Treatment of Acquired Severe Aplastic Anaemia in Patients Under 40 with an HLA-Matched Sibling Donor
This protocol applies to acquired severe or very severe aplastic anaemia (SAA/vSAA) in patients under 40 years of age who have a confirmed HLA-matched sibling donor available — a setting in which haemopoietic stem cell transplantation is the indicated approach.
Clinical Scenario
The diagnosis of SAA or vSAA requires bone marrow cellularity below 25%, together with at least two of the following peripheral blood criteria:
- Neutrophil count <0.5 × 10‑9/L
- Platelet count <20 × 10‑9/L
- Reticulocyte count <60 × 10‑9/L (automated count)
Age <40 years
For patients in this age group with a confirmed matched sibling donor, up-front HSCT from the matched sibling is the standard indicated treatment path.
Approach
When graft failure occurs following an initial transplant in this setting, a second haemopoietic stem cell transplant is the next step. This involves a specific conditioning regimen followed by targeted post-transplant immunosuppression.
The complete conditioning schedule, agent selection, sequencing, and post-transplant management protocol are in the full structured regimen below.
References
DOI: 10.1111/bjh.19236
Severe AA (SAA): Marrow cellularity <25% (or 25%–50% with <30% residual haematopoietic cells), plus at least two of: (a) neutrophil count <0.5 × 10‑9/L; (b) platelet count <20 × 10‑9/L; (c) reticulocyte count <60 × 10‑9/L (using an automated reticulocyte count)
Up-front HSCT from a MSD is indicated for SAA in young and adult patients aged <40 years who have a MSD.
There is no consensus, but the following FATG conditioning is commonly used: fludarabine 30 mg/m² × 5, ATG and CSA as postgraft immunosuppression
View source ↗