MYELOPROLIFERATIVE DISEASES: TWO DIAGNOSIS IN THE SAME PATIENT
POSTER 4
Maria Eduarda Couto1, Isabel Oliveira2 and José Mariz2
(1)Onco-hematology Service, Instituto Português de Oncologia do Porto, F.G., E.P.E., Porto, Portugal
(2)Onco-hematology Department, Instituto Português de Oncologia do Porto, F.G., E.P.E., Porto,
Portugal
Introduction: Philadelphia negative myeloproliferative diseases (MPD) are characterized by
elevated blood counts, thrombotic as well as hemorrhagic events, a variety of symptoms,
cumulative risk of progression to myelofibrosis or transformation to acute myeloid leukemia
over time and long survival. They have a genetic base in common that makes possible to
change from one diagnosis to another throw clonal expansion over time.
Aim and Methods: The clinical file of a patient diagnosed and treated in our center was
reviewed, in order to characterize the disease course.
Results: A 47-year-old male was diagnosed with Essential Thrombocytosis (ET) in 2010, with
the mutation p.V617F in the gene JAK2 identified (hemoglobin 17,2 g/dL, hematocrit 0,475
L/L, leucocytes 9,19 x10⁹/L, platelets 612 x10⁹/L, bone marrow compatible with ET, normal
erythrocyte mass). Since then he started daily aspirin. In 2014 he was also prescribed with
hydroxyurea (HU) 500 mg/day for a progressive increase in the hemoglobin (19,2 g/dL),
leucocytes (11,68 x10⁹/L) and hematocrit (55,9%), with controlled platelets count (559
x10⁹/L). The disease progressively seemed to change to a Polycythemia Vera (PV) spectrum
(normal gasometer but high erythrocyte mass). For this reason the patient did several
phlebotomies of 400 mL between 2014 and 2018 (20 times) until achieving hematocrit control
(<45%). Since then, he remains in surveillance with HU 1 gr/daily and daily aspirin. One
hemogram of 2019 showed hemoglobin 14,9 g/dL, hematocrit 0,40 L/L, leucocytes 7,02
x10⁹/L, platelets 246 x10⁹/L. He has a normal quality of life for his age and does exercise
regularly (20 km by bicycle on weekends and also running).
Conclusion: A patient with an ET had clonal expansion of the erythroid lineage through a
mechanism dependent on the JAK2 gene, a mutation firstly identified when the ET was found
and also shared with PV as the main event. Patients with MPD should be surveilled regularly,
as a fast and appropriate approach are important to ensure disease control and a good quality
of life (which is mainly affected by the relevant risk of thrombotic and hemorrhagic events).