[Development of psychological and intellectual performance in transplanted sickle cell disease patients: a prospective study from pretransplant period to 5 years after HSCT]

Abstract

Rationale: Allogeneic hematopoietic stem-cell transplantation (HSCT) is the only curative treatment for sickle cell disease (SCD). Cerebral vasculopathy was the principal indication for transplantation. These children could present impaired neuropsychological development related to different causes, hence the value of exploring their intellectual capacities before and after transplantation.

Material and methods: Prospective longitudinal study from 1992 to 2006 in all transplanted SCD patients. The patients were assessed using Wechsler scales with four different indices: verbal comprehension, perceptual reasoning, working memory, and processing speed (PSI), providing a full-scale intellectual quotient (IQ).

Results: Fifteen SCD patients (8 females and 7 males; mean age, 8.9 years) were evaluated before and 36 and 60 months after transplantation. All were from Africa and lived in France. All patients except 2 had experienced ischemic stroke before HSCT. The median full-scale IQ was 87, 94, and 94 before transplantation and 36 months and 60 months after HSCT, respectively.

Discussion: At pre-HSCT evaluation, full-scale IQ was considered as "low average". This relatively poor result could be related to impairment of PSI, which reflects frequent graphic and motor abnormalities related to the previous stroke experienced by almost all patients. At 3 years after HSCT, all indices including IQ had increased. Only the PSI had decreased, this observation being potentially related to previous stroke and to the depression frequently experienced by the transplant recipient patient after the acute phase, when the disease is cured. At 5 years after HSCT, the median full-scale IQ was stable and the PSI had increased.

Conclusion: At the end of follow-up, the patients improved their physical and psychological well-being. This allowed them to build projects for the future and to manifest the desire of becoming an adult. Bone marrow transplantation in this cohort of children with SCD and severe cerebral vasculopathy is associated with improved performance as measured by the Wechsler scale.