Polycythemia

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. Relative Absolute Secondary Primary 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 hyperviscosity sludging of blood flow 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

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