Acute axonal damage predicts clinical outcome in patients with multiple sclerosis

The objectives of this study were (1) to determine how cerebrospinal fluid (CSF) neurofilament heavy chain (NfH(SM134) and NfH(SM135)) levels relate to clinical outcome in optic neuritis (ON) and multiple sclerosis (MS) relapse patients treated with high dose oral methylprednisolone; and (2) to correlate neurofilament and myelin basic protein (MBP) concentrations, particularly as the latter was previously associated with clinical disability. Fifty subjects participated in two double-blind, randomized, placebo-controlled clinical trials. Eight/18 patients in the ON trial and 15/32 subjects in the MS attack trial were treated with oral methylprednisolone. In the MS attack trial group, CSF NfH(SM134) and NfH(SM135) measured at week 3 and deltaCSF NfH(SMI34) levels from baseline to week 3 were predictive of clinical outcome at week 8 and 52. In the ON group, no such association was seen. When both groups were combined, baseline CSF NfH(SHM134) and NfH(SM135) correlated positively with baseline enhancing lesion volume (ELV) (r(s) =0.50, P <0.01 and rS =0.53, P <0.01, respectively). Levels of NfH(SM135) at baseline and week 3 also strongly correlated with the MBP concentration. This study supports the view that acute inflammation in ON and MS results in axonal pathology and that the latter has a role in determining functional impairment.