WBC pptx

WBC Disorders

Overview of WBC Disorders

  • Definition and significance of White Blood Cells (WBCs)
  • Connection to various diseases affecting the immune system

Infectious Mononucleosis ("Mono")

  • Definition: Self-limiting lymphoproliferative disorder
  • Infection Source: Caused by Epstein-Barr virus (EBV)
  • Primarily Affected Population: Most prevalent in adolescence and young adults
  • Transmission: Main mode of transmission is via EBV-contaminated saliva
  • Pathogenesis: Proliferation of atypical lymphocytes
  • Onset: Insidious; incubation period is 4-8 weeks
Clinical Manifestations
  • Symptoms: Lymphadenopathy, hepatitis, and splenomegaly
Laboratory Findings
  • WBC Count: Increased to approximately 12,000 - 18,000 cells/L, mostly (95%) lymphocytes
  • Acute Phase Duration: 2-3 weeks
  • Debility Duration: Some degree of debility/lethargy lasts 2-3 months
Treatment
  • Approach: Symptomatic and supportive treatment only

Myelodysplastic Syndrome

  • Definition: A group of related hematologic disorders characterized by changes in the quantity and quality of bone marrow components
  • Affected Population: Primarily affects the elderly population (age > 65)
  • Clinical Manifestations (CM): Results in cytopenias, which can present as anemia, increased risk of infections, and spontaneous bleeding or bruising
  • Etiology: Unknown; however, environmental triggers may be involved
Diagnostics
  • Methods: Laboratory tests and bone marrow biopsy are key for diagnosis
Treatment
  • Options: Treatment depends on disease severity and includes supportive care, Granulocyte colony-stimulating factor (G-CSF), erythropoietin, chemotherapy, or bone marrow transplant

Leukemias

  • Definition: Malignant neoplasms arising from a single hematopoietic cell line
  • Characteristics of Leukemic Cells:
      - Immature and unregulated (undifferentiated)
      - Proliferate primarily in the bone marrow
      - Circulate in the bloodstream
      - Infiltrate the spleen and lymph nodes
  • Patient Demographics: Affect both children and adults
Classification of Leukemias
  1. Based on Predominant Cell Type:
       - Lymphocytic
       - Myelocytic
  2. Based on Disease Progression:
       - Acute Leukemias
         - Acute Lymphocytic (Lymphoblastic) Leukemia (ALL): Most common type in children
         - Acute Myelocytic Leukemia (AML): Primarily affects adults
       - Chronic Leukemias
         - Chronic Lymphocytic Leukemia (CLL): Most common in older adults
         - Chronic Myelocytic Leukemia (CML): Affects both adults and children
Leukemogenesis (Pathogenesis of Leukemia)
  • Causes: Not fully understood; involves potential increased exposure to radiation
  • Description of Leukemic Cells:
      - Immature WBCs that proliferate excessively with a prolonged lifespan
      - Failure to perform functions of mature leukocytes, leading to inefficacy in phagocytosis
      - Interference with normal maturation of bone marrow cells, including RBCs and platelets
Acute Leukemia
  • Onset: Sudden and aggressive (stormy)
  • Symptoms/Signs (S/S):
      - Associated with decreased mature WBCs, red blood cells, and platelets
      - All → 80% of childhood leukemias
      - AML → predominately an adult pathology
  • Diagnosis: Based on presence of immature WBCs (blasts), which may constitute 60-100% of cells in blood/tissue biopsy
Chronic Leukemia
  • Onset: More insidious and often discovered incidentally via routine blood count
      - CLL → typically seen in older adults with relatively mature lymphocytes that are immunologically incompetent
      - CML → affects both adults and children, characterized by leukocytosis with immature cell types
Treatment Goals
  • Objective: Achieve remission for patients
  • Methods:
      - Cytotoxic chemotherapy
      - Stem cell transplant
        - Allogeneic: From a volunteer donor
        - Syngeneic: From an identical twin
        - Autologous: From the patient’s own cells
  • Risks: Include infection, potential for transplant rejection, and disease relapse
Bone Marrow Biopsy Findings in Leukemia
  • Expected Findings:
      - Presence of immature WBCs
      - Neutrophils
      - Potential presence of red blood cells and macrophages

