Victor Politi, M.D., FACPVictor Politi, M.D., FACP
Medical Director, SVCMC, School ofMedical Director, SVCMC, School of
Allied Health Professions, PhysicianAllied Health Professions, Physician
Assistant ProgramAssistant Program
Polycythemia vera is a chronicPolycythemia vera is a chronic
myeloproliferative disorder characterizedmyeloproliferative disorder characterized
by increased red blood cell mass (RCM),by increased red blood cell mass (RCM),
or erythrocytosisor erythrocytosis
The resultant hyperviscosity of the bloodThe resultant hyperviscosity of the blood
predisposes such patients to thrombosispredisposes such patients to thrombosis
Increased RCM is accompanied byIncreased RCM is accompanied by
increased white blood cell (myeloid) andincreased white blood cell (myeloid) and
platelet (megakaryocytic) production,platelet (megakaryocytic) production,
which is due to an abnormal clone of thewhich is due to an abnormal clone of the
hematopoietic stem cells with increasedhematopoietic stem cells with increased
sensitivity to the different growth factorssensitivity to the different growth factors
for maturation.for maturation.
Its etiology is not fully established, butIts etiology is not fully established, but
hypersensitivity to interleukin-3 may play ahypersensitivity to interleukin-3 may play a
role in the sustained erythrocytosisrole in the sustained erythrocytosis
observed in this disease.observed in this disease.
Polycythemia vera should be suspected inPolycythemia vera should be suspected in
patients with elevated hemoglobin orpatients with elevated hemoglobin or
hematocrit levels, splenomegaly, or portalhematocrit levels, splenomegaly, or portal
venous thrombosis.venous thrombosis.
Secondary causes of increased red bloodSecondary causes of increased red blood
cell mass (e.g., heavy smoking, chroniccell mass (e.g., heavy smoking, chronic
pulmonary disease, renal disease) arepulmonary disease, renal disease) are
more common than polycythemia veramore common than polycythemia vera
and must be excludedand must be excluded
Patients may present with complaints of pruritusPatients may present with complaints of pruritus
after bathing, burning pains in the distalafter bathing, burning pains in the distal
extremities (erythromelalgia), gastrointestinalextremities (erythromelalgia), gastrointestinal
disturbances, or nonspecific complaints such asdisturbances, or nonspecific complaints such as
weakness, headaches, or dizziness.weakness, headaches, or dizziness.
Other patients are diagnosed after an incidentalOther patients are diagnosed after an incidental
finding of an elevated hemoglobin and/orfinding of an elevated hemoglobin and/or
hematocrit level on a complete blood count.hematocrit level on a complete blood count.
Diagnosis is made using criteriaDiagnosis is made using criteria
developed by the Polycythemia Veradeveloped by the Polycythemia Vera
Study Group; major criteria includeStudy Group; major criteria include
elevated red blood cell mass, normalelevated red blood cell mass, normal
oxygen saturation, and palpableoxygen saturation, and palpable
Untreated patients may survive for six toUntreated patients may survive for six to
18 months, whereas adequate treatment18 months, whereas adequate treatment
may extend life expectancy to more thanmay extend life expectancy to more than
10 years.10 years.
Treatment includes phlebotomy with theTreatment includes phlebotomy with the
possible addition of myelosuppressivepossible addition of myelosuppressive
agents based on a risk-stratified approach.agents based on a risk-stratified approach.
Agents under investigation includeAgents under investigation include
interferon alfa-2b, anagrelide, and aspirin.interferon alfa-2b, anagrelide, and aspirin.
Consultation with a hematologist isConsultation with a hematologist is
Normal stem cells are present in the boneNormal stem cells are present in the bone
marrow of patients with PV.marrow of patients with PV.
Also present are abnormal clonal stemAlso present are abnormal clonal stem
cells that interfere with or suppress normalcells that interfere with or suppress normal
stem cell growth and maturation.stem cell growth and maturation.
Evidence indicates that the etiology ofEvidence indicates that the etiology of
panmyelosis is unregulated neoplasticpanmyelosis is unregulated neoplastic
The origin of the stem cell transformationThe origin of the stem cell transformation
remains unknownremains unknown
Polycythemia veraPolycythemia vera
Bone marrow film at 100X magnificationBone marrow film at 100X magnification
demonstrating hypercellularity anddemonstrating hypercellularity and
increased number of megakaryocytesincreased number of megakaryocytes
Thromboses and bleeding are frequent inThromboses and bleeding are frequent in
persons with PV and myeloproliferativepersons with PV and myeloproliferative
disease (MPD), and they result from thedisease (MPD), and they result from the
disruption of hemostatic mechanismsdisruption of hemostatic mechanisms
because ofbecause of
an increased level of red blood cellsan increased level of red blood cells
an elevation of the platelet countan elevation of the platelet count
Tissue factor is also synthesized by bloodTissue factor is also synthesized by blood
leukocytes, the level of which is increasedleukocytes, the level of which is increased
in persons with MPD, which can contributein persons with MPD, which can contribute
to thrombosis.to thrombosis.
