Abstract 35: Changes In Sickle Cell Vasculopathy After Hematopoietic Stem Cell Transplantation

Introduction: Cerebral vasculopathies (stenoses and aneurysms) are a major cause of stroke and disability in adults and children with sickle cell disease (SCD). HSCT has been shown to prevent or improve large vessel intracranial stenosis in children when compared to standard care (Verlhac 2020). We sought to determine the impact of HSCT on the development and progression of cerebral vasculopathies in adults with SCD. Methods: The study population included patients with SCD (HbSS, HbSC, and HbS/beta-thalassemia) that were enrolled in NIH studies (14-H-0077, 09-H-0225, 03-H-0170) and underwent HSCT from 2004-19 and received pre- and post-transplant MRI/MRA studies. MRA images were reviewed by two independent readers and scored for stenoses in eight intracranial arteries, Moyamoya collateralization, and presence and progression of intracranial aneurysms. Changes in vasculopathy were compared before and after transplantation. Results: Eighty-seven patients were included in the study, mean age 32.2 yrs. and 58% male. Median follow-up period was 3.3 yrs. (range: 0.5-17 yrs.), and 28% had evidence of vasculopathy at transplant; 17% with stenotic vasculopathy and 13% with aneurysm(s). None of the patients without vasculopathy developed stenoses or aneurysms after HSCT. MRA stenoses scores improved after HSCT in 62% of patients with vasculopathy, with a median change of 1.0 (range: 1-6; p=0.01). All intracranial aneurysms identified at transplant remained unchanged in follow-up. Conclusions: Hematopoietic stem cell transplantation improved or prevented the development of vasculopathy in adults with sickle cell disease.