Secondary failure of lentiviral vector gene therapy in a cerebral adrenoleukodystrophy patient with an ABCD1 whole-gene deletion.

A 9-year-old boy with adrenoleukodystrophy due to ABCD1 whole-gene deletion was diagnosed with active cerebral adrenoleukodystrophy characterized by demyelination and gadolinium enhancement on brain MRI. He underwent hematopoietic cell transplant (HCT) with autologous CD34+ cells transduced with an ABCD1-expressing lentiviral vector (eli-cel [elivaldogene autotemcel]) as part of the ALD-104 clinical trial. Fifty days after HCT, the patient's MRI showed gadolinium resolution; the whole-blood vector copy number (VCN) was 0.666 copies/mL. Six months following HCT, an MRI showed re-emergence of gadolinium enhancement; the VCN had decreased to 0.029 copies/mL. Polyclonal antibodies to the ABCD1 gene product were detectable 9 months after transplant, showing reactivity to peroxisomes, suggesting an immune response; however, no antibody binding to human CD34+ cells could be shown. The patient underwent a successful allogeneic HCT 12 months after gene therapy with resultant gadolinium resolution, cerebral disease stabilization, and the disappearance of antibodies. The coincident VCN loss and appearance of antibody to the ABCD1 gene product is of interest, and we postulate that it is related to the patient's whole ABCD1 gene deletion. We suggest close monitoring of loss of gene therapy efficacy due to immune response in patients with full deletions who are considering gene therapy.

Phototherapy Alters the Plasma Metabolite Profile in Infants Born Preterm with Hyperbilirubinemia.

OBJECTIVE: To investigate the effects of gestational age (GA) and phototherapy on the plasma metabolite profile of preterm infants with neonatal hyperbilirubinemia (NHB). STUDY DESIGN: From a cohort of prospectively enrolled infants born preterm (n = 92), plasma samples of very preterm (VPT; GA, 28 + 0 to 31 + 6 weeks, n = 27) and moderate/late preterm (M/LPT; GA, 32 + 0 to 35 + 6 weeks, n = 33) infants requiring phototherapy for NHB were collected prior to the initiation of phototherapy and 24 hours after starting phototherapy. An additional sample was collected 48 hours after starting phototherapy in a randomly selected subset (n = 30; VPT n = 15; M/LPT n = 15). Metabolite profiles were determined using ultraperformance liquid chromatography tandem mass spectroscopy. Two-way ANCOVA was used to identify metabolites that differed between GA groups and timepoints after adjusting for total serum bilirubin levels (false discovery rate q-value < 0.05). Top impacted pathways were identified using pathway over-representation analysis. RESULTS: Phototherapy was initiated at lower total serum bilirubin (mean ± SD mg/dL) levels in VPT compared with M/LPT infants (7.3 ± 1.4 vs 9.9 ± 1.9, P < .01). We identified 664 metabolites that were significant for a phototherapy effect, 191 metabolites significant for GA, and 46 metabolites significant for GA × phototherapy interaction (false discovery rate q-value < 0.05). Longer duration phototherapy had a larger mean effect size (24 hours postphototherapy: d = 0.36; 48 hours postphototherapy: d = 0.43). Top pathways affected by phototherapy included membrane lipid metabolism, one-carbon metabolism, creatine biosynthesis, and oligodendrocyte differentiation. CONCLUSION: Phototherapy alters the plasma metabolite profile more than GA in preterm infants with NHB, affecting pathways related to lipid and one-carbon metabolism, energy biosynthesis, and oligodendrocyte differentiation.

Natural history of craniovertebral abnormalities in a single-center study in 54 patients with Hurler syndrome.