Hyperhomocystinemia is a risk factor forHyperhomocystinemia is a risk factor for
thrombosis and is also widely prevalent inthrombosis and is also widely prevalent in
patients with MPD (35% in controls, 56%patients with MPD (35% in controls, 56%
in persons with PV).in persons with PV).
Polycythemia vera is a rare diseasePolycythemia vera is a rare disease
The peak incidence of PV is age 50-70The peak incidence of PV is age 50-70
However, it occurs in persons of all ageHowever, it occurs in persons of all age
groups, including those in early adulthood andgroups, including those in early adulthood and
childhood, albeit rarely.childhood, albeit rarely.
The disease is slightly more common inThe disease is slightly more common in
males than in females.males than in females.
The disease usually develops slowlyThe disease usually develops slowly
Symptoms are often insidious in onsetSymptoms are often insidious in onset
They are often related to blood hyperviscosityThey are often related to blood hyperviscosity
secondary to a marked increase in the cellularsecondary to a marked increase in the cellular
elements of blood, which impairselements of blood, which impairs
Symptoms are related to hyperviscosity,Symptoms are related to hyperviscosity,
sludging of blood flow, and thromboses,sludging of blood flow, and thromboses,
which lead to poor oxygen delivery andwhich lead to poor oxygen delivery and
symptoms that include:symptoms that include:
headache, dizziness, vertigo, tinnitus, visualheadache, dizziness, vertigo, tinnitus, visual
disturbances, angina pectoris, or intermittentdisturbances, angina pectoris, or intermittent
Bleeding complications ,, includeBleeding complications ,, include
epistaxis, gum bleeding, ecchymoses, andepistaxis, gum bleeding, ecchymoses, and
GI bleeding.GI bleeding.
Thrombotic complications ,, includeThrombotic complications ,, include
venous thrombosis or thromboembolismvenous thrombosis or thromboembolism
and an increased prevalence of strokeand an increased prevalence of stroke
and other arterial thromboses.and other arterial thromboses.
Abdominal pain due to peptic ulcerAbdominal pain due to peptic ulcer
disease is present because PV isdisease is present because PV is
associated with increased histamine levelsassociated with increased histamine levels
and gastric acidity or possible Budd-Chiariand gastric acidity or possible Budd-Chiari
syndrome (hepatic portal vein thrombosis)syndrome (hepatic portal vein thrombosis)
or mesenteric vein thrombosis.or mesenteric vein thrombosis.
Splenomegaly, when present, can causeSplenomegaly, when present, can cause
early satiety because ofearly satiety because of
gastric filling being impaired by the enlargedgastric filling being impaired by the enlarged
spleen or, rarely, symptoms of splenicspleen or, rarely, symptoms of splenic
Weight loss may result from early satietyWeight loss may result from early satiety
or from the increased myeloproliferativeor from the increased myeloproliferative
activity of the abnormal clone.activity of the abnormal clone.
Pruritus results from increased histaminePruritus results from increased histamine
levels released from increased basophilslevels released from increased basophils
and mast cells and can be exacerbated byand mast cells and can be exacerbated by
a warm bath or shower.a warm bath or shower.
This occurs in up to 40% of patients.This occurs in up to 40% of patients.
The following symptoms are due to theThe following symptoms are due to the
manifestations of myeloproliferativemanifestations of myeloproliferative
disorders with extramedullarydisorders with extramedullary
Splenomegaly - Present in 75% of patients atSplenomegaly - Present in 75% of patients at
the time of diagnosisthe time of diagnosis
Hepatomegaly - Present in approximatelyHepatomegaly - Present in approximately
30% of patients with PV30% of patients with PV
Hypertension is common in patients withHypertension is common in patients with
PV. The red blood cell mass shouldPV. The red blood cell mass should
differentiate PV from Gaisbock syndrome,differentiate PV from Gaisbock syndrome,
which is hypertension andwhich is hypertension and
pseudopolycythemia (ie, high hemoglobinpseudopolycythemia (ie, high hemoglobin
levels due to low plasma volume).levels due to low plasma volume).
Polycythemia is characterized byPolycythemia is characterized by
increased cell counts in all cell lines in theincreased cell counts in all cell lines in the
myeloid series (ie, red blood cells, whitemyeloid series (ie, red blood cells, white
blood cells [preferentially granulocytes],blood cells [preferentially granulocytes],
and platelets).and platelets).
