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polycythemia in depth and their types with descriptions
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- 2. INTRODUCTION Polycythemia orerythrocytosis is characterized by an increase in the red cell mass, measured as increased hemoglobin and hematocrit above the normal level, which is Male: 138 to 172 grams per liter (g/L) and Female: 121 to 151 g/L. We see that the prefix 'poly' means many, the word 'cyt' refers to cells and the suffix 'emia' refers to in the blood So polycythemia is literally 'many cells in the blood’.
- 3. Continued>> For example,If you are a casual fan of professional sports, you have probably heard about an athlete who was fined or kicked out of their sport due to blood doping. When an athlete 'dopes' their blood, what they are really doing is injecting themselves with extra blood or a substance that increases the number of oxygen-carrying red blood cells in their body. With more oxygen comes more endurance and an unfair edge over their competition.
- 4. Continued>> From ahealth standpoint, this is not such a great idea because the athlete is actually creating a blood condition known as polycythemia, which is a blood disorder in which there are too many red blood cells. These extra cells thicken the blood, making a person more prone to blood clots, which in turn heightens their risk of heart attack or stroke.
- 5. Continued>> POLYSTHEMIA isused when hematocrites is elevated:- > 55% in male. > 50% in female.
- 6. Pathophysiology •Normal RBCproduction results in daily replacement of 0.8 - 1% of circulating RBCs. •The functional capacity of the erythron requires:- normal renal production of EPO a functioning erythroid marrow an adequate supply of substrates for hemoglobin synthesis. •A defect in any of these key components can lead to anemia
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- 8. 1. Polycythemia Vera/primary polycythemia POLYSTHEMIA VERA:- is overproduction (proliferation) of red blood cells due to bone marrow disease (myeloproliferative disorder). Its most prominent feature is an elevated absolute red blood cell mass because of uncontrolled red blood cell production. This is accompanied by increased white blood cell (myeloid) and platelet production, which is due to an abnormal clone of the hematopoietic stem cells with increased sensitivity to the different growth factors for maturation.
- 9. Epidemiology Polycythaemia verais a rare chronic disease diagnosed in an estimated 2 to 3 people per 100,000 population. Although it can occur at any age, polycythemia vera usually affects older people, with most patients diagnosed over the age of 55 years. Polycythaemia vera is rare in children and young adults. It occurs more commonly in males than in females.
- 10. Signs and symptomsof polycythemia vera Impaired oxygen delivery due to sludging of blood may lead to the following symptoms: Headache Dizziness Vertigo Tinnitus Visual disturbances Angina pectoris Intermittent claudication
- 11. Bleeding complications,seen in approximately 1% of patients with PV, include epistaxis, gum bleeding, ecchymoses, and gastrointestinal (GI) bleeding. Thrombotic complications (1%) include venous thrombosis or thromboembolism and an increased prevalence of stroke and other arterial thromboses.
- 12. Complications Possible complicationsof polycythemia vera include: Blood clots - Polycythemia vera causes an increase in blood thickness and decrease in blood flow, as well as abnormalities in the platelets, and this increase the risk of blood clots. Blood clots can cause a stroke, a heart attack, or blockage of an artery in the lungs (pulmonary embolism) or in a vein deep within a muscle (deep vein thrombosis. It is the major cause of death in 10-40% of patients.
- 13. Pathophysiology The bonemarrow of patients with polycythemia vera (PV),contains normal stem cells but also contains abnormal clonal stem cells that interfere with or suppress normal stem cell growth and maturation. Evidence indicates that the etiology of panmyelosis is unregulated neoplastic proliferation. The origin of the stem cell transformation remains unknown.
