Disorders of White Blood Cells and Lymphoid Tissues Study Notes

Chapter 24: Disorders of White Blood Cells and Lymphoid Tissues

Overview

  • Title: Disorders of White Blood Cells and Lymphoid Tissues
  • Publisher: Lippincott Williams & Wilkins, a Wolters Kluwer business.
  • Copyright Year: 2007.

Neutropenia

  • Definition: Neutrophil count less than 1000 cells/mm³.
    • Significant Risk: Increased susceptibility to infections, especially respiratory infections.
    • Causes of Neutropenia:
    • Aplastic anemia.
    • Bone marrow suppression due to chemotherapy, radiotherapy, autoimmune disorders.
    • Other factors may include viral infections and congenital disorders.
    • Neutropenic Precautions:
    • Guidelines followed to prevent infections in neutropenic patients.

Infectious Mononucleosis

  • Definition: Self-limiting lymphoproliferative disorder.
  • Common Population: Primarily affects adolescents and young adults, especially those aged 15-24.
  • Cause: Epstein-Barr Virus (EBV), a member of the herpes virus family.
  • Characteristics: Once infected, the virus inhibits the immune response for a lifetime, leading to lifelong risk.

Symptoms of Infectious Mononucleosis

  • Onset Symptoms:
    • Malaise
    • Anorexia
    • Chills
  • Progressing Symptoms:
    • Fever
    • Pharyngitis
    • Lymphadenopathy (swollen lymph nodes)
  • Duration:
    • Incubation period of approximately 4-6 weeks.

Transmission

  • Method: Contracted through saliva, mucus, and tears, commonly referred to as the “Kissing Disease.”

Diagnostic Tests

  • Mono Spot Test.
  • Assessment of Liver Enzymes (indicative of liver involvement).
  • Cytomegalovirus (CMV) tests, as CMV can mimic mononucleosis symptoms.

Treatment

  • Primary Management:
    • Rest
    • Throat soothing measures
    • Pain relief: Acetaminophen or Ibuprofen
    • Gradual return to physical activity

White Blood Cells (WBCs) Production

  • Location: Formed and differentiated in the bone marrow.
  • Significance: Neoplasms originating in the bone marrow can lead to disorders such as leukemias and plasma cell dyscrasias.
  • Maturation: WBCs travel to lymphoid organs to mature and develop.

Lymphomas

  • Hodgkin's Lymphoma:

    • Histological Analysis: Requires biopsy showing Reed-Sternberg cells.
    • Prevalence: Occurs in approximately 50% of cases, more common in males than females.
    • Symptoms: Painless lymphadenopathy, malaise, fever, night sweats.
    • Treatment: Radiation and chemotherapy; 5-year cure rate of 94-96%.

  • Non-Hodgkin's Lymphoma:

    • Definition: Malignant neoplasms affecting lymph nodes that can arise from T or B cells.
    • Prevalence: Approximately 95% of cases occur in adults.
    • Symptoms: Similar to Hodgkin’s lymphoma but lacks Reed-Sternberg cells.
    • Treatment: Quicker metastasis can occur; sensitive to chemotherapy/radiation.

Leukemias

  • Definition: Malignant neoplasms of hematopoietic stem cells leading to the replacement of bone marrow.
  • Classification: Based on the type of cell involved:
    • Lymphocytic
    • Myelogenous
  • Types: Further classified into acute and chronic.

Acute Leukemias

  • Acute Lymphocytic Leukemia (ALL):

    • Characterization: Involves the presence of lymphoblasts (immature lymphocytes).
    • Demographic: Most common in children aged 2-4 years.
    • Symptoms: Abrupt onset of bone pain, fever, infections.

  • Acute Myelogenous Leukemia (AML):

    • Correlation: Linked with Down’s syndrome and exposure to toxins.
    • Symptoms: Similar to ALL, affects blood cell maturation.

Diagnosis and Treatment of Acute Leukemias

  • Methods of Diagnosis:
    • Bone marrow biopsy via lumbar puncture.
    • Blood studies to determine levels of immature cells.
  • Treatment Approaches:
    • Bone marrow or stem cell transplantation.

Chronic Leukemias

  • Chronic Lymphocytic Leukemia (CLL):
    • Features: Invasion and disruption of bone marrow and lymphoid tissue.
  • Chronic Myeloid Leukemia (CML):
    • Characterization: Associated with a genetic mutation known as the Philadelphia chromosome.
    • Demographics: Commonly affects adults over the age of 60, constitutes about 15% of all leukemias in the U.S.

Symptoms of Chronic Leukemias

  • Signs of CLL:
    • Fatigue, lymphadenopathy.
  • Signs of CML:
    • Anemia, thrombocytopenia (a reduction in platelets), night sweats, bone pain, and splenomegaly (enlarged spleen).

Treatment of Chronic Leukemias

  • Supportive Measures:
    • Stem cell transplantation.
    • Transfusions for RBC and platelets.
    • Chemotherapy only after the destruction of the patient's stem cells.

Symptoms of Leukemia

  • Key Symptoms:
    • Anemia (decreased hemoglobin).
    • Neutropenia (risk of infection).
    • Thrombocytopenia (risk of bleeding).
    • Immature white blood cells present in large numbers.

Myeloma (Multiple Myeloma)

  • Definition: Malignant proliferation of B cells leading to abnormal antibody production and immune depression.
  • Characteristics:
    • Increased activity of osteoclasts with potential tumors forming in other organs.
    • Bone destruction indicated by pathologic fractures.
  • Demographics: Typically affects men over 60 years of age.
  • Risk Factors: Exposure to pesticides, radiation, and specific genetic abnormalities.

Symptoms of Myeloma

  • Related Symptoms:
    • Bone pain, pathological fractures, weight loss, and weakness.

Diagnosis and Treatment of Myeloma

  • Diagnostic Identifiers:
    • Presence of Bence-Jones protein in urine.
    • Assessment of hypercalcemia.
  • Main Treatment Options:
    • Chemotherapy.
    • Stem cell transplantation.