OBJECTIVE: Craniovertebral junction (CVJ) abnormalities are common and well documented in mucopolysaccharidosis type I-Hurler syndrome (MPS IH), often causing severe spinal canal narrowing. However, the requirement for surgical decompression and/or fusion is uncommon. Although hematopoietic cell transplant (HCT) has been shown to prolong the lives of patients with MPS IH, its effect in halting or reversing musculoskeletal abnormalities is less clear. Unfortunately, there are currently no universal guidelines for imaging or indication for surgical interventions in these patients. The goal of this study was to track the progression of the CVJ anatomy in patients with MPS IH following HCT, and to examine radiographic features in patients who needed surgical intervention. METHODS: Patients with MPS IH treated at the University of Minnesota with allogeneic HCT between 2008 and 2020 were retrospectively reviewed. Patients who underwent CVJ surgery were identified with chart review. All MPS IH cervical scans were examined, and the odontoid retroflexion angle, clivoaxial angle (CXA), canal width, and Grabb-Oakes distance (pB-C2) were measured yearly for up to 7 years after HCT. Longitudinal models based on the measurements were made. An intraclass correlation coefficient was used to measure interrater reliability. Nine children without MPS IH were examined for control CVJ measurements. RESULTS: A total of 253 cervical spine MRI scans were reviewed in 54 patients with MPS IH. Only 4 (7.4%) patients in the study cohort required surgery. Three of them had posterior fossa and C1 decompression, and 1 had a C1-2 fusion. There was no statistically significant difference in the spinal parameters that were examined between surgery and nonsurgery groups. Among the measurements, canal width and CXA varied drastically in patients with different neck positions. Odontoid retroflexion angle and CXA tended to decrease with age. Canal width and pB-C2 tended to increase with age. CONCLUSIONS: Based on the data, the authors observed an increase in canal width and pB-C2, whereas the CXA and odontoid retroflexion angle became more acute as the patients aged after HCT. The longitudinal models derived from these data mirrored the development in children without MPS IH. Spinal measurements obtained on MR images alone are not sufficient in identifying patients who require surgical intervention. Symptom monitoring and clinical examination, as well as pathological spinal cord changes on MRI, are more crucial in assessing the need for surgery than is obtaining serial imaging.

Targeting VEGF-mediated blood-brain barrier disruption in advanced cerebral leukodystrophy.

The earliest clinical manifestation of cerebral adrenoleukodystrophy (CALD) is adrenal insufficiency (AI) characterized by elevations in ACTH and loss of cortisol. We showed high (though physiologically achievable) levels of ACTH increases endothelial permeability, increases anisotropy, and increases VEGF secretion. An ACBD1 knockout endothelial cell line had increased sensitivity to ACTH and VEGF. Inhibition of VEGF via application of anti-VEGF (bevacizumab) improved permeability. Six boys with advanced CALD were treated with bevacizumab combined with dexamethasone and ruxolitinib as immune suppressants. Most boys had decreases in gadolinium enhancement on MRI indicating improvement in endothelial function, though all boys continued to progress symptomatically.

Diffusion Tensor Imaging in Boys With Adrenoleukodystrophy: Identification of Cerebral Disease and Association With Neurocognitive Outcomes.

BACKGROUND AND OBJECTIVES: Childhood cerebral adrenoleukodystrophy (C-ALD) is a severe inflammatory demyelinating disease that must be treated at an early stage to prevent permanent brain injury and neurocognitive decline. In standard clinical practice, C-ALD lesions are detected and characterized by a neuroradiologist reviewing anatomical MRI scans. We aimed to assess whether diffusion tensor imaging (DTI) is sensitive to the presence and severity of C-ALD lesions and to investigate associations with neurocognitive outcomes after hematopoietic cell therapy (HCT). METHODS: In this retrospective cohort study, we analyzed high-resolution anatomical MRI, DTI, and neurocognitive assessments from boys with C-ALD undergoing HCT at the University of Minnesota between 2011 and 2021. Longitudinal DTI data were compared with an age-matched group of boys with ALD and no lesion (NL-ALD). DTI metrics were obtained for atlas-based regions of interest (ROIs) within 3 subdivisions of the corpus callosum (CC), corticospinal tract (CST), and total white matter (WM). Between-group baseline and slope differences in fractional anisotropy (FA) and axial (AD), radial (RD), and mean (MD) diffusivities were compared using analysis of covariance accounting for age, MRI severity (Loes score), and lesion location. RESULTS: Among patients with NL-ALD (n = 14), stable or increasing FA, stable AD, and stable or decreasing RD and MD were generally observed during the 1-year study period across all ROIs. In comparison, patients with mild posterior lesions (Loes 1-2; n = 13) demonstrated lower baseline FA in the CC splenium (C-ALD 0.50 ± 0.08 vs NL-ALD 0.58 ± 0.04; pBH = 0.022 adjusted Benjamini-Hochberg p-value), lower baseline AD across ROIs (e.g., C-ALD 1.34 ± 0.03 ×10-9 m2/s in total WM vs NL-ALD 1.38 ± 0.04 ×10-9 m2/s; pBH = 0.005), lower baseline RD in CC body and CST, and lower baseline MD across ROIs except CC splenium. Longitudinal slopes in CC splenium showed high sensitivity and specificity in differentiating early C-ALD from NL-ALD. Among all patients with C-ALD (n = 38), baseline Loes scores and DTI metrics were associated with post-HCT neurocognitive functions, including processing speed (e.g., FA WM Spearman correlation coefficient R = 0.64) and visual-motor integration (e.g., FA WM R = 0.71). DISCUSSION: DTI was sensitive to lesion presence and severity as well as clinical neurocognitive effects of C-ALD. DTI metrics quantify C-ALD even at an early stage.

