diagnosis of ET and PMF; the combination of molecular testing and histologic review should also facilitate diagnosis of ET associated with borderline thrombocytosis. Accordingly, revision of the current World Health Organization (WHO) diagnostic criteria for PV, ET, and PMF is warranted; JAK2 mutation analysis should be listed as a major criterion for PV diagnosis, and the platelet count threshold for ET diagnosis can be lowered from 600 to 450 x 10(9)/L. The current document was prepared by an international expert panel of pathologists and clinical investigators in myeloproliferative disorders; it was subsequently presented to members of the Clinical Advisory Committee for the revision of the WHO Classification of Myeloid Neoplasms, who endorsed the document and recommended its adoption by the WHO.
Tefferi
Ayalew
A
Mayo Clinic, Rochester, MN 55905, USA. ayalew@mayo.edu
Thiele
Juergen
J
Orazi
Attilio
A
Kvasnicka
Hans Michael
HM
Barbui
Tiziano
T
Hanson
Curtis A
CA
Barosi
Giovanni
G
Verstovsek
Srdan
S
Birgegard
Gunnar
G
Mesa
Ruben
R
Reilly
John T
JT
Gisslinger
Heinz
H
Vannucchi
Alessandro M
AM
Cervantes
Francisco
F
Finazzi
Guido
G
Hoffman
Ronald
R
Gilliland
D Gary
DG
Bloomfield
Clara D
CD
Vardiman
James W
JW
D006801:Humans; D048056:Mitogen-Activated Protein Kinase 9 / Q000235:genetics; D009154:Mutation; D011087:Polycythemia Vera / Q000175:diagnosis / Q000235:genetics; D055728:Primary Myelofibrosis / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D013920:Thrombocythemia, Essential / Q000175:diagnosis / Q000235:genetics; D014944:World Health Organization
D048056:Mitogen-Activated Protein Kinase 9