Glutamate and Nitric Oxide as biomarkers for disease activity in patients with multiple sclerosis.

BACKGROUND: Despite multiple diagnostic tests, multiple sclerosis (MS) remains a clinical diagnosis with supportive paraclinical evidence. OBJECTIVE: To measure glutamate and nitric oxide serum levels in MS patients during and in between relapses to assess their potential role as biomarkers of disease activity and relapses. SUBJECTS AND METHODS: This cross sectional study was carried out on 70 MS patients and 40 age and sex matched apparently healthy controls. MS patients were divided into 2 groups; group 1 that included thirty MS patients without history of relapse within the last 3 months prior to recruitment and group 2 that included forty MS patients with history of relapse within the last 30 day prior to recruitment. RESULTS: Serum glutamate was significantly higher in group 2 (24.67 ±â€¯9.58 µg/ml) compared to group 1(12.5 ±â€¯4.9 µg/ml) (P value < 0.0001) and apparently healthy controls (3.5 ±â€¯1.3 µg/ml) (P value < 0.0001). Serum nitric oxide was significantly higher in group 2 (84.87 ±â€¯29.6 nmol/µl) than group 1 (41.99 ±â€¯24.2 nmol/µl) (P value < 0.0001) and apparently healthy controls (12.03 ±â€¯3.59 nmol/µl) (P value < 0.0001). Cutoff values of 17.5 µg/ml for glutamate and 75.2 nmol/µl for nitric oxide were found to predict occurrence of a relapse (sensitivity = 70% and 72.5% and specificity= 90% and 93.3% respectively). CONCLUSION: Serum glutamate and nitric oxide can be potential easily-accessible biomarkers of disease activity and relapses in MS patients.