OBJECTIVES: Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) is a rare neurological disorder associated with the onset and progression of neurological symptoms which result in diminishing quality of life and eventually death. As with most rare diseases, there is little patient-reported data with which to understand and address patient needs. This study explores the impact of ALSP in the real world, from the patient perspective.

METHODS: This is a two-year prospective, observational digital study of adults (or caregiver proxy if the patient cannot participate themselves) with confirmed diagnosis of ALSP or colony-stimulating factor 1 receptor (CSF1R) gene mutation, residing in the following countries: Germany, the Netherlands, the UK, and the USA. The planned sample size is 300.

Recruitment is via patient associations, word of mouth, and referral from physicians. Participants use a bespoke smartphone application (ALSP Registry) to check eligibility, provide informed consent, and contribute data. Data entry is as follows: (1) background surveys upon enrollment, covering demographics, diagnosis, and family history; (2) regular (quarterly, biannual, or annual) completion of surveys covering current symptoms and treatments, medical care (including associated costs), and work/study impacts; (3) quarterly completion of the EQ-5D-5L, a generic patient-reported outcomes instrument. Analyses are planned for when the study has been running in a majority of the countries for 12 and 24 months. Ethical approval of the study was sought at country-level where necessary.

RESULTS: Participant recruitment started in January 2022.

CONCLUSIONS: To our knowledge, this is the first global study capturing the patient-reported impact of ALSP. Collecting data directly from participants enables those with ALSP to share their own experiences of living with the condition. It will be the basis for scientific collaboration and will foster multidisciplinary knowledge on ALSP to improve patients’ health outcomes.