Risk-adapted procedures for HSCT from alternative donor in children with severe aplastic anaemia.

The outcome of haematopoietic SCT (HSCT) from matched unrelated donors in children with severe aplastic anaemia (SAA) has improved significantly in the last decade and should be offered to all children who fail to respond to their first course of combined immunosuppressive therapy. High-resolution typing for HLA class I and II is mandatory for donor selection. In 10/10 or 9/10 alleles matched donors, a non-TBI conditioning based on fludarabine, CY and anti-thymocyte globulin is sufficient to allow for sustained engraftment when unmanipulated BM is used. Owing to increased rates of cGVHD after PBSC transplantation are reported in young patients, BM is the preferred stem cell source. HSCT from mismatched related and unrelated donors are still high-risk procedures. New techniques for graft manipulation such as CD3/CD19 depletion might improve engraftment and immune reconstitution. In T-cell depleted grafts, irradiation-based conditioning seems to be inevitable to reduce the high risk for rejection.