WBC Disorders Practice Flashcards

WBC Disorders

Examples of Diseases of WBC's

Infectious Mononucleosis ("Mono")

  • Definition: Self-limiting lymphoproliferative disorder

  • Infection: Involves B lymphocytes

  • Caused by: Epstein-Barr virus (EBV)

  • Demographics: Most prevalent in adolescents and young adults

  • Transmission: Main mode is via EBV-contaminated saliva

  • Pathogenesis: Atypical lymphocytes proliferate

  • Onset: Insidious, with incubation period of 4-8 weeks

Clinical Manifestations

  • Symptoms include:
      - Lymphadenopathy
      - Hepatitis
      - Splenomegaly

Laboratory Findings

  • WBC count increased ranging from 12,000 to 18,000; 95% lymphocytes

  • Acute phase: Lasts approximately 2-3 weeks

  • Debility/Lethargy: May persist for 2-3 months

Treatment

  • Focused on symptomatic and supportive care

Myelodysplastic Syndrome

  • Definition: A group of related hematologic disorders characterized by a change in the quantity and quality of bone marrow elements

  • Affected Demographic: Primarily affects individuals over 65 years of age

Clinical Manifestations

  • Cytopenias leading to:
      - Anemia
      - Increased susceptibility to infections
      - Spontaneous bleeding or bruising

Etiology

  • Unknown causes, possibly linked to environmental triggers

Diagnostics

  • Based on laboratory assessments and bone marrow biopsy

Treatment

  • Dependent on severity: Approaches include supportive care, Granulocyte colony-stimulating factor (G-CSF), erythropoietin, chemotherapy, and bone marrow transplantation

Leukemias

  • Definition: Malignant neoplasms arising from a single hematopoietic cell line

  • Characteristics of Leukemic Cells:
      - Immature and unregulated (undifferentiated)
      - Proliferate within the bone marrow
      - Circulate in the bloodstream
      - Infiltrate spleen and lymph nodes

  • Demographics: Affects both children and adults

Leukemia Classifications

  • Classified by predominant cell type:
      - Lymphocytic or Myelocytic
      - Acute or Chronic

  • Types include:
      - Acute Lymphocytic Leukemia (ALL): Most common childhood leukemia
      - Chronic Lymphocytic Leukemia (CLL): Most common leukemia among older adults
      - Acute Myelocytic Leukemia (AML)
      - Chronic Myelocytic Leukemia (CML)

Hematopoiesis

  • Involvement of various stem cells:
      - Pluripotential Stem Cell
        - Myeloid Stem Cells
        - Lymphoid Stem Cells
         - Granulocyte-Macrophage Stem Cells
        - Erythropoietic Stem Cells
        - Megakaryocytic Stem Cells

Leukemia Pathogenesis

  • Causes: Not fully understood; increased exposure to radiation noted

  • Pathogenesis: Leukemic cells are:
      - Immature WBCs with increased proliferation rates and prolonged lifespan
      - Ineffective as phagocytes, unable to perform mature leukocyte functions
      - Interfere with the maturation of normal bone marrow cells, including RBCs and platelets

Acute Leukemia

  • Onset: Sudden, stormy

  • Symptoms: Related to decreased mature WBCs, RBCs, and platelets
      - ALL: Represents 80% of childhood acute leukemias
      - AML: Primarily seen in adult populations

  • Diagnosis: Based on blood/bone marrow analysis showing 60-100% immature WBCs (blasts)

Chronic Leukemia

  • Onset: More insidious

  • Discovery: May be found during routine exams or blood counts
      - CLL: Common in older adults, characterized by relatively mature lymphocytes that are immunologically incompetent
      - CML: May affect both adults and children, presents with leukocytosis with immature cell types

Treatment Goals

  • Aim to attain remission
      - Cytotoxic chemotherapy
      - Stem Cell Transplant:
        - Allogeneic (volunteer donor)
        - Syngeneic (identical twin)
        - Autologous (patient’s own cells)

  • Risks include: Infection, rejection, and relapse

Expected Findings During Bone Marrow Biopsy

  • Immature WBCs

  • Neutrophils

  • Red blood cells

  • Macrophages

Malignant Lymphomas

  • Definition: Neoplasms derived from lymphoid tissue

  • Types include:
      - Hodgkin Disease
      - Non-Hodgkin Disease

Hodgkin Disease

  • Characteristics: Painless, progressive, rubbery enlargement of a single or group of nodes (usually in neck area)

  • Reed-Sternberg Cell: Distinctive tumor cell found in lymph biopsy

Diagnosis

  • Based on:
      - Peripheral blood analysis (abnormal CBC)
      - Lymph node biopsy
      - Bone marrow examination
      - Radiographic evaluation (CT, MRI, PET)

  • Etiology: Unknown, potential interacting factors include EBV, genetic predisposition, environmental toxins

Clinical Manifestations

  • Insidious onset with painless enlarged lymph nodes & other nonspecific symptoms

Treatments

  • Options include chemotherapy, radiation, stem cell transplant

  • Prognosis: Generally good due to slow and predictable spread

Non-Hodgkin Disease

  • Definition: Another neoplastic disorder of lymphoid tissue, distinguished by early spread to liver, spleen, and bone marrow

  • Characteristics: Painless, superficial lymphadenopathy with potential for extranodal symptoms

  • Etiology: Unknown; most patients have widespread disease at the time of diagnosis

Clinical Manifestations

  • Painless lymph node enlargement with nonspecific symptoms

Diagnosis

  • Similar to Hodgkin's lymphoma but with increased extranodal site involvement

Treatment

  • Options include chemotherapy, radiation, stem cell transplant in refractory cases, and biologic drug therapy

  • Prognosis: Generally poorer than Hodgkin’s due to rapid and unpredictable spread

Lymphadenopathy Locations

  • Cervical Nodes

  • Thymus

  • Axillary Nodes

  • Spleen

  • Inguinal Nodes

  • Vessels

Difference Between Hodgkin and Non-Hodgkin Lymphoma

  • Unknown etiology for both

  • Both treated with chemotherapy

  • Signs may include abnormal lab values in CBC

  • Presence of Reed-Sternberg cells specific to Hodgkin lymphoma

Multiple Myeloma

  • Definition: Plasma cell cancer originating from B cells

  • Characteristics: Atypical proliferation of immunoglobulins, particularly the monoclonal antibody “M protein”

  • Malignancy Impact: Malignant cells invade bone resulting in increased osteoclast activity, leading to bone destruction/resorption

  • Impact on Immunity: Unable to maintain humoral immunity

  • Clinical Manifestations:
      - Bone pain and fractures
      - Symptoms related to impaired production of RBCs and WBCs

  • Demographics: More prevalent in men (2:1), average age at diagnosis 65 years; higher incidence in African Americans compared to Whites

  • Etiology: Unknown

Diagnostics

  • Laboratory, radiographic assessments, and bone marrow examination
      - Findings include:
        - Monoclonal antibody protein in serum and urine
        - Pancytopenia
        - Hypercalcemia
        - Presence of Bence Jones proteins in urine
        - Elevated serum creatinine
        - Osteolytic lesions on X-ray

Treatment Options

  • Monitoring

  • Corticosteroids

  • Chemotherapy

  • Biologic therapy

  • Stem cell transplants

  • Bisphosphonates

  • Importance of adequate hydration

Manifestation of Multiple Myeloma

  • Symptoms may include:
      - Lymphadenopathy
      - Presence of “blasts”
      - Splenomegaly
      - Bone pain

References