In addition to the risk of stroke and cognitive decline, children with sickle cell disease (SCD) may lose approximately one IQ point per year on a full scale IQ (FSIQ) test. For the first time, researchers report stabilization of IQ and central nervous system (CNS) outcomes after unrelated allogeneic hematopoietic cell transplantation (HCT) for patients with SCD, including those who experienced prior neurologic complications.
The Sickle Cell Unrelated Transplant Trial (SCURT) prospectively assessed cognition and magnetic resonance imaging (MRI) of the brain pre-HCT and two years after HCT. The 29 study participants had a mean age of 12.5 years (range: 6.7-17.4). Of those, 13 completed pre/post intelligence measurements. Eleven of the 13 completed baseline and post-HCT imaging studies. Seven children had experienced stroke prior to HCT and one had a high transcranial Doppler result with an abnormal MRI. Financial-related travel barriers, death and graft rejection were the reasons given for patients with incomplete post-HCT testing.
At follow-up, eight of 13 children had higher FSIQ and performance IQ, with seven of 13 having higher or stable verbal IQ. Six recipients had stable MRIs; two had resolution of all infarction areas. At the 2-year time point post-HCT, research noted three children had additional infarcts with no additional testing done between baseline and 2-year follow-up.
Despite the small sample size, preliminary results suggest that allogeneic HCT may stabilize the cognitive decline associated with SCD and researchers recommended longer-term follow to assess the potential for ongoing benefits.