Asif M. Paker

Hematopoietic Stem-Cell Gene Therapy for Cerebral Adrenoleukodystrophy

BACKGROUND In X‐linked adrenoleukodystrophy, mutations in ABCD1 lead to loss of function of the ALD protein. Cerebral adrenoleukodystrophy is characterized by demyelination and neurodegeneration. Disease progression, which leads to loss of neurologic function and death, can be halted only with allogeneic hematopoietic stem‐cell transplantation. METHODS We enrolled boys with cerebral adrenoleukodystrophy in a single‐group, open‐label, phase 2–3 safety and efficacy study. Patients were required to have early‐stage disease and gadolinium enhancement on magnetic resonance imaging (MRI) at screening. The investigational therapy involved infusion of autologous CD34+ cells transduced with the elivaldogene tavalentivec (Lenti‐D) lentiviral vector. In this interim analysis, patients were assessed for the occurrence of graft‐versus‐host disease, death, and major functional disabilities, as well as changes in neurologic function and in the extent of lesions on MRI. The primary end point was being alive and having no major functional disability at 24 months after infusion. RESULTS A total of 17 boys received Lenti‐D gene therapy. At the time of the interim analysis, the median follow‐up was 29.4 months (range, 21.6 to 42.0). All the patients had gene‐marked cells after engraftment, with no evidence of preferential integration near known oncogenes or clonal outgrowth. Measurable ALD protein was observed in all the patients. No treatment‐related death or graft‐versus‐host disease had been reported; 15 of the 17 patients (88%) were alive and free of major functional disability, with minimal clinical symptoms. One patient, who had had rapid neurologic deterioration, had died from disease progression. Another patient, who had had evidence of disease progression on MRI, had withdrawn from the study to undergo allogeneic stem‐cell transplantation and later died from transplantation‐related complications. CONCLUSIONS Early results of this study suggest that Lenti‐D gene therapy may be a safe and effective alternative to allogeneic stem‐cell transplantation in boys with early‐stage cerebral adrenoleukodystrophy. Additional follow‐up is needed to fully assess the duration of response and long‐term safety. (Funded by Bluebird Bio and others; STARBEAM ClinicalTrials.gov number, NCT01896102; ClinicalTrialsRegister.eu number, 2011‐001953‐10.)

Docosahexaenoic acid therapy in peroxisomal diseases Results of a double-blind, randomized trial

Objectives: Peroxisome assembly disorders are genetic disorders characterized by biochemical abnormalities, including low docosahexaenoic acid (DHA). The objective was to assess whether treatment with DHA supplementation would improve biochemical abnormalities, visual function, and growth in affected individuals. Methods: This was a randomized, double-blind, placebo-controlled trial conducted at a single center. Treatment groups received supplements of DHA (100 mg/kg per day). The primary outcome measures were the change from baseline in the visual function and physical growth during the 1 year follow-up period. Results: Fifty individuals were enrolled and randomized. Two were subsequently excluded from study analysis when it was determined that they had a single enzyme disorder of peroxisomal β oxidation. Thirty-four returned for follow-up. Nine patients died during the trial of their disorder, and 5 others were lost to follow-up. DHA supplementation was well tolerated. There was no difference in the outcomes between the treated and untreated groups in biochemical function, electroretinogram, or growth. Improvements were seen in both groups in certain individuals. Conclusions: DHA supplementation did not improve the visual function or growth of treated individuals with peroxisome assembly disorders. Classification of evidence: This interventional study provides Class II evidence that DHA supplementation did not improve the visual function or growth of treated individuals with peroxisome assembly disorders during an average of 1 year of follow-up in patients aged 1 to 144 months.

Hematopoietic stem cell transplantation in the leukodystrophies: a systematic review of the literature.

OBJECTIVE The objective of this study is to systematically review the literature on worldwide numbers of leukodystrophy patients undergoing hematopoietic stem cell transplantation (HSCT) as well as the safety and efficacy of the procedure in this patient population. MATERIALS AND METHODS A PubMed and EMBASE search up to June 2012 was conducted with a manual search of references from relevant articles. Selected studies were evaluated using internationally accepted criteria. The effect estimates of HSCT upon survival in early-stage disease versus late-stage disease were compared. RESULTS One hundred and fifty-two studies qualified for inclusion and reported on a total of 689 patients. Study quality ranged from poor to good; no study was rated excellent. Small sample sizes limited most studies. Meta-analysis in a subset of larger studies indicates that transplantation in earlier stages of disease fairs better than in the late stages. Beyond survival, little longitudinal data on functional outcome is reported and neurological outcome is sparse. CONCLUSION Further studies are needed to determine the neurological outcome following HSCT in the leukodystrophies. HSCT in the early stages of cerebral disease is still recommended for select leukodystrophies.

Hemichorea in a patient with diabetic ketoacidosis

BACKGROUND Chorea is a common presenting feature of metabolic disorders, including nonketotic hyperglycemia in patients with type 2 diabetes mellitus, but rarely has been reported in diabetic ketoacidosis, hypothyroidism and vitamin B12 deficiency. METHODS Review the literature for reported cases of chorea as a presenting manifestation in metabolic disorders. RESULTS We report a case of hemichorea in a patient with type 2 diabetes mellitus complicated by diabetic ketoacidosis. The patient had a two day history of right sided hemichorea and decreased level of consciousness. Initial laboratory studies revealed hyperglycemia, ketosis and an anion gap metabolic acidosis consistent with diabetic ketoacidosis. Once treatment was started the choreiform movements significantly improved over three weeks. CONCLUSION Although DKA has been rarely reported as a trigger for chorea, it should be in the differential diagnosis of a patient presenting with an acute chorea. Given the reversible nature of this disease, early recognition and treatment are imperative.