A brief description on Polycythemia

1. Polycythemia
Lecture slides
Pratap Sagar Tiwari, MD

2.  It is a disease state in which the proportion of blood
volume that is occupied by red blood cells increases.
 An increase in the no of red blood cells =absolute
polycythemia
 Due to decrease in the volume of plasma =relative
polycythemia
Definition

3.  Hematocrit — Polycythemia in the adult patient is
suspected when the HCT is >48 or >52 % in F and M,
respectively.
 (The hematocrit (HCT) is expressed as the percent of a
blood sample occupied by intact RBCs. )
 Hemoglobin concentration — when the HGB is >16.5
or >18.5 g/dL in F and M, respectively.
 (The hb concentration (HGB) is its content in grams per
100 mL of whole blood. )
Definition.. continue

4. RelativeAbsolute
SecondaryPrimary Polycythemia overtransfusion
Increase rbc Decrease bld volume
Myeloproliferative disorder
Polycythemia Vera
Dec O2, altitude, Ca
Polycythemia

5.  It is an apparent rise of the erythrocyte level in the
blood.
 The underlying cause is reduced blood plasma.
 Relative polycythemia is often caused by loss of body
fluids, such as through burns, dehydration and stress.
 A specific type of relative polycythemia is Gaisböck
syndrome: mild obesity, diastolic htn, ↓ in plasma vol
with relative ↑ in RBC
Relative polycythemia

6.  Overproduction of RBC may be due to a primary
process in the bone marrow= myeloproliferative
syndrome
 May be a reaction to chronically low oxygen levels.
 Overtransfusion
Absolute polycythemia

7.  Renal-cell carcinoma
 liver tumors
 von Hippel-Lindau disease
 Uterine fibroids
 Hemangioblastoma
SP:Erythropoietin secreting tumors

8.  Chronic pulmonary disease
 Right-to-left cardiac shunts
 Sleep apnea
 Massive obesity (Pickwickian syndrome)
 High altitude
 Chronic carbon monoxide poisoning (including heavy
smoking)
SP:Hypoxemia secondary to:

9.  Polycythemia vera is one of the chronic
myeloproliferative disorders (neoplasms), collectively
characterized by clonal proliferation of myeloid cells.
 The most prominent feature of this disease is an
elevated absolute RBC mass because of uncontrolled
red blood cell production.
 This is accompanied by ↑ WBC and platelet production
as well.
PP: Polycythemia Vera

10.  There is mutation on the Janus kinase-2 gene (JAK2)
 JAK2 is directly involved in the intracellular signaling
of progenitor cells in bone marrow.
 The peak incidence of PV is age 50-70 years.
Pathophysiology

11.  Symptoms of PV are often insidious in onset, and they are
often related to blood hyperviscosity.
 Symptoms are related to
1. hyperviscosity
2. sludging of blood flow
3. thromboses
 which lead to poor oxygen delivery and symptoms that
include headache, dizziness, vertigo, tinnitus, visual
disturbances, angina pectoris, or intermittent
claudications.
Presentation

12.  Bleeding complications (1%) include epistaxis, gum
bleeding, ecchymoses, and gastrointestinal (GI)
bleeding.
 Thrombotic complications (1%) include venous
thrombosis or thromboembolism and an ↑prevalence
of stroke and other arterial thromboses.
Presentation……….continue

13.  Abdominal pain due to PUD is present because PV is
associated with ↑ histamine levels and gastric acidity.
 Splenomegaly, when present, can cause early satiety
because of gastric filling being impaired by the
enlarged spleen .
 Pruritus(40%) results from ↑ histamine levels released
from ↑ basophils and mast cells.
Presentation……….continue

14.  Plethoric face
 Splenomegaly –75%
 Hepatomegaly –30%
Physical

15.  Polymerase chain reaction :JAK2 mutation
 Serum Epo assay: are often below the lower limit of
normal .
 Leukocyte alkaline phosphatase distinguises PV from
CML.
Investigation

16.  Phlebotomy or bloodletting.
 (Reduce the hematocrit to the range of <45%.)
 Anagrelide is a inhibits megakaryocyte maturation, thereby
decreasing platelet counts.
 JAK1/JAK2 inhibitor : ruxolitinib
 Hydroxyurea & Interferon alfa
 PROGNOSIS — The median survival of untreated symptomatic
patients with PV was initially estimated at 6 to 18 months from the
time of diagnosis, whereas current survival of treated patients is 10
years or more.
Treatment

17. End of slides