Increased S-nitrosothiols are associated with spinal cord injury in multiple sclerosis

•Serum nitrite/nitrate are augmented in relapsing-remitting multiple sclerosis (MS).•Serum S-nitrosothiol is increased in relapsing-remitting and secondary-progressive MS.•Serum S-nitrosothiol is selectively increased in patients with spinal cord injury.•High S-nitrosothiol may be a potential serum biomarker for spinal cord injury in MS.

Multiple sclerosis (MS) is an immune-mediated disorder associated with inflammation, demyelination and axonal damage. In search of potential biomarkers of spinal cord lesions in MS related to nitric oxide metabolites, we measured total nitrite and nitrate levels, and protein-bound nitrotyrosine and S-nitrosothiol concentrations in the serum of MS patients at different stages of the disease. Sixty-eight patients and 36 healthy volunteers were included in the study. Total nitrite and nitrate levels were augmented in relapsing-remitting MS, while increased S-nitