Chapt 29-30 Alterations of Hematologic System

Anemia Overview

• Definition: Anemia is characterized by a reduction in:

  • Number of erythrocytes (red blood cells)

  • Quality or quantity of hemoglobin

• Causes:

  • Impaired erythrocyte production

  • Acute or chronic blood loss

  • Increased erythrocyte destruction

  • Combination of factors

Classifications of Anemia

• Etiologic factor (cause), cell size, and hemoglobin content:

  • Anemias due to blood loss:

  • Normocytic-normochromic: Post-hemorrhagic anemia

  • Anemias of diminished erythropoiesis:

  • Macrocytic (megaloblastic):

    • Pernicious anemia (Vitamin B12 deficiency)

    • Folate deficiency anemia

  • Microcytic hypochromic:

    • Iron deficiency anemia

    • Anemia of chronic disease

    • Aplastic anemia

    • Hemolytic anemia

Clinical Manifestations of Anemia

• Symptoms:

  • Reduced oxygen-carrying capacity, hypoxia

  • Reduced blood oxygen levels, hypoxemia

  • Dyspnea (difficulty breathing), palpitations, dizziness, fatigue, pallor

  • Neurological changes and gastrointestinal (GI) changes

• Treatment Options:

  • Blood transfusions

  • Dietary correction

  • Vitamin or iron supplements

  • Address underlying causes

Normocytic-Normochromic Anemia

• Posthemorrhagic anemia resulting from sudden blood loss leading to a normocytic response from the bone marrow

Megaloblastic Anemias

• Characteristics:

  • Larger than normal erythrocytes(RBC) that die prematurely (eryptosis)

  • Identified through defective DNA synthesis due to:

  • Vitamin B12 or folate (B9) deficiency

• Types:

  • Pernicious anemia: Severe vitamin B12 deficiency leading to neurological complications, often not reversible with treatment

  • Symptoms: Weakness, fatigue, paresthesia, loss of appetite, weight loss, smooth, beefy red tongue

  • Folate deficiency anemia: Symptoms include severe cheilosis and stomatitis, treated with folate supplementation (not lifelong)

Microcytic-Hypochromic Anemias

• Characteristics:

  • Smaller than normal RBCs with a reduced hemoglobin concentration

• Iron Deficiency Anemia:

  • Most common worldwide

  • Causes: Dietary lack, impaired absorption, increased need, chronic blood loss, and certain medications

Anemia of Chronic Disease

• Description: Mild to moderate anemia resulting from chronic systemic issues, like infections or cancer

• Pathophysiology:

  • Reduced erythrocyte lifespan, impaired erythropoietin response, disruption of iron metabolism

Aplastic Anemia

• Definition: A condition causing pancytopenia (low blood cell counts)

• Most commonly due to autoimmune disorders or exposure to certain chemicals and drugs

• Symptoms: Hypoxemia, pallor, weakness, and treatment may include stem cell transplants

Hemolytic Anemia

• Definition: Accelerated destruction of red blood cells with symptoms ranging from jaundice to splenomegaly

• Types:

  • Autoimmune variants, drug-induced, and paroxysmal nocturnal hemoglobinuria

Myeloproliferative Red Blood Cell Disorders: Polycythemia

• Description: Overproduction of red blood cells

  • Relative polycythemia: Due to dehydration

  • Absolute polycythemia: Can be primary (polycythemia vera) or secondary to elevated erythropoietin

Disorders of Platelet Function

• Thrombocytopenia: Low platelet counts leading to bleeding complications

  • Causes: ITP (Immune Thrombocytopenic Purpura), TTP (Thrombotic Thrombocytopenic Purpura)

• Thrombocythemia: Elevated platelet counts causing thrombus formation or bleeding risks

Coagulation Disorders

• Disseminated Intravascular Coagulation (DIC): Simultaneous clotting and bleeding

  • Characterized by activation of clotting cascades

  • Treatment focuses on addressing underlying causes and restoring balance

Leukopenia and Leukocytosis

• Leukopenia: Low white blood cell counts, significant in terms of infection risk

• Leukocytosis: Elevated counts often indicative of stress response or infection

Leukemias

• Classification based on cell origin and progression (acute vs chronic)

  • Acute Lymphocytic Leukemia (ALL): Common in children, characterized by lymphoblast presence

  • Acute Myelogenous Leukemia (AML): Common in adults, related to acquired mutations

  • Chronic Myelogenous Leukemia (CML): Often presents with the Philadelphia chromosome

  • Chronic Lymphocytic Leukemia (CLL): Affects mature B lymphocytes with varied survival rates

Lymphomas

• Hodgkin Lymphoma: Characterized by Reed-Sternberg cells, spreads in an orderly fashion

• Non-Hodgkin Lymphoma: Diverse group with multiple subtypes, usually presents with painless lymphadenopathy

Multiple Myeloma

• Proliferation of malignant plasma cells in the bone marrow resulting in a variety of systemic effects, including kidney damage from light chains

  • Treatments include chemotherapy and monoclonal antibodies

Splenic Function Alterations

• Splenomegaly: Can lead to anemia due to increased RBC destruction, treatment may include splenectomy