However, if red blood cell levels are increased,However, if red blood cell levels are increased,
several conditions must be excluded, including:several conditions must be excluded, including:
conditions that increase red blood cells secondary toconditions that increase red blood cells secondary to
systemic hypoxic conditions or an artificial conditionsystemic hypoxic conditions or an artificial condition
stimulating Epo secretion in the kidneysstimulating Epo secretion in the kidneys
granulocytosis from infections or mobilization bygranulocytosis from infections or mobilization by
secondary causes, as in leukemoid reactionssecondary causes, as in leukemoid reactions
thrombocytosis from bleeding and iron deficiency.thrombocytosis from bleeding and iron deficiency.
Secondary Causes of IncreasedSecondary Causes of Increased
Red Cell Mass (Erythrocytosis)Red Cell Mass (Erythrocytosis)
Chronic pulmonary or cardiac diseaseChronic pulmonary or cardiac disease
Decreased 2,3-diphosphoglycerateDecreased 2,3-diphosphoglycerate
High oxygen affinity hemoglobinopathyHigh oxygen affinity hemoglobinopathy
Increased carboxyhemoglobin (in smokers) andIncreased carboxyhemoglobin (in smokers) and
Residence at high altitudeResidence at high altitude
Adrenal cortical hypersecretionAdrenal cortical hypersecretion
Tumors producing erythropoietin or anabolic steroidsTumors producing erythropoietin or anabolic steroids
Relative (stress)Relative (stress)
Disorders associated with decreased plasma volumeDisorders associated with decreased plasma volume
(e.g., diarrhea, emesis, renal diseases)(e.g., diarrhea, emesis, renal diseases)
PV should be suspected when hemoglobinPV should be suspected when hemoglobin
and/or hematocrit levels are elevatedand/or hematocrit levels are elevated
(> than 18 g per dL [180 g per L] in white men(> than 18 g per dL [180 g per L] in white men
and > than 16 g per dL [160 g per L] in blacksand > than 16 g per dL [160 g per L] in blacks
and women)and women)
hematocrit level greater than 52 percenthematocrit level greater than 52 percent
(0.52) in white men and 47 percent (0.47)(0.52) in white men and 47 percent (0.47)
in blacks and womenin blacks and women
PV also should be suspected in patientsPV also should be suspected in patients
with portal venous thrombosis andwith portal venous thrombosis and
splenomegaly with or withoutsplenomegaly with or without
thrombocytosis and leukocytosis.thrombocytosis and leukocytosis.
Diagnosis:Diagnosis: Other Signs and Symptoms ofOther Signs and Symptoms of
Polycythemia VeraPolycythemia Vera
More CommonMore Common
Hematocrit level >52 percentHematocrit level >52 percent
(0.52) in white men, >47(0.52) in white men, >47
percent (0.47) in blacks andpercent (0.47) in blacks and
Hemoglobin level >18 g per dLHemoglobin level >18 g per dL
(180 g per L) in white men,(180 g per L) in white men,
>16 g per dL (160 g per L) in>16 g per dL (160 g per L) in
blacks and women)blacks and women)
Pruritus after bathingPruritus after bathing
Weight lossWeight loss
Less CommonLess Common
Budd-Chiari syndromeBudd-Chiari syndrome
Hemorrhagic eventsHemorrhagic events
Ischemic digitsIschemic digits
Thrombotic eventsThrombotic events
Transient neurologicTransient neurologic
complaints (headache, tinnitus,complaints (headache, tinnitus,
dizziness, blurred vision,dizziness, blurred vision,
Atypical chest painAtypical chest pain
In making the diagnosis of PV, once aIn making the diagnosis of PV, once a
secondary cause is ruled out, thesecondary cause is ruled out, the
diagnosis of PV is made using adiagnosis of PV is made using a
combination of major and minor criteriacombination of major and minor criteria
defined by the Polycythemia Vera Studydefined by the Polycythemia Vera Study
Group (PVSG).Group (PVSG).
