Neurofilament light chain as a biomarker to indicate early activation of cerebral disease in boys with adrenoleukodystrophy.

backgroundAdrenoleukodystrophy (ALD) is associated with disruption in very long chain fatty acid (VLCFA) processing due to a genetic mutation in the X-linked ABCD1 gene. The buildup of VLCFAs predisposes males to adrenal insufficiency (AI) and cerebral demyelination (cerebral ALD). If diagnosed early, these conditions can be treated effectively by hormone replacement and hematopoietic stem cell transplant, respectively. ALD is now included on the newborn screen panel in the majority of the United States. Thus far, there are no predictive tools to identify the development of early cerebral disease, necessitating frequent imaging surveillance with biannual MRIs starting at age 2 years through 12 years, then per annum for the remainder of the patient's life. A bloodborne biomarker has been desirable to efficiently predict the onset of cerebral disease and reduce the healthcare burden on the family as well as healthcare expense.

methodsWe prospectively measured plasma neurofilament light (NfL) chain levels in five boys with ALD who ultimately developed cerebral ALD.

resultsWe describe that baseline plasma NfL levels can be established for boys with ALD and that an increase of 50% above baseline occurs at the time that cerebral disease develops.

conclusionsAs far as we are aware, this is the first report highlighting that a bloodborne biomarker, plasma NfL, could potentially be used as a concomitant indicator of cerebral disease initiation, thus simplifying surveillance for cerebral ALD.