Comparative dose effectiveness of intravenous and intrathecal AAV9.CB7.hIDS, RGX-121, in mucopolysaccharidosis type II mice.

Mucopolysaccharidosis type II (MPS II) is an X-linked recessive lysosomal disease caused by iduronate-2-sulfatase (IDS) deficiency, leading to accumulation of glycosaminoglycans (GAGs) and the emergence of progressive disease. Enzyme replacement therapy is the only currently approved treatment, but it leaves neurological disease unaddressed. Cerebrospinal fluid (CSF)-directed administration of AAV9.CB7.hIDS (RGX-121) is an alternative treatment strategy, but it is unknown if this approach will affect both neurologic and systemic manifestations. We compared the effectiveness of intrathecal (i.t.) and intravenous (i.v.) routes of administration (ROAs) at a range of vector doses in a mouse model of MPS II. While lower doses were completely ineffective, a total dose of 1 × 109 gc resulted in appreciable IDS activity levels in plasma but not tissues. Total doses of 1 × 1010 and 1 × 1011 gc by either ROA resulted in supraphysiological plasma IDS activity, substantial IDS activity levels and GAG reduction in nearly all tissues, and normalized zygomatic arch diameter. In the brain, a dose of 1 × 1011 gc i.t. achieved the highest IDS activity levels and the greatest reduction in GAG content, and it prevented neurocognitive deficiency. We conclude that a dose of 1 × 1010 gc normalized metabolic and skeletal outcomes, while neurologic improvement required a dose of 1 × 1011 gc, thereby suggesting the prospect of a similar direct benefit in humans.

Hemangiosarcoma Cells Promote Conserved Host-derived Hematopoietic Expansion.

Hemangiosarcoma and angiosarcoma are soft-tissue sarcomas of blood vessel-forming cells in dogs and humans, respectively. These vasoformative sarcomas are aggressive and highly metastatic, with disorganized, irregular blood-filled vascular spaces. Our objective was to define molecular programs which support the niche that enables progression of canine hemangiosarcoma and human angiosarcoma. Dog-in-mouse hemangiosarcoma xenografts recapitulated the vasoformative and highly angiogenic morphology and molecular characteristics of primary tumors. Blood vessels in the tumors were complex and disorganized, and they were lined by both donor and host cells. In a series of xenografts, we observed that the transplanted hemangiosarcoma cells created exuberant myeloid hyperplasia and gave rise to lymphoproliferative tumors of mouse origin. Our functional analyses indicate that hemangiosarcoma cells generate a microenvironment that supports expansion and differentiation of hematopoietic progenitor populations. Furthermore, gene expression profiling data revealed hemangiosarcoma cells expressed a repertoire of hematopoietic cytokines capable of regulating the surrounding stromal cells. We conclude that canine hemangiosarcomas, and possibly human angiosarcomas, maintain molecular properties that provide hematopoietic support and facilitate stromal reactions, suggesting their potential involvement in promoting the growth of hematopoietic tumors. SIGNIFICANCE: We demonstrate that hemangiosarcomas regulate molecular programs supporting hematopoietic expansion and differentiation, providing insights into their potential roles in creating a permissive stromal-immune environment for tumor progression.