Cerebrospinal fluid apolipoprotein E and phospholipid transfer protein activity are reduced in multiple sclerosis; relationships with the brain MRI and CSF lipid variables

•CSF apoE and PLTP activity are reduced in multiple sclerosis patients.•CSF apoE and PLTP activity strongly correlate with each other.•CSF apoE strongly correlates with Aβ42, tau, CSF cholesterol and 24OH-cholesterol.•CSF PLTP activity strongly correlates with CSF cholesterol in controls.•ApoE and PLTP contribute to the variance of the brain volume in MS.

Apolipoprotein E (apoE), phospholipid transfer protein (PLTP) activity, lipids, total tau and beta amyloid 1-42 (Aβ42) were measured in cerebrospinal fluid (CSF) from controls (n=38) and multiple sclerosis (MS) patients (n=91). ApoE and PLTP activity were significantly reduced in MS compared to non-inflammatory disease controls (NINDC; p<0.05). In NINDC and MS, apoE correlated with PLTP activity (rs=0.399 and 0.591, respectively), Aβ42 (rs=0.609 and 0.483, respectively), and total tau (rs=0.748 and 0.380, respectively; all p<0.05). CSF apoE and PLTP significantly contributed to the variance of the normalized brain volume (NBV) and T2 lesion volume in MS (p<0.001 and <0.05, respectively). ApoE correlated with CSF cholesterol and 24-hydroxycholesterol in all groups; PLTP activity correlated with CSF cholesterol in controls (p<0.05).