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. MATERIALS AND 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.

Progressive declines in neurocognitive function among survivors of hematopoietic stem cell transplantation for pediatric hematologic malignancies.

Neurocognitive function of pediatric patients is of great concern after hematopoietic stem cell transplantation (HSCT). We evaluated the neurocognitive function of pediatric patients pre-HSCT, 1, 3, and 5 years post-HSCT. All patients had a hematologic malignancy and received therapy to their central nervous system. Healthy siblings were tested as a comparison group. Pediatric patients with a hematologic malignancy did not have a significant decrease in their cognitive function before HSCT compared with their siblings except in areas of academic achievement. Our study population had significant declines in visual motor skills and memory test scores within the first year post-HSCT. By 3 years post-HSCT, there was an improvement in the visual motor development scores and memory scores, but there were new deficits in verbal skills. By 5 years post-HSCT, there were progressive declines in verbal skills (P=0.005), performance skills (0.04), and new deficits seen in long-term verbal memory scores (0.04). On the basis of the raw scores, most of these tests showed that patients had an inability to acquire new skills at a rate comparable to their age-matched healthy peers. However, long-term memory scores showed definite declines. The greatest decline in neurocognitive function occurred in those patients who received cranial irradiation either as part of their initial therapy or as part of their HSCT conditioning. Pediatric patients who received HSCT for hematologic malignancies have neurocognitive deficiencies that are both acute and chronic. Although some patients have acute deficits that appear and improve over time, other patients have progressive declines in neurocognitive function that are chronic.

Neuroradiographic, endocrinologic, and ophthalmic correlates of adverse developmental outcomes in children with optic nerve hypoplasia: a prospective study.

BACKGROUND: Developmental delay has been reported to occur with optic nerve hypoplasia, a leading cause of pediatric blindness, but has not been systematically examined for its prevalence and correlation with associated pathologies of optic nerve hypoplasia. OBJECTIVE: The purpose of this study was to determine the developmental outcomes of children with optic nerve hypoplasia and the correlation of development with neuroradiographic, endocrinologic, and ophthalmic findings. METHODS: We conducted a prospective analysis of 73 subjects diagnosed with optic nerve hypoplasia at <36 months of age for developmental outcomes at 5 years of age. Subjects underwent neuroradiographic imaging, endocrinologic testing and examination, and ophthalmologic examination; developmental outcomes were assessed by using the Battelle Developmental Inventory. RESULTS: At 5 years of age, developmental delay was present in 71% of subjects with optic nerve hypoplasia. Of patients with unilateral (18%) and bilateral optic nerve hypoplasia, 39% and 78%, respectively, experienced developmental delay. Corpus callosum hypoplasia and hypothyroidism were significantly associated with poor outcome in all of the developmental domains and an increased risk of delay. Absence of the septum pellucidum was not associated with adverse development. Six subjects had neither a neuroradiographic nor an endocrinologic abnormality, and of those, 4 were developmentally delayed. CONCLUSIONS: These prospective data confirm the significant association of developmental delay with optic nerve hypoplasia and identify corpus callosum hypoplasia and hypothyroidism as strong correlates. A diagnosis of optic nerve hypoplasia warrants neuroradiographic and endocrinologic testing for risk factors of delay and developmental assessments for early intervention planning.

Busulfan and cyclophosphamide as a conditioning regimen for pediatric acute lymphoblastic leukemia patients undergoing bone marrow transplantation.

Bone marrow transplantation (BMT) has become the standard therapy for children with relapsed acute lymphoblastic leukemia. The authors report their experience with histocompatible BMT for 52 children with acute lymphoblastic leukemia conditioned with a non-total body irradiation (TBI) regimen using busulfan and cyclophosphamide (Bu/Cy). The efficacy and long-term toxicity of the Bu/Cy regimen were determined. Overall survival was 35%. One-year, 3-year, and 7-year event-free survival rates were 54%, 33%, and 23%, respectively. Of the 52 BMT recipients, 26 relapsed. Thirteen of the relapsed patients received a second BMT and three were surviving as of this writing. The most frequent cause of death was leukemia relapse. An initial remission duration of less than 18 months was a factor in decreasing the event-free survival. The Bu/Cy regimen was well tolerated, with minimal transplant-related mortality. Neurocognitive function was tested before BMT and 1 year after BMT. When 1-year posttransplant neurocognitive test scores were compared with pretransplant scores, there was no decrease. However, there was a significant decrease in the pretransplant neurocognitive test scores in BMT recipients compared with their normal siblings. The use of Bu/Cy as a conditioning regimen for BMT does not appear to affect posttransplant neurocognitive function. Other long-term side effects, such as endocrinopathies and secondary malignancies, were also minimal. These data show that the Bu/Cy regimen is well tolerated, but the overall survival rate remains low.

Second hematopoietic stem cell transplantation in pediatric patients: overall survival and long-term follow-up.

Despite potent intensive conditioning regimens, hematopoietic stem cell transplantation (HSCT) may fail because of either relapse of the malignancy or the rejection of the graft. We report on 27 pediatric patients who received a second HSCT from an allogeneic donor for relapsed malignancy or graft failure. One-year, 5-year, and 10-year probabilities of survival for all patients were 53%, 36%, and 24%, respectively. Twenty patients received second HSCTs for relapsed malignancy, of whom 6 were alive and disease free at the time of this report. Seven patients received a second HSCT for graft failure, of whom 3 were alive and well as of this report. Twenty-five patients were tested for immune reconstitution following their second HSCT. Sixteen patients developed antigen-specific T-lymphocyte responses; the median time to development of antigen-specific responses was 13 months. There was no significant neurocognitive decline in patients tested 1 to 3 years following their second HSCT. Endocrine evaluations revealed deficiencies in growth hormone (7 patients), gonadal function (3 patients), and thyroid function (2 patients). Three patients developed significant abnormalities of tooth development, including absence of secondary teeth. These results show that a second HSCT offers curative therapy for selected pediatric patients whose first HSCT failed. Although toxicity is considerable following a second transplantation, the major causes of mortality continue to be relapse and infection.