Myeloproliferative Disorders Overview

Myeloproliferative Disorders

• Myeloproliferative neoplasms are a group of blood cancers that develop because of an acquired abnormality in hematopoietic stem cells.
• This abnormality leads to an overproduction of one or more types of blood cells.
• Polycythemia vera is a myeloproliferative neoplasm that is characterized by an overproduction of red blood cells.
• Risk factors include a JAK2 genetic mutation, a predisposition to the mutation, and acquired mutations after exposure.
• S&S include headache, dizziness, tinnitus, blurred vision, fatigue, epistaxis, pruritis, conjunctival injection, engorged retinal veins, and a palpable spleen.
• Diagnostics include elevated hemoglobin and hematocrit levels, elevated white blood cell count, elevated platelet count, normal red blood cell morphology, decreased erythropoietin levels, and elevated vitamin B12 levels.
• Treatment includes phlebotomy to reduce blood volume, low-dose aspirin to prevent blood clots, and smoking cessation.
• Prognosis is typically good, with a 15-year survival rate of 80%.
• Essential Thrombocytosis is a myeloproliferative disorder that involves an overproduction of platelets.
• Risk factors include JAK2 mutation, and being between 50 and 60 years old, women are more likely to have it than men.
• S&S include thrombosis, erythromelalgia, and bleeding (rare).
• Diagnostics includes elevated platelet count, elevated white blood cell count, normal red blood cell count, and a JAK2 mutation.
• Treatment includes hydroxyurea or anagrelide to reduce platelet production, and aspirin to prevent blood clots.
• Prognosis can range from asymptomatic to progression into myelofibrosis, leukemia, splenic infarction, or polycythemia vera.

White Blood Cell Disorders

• Leukocytosis is a condition in which the white blood cell count is elevated.
• Risk factors include infection, inflammation, medications, asplenia, cigarette smoking, stress, exercise, and malignancies.
• S&S include weight loss, fever, lymphadenopathy, rash, and drug use.
• Diagnostics include a complete blood count, comprehensive metabolic panel, bone marrow biopsy, and flow cytometry.
• Treatment is directed at the underlying cause.
• Leukopenia is a condition in which the white blood cell count is low.
• Risk factors include neutropenia and insufficient production of intrinsic factor.
• S&S include fever, neurologic symptoms, glossitis, and signs of anemia.
• Diagnostics include complete blood count, serum vitamin B12 level, homocysteine level, methylmalonic acid level, reticulocyte count, peripheral smear, and bone marrow biopsy
• Treatment includes supplementation with vitamin B12 and treatment of the underlying cause.

Macrocytic Anemia

• Folate deficiency is a type of macrocytic anemia characterized by a lack of folate in the body.
• Risk factors include inadequate intake, increased demand, increased loss, and medications that interfere with absorption.
• S&S include symptoms of anemia, glossitis, and no neurologic signs,
• Diagnostics include decreased hemoglobin, elevated MCV, decreased folate levels, and macro-ovalocytes and hypersegmented neutrophils on peripheral smear.
• Treatment includes oral folic acid supplementation.

Aplastic Anemia

• Aplastic Anemia is a bone marrow failure that results in pancytopenia.
• Risk factors include autoimmune disorders, congenital defects, viral infections, pregnancy, medications, and toxins.
• S&S include anemia, neutropenia, thrombocytopenia, and signs of anemia.
• Diagnostics include pancytopenia, decreased reticulocyte count, and a bone marrow biopsy that shows hypocellularity.
• Treatment includes erythroid growth factors, myeloid growth factors, transfusions of red blood cells and platelets, and antibiotics for infection.
• Prognosis is variable and depends on the severity of the anemia and the cause.  

Heparin-Induced Thrombocytopenia

• Heparin-Induced Thrombocytopenia (HIT) is a potentially life-threatening condition that occurs when a patient develops antibodies against heparin.
• Risk factors include exposure to unfractionated heparin and having a history of HIT.
• S&S can be asymptomatic initially, but as the condition worsens, it can cause thrombosis, bleeding, and platelet count decrease.
• Diagnostics include PF4 Ab (ELISA), and use the 4T score to predict risk.
• Treatment includes stopping heparin, switching to an alternative anticoagulant, and a consultation with a hematologist.