Abstract

Aims: To investigate whether plasma biomarkers for axonal injury and inflammation are related to loss and recovery of visual function in acute optic neuritis (ON).

Methods: Eighteen patients with ON and 14 controls were investigated in a longitudinal, prospective study. Plasma phosphorylated neurofilament heavy chain (NfH^SMI35; a surrogate marker of axonal injury), nitric oxide metabolites (NOx), and citrulline (surrogate markers of inflammation) were measured.

Results: Patients with ON had higher median plasma NfH^SMI35 values than controls (0.17 versus 0.005 ng/ml; p < 0.05) and higher NOx values (49 versus 35.5μM; p < 0.001). Plasma NfH^SMI35 values correlated inversely with visual acuity at presentation (R  =  −0.67; p  =  0.01). NfH^SMI35 was higher in patients with poor recovery of visual acuity than in those with good recovery (0.25 ng/ml versus 0.09 ng/ml; p < 0.05). Three of four patients with high NfH^SMI35 and high NOx values experienced a poor recovery as opposed to only one of five with high NOx but normal NfH^SMI35 values.

Conclusions: NfH^SMI35, a surrogate marker for axonal damage, is a prognostic indicator and should be considered in the design of neuroprotective treatment strategies.