Polycythemia Flashcards
Secondary polycythemia can result from:
oxygen desaturation <92% increase EPO levels, testosterone therapy, ovarian leiomyomas, EPO secreting tumors (like renal cell)
when to stop testosterone therapy on a patient who has developed polycythemia?
when Hct >54%
25% of pts on testosterone therapy develop polycythemia. Also see polycythemia happen as a dose dependent phenomenon.
definition of polycythemia
Hgb > 16.5 in men and >16 in women
primary polycythemia or EPO independent happens because of
chronic myeloproliferative disorder sometimes called polycythemia vera.
activating mutation is a JAK2-V617F gene seen in 97% of all polycythemia vera
what is the clinical presentation of polycythemia vera?
see aquagenic pruritis (post showering itching), erythromelalgia (redness and paresthesias of extremities), thrombosis, hemorrhage
can have headaches and fatigue
what is seen on lab for a pts who has polycythemia vera or primary polycythemia?
low EPO, positive JAK2 mutation (97% positive)
Side effects of secondary polycythemia
increased risk for VTE or cardiovascular events.
Secondary polycythemia is a result in
EPO dependent; there’s something driving EPO elevation and needs work up. Either sleep study, abdominal imaging, or review of medications, or if pt lives in a high altitude area.
polycythemia vera (clinical features) will have
high blood viscosity
HTN
erythromelalgia (burning cyanosis in hands and feet and transient visual disturbances.
high RBC turnover and gouty arthritis and aquagenic pruritis and bleeding.
erythromelalgia
burning cyanosis in hands and feet and redness
seen with polycythemia vera
treated with aspirin.
what are the physical exam findings for polycythemia vera
see facial plethora (ruddy cyanosis) and splenomegaly
may have arterial or venous thrombosis or TIAs.
laboratory findings of polycythemia vera
Hgb>16.5 in men and Hgb>16 in women.
elevated Hgb or HCT>48% in female and >49% in men.
leukocytosis and thrombocytosis
see low EPO level
JAK2 mutation positive
complications of polycythemia vera
thrombosis- stroke, VTE
can develop into post PV primary myelofibrosis (5-10 yrs after diagnosis)
or can develop into acute leukemia (AML)
treatment of polycythemia vera
increased risk for thrombus (age>60, active thrombus or prior thrombus):
-treat with hydroxyurea
if no active thrombus or at low risk for thrombus (age <60 and no prior thrombosis):
-treat with serial phlebotomy to get Hct <45, ASA, and symptom management.
what is polycythemia vera
clonal myeloproliferative disorder associated with proliferation of RBC independent of EPO and other cytokines.
EPO levels are low and 97% cases will have JAK2 positivity
Treatment of people with high risk polycythemia vera
> 60 yrs and have active thrombus or prior thrombus
phlebotomy to achieve hematocrit <45
need hydroxyurea
primary polycythemia labs
low EPO
Includes polycythemia vera (Jak2 mutation) and EPO receptor mutations
secondary polycythemia labs
normal or high EPO
Results from hypoxemia - cardiopulmonary disease, OSA, high altitude
EPO producing tumor (renal, hepatic)
Congenital (high affinity to hgb)
following renal transplant
Androgen supplementation
polycythemia work up given high EPO levels
need to get a post exercise and nocturnal oxygen saturation testing.
if there’s a history of cigarette use, dypsnea and obesity need to rule out pulmonary disease leading to hypoxia as a reason for post exercise and nocturnal oxygen saturation testing.
when to get CT scan in polycythemia evaluation
when we look for an EPO producing tumor. This is for people who have normal oxygen saturation testing and have signs of malignancy.
Is a bone marrow biopsy necessary for diagnosing polycythemia vera?
no. not necessary
Can get JAK2 testing based on blood.
only get it if JAK2 mutation is negative and suspecting a myeloproliferative disorder.
what is relative polycythemia ?
this is increased blood cell mass due to dehydration
initial labs to consider for polycythemia vera?
CBC, serum EPO evaluation
JAK2 mutation
EPO will be low in polycythemia vera.
what is a dreaded side effect of polycythemia vera?
it can transform into AML or post polycythemia vera myelofibrosis.
post AML transformation - poor prognosis.
when do we use ruxolitinib?
Jak1/2 inhibitor - used for treatment of polycythemia vera who are intolerant of hydroxyurea and for refractory polycythemia vera.
High EPO =
renal cell carcionma sometimes hepatoceullar carcinoma cerebellar hemangioblastoma pheochromocytoma uterine myomata
polycythemia vera WILL NOT HAVE HIGH EPO
clues to tumor related erythrocytosis are:
microscopic hematuria (kidney cancer)
abnormal liver tests, hep B or hematochromatosis or cirrhosis
HA or abnormal neurological findings (hemangioblastoma)
hypertension
abnormal electrolyte levels
hyperglycemia (pheochromocytoma)
menorrhagia (uterine myomata)