Although new diagnostic modalities haveAlthough new diagnostic modalities have
been developed, these criteria remain thebeen developed, these criteria remain the
standard method to diagnose PVstandard method to diagnose PV
A diagnosis of polycythemia vera is made when a patent fulfillsA diagnosis of polycythemia vera is made when a patent fulfills
all three of the major criteriaall three of the major criteria
any two major and any two minor criteriaany two major and any two minor criteria
Major CriteriaMajor Criteria
total RBC voltotal RBC vol
Men > or = to 36 mL/kgMen > or = to 36 mL/kg
Women > or = to 32 mL/kgWomen > or = to 32 mL/kg
arterial 02 saturation > or = to 92%arterial 02 saturation > or = to 92%
Minor CriteriaMinor Criteria
Thrombocytosis with platelet count > 400,000/mLThrombocytosis with platelet count > 400,000/mL
Leukocytosis with WBC > 12,000/mLLeukocytosis with WBC > 12,000/mL
Increased leukocyte alkaline phosphatase LAP > 100U/L (no infection)Increased leukocyte alkaline phosphatase LAP > 100U/L (no infection)
Serum B12 > 900 pg/mL or binding capacity UB12 BC > 2200 pg/mLSerum B12 > 900 pg/mL or binding capacity UB12 BC > 2200 pg/mL
Serum Epo assaySerum Epo assay
Epo levels in patients with PV are oftenEpo levels in patients with PV are often
below the lower limit of normal comparedbelow the lower limit of normal compared
with patients with secondarywith patients with secondary
erythrocytosis and pseudoerythrocytosiserythrocytosis and pseudoerythrocytosis
but the levels for PV and secondarybut the levels for PV and secondary
erythrocytosis or pseudoerythrocytosiserythrocytosis or pseudoerythrocytosis
overlap and are nonspecific for differentiatingoverlap and are nonspecific for differentiating
these conditions.these conditions.
Bone marrow morphology andBone marrow morphology and
Overall hypercellularity with expansion of all cellOverall hypercellularity with expansion of all cell
lines with megakaryocytic proliferation and thelines with megakaryocytic proliferation and the
presence of myelofibrosis can help diagnose PVpresence of myelofibrosis can help diagnose PV
and MPDand MPD
PV patients may have normal bone marrowPV patients may have normal bone marrow
These results are nonspecific and may beThese results are nonspecific and may be
observed in the other Philadelphiaobserved in the other Philadelphia
chromosome–negative MPDs.chromosome–negative MPDs.
Bone marrow findings forBone marrow findings for
Polycythemia vera includePolycythemia vera include
Moderate to marked hypercellularityModerate to marked hypercellularity
trilineage hyperplasiatrilineage hyperplasia
megakaryocytes increased;megakaryocytes increased;
dilated sinusoids with intravasculardilated sinusoids with intravascular
decreased or absent iron storesdecreased or absent iron stores
increased reticulin (only in a minority ofincreased reticulin (only in a minority of
Peripheral blood findingsPeripheral blood findings
Increased hemoglobin & hematocritIncreased hemoglobin & hematocrit
Normal red blood cell morphology, unless ironNormal red blood cell morphology, unless iron
deficient or spent phasedeficient or spent phase
Normoblasts may be presentNormoblasts may be present
Mild to moderate leukocytosisMild to moderate leukocytosis
Mild neutrophilia and/or basophiliaMild neutrophilia and/or basophilia
This disease may also alter the results of theThis disease may also alter the results of the
following tests:following tests:
Lactate dehydrogenaseLactate dehydrogenase
Serum uric acidSerum uric acid
T- wbcT- wbc
RBC countRBC count
Platelet aggregation testPlatelet aggregation test
Leukocyte alkaline phosphataseLeukocyte alkaline phosphatase
Automated red blood cell counts and hematocrit valuesAutomated red blood cell counts and hematocrit values
(including hemoglobin levels) may be deceptive with(including hemoglobin levels) may be deceptive with
regard to the total red blood cell mass.regard to the total red blood cell mass.
Direct measurement of the red blood cell mass shouldDirect measurement of the red blood cell mass should
show an increase with a normal or slightly decreasedshow an increase with a normal or slightly decreased
plasma volume.plasma volume.
This is a nuclear medicine test that uses radiochromium-labeledThis is a nuclear medicine test that uses radiochromium-labeled
red blood cells to measure actual red blood cell and plasmared blood cells to measure actual red blood cell and plasma
However, patients with hemoglobin concentrations of atHowever, patients with hemoglobin concentrations of at
least 20 g/dL or hematocrit values of at least 60% inleast 20 g/dL or hematocrit values of at least 60% in
males and 56% in females always have an elevated redmales and 56% in females always have an elevated red
blood cell mass.blood cell mass.
The red blood cells in patients with PV areThe red blood cells in patients with PV are
usually normochromic normocytic unlessusually normochromic normocytic unless
the patient has been bleeding fromthe patient has been bleeding from
underlying peptic ulcer disease orunderlying peptic ulcer disease or
phlebotomy treatment (wherein the cellsphlebotomy treatment (wherein the cells
may be hypochromic and microcytic,may be hypochromic and microcytic,
reflecting low iron stores).reflecting low iron stores).
