NEFL and X-linked adrenoleukodystrophy: With acute neuroinflammatory demyelination in CCALD or ACALD, blood NfL concentrations were markedly increased when compared with asymptomatic childhood/adolescent X-ALD or non-inflammatory AMN patients of similar age, respectively (raw data children/adolescents: median 158.8; IQR [25.3–545.1] pg/mL vs 4.2 [3.3–4.9] pg/mL; model estimate of mean ratio CCALD vs asymptomatic X-ALD: 24.2, CI: 13.1–44.6; adj.