Hematopoietic Stem Cell Transplant for Sickle Cell Disease: PATIENT SELEction and Timing Based on Sickle Cell-Related Multiple Chronic Conditions

Hematopoietic stem cell transplant (HSCT) is the only cure for patients with sickle cell disease (SCD). Although most SCD patients experience progressive end-organ damage and shortened lifespans, not all patients follow the same disease course, tempo, or outcome. Therefore, the dilemma facing physicians is weighing the selection of patients and timing for the procedure against donor type and transplant-related mortality and morbidity that go up with increasing age. On the other hand, the dilemma facing the patients and families is how acceptable HSCT that carries some mortality risks to them. We have analyzed the chronic conditions due to SCD in 449 patients to determine whether SCD-related multiple chronic conditions (MCC) can be risk-stratified to identify the group of patients predicted to not only have shortened lifespans but also functional limitation and poor quality of life so that these at-risk patients can be offered HSCT early and before MCC develops. We identified that the age of onset of the first SCD-related chronic conditions strongly predicted for the risks for disease-related MCC. SCD patients who suffered their first disease-related chronic condition before age 30 years developed MCC at a rate of 19.1 times faster than those at a later age. These patients are therefore high-risk patients and should be offered HSCT early in the course of their disease before multiple organ damage intervenes, even if matched-related donors are not available. This patient selection and timing approach provides a forum for an easy-to-understand and real-time discussion, including the choice of donor type, with SCD patients and families when considering HSCT.