An elevated white blood cell count (>12,000/µL)An elevated white blood cell count (>12,000/µL)
occurs in approximately 60% of patients. It isoccurs in approximately 60% of patients. It is
mainly composed of neutrophils with a left shiftmainly composed of neutrophils with a left shift
and a few immature cells.and a few immature cells.
Mild basophilia occurs in 60% of patients.Mild basophilia occurs in 60% of patients.
The leukocyte alkaline phosphatase score is elevatedThe leukocyte alkaline phosphatase score is elevated
(>100 U/L) in 70% of patients.(>100 U/L) in 70% of patients.
This technique is only semiquantitative and isThis technique is only semiquantitative and is
susceptible to laboratory errors unless it can besusceptible to laboratory errors unless it can be
performed by flow cytometry, which is not routinelyperformed by flow cytometry, which is not routinely
The platelet count is elevated to 400,000-The platelet count is elevated to 400,000-
800,000/mL in approximately 50% of800,000/mL in approximately 50% of
The release of potassium into the serumThe release of potassium into the serum
caused by the increased number ofcaused by the increased number of
platelets during in vitro coagulation mayplatelets during in vitro coagulation may
cause a pseudohyperkalemia in thecause a pseudohyperkalemia in the
serum, while the true plasma potassiumserum, while the true plasma potassium
level in vivo is actually within the referencelevel in vivo is actually within the reference
range, as shown by measuring plasmarange, as shown by measuring plasma
levels and the lack of ECG changes.levels and the lack of ECG changes.
Abnormal platelet function (as measuredAbnormal platelet function (as measured
by platelet aggregation tests withby platelet aggregation tests with
epinephrine, adenosine diphosphate, orepinephrine, adenosine diphosphate, or
collagen) may be demonstrated, butcollagen) may be demonstrated, but
bleeding time may be normal.bleeding time may be normal.
Some patients' platelet-rich plasmaSome patients' platelet-rich plasma
aggregates spontaneously without theaggregates spontaneously without the
addition of any of the above substances.addition of any of the above substances.
This indicates a propensity for thrombosesThis indicates a propensity for thromboses
Bone marrow studies are not necessary toBone marrow studies are not necessary to
establish the diagnosis but the findings of:establish the diagnosis but the findings of:
hyperplasia of the erythroid, granulocytic andhyperplasia of the erythroid, granulocytic and
megakaryocytic cell linesmegakaryocytic cell lines
support the diagnosis of asupport the diagnosis of a
myeloproliferative process.myeloproliferative process.
Iron stores are decreased or absentIron stores are decreased or absent
because of the increased red blood cellbecause of the increased red blood cell
mass, and macrophages may be maskedmass, and macrophages may be masked
in the myeloid hyperplasia that is present.in the myeloid hyperplasia that is present.
Fibrosis is increased and detected earlyFibrosis is increased and detected early
by silver stains for reticulinby silver stains for reticulin
Cytogenetics of the bone marrow cellsCytogenetics of the bone marrow cells
show a clonal abnormality inshow a clonal abnormality in
30% of patients who are not treated and in30% of patients who are not treated and in
50% of patients who are treated with50% of patients who are treated with
alkylating or myelosuppressive agents.alkylating or myelosuppressive agents.
These chromosomal abnormalities includeThese chromosomal abnormalities include
deletions of the long arm of chromosome 5 or 20deletions of the long arm of chromosome 5 or 20
(5q-, 20q-) and trisomy 8 (+8) or 9 (+9).(5q-, 20q-) and trisomy 8 (+8) or 9 (+9).
Leukemic transformation is usually associated withLeukemic transformation is usually associated with
multiple or complex abnormalities.multiple or complex abnormalities.
Hyperuricemia occurs in 40% of patientsHyperuricemia occurs in 40% of patients
and reflects the high turnover rate of boneand reflects the high turnover rate of bone
marrow cells releasing DNA metabolites.marrow cells releasing DNA metabolites.
Imaging StudiesImaging Studies
An enlarged spleen is often palpable andAn enlarged spleen is often palpable and
does not require any imaging studies.does not require any imaging studies.
In some patients with posteriorly enlargedIn some patients with posteriorly enlarged
spleens or in those who are obese,spleens or in those who are obese,
ultrasonography or CT scanning may beultrasonography or CT scanning may be
able to detect an enlargement missedable to detect an enlargement missed
during the physical examination.during the physical examination.
Other TestsOther Tests
The serum Epo level should be decreasedThe serum Epo level should be decreased
in nearly all patients with PV and no recentin nearly all patients with PV and no recent
This distinguishes polycythemia fromThis distinguishes polycythemia from
secondary causes of polycythemia insecondary causes of polycythemia in
which the serum Epo level is generallywhich the serum Epo level is generally
within the reference range or is elevated.within the reference range or is elevated.
