True about polycythemia rubra vera is all Except: (LQ)
Polycythemia Vera (Ref. Hari- 18th ed., Pg.- 898)
It is a myeloproliferative disorder with an absolute increase in red blood cell mass.
A mutation is JAK-2 plays an important role
Clinical symptoms are due to increased (Ref. Hari-18th ed., Pg.-899)
1. Blood Viscosity
2. Vascular stasis
3. Thrombotic tendency
4. Hemorrhagic diathesis (uncommon).
a. Patients are plethoric and cyanotic (owing to stagnation and deoxygenation of blood in periphery)
b. Angina, CNS disturbance, gout (hyperuricemia), headache, dizziness, hypertension, Visual disturbance
c. GI symptoms, peptic ulcer disease, hematemesis, melena, abdominal pain, (splenic or renal infarction)
d. Pruritus exaggerated by a warm bath due to release of histamine from basophils may also occur.
e. Massive Splenomegaly is present.
f. Digital ischemia, easy bruising, epistaxis, acid-peptic disease, or gastrointestinal hemorrhage may occur due to
g. vascular stasis or thrombocytosis.
h. Erythema, burning, and pain in the extremities, a symptom complex known as erythromelalgia, is another
i. complication of the thrombocytosis of PV due to increased platelet stickiness.
j. Given the large turnover of hematopoietic cells, hyperuricemia with secondary gout, uric acid stones, and
k. symptoms due to hypermetabolism can also complicate the disorder.
Criteria for Diagnosis of Polycythemia Vera
1. Total red cell mass:
2. Male ≥ 36 ml/kg
3. Female ≥ 32 ml/kg
4. Arterial oxygen saturation ≥ 92%
1. Thrombocytosis (platelets > 4 lacs/mL)
2. Leukocytosis (white blood cells > 1200/mL)
3. Increased leukocyte alkaline phosphatase (LAP) score
4. Serum B12 > 900 pg/ml or B12 binding capacity > 2200 pg/ml.
5. PV is diagnosed when A1 + A2 + A3 or A1 + A2 and any 2 from category B are present
1. PCV is elevated > 60%
2. Elevated RBC count 7 – 10 million/μL
3. Hb level > 18 gm/dL in males and > 16 gm/dL in females
4. Elevated white cell and platelet counts
5. Hypercellular marrow with erythropoiesis or granulopoiesis and megakaryocytes
6. Absent iron stores.
7. Elevated serum B12 levels > 900 pg/ml
8. Elevated neutrophil alkaline phosphatase score.
9. Hyperuricemia, pseudohyperkalemia (due to release of potassium from platelets during in vitro coagulation).
10. O2 saturation > 92% at room temperature.
11. Serum iron may be reduced.
12. erythropoietin ↓,
13. Microcytic with erythrocytosis
14. Thrombosis or bleeding both can happen.
Causes of Microcytosis with erythrocytosis
1. Beta thalassemia
2. Chronic Hypoxia
1. Infection is not a feature.
2. O2 saturation > 92% at room temperature
3. ESR is not raised
4. Pruritus and hypertension are the feature
5. LAP score is increased
Extra Edge: Causes of decrease ESR = PCV, CHF, SSA, Afibrogenemia