TITLE:
The JAK2V617F Mutation Seen in Myeloproliferative Neoplasms (MPNs) Occurs in Patients with Inflammatory Bowel Disease: Implications of a Pilot Study
AUTHORS:
Emil Kuriakose, Elena Lascu, Y. Lynn Wang, Stefani Gjoni, Nicholas C. P. Cross, Ruth Baumann, Kerilee Tam, Ellen Scherl, Randy S. Longman, Richard T. Silver
KEYWORDS:
JAK2V617F; Myeloproliferative Neoplasms; Inflammatory Bowel Disease; Thrombocythemia; Polycythemia
JOURNAL NAME:
International Journal of Clinical Medicine,
Vol.4 No.12A,
December
24,
2013
ABSTRACT: Patients with
IBD frequently have hematologic abnormalities suggestive of JAK2 mutated MPNs,
but are traditionally classified as reactive processes. Haplotype 46/1 is a
well-characterized genetic predisposition, common to both inflammatory bowel
disease (IBD) and myeloproliferative neoplasms (MPN). In view of this shared
genetic predisposition, we measured the frequency of the JAK2V617F mutation in IBD patients with thrombocytosis or erythrocytosis, in order to
ascertain whether a higher than expected proportion of these patients may in
fact have underlying MPNs. 1121 patients were identified with an active
diagnosis of Crohn’s disease or ulcerative colitis, of which 474 had either
thrombocytosis or erythrocytosis. Patients with abnormal counts were tested for
the JAK2V617F mutation during routine follow-up visits. Interim analysis of first 23 patients tested was performed to
assess whether the JAK2V617F positivity rate was statistically
significant compared with known expected frequencies in a comparable control
population. Of 23 patients, 13 patients had thrombocytosis and 10 had
erythrocytosis. Three patients with thrombocytosis (23%), and 1 patient with
erythrocytosis (10%), tested positive for JAK2V617F, exceeding the
expected thresholds for statistical significance. In patients with IBD and
thrombocytosis or erythrocytosis, a meaningful proportion may harbor an
undiagnosed MPN, as indicated by clonal abnormalities such as JAK2V617F.
These findings imply the need for increased testing of these patients for
clonal hematologic abnormalities, and importantly, if found, suggest the need
for therapeutic strategies with drugs, such as JAK2 inhibitors, in patients
with both MPN and IBD.