Each lab has its own reference range forEach lab has its own reference range for
serum Epo levelserum Epo level
The objective of treatment is to reduce theThe objective of treatment is to reduce the
high blood viscosity (thickness of thehigh blood viscosity (thickness of the
blood) due to the increased red blood cellblood) due to the increased red blood cell
mass and to prevent hemorrhage andmass and to prevent hemorrhage and
No single treatment is available for PV.No single treatment is available for PV.
Thrombosis accounts for the majority ofThrombosis accounts for the majority of
morbidity and mortality. The major goal ofmorbidity and mortality. The major goal of
treatment is to prevent thrombotic events.treatment is to prevent thrombotic events.
Examples of thrombotic events includeExamples of thrombotic events include
arterial and venous thrombosis,arterial and venous thrombosis,
cerebrovascular accident, deep venouscerebrovascular accident, deep venous
thrombosis, myocardial infarction,thrombosis, myocardial infarction,
peripheral arterial occlusion, andperipheral arterial occlusion, and
pulmonary infarctpulmonary infarct
The mainstay of treatment for PV isThe mainstay of treatment for PV is
phlebotomy, which is aimed at reducingphlebotomy, which is aimed at reducing
hyperviscosity by decreasing the venoushyperviscosity by decreasing the venous
hematocrit level to less than 45 percenthematocrit level to less than 45 percent
(0.45) in white men and 42 percent (0.42)(0.45) in white men and 42 percent (0.42)
in blacks and women.in blacks and women.
The PVSG reported the best medianThe PVSG reported the best median
survival, 12.6 years, for this type ofsurvival, 12.6 years, for this type of
Phlebotomy is a simple procedure withoutPhlebotomy is a simple procedure without
many risks, except for the eventualmany risks, except for the eventual
development of iron deficiencydevelopment of iron deficiency
Patients with hematocrit values of lessPatients with hematocrit values of less
than 70% may be bled twice a week tothan 70% may be bled twice a week to
reduce the hematocrit to the range ofreduce the hematocrit to the range of
Patients with severe plethora who havePatients with severe plethora who have
altered mentation or associated vascularaltered mentation or associated vascular
compromise can be bled more vigorously,compromise can be bled more vigorously,
with daily removal of 500 mL of wholewith daily removal of 500 mL of whole
Elderly patients with some cardiovascularElderly patients with some cardiovascular
compromise or cerebral vascularcompromise or cerebral vascular
complications should have the volumecomplications should have the volume
replaced with saline solution after eachreplaced with saline solution after each
procedure to avoid postural hypotensionprocedure to avoid postural hypotension
Because phlebotomy is the most efficientBecause phlebotomy is the most efficient
method of lowering the hemoglobin andmethod of lowering the hemoglobin and
hematocrit levels to the reference range, all newhematocrit levels to the reference range, all new
patients are initially phlebotomized to decreasepatients are initially phlebotomized to decrease
the risk of complications.the risk of complications.
The presence of elevated platelet counts thatThe presence of elevated platelet counts that
may be exacerbated by the phlebotomy is anmay be exacerbated by the phlebotomy is an
indication to use myelosuppressive agents toindication to use myelosuppressive agents to
avoid thrombotic or hemorrhagic complicationsavoid thrombotic or hemorrhagic complications
Once the patient's hemoglobin andOnce the patient's hemoglobin and
hematocrit values are reduced to withinhematocrit values are reduced to within
the reference range (ie, <45%), implementthe reference range (ie, <45%), implement
a maintenance program either by inducinga maintenance program either by inducing
iron deficiency by continuousiron deficiency by continuous
phlebotomies (frequency of the procedurephlebotomies (frequency of the procedure
depends on the rate of reaccumulation ofdepends on the rate of reaccumulation of
red blood cells) or using ared blood cells) or using a
myelosuppressive agent.myelosuppressive agent.
The use of myelosuppressive agents such as radioactiveThe use of myelosuppressive agents such as radioactive
phosphorus (32P), chlorambucil (Leukeran), busulfanphosphorus (32P), chlorambucil (Leukeran), busulfan
(Myleran), pipobroman (Vercyte), and hydroxyurea(Myleran), pipobroman (Vercyte), and hydroxyurea
(Hydrea) in conjunction with phlebotomy has been(Hydrea) in conjunction with phlebotomy has been
Chlorambucil, busulfan, and pipobroman, all alkylatingChlorambucil, busulfan, and pipobroman, all alkylating
agents, have fallen out of favor because of concernsagents, have fallen out of favor because of concerns
about rates of iatrogenic leukemia.about rates of iatrogenic leukemia.
