Serum uric acid levels in optic neuritis

Abstract

Uric acid, an antioxidant, is reduced in multiple sclerosis (MS). Patients with gout have a reduced incidence of MS. O ptic neuritis (O N), often the first manifestation of MS, is not known to be associated with reduced uric acid. Patients with recent onset of O N were investigated to determine whether uric acid levels were reduced at presentatio n. Twenty-o ne patients with O N were included, 17 females and 4 males. The mean (SD) serum uric acid in the O N female group was 184.4 (±55.1) mmol/L (range, 116- 309 mmol/L), whilst in the control group it was 235.2 (±50.2) mmol/L (range, 172- 381 mmol/L). The difference was statistically significant (x² = 8.93, P = 0.003). In the small male cohort, mean (SD) serum uric acid was 305 (±52.1) mmol/L, whilst in the control group it was 328 (±80.4) mmol/L. These differences were not statistically significant. Reduced antioxidant reserve is possibly an early patho genic mechanism in inflammatory demyelination, and raises the possibility that low uric acid levels could be an indicator of disease activity. Since optic neuropathies of other causes were not investigated, future research needs to determine whether low uric acid represents a unique feature of optic neuritis or is seen in other optic neuropathies.