Aplastic Anaemia Overview and Causes

Aplastic Anaemia Overview

• Aplastic anaemia (AA) leads to pancytopenia, characterized by decreased blood counts across all cell lines: red blood cells, white blood cells, and platelets.
• Aplasia refers to the replacement of active bone marrow with non-functioning fatty marrow.

Causes of Pancytopenia

• Pancytopenia can result from:
  • Decreased bone marrow production (e.g., aplastic anaemia).
  • Increased peripheral destruction (e.g., hypersplenism).

Classification of Aplastic Anaemia

• Congenital Aplastic Anaemia
• Acquired Aplastic Anaemia
  • Primary (Idiopathic)
  • Secondary, which includes:
    • Cytotoxic drugs (e.g., Busulphan).
    • Ionizing radiation (e.g., radiotherapy).
    • Chemicals such as benzene.
    • Drugs that may cause marrow depression (e.g., chloramphenicol).
    • Viral infections, notably Epstein-Barr virus.

Clinical Features

• Symptoms reflect bone marrow failure:
  • Features of anaemia (fatigue, pallor).
  • Bleeding issues due to thrombocytopenia, such as:
    • Bruising
    • Bleeding gums
    • Epistaxis (nosebleeds)
    • Menorrhagia (heavy menstrual bleeding)
  • Increased infections resulting from leucopenia, especially oral and throat infections.
  • Typically, no organomegaly (enlargement of organs) is observed.

Investigations

• Complete Blood Count (CBC) Findings:
  • Decreased hemoglobin (anaemia).
  • Reduced white blood cells (leucopenia).
  • Low platelet count (thrombocytopenia).
• Reticulocyte Count: Typically low.
• Peripheral Blood Film: Shows normochromic normocytic red blood cells.
• Bone Marrow Examination: Hypoplastic, with over 75% replacement of red marrow by fat.

Management Strategies

• General Measures:
  • Identify and remove causative factors when possible.
  • Implement supportive measures:
    • Blood transfusions to correct anaemia.
    • Platelet concentrates to manage thrombocytopenia.
    • Treat existing infections or provide prophylactic antibiotics.
• Specific Management:
  • Bone marrow transplantation (hematopoietic stem cell transplantation) is a critical treatment option.
  • Some cases may experience spontaneous recovery without intervention.

This quiz covers the essential aspects of aplastic anaemia, including its definition, causes, and classification. Learn about the clinical features and how this condition impacts blood cell production. Test your knowledge on congenital and acquired forms of aplastic anaemia and their underlying factors.