OBJECTIVES: Adrenoleukodystrophy (ALD) is a rare X-linked degenerative syndrome, the most severe form of which, cerebral ALD (cALD), presents in childhood and is a target of emerging gene therapies. Due to its rarity, data on ALD patients is limited. This study aimed to use Swedish population registries to identify and characterize patients diagnosed with ALD, and to describe the disease burden of cALD.

METHODS: All male patients diagnosed with ALD (ICD-10-SE: E71.3D) in the Swedish Patient Registry between January 2001 and June 2019 were identified. Among ALD patients, cALD patients were identified based on exposure to allogeneic hematopoietic stem cell transplantation (allo-HSCT) and/or records of cALD-associated symptoms. Patient characteristics, treatment, and healthcare resource utilization were described using linked Swedish national registry data.

RESULTS: Overall, 40 ALD patients including 33 cALD patients were identified. Among the cALD patients, 18% received allo-HSCT and 82% were identified based on cALD-associated symptoms only. Common clinical manifestations of cALD included musculoskeletal problems, hearing loss/visual impairment, and behavioral issues. Median age at diagnosis was 7.5 years for cALD patients who received allo-HSCT, 29.0 years for non-transplanted ALD patients with cerebral symptoms, and 33.0 years for the remaining ALD patients. Median time from ALD diagnosis to allo-HSCT was 2.5 months. After allo-HSCT, all cALD patients had treatment records indicative of infection and adrenal morbidities, and received systemic corticosteroids and/or immunotherapy in the subsequent 4 years. In the 2^nd and 3^rd follow-up year after transplant, cALD patients who received allo-HSCT spent on average 20.4 and 23.4 days in secondary healthcare, respectively. Median 5-year overall survival rate was 100% for cALD patients who received allo-HSCT and 92% for non-transplanted patients with cerebral symptoms.

CONCLUSIONS: With novel therapy options in development, this retrospective study contributes with novel insights related to the real-world disease burden of ALD in the Swedish population.