Algorithm for initial management of SAA. In patients who are not candidates for a matched related HSCT, immunosuppression with horse ATG plus cyclosporine should be the initial therapy. We assess for response at 3 and 6 months but usually wait 6 months before deciding on further interventions in case of nonresponders. In patients who are doing poorly clinically with persistent neutrophil count less than 200/μL, we proceed to salvage therapies earlier between 3 and 6 months. Transplant options are reassessed at 6 months, and donor availability, age, comorbidities, and neutrophil count become important considerations. We favor a matched unrelated HSCT in younger patients with a histocompatible donor and repeat immunosuppression for all other patients. In patients with a persistently low neutrophil count in the very severe range, we may consider a matched unrelated donor HSCT in older patients. In patients who remain refractory after 2 cycles of immunosuppression, further management is then individualized taking into consideration suitability for a higher risk HSCT (mismatched unrelated, haploidentical, or umbilical cord donor), age, comorbidities, neutrophil count, and overall clinical status. Some authorities in SAA consider 50 years of age as the cut-off for sibling HSCT as first-line therapy.