Low Rates of Cerebral Infarction after Hematopoietic Stem Cell Transplantation in Patients with Sickle Cell Disease at High Risk for Stroke.

Abstract Background Hematopoietic stem cell transplantation (HSCT) can be curative for sickle cell disease (SCD). SCD patients with cerebrovascular disease are often referred for HSCT. The objective of this study was to describe neurologic outcomes after transplant in patients with pre-existing SCD and cerebrovascular comorbidity. Methods Patients with SCD treated with HSCT at a single center between 1996 and 2019 were identified. Patients with cerebral ischemia and/or vasculopathy prior to HSCT were included. Patients with graft failure were excluded. The cohort was divided into 3 groups: 1) symptomatic stroke, 2) vasculopathy without symptomatic stroke and 3) isolated silent cerebral infarctions (SCI). Magnetic resonance imaging/angiography and neurologic assessments pre- and post-HSCT were analyzed to assess outcome. Results In a cohort of 44, there were 25 symptomatic infarction, 10 vasculopathy and 9 isolated SCI patients. Post-HSCT ischemic injury (2 symptomatic strokes, 2 SCIs) was identified in 4 patients, all with prior symptomatic infarction. Within this group (n=25), the post-HSCT incidence of subsequent symptomatic infarction was 1.6 events/100 patient-years and SCIs occurred at a rate of 2.2 events/100 patient-years. No patient had progression of vasculopathy post-HSCT. Conclusion There is a low incidence of new ischemic injury after successful HSCT for SCD. Patients with a history of both symptomatic stroke and vasculopathy are at highest risk for post-HSCT ischemic injury.