Serum uric acid in Friedreich Ataxia

Abstract

Serum uric acid (UA) is a circulating antioxidant whose levels are typically lower in patients with idiopathic neurodegenerative diseases than healthy controls, reflecting a higher oxidative stress. Here we provided the first assessment of serum UA in Friedreich Ataxia (FRDA), an inherited neurodegenerative disorder, aimed at exploring novel disease biomarkers. Serum UA was measured in 19 FRDA patients and compared to 26 healthy controls (CTL). Multivariate analysis was conducted to eliminate main confounding factors (age, gender and BMI). Diagnostic accuracy was tested with ROC curve analysis and cut-off point calculation. Clinical predictive value was quantified by means Spearman's correlation with SARA score and other clinical parameters. Serum UA levels resulted significantly higher in FRDA than CTL (p = .016), independently from age, gender and BMI. At the cut-off value of 4.45 mg/dl, serum UA discriminates FRDA from CTL with >70% of sensitivity and >60% of specificity. No correlations emerged with clinical data. Contrarily to other neurodegenerative diseases, in FRDA, we observed an independent increase of serum UA content. Taking in account previous experimental findings, we hypothesize that such a finding may result from biochemical impairment induced by the genetic defect, acting as a sort of compensatory antioxidant defense although proper dedicated studies are mandatory. This preliminary report focuses UA as a potential biomarker for FRDA and encourages further studies on novel therapeutic strategies.

Keywords: Biomarker; FRDA; Friedreich ataxia; Uric acid.