- 14. Physical examinationfindings may include the following: Splenomegaly (75% of patients) Hepatomegaly (30%) Plethora Hypertension
- 15. Treatment measuresare as follows: Phlebotomy – To keep hematocrit below 45% Aspirin – 81 mg daily Cytoreductive therapy – For patients at high risk for thrombosis Splenectomy in patients with painful splenomegaly or repeated episodes of splenic infarction Hydroxyurea is the most commonly used cytoreductive agent. If hydroxyurea is not effective or not tolerated, alternatives include the following: Interferon alfa Busulfan – In patients older than 65 years Ruxolitinib Fedratinib
- 16. 2. Secondary polycythemia SECONDARY POLYSYTHEMIA is an absolute increase in red blood cell mass that is caused by enhanced stimulation of red blood cell production. Secondary polycythemia is an apparent rise of the erythrocyte level in the blood; however, the underlying cause is reduced blood plasma. A specific type of relative polycythemia is Gaisböck syndrome.
- 17. Continued>> Gaisbock syndromeis characterized by hypertension and erythrocytosis without splenomegaly, leukocytosis, or thrombocytosis. It is associated with mild obesity and increased blood viscosity, explaining why patients often develop cardiovascular complications
- 18. Pathophysiology Increased hemoglobinand hematocrit values reflect an increase in the ratio of red blood cell mass to plasma volume. Any change in either the hemoglobin or the hematocrit can alter test results.
- 19. In primarypolycythemia, the disorder results from a mutation expressed within the hematopoietic stem cell or progenitor cells, which drives the overproduction and accumulation of red blood cells. The secondary polycythemic disorders may be acquired or congenital; however, they are driven by factors that are independent of the function of hematopoietic stem cells. Elevated hemoglobin levels due to chronic hypoxia in patients with chronic lung disorders such as COPD or sleep apnea are the result of an increased production of erythropoietin, which in turn causes increased production of red blood cells.
- 20. Congenital causes Hemoglobinmutants associated with tight binding to oxygen and a failure to deliver oxygen in the venous blood can cause high EPO levels. The high level of EPO is compensatory to elevate hemoglobin levels to deliver an optimal amount of oxygen to the tissues. Hypoxia-inducible factor 1-alpha (HIF1-alpha) binds to the hypoxia-responsive element, which is downstream of the gene for EPO. The activity of HIF1- alpha is increased by a lowered oxygen tension.
- 21. Epidemiology The frequencyof secondary polycythemia depends on the underlying disease. The mortality and morbidity of secondary polycythemia depend on the underlying condition.
- 22. Prognosis The prognosisof patients with secondary polycythemia is driven by the underlying disorder. The polycythemia itself, when physiologic and not sufficiently extreme to cause significant hyperviscosity, generally has no effect on life span. However, patients with secondary polycythemia generally have a shorter survival following diagnosis than patients with polycythemia vera.
- 23. SYMPTOMS Headaches, dyspnea,numbness or tingling in the fingers. Blurred vision Sweating during nights. Redness of the skin especially the face, may look red, ruddy cyanosis. Weight loss. Hypertension.
- 24. CLINICAL MANIFESTATION ANDCOMPLICATION Hypertension caused by hypervolemia and hyperviscosity. Subjective complaints of headache, vertigo, dizziness, tinnitus, and visual disturbance. Generalized pruritus related to histamine release from an increased number of basophils. Paresthesias and erythromelalgia. Angina, heart failure, intermittent claudication, and thrombophlebitis, which may be complicated by embolization. Hemorrhagic phenomena caused by either vessel rupture from over- distension on inadequate platelet function may result ecchymoses, epitaxis, or GI bleeding.
- 25. DIAGNOSTIC STUDIES Elevated hemoglobinand RBC count with microcytosis. EPO level Elevated WBC count with basophilia Elevated platelet count and platelet dysfunction Elevated leucocytes alkaline phosphatase, uric acid and cobalamin levels Elevated histamine levels. Bone marrow examination.
- 26. COLLABORATIVE CARE Phlebotomy Avoid iron supplementation Hydration therapy Myelosuppressive agents like:- - Hydroxyurea - Busulfan -Chlorambucil -Ruxolitinib
- 27. Continued>>> Low-dose aspirin Anagrelide ( to reduce platelet count & inhibit platelet aggregation) Allopurinol (reduce the number of acute gouty attacks).
- 28. Reference Harrison principlesof internal medicine 21st edition https:/www.medscape.com