The agent 32P remains in use with supplementalThe agent 32P remains in use with supplemental
phlebotomy and has a reported median survival similarphlebotomy and has a reported median survival similar
to that of phlebotomy alone-10.9 years according toto that of phlebotomy alone-10.9 years according to
PVSG data.PVSG data.
In patients treated with chlorambucil andIn patients treated with chlorambucil and
32P the PVSG demonstrated a decreased32P the PVSG demonstrated a decreased
survival rate and increased mortality ratesurvival rate and increased mortality rate
from acute leukemia in the first 5 years,from acute leukemia in the first 5 years,
and a total of 17% of patients hadand a total of 17% of patients had
leukemia after 15 years with.leukemia after 15 years with.
Hydroxyurea has been the mainstayHydroxyurea has been the mainstay
therapy for PV after the PVSG resultstherapy for PV after the PVSG results
indicated it is an effective agent forindicated it is an effective agent for
myelosuppression; however, concernsmyelosuppression; however, concerns
have been raised regarding long-termhave been raised regarding long-term
risks for leukemic transformation.risks for leukemic transformation.
In the PVSG trial, HU therapy reduced theIn the PVSG trial, HU therapy reduced the
risk of thrombosis compared withrisk of thrombosis compared with
phlebotomy alonephlebotomy alone
Recombinant interferon alfa-2b reducesRecombinant interferon alfa-2b reduces
myeloproliferation and splenomegaly, and alleviates themyeloproliferation and splenomegaly, and alleviates the
symptom of pruritus.symptom of pruritus.
It has no established mutagenic potential, and thus mayIt has no established mutagenic potential, and thus may
prove a valuable option for younger patients and thoseprove a valuable option for younger patients and those
with significant splenomegaly.with significant splenomegaly.
A small case series of 11 patients found that the patients'A small case series of 11 patients found that the patients'
red cell indices could be normalized over six to 12red cell indices could be normalized over six to 12
months with interferon therapy alone, and withoutmonths with interferon therapy alone, and without
evidence of thrombosis.evidence of thrombosis.
However, many patients discontinue interferon becauseHowever, many patients discontinue interferon because
of side effects, and high cost of treatment.of side effects, and high cost of treatment.
splenectomy in patients with painfulsplenectomy in patients with painful
splenomegaly or repeated episodes ofsplenomegaly or repeated episodes of
thrombosis causing splenic infarctionthrombosis causing splenic infarction
Occasionally, chemotherapy may be givenOccasionally, chemotherapy may be given
to suppress the bone marrow.to suppress the bone marrow.
The use of anti-platelet therapy (such asThe use of anti-platelet therapy (such as
aspirin) is controversial because it mayaspirin) is controversial because it may
cause gastric bleeding.cause gastric bleeding.
Allopurinol is given for hyperuricemiaAllopurinol is given for hyperuricemia
A risk-stratified approach to the management ofA risk-stratified approach to the management of
PV is currently recommendedPV is currently recommended
Patients treated with phlebotomy alone benefitPatients treated with phlebotomy alone benefit
from low rates of malignancy but experiencefrom low rates of malignancy but experience
more thrombosis events during the first fewmore thrombosis events during the first few
years of treatment.years of treatment.
Patients treated with myelosuppressive agentsPatients treated with myelosuppressive agents
and supplemental phlebotomy avoid this earlyand supplemental phlebotomy avoid this early
thrombotic risk but in turn have significant ratesthrombotic risk but in turn have significant rates
of malignant transformation after about six yearsof malignant transformation after about six years
of therapyof therapy
High-risk patientsHigh-risk patients
those 60 years or olderthose 60 years or older
or those with a history of thrombosisor those with a history of thrombosis
A myelosuppressive agent with supplementalA myelosuppressive agent with supplemental
phlebotomy is reasonable in this groupphlebotomy is reasonable in this group
This group's generally shorter life expectancy lessensThis group's generally shorter life expectancy lessens
the threat of eventual iatrogenic malignancy.the threat of eventual iatrogenic malignancy.
