Aplastic anaemia is a rare and heterogeneous disorder. It is defined as pancytopenia with a hypocellular bone marrow in the absence of an abnormal infiltrate or marrow fibrosis.
Clinical features and diagnosis
Proposed diagnostic criteria (both I and II must be fulfilled in the absence of neoplasia):
I- At least 2 of the following complete blood count (CBC) findings: granulocytes < 500/L, platelets < 20,000/μL, corrected reticulocyte count < 20.000/μL
II- Bone marrow must be either markedly hypoplastic (< 25% of NAAC*) or moderately hypoplastic (25-50% of NAAC*) with <30% of cells being hematopoietic (*NAAC = normal age appropriate cellularity)
The modified Camitta criteria are used to assess severity:
- Severe AA (SAA): Marrow cellularity <25% (or 25–50% with <30% residual haematopoietic cells), plus at least 2 of: (i) neutrophils <500/μL, (ii) platelets <20.000/μL, (iii) reticulocyte count <20.000/μL.
- Very Severe AA (VSAA): As for SAA but neutrophils <200/μL.
- Non‐severe AA (NSAA): AA not fulfilling the criteria for SAA or VSAA
- Killick SB, Bown N, Cavenagh J, Dokal I, Foukaneli T, Hill A, Hillmen P, Ireland R, Kulasekararaj A, Mufti G, Snowden JA, Samarasinghe S, Wood A, Marsh JC; British Society for Standards in Haematology. Guidelines for the diagnosis and management of adult aplastic anaemia. Br J Haematol. 2016 Jan;172(2):187-207. [Medline]
- Clucas D, Fox LC, Wood EM, Hong FS, Gibson J, Bajel A, Szer J, Blombery P, McQuilten ZK, Hiwase D, Firkin F, Cole-Sinclair MF; Australian Aplastic Anaemia Registry Steering Committee. Revisiting acquired aplastic anaemia: Current concepts in diagnosis and management. Intern Med J. 2018 Oct 15. [Medline]
Created Nov 02, 2018.