Malignant Lymphomas

  • Definition: Neoplasms derived from lymphoid tissue
Types of Malignant Lymphomas
  1. Hodgkin Disease
  2. Non-Hodgkin Disease
Hodgkin Disease
  • Characterization: Painless, progressive, rubbery enlargement of a single or group of lymph nodes, typically in the neck area
  • Distinctive Tumor Cell: Reed-Stenberg cell, identified in lymph node biopsy
  • Diagnosis: Made through peripheral blood analysis (abnormal CBC), lymph node biopsy, bone marrow examination, and radiographic evaluations (CT, MRI, PET scans)
  • Etiology: Unknown; possible factors include Epstein-Barr virus, genetic predisposition, and exposure to environmental toxins
Clinical Manifestations of Hodgkin Disease
  • Symptoms: Insidious onset, painless enlarged lymph nodes, and nonspecific symptoms
Treatment
  • Options:
      - Chemotherapy
      - Radiation therapy
      - Stem cell transplant
  • Prognosis: Generally positive due to the slow and predictable nature of disease spread
Non-Hodgkin Disease
  • Characteristics: Second form of lymphoid tissue neoplasm; however, it tends to spread early to organs such as the liver, spleen, and bone marrow
  • Symptoms: Similar to Hodgkin disease but includes widespread painless superficial lymphadenopathy and extranodal manifestations
  • Etiology: Not clearly understood; majority of patients have advanced disease at time of diagnosis
Clinical Manifestations of Non-Hodgkin Disease
  • Symptoms: Painless lymph node enlargement alongside nonspecific symptoms
Treatment Options For Non-Hodgkin Disease
  • Methods:
      - Chemotherapy
      - Radiation therapy
      - For refractory cases, consider stem cell transplant and biologic drug therapy
  • Prognosis: Generally poorer compared to Hodgkin disease due to faster and unpredictable spread

Lymphadenopathy

  • Anatomical Locations:
      - Cervical nodes
      - Axillary nodes
      - Inguinal nodes
      - Spleen
      - Thymus
Specific Case of Lymphadenopathy
  • Location: Focus on cervical lymph nodes and clinical implications related to lymph node enlargement
Differentiation Between Hodgkin and Non-Hodgkin Lymphomas
  • Distinct Feature: Presence of Reed-Sternberg cells in Hodgkin lymphoma vs. absence in Non-Hodgkin lymphoma

Multiple Myeloma

  • Definition: Cancer of plasma cells (B cells)
  • Pathophysiology: Involves atypical proliferation of “M protein” (a monoclonal antibody);
      - Malignant cells invade bone, leading to increased osteoclast activity, resulting in bone destruction and resorption
      - Impairment of humoral immunity
  • Demographics: More common in men (2X), average age around 65 years; higher prevalence in African Americans compared to Whites
  • Etiology: Unknown
Clinical Manifestations of Multiple Myeloma
  • Symptoms: Gradual onset, characterized by skeletal pain and hypercalcemia, alongside symptoms arising from impaired production of RBCs and WBCs
Diagnostic Approaches
  • Methods:
      - Laboratory tests
      - Radiographic assessments
      - Bone marrow examinations
      - Look for markers such as monoclonal antibody proteins in serum and urine, pancytopenia, hypercalcemia, Bence Jones proteins in urine, elevated serum creatinine, and osteolytic lesions evident on X-rays
Treatment Options for Multiple Myeloma
  • Methods:
      - Monitoring (watching)
      - Corticosteroids
      - Chemotherapy and biologic therapy
      - Stem cell transplant
      - Use of bisphosphonates and ensuring adequate hydration

Conclusion

  • Summary of major types of WBC disorders, their clinical features, risk factors, diagnostic strategies, and treatment approaches.

References

  • CDC Website on Epstein-Barr Virus: https://www.cdc.gov/epstein-barr/about-mono.html
  • Copstead, L. E., & Banasik, J. L. (2019). Pathophysiology. St. Louis, Mo: Elsevier.