Patients in this group stand to gain from the benefit ofPatients in this group stand to gain from the benefit of
lower early thrombosis rates with myelosuppressivelower early thrombosis rates with myelosuppressive
Indeterminate riskIndeterminate risk
< than age 60 and have no history of< than age 60 and have no history of
thrombocytosis, but do have cardiovascular orthrombocytosis, but do have cardiovascular or
other risk factorsother risk factors
Therapy in this group should beTherapy in this group should be
individualized, possibly with the addition ofindividualized, possibly with the addition of
agents acting on platelet function oragents acting on platelet function or
low risklow risk
< than 60 years and have no thrombosis-< than 60 years and have no thrombosis-
related risk factorsrelated risk factors
Phlebotomy alone may be the treatment ofPhlebotomy alone may be the treatment of
choice with the goal of reducing thechoice with the goal of reducing the
hematocrit level to less than 45 percenthematocrit level to less than 45 percent
(0.45) or lower based on gender and race(0.45) or lower based on gender and race
Consultation with a hematologist isConsultation with a hematologist is
recommended to apply such strategies,recommended to apply such strategies,
and newer agents may be tailored toand newer agents may be tailored to
patients on an individualized basis.patients on an individualized basis.
Polycythemia vera usually developsPolycythemia vera usually develops
slowly, and most patients treatedslowly, and most patients treated
appropriately do not experience anyappropriately do not experience any
problems related to the disease.problems related to the disease.
However, the abnormal bone marrow cellsHowever, the abnormal bone marrow cells
may begin to grow uncontrollably leadingmay begin to grow uncontrollably leading
to acute myelogenous leukemia.to acute myelogenous leukemia.
Patients with polycythemia vera also havePatients with polycythemia vera also have
an increased tendency to form blood clotsan increased tendency to form blood clots
that can result in strokes or heart attacks.that can result in strokes or heart attacks.
Some patients may experience abnormalSome patients may experience abnormal
bleeding because their platelets arebleeding because their platelets are
PV is a chronic disease, and its naturalPV is a chronic disease, and its natural
history of 1.5-3 years of median survival inhistory of 1.5-3 years of median survival in
the absence of therapy has beenthe absence of therapy has been
extended to at least 10-20 years becauseextended to at least 10-20 years because
of new therapeutic tools.of new therapeutic tools.
The major causes of morbidity andThe major causes of morbidity and
mortality are as follows:mortality are as follows:
Hemorrhagic complicationsHemorrhagic complications
Peptic ulcer diseasePeptic ulcer disease
Myelofibrosis and pancytopeniaMyelofibrosis and pancytopenia
Acute leukemia or a myelodysplasticAcute leukemia or a myelodysplastic
reported in 15-60% of patientsreported in 15-60% of patients
major cause of death in 10-40% ofmajor cause of death in 10-40% of
Venous and arterial thromboses haveVenous and arterial thromboses have
resulted in pulmonary emboli, renal failureresulted in pulmonary emboli, renal failure
from renal vein or artery thrombosis,from renal vein or artery thrombosis,
intestinal ischemia from mesenteric veinintestinal ischemia from mesenteric vein
thromboses, or peripheral arterial emboli.thromboses, or peripheral arterial emboli.
Hemorrhagic complicationsHemorrhagic complications
occur in 15-35% of patientsoccur in 15-35% of patients
lead to death in 6-30% of these patientslead to death in 6-30% of these patients
Bleeding is usually the consequence ofBleeding is usually the consequence of
vascular compromise resulting fromvascular compromise resulting from
ischemic changes from thrombosis orischemic changes from thrombosis or
Peptic ulcer diseasePeptic ulcer disease
Associated with PV at a 3 to 5 fold higherAssociated with PV at a 3 to 5 fold higher
rate than that of the general populationrate than that of the general population
This has been attributed to increasedThis has been attributed to increased
histamine serum levelshistamine serum levels
Myelofibrosis and pancytopeniaMyelofibrosis and pancytopenia
Occur in 3-10% of patients, usually late inOccur in 3-10% of patients, usually late in
the diseasethe disease
In these patients, infections and bleedingIn these patients, infections and bleeding
complications may be the most seriouscomplications may be the most serious
health threatshealth threats
red blood cell transfusions may bered blood cell transfusions may be
required to maintain adequate red bloodrequired to maintain adequate red blood
cell counts and to improve fatigue andcell counts and to improve fatigue and
other anemia-related symptoms.other anemia-related symptoms.
Acute leukemia or aAcute leukemia or a
myelodysplastic syndromemyelodysplastic syndrome
Develops in 1.5% of patients treated withDevelops in 1.5% of patients treated with
phlebotomy alonephlebotomy alone
The transformation risksThe transformation risks
increase to 13.5% within 5 years with treatment usingincrease to 13.5% within 5 years with treatment using
And 10.2% within 6-10 years in patients treated withAnd 10.2% within 6-10 years in patients treated with
At 15 years, the transformation risk for HU isAt 15 years, the transformation risk for HU is
5.9%, which, although not statistically significant,5.9%, which, although not statistically significant,
is a worrisome trendis a worrisome trend