Cerebrospinal Fluid Levels of Soluble Amyloid Precursor Protein and β-Amyloid 42 in Patients with Multiple Sclerosis, Neuromyelitis Optica and Clinically Isolated Syndrome

Amyloid precursor protein (APP) accumulation in axonal ovoids is a sensitive marker for acute axonal injury in multiple sclerosis (MS) lesions. This study measured levels of alpha-cleaved soluble APP (alpha sAPP) and beta-amyloid 42 (A beta 42) in the cerebrospinal fluid (CSF) of 42 MS, 10 neuromyelitis optica and 25 clinically isolated syndrome patients and 21 healthy controls, and analysed the correlation between alpha sAPP and A beta 42 levels and relevant clinical parameters. The CSF concentrations of alpha sAPP and A beta 42 in patients and controls were not significantly different. There was a significant inverse correlation in patients between CSF alpha sAPP concentration and the Expanded Disability Status Scale (EDSS), but no significant correlation between CSF A beta 42 concentration and EDSS. The concentration of alpha sAPP in the CSF of statin-treated patients was significantly higher than in those not treated with statins, suggesting that statins may have a neuroprotective effect. In conclusion, alpha sAPP was present at similar levels in the CSF of patients with neuromyelitis optica, MS and clinically isolated syndrome and healthy controls, and an inverse correlation existed between CSF alpha sAPP concentration and neurological disability.