Serum uric acid levels and their correlation with clinical and cerebrospinal fluid parameters in patients with neuromyelitis optica.

Although uric acid (UA) concentration has been considered a surrogate marker for monitoring the progression of multiple sclerosis (MS), less is known about the relationship between UA and the progression of neuromyelitis optica (NMO). We therefore investigated the correlations between serum UA concentrations and the clinical and cerebrospinal fluid (CSF) parameters in patients with NMO. Factors assessed in patients with NMO included gender, disease duration, disease disability, CSF white blood cell (WBC) counts, oligoclonal bands (OB), 24 hour immunoglobulin (Ig)G index, and myelin basic protein (MBP) concentration. Mean serum UA concentrations were compared in patients with NMO and in a control group of patients with cerebral infarction (CI). We found that mean serum UA concentrations were significantly lower in patients with NMO compared to those with CI (206.81 compared to 274.00 μmol/L, p=0.00). Serum UA concentration was correlated directly with NMO duration (p=0.013) and was inversely correlated with the Expanded Disability Status Scale score (p=0.021). Patients with NMO with lower serum UA concentrations tended to be positive for OB, to have higher CSF protein and MBP concentrations, and to have higher WBC counts and 24 hour IgG index, but no correlation was statistically significant. UA may be a useful surrogate marker for monitoring NMO activity.