Cerebrospinal fluid myelin basic protein is elevated in multiple system atrophy
Anna Santaella, H. Bea Kuiperij, Anouke van Rumund, Rianne A.J. Esselink, Bastiaan R. Bloem, Marcel M. Verbeek
Abstract
INTRODUCTION: Parkinson's disease (PD) and multiple system atrophy (MSA) have overlapping symptoms, challenging an early diagnosis. Diagnostic accuracy is important because PD and MSA have a different prognosis and response to treatment. Here, we aimed to evaluate the diagnostic value of brain-specific structural proteins in cerebrospinal fluid (CSF) of PD and MSA patients, as well as their association with cognitive decline. METHODS: CSF samples were collected from patients with clear signs of parkinsonism, but with uncertain diagnosis at the time of inclusion. Clinical diagnoses of PD (n = 55) and MSA (n = 22) were established after 3 and 10 years of follow-up and re-evaluated after 12 years, according to the most updated clinical criteria. CSF from controls (n = 118) was studied for comparison. Neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP), S100 calcium-binding protein B (S100B) and myelin basic protein (MBP) levels in CSF were measured using ELISA. Protein levels were also correlated with cognitive decline, i.e. worsening of the mini mental state examination (MMSE) over a period of three years. RESULTS: MBP concentrations were increased in MSA compared to PD and controls (p < 0.005) and could differentiate MSA and PD with high accuracy (AUC = 0.781; p < 0.001). Concentrations of MPB, GFAP and S100B, but not NSE, were significantly elevated in PD patients compared to controls (p = 0.05). None of the brain-specific structural proteins correlated with MMSE progression. CONCLUSIONS: Our results demonstrate that MBP differentiates PD from MSA at early stages of the disease, indicating that demyelination and axonal damage may already occur in early stages of MSA.