Aplastic Anemia Diagnosis & Classification

Classification of aplastic anemia

Non-severe AA≥ 2 of the following:
  • Hemoglobin < 10 g/dL
  • Platelets < 50 x109/L
  • Neutrophils < 1.5 x109/L
Severe AAMarrow cellularity < 25%, or 25 – 50% with < 30% residual hematopoietic cells, AND ≥ 2 of the following:
  • Reticulocytes < 20 x109/L
  • Platelets < 20 x109/L
  • Neutrophils < 0.5 x109/L
Very severe AAMeets criteria for severe AA, AND neutrophils < 0.2 x109/L

The following investigations are required for a diagnosis of AA:

  • CBC and reticulocyte count
  • Blood film examination
  • HbF % in children
  • Bone marrow aspirate and trephine biopsy, including cytogenetics (erythroid dysplasia is common in AA, but granulocytic or megakaryocytic dysplasia should lead to consideration of hypoplastic MDS)
  • Peripheral blood chromosomal breakage analysis to exclude Fanconi anemia if age <50 years
  • Flow cytometry for GPI-anchored proteins, and urinary hemosiderin if positive
  • Vitamin B12 and folate
  • Liver function tests
  • Viral serology for Hepatits A, B and C, EBV, CMV, HIV
  • Anti-nuclear antibody and anti-dsDNA
  • Chest X-ray
  • Abdominal ultrasound scan and echocardiogram
  • Peripheral blood gene mutation analysis for dyskeratosis congenita if clinical features or lack of response to immunosuppressive therapy

These criteria for the diagnosis and grading of aplastic anemia were collated and published in the 2009 British Committee for Standards in Haematology Guidelines for the Diagnosis and Management of Aplastic Anaemia.1

AA: aplastic anemia
CBC: complete blood count
HbF: fetal hemoglobin
MDS: myelodysplasia