Glutamate as a new path in discrimination between neuromyelitis optica spectrum disorder and multiple sclerosis

Abstract

Abstract Background Neuromyelitis optica spectrum disorder (NMOSD) used to be considered as a variant of multiple sclerosis (MS), however the recent detection of a highly specific serum biomarkers for NMOSD have made clear that NMOSD is a condition distinct from MS. The aim was to explore the role of serum glutamate level in the discrimination between NMOSD and relapsing remitting (RR) MS patients during and in between relapses. The study comprised two groups; first group, a total of 30 NMOSD patients, they were furtherly subdivided into NMOSD in remission, 15 patients without recent relapses in the last 3 months, NMOSD with relapse, 15 patients with recent relapses in the last 3 months, the second group, 30 definite, RRMS patients, they were further subdivided into RRMS in remission, 15 patients without recent relapses in the last 3 months RRMS with relapse, 15 patients with recent relapses in the last 3 months. Results Without relapse, NMOSD patients have higher level of serum glutamate than RRMS patients with (P values = 0.005), a significant difference between EDSS in NMOSD patients and RRMS patients (P = 0.0001), The cut-off value of glutamate serum level between NMOSD in remission and RRMS in remission was > 10.3 μg/mL, yet its level for differentiation between group RRMS in remission and RRMS with relapse was > 12.6 μg/mL. Conclusion Glutamate cut-off value might be a reliable tool to discriminate between NMOSD and RRMS.