Long-term neurocognitive function of pediatric patients with severe combined immune deficiency (SCID): pre- and post-hematopoietic stem cell transplant (HSCT).
BACKGROUND
Hematopoietic stem cell transplantation (HSCT) is the only cure for patients with severe combined immunodeficiency (SCID). The purpose of this study was to evaluate long-term neurodevelopment of patients with SCID following myeloablative chemotherapy and HSCT.


METHODS
Sixteen pediatric patients diagnosed with SCID were tested using the Bayley Scales of Infant Development and the validated Vineland Adaptive Behavior Scales (VABS) pre- and 1-year post-HSCT. Three years post-HSCT, there were 11 patients available for testing and four patients available 5 years post-HSCT. Patients greater than 3 years of age were administered the Wechsler Preschool and Primary Scale of Intelligence. Both raw scores and scaled scores were analyzed.


RESULTS
There was a significant decrease 1 year post-HSCT in the Bayley Mental Developmental Index (MDI) [92.5 (pre) vs. 70.81 (1 year post), p < 0.0001] and the VABS [99.73 (pre) vs. 79.87 (1 year post), p = <0.0001]. There was a significant decrease over time in the MDI [95.00 (pre) vs. 72.64 (1 year post) vs. 71.82 (3 years post), p < 0.0001], but no significant change between 1 and 3 years post-HSCT. There was no change in the Bayley Psychomotor Development Scale (PDI) [82.4 (pre) vs. 84.8 (1 year post), p = 0.68]. The PDI scores decreased over time [86.29 (pre) vs. 86 (1 year post) vs. 74.14 (3 years post), p = 0.045]. Although there was a decrease in scaled scores, there was not a loss of skills. Analysis of raw scores showed that there was an increase in the raw test scores, which indicated that these children acquired developmental skills, but at a slower rate than normal infants and toddlers. Younger children had a more significant decrease in adaptive scores compared with older children.


CONCLUSIONS
These findings may reflect the effects of the isolation and prolonged hospitalization that characterizes the immediate post-transplant period. Patients miss out on social interactions and learning opportunities that normally occur at their respective stages of development. These restrictions keep patients from acquiring developmentally appropriate cognitive skills as well as gross and fine motor developmental milestones. Longitudinal follow-up will be important to quantify acquisition of skills.
Lin
Malinda
M
Department of Pediatrics, Keck School of Medicine, Los Angeles, CA, USA.
Epport
Karen
K
Azen
Colleen
C
Parkman
Robertson
R
Kohn
Donald B
DB
Shah
Ami J
AJ
D000223:Adaptation, Psychological; D000074323:Alemtuzumab; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002066:Busulfan / Q000627:therapeutic use; D002657:Child Development; D003071:Cognition; D003520:Cyclophosphamide / Q000627:therapeutic use; D005500:Follow-Up Studies; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007223:Infant; D019653:Myeloablative Agonists / Q000627:therapeutic use; D009483:Neuropsychological Tests; D011597:Psychomotor Performance; D016511:Severe Combined Immunodeficiency / Q000188:drug therapy / Q000523:psychology* / Q000601:surgery*; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm; D000970:Antineoplastic Agents; D019653:Myeloablative Agonists; D000074323:Alemtuzumab; D003520:Cyclophosphamide; D002066:Busulfan