Neuroprotective associations of apolipoproteins A-I and A-II with neurofilament levels in early multiple sclerosis

Abstract

The role of cholesterol homeostasis in neuroaxonal injury in multiple sclerosis is not known. The objective of the study is to investigate the associations of cerebrospinal fluid (CSF) and serum neurofilament light chain levels (CSF-NfL and sNfL, respectively), which are biomarkers of neuroaxonal injury, with cholesterol biomarkers at the clinical onset of multiple sclerosis. sNfL, serum cholesterol profile (total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol), serum apolipoprotein (Apo) levels (ApoA-I, ApoA-II, ApoB, and ApoE), and albumin quotient were obtained for 133 patients (63% female, age: 29.9±8.0years) during the first demyelinating event. CSF-NfL was available for 103 (77%) patients. CSF-NfL and sNfL were negatively associated with serum ApoA-II (P=.005, P<.001) and positively associated with albumin quotient (P<.001, P<.0001). In addition, higher CSF-NfL was associated with lower serum ApoA-I (P=.009) levels and higher sNfL was associated with lower high-density lipoprotein cholesterol (P=.010). In stepwise regression, age (P=.045), serum ApoA-II (P=.022), and albumin quotient (P<.001) were associated with CSF-NfL; albumin quotient (P=.002) and ApoA-II (P=.001) were associated with sNfL. Path analysis identified parallel pathways from ApoA-II (P=.009) and albumin quotient (P<.001) to the sNfL outcome that were mediated by CSF-NfL (P<.001). The associations of CSF-NfL with ApoA-I (P=.014) and ApoA-II (P=.015) and sNfL with ApoA-II (P<.001) remained significant after adjusting for number of contrast-enhancing lesions and T2 lesion volume. Lower serum ApoA-II and ApoA-I levels are associated with greater neuroaxonal injury as measured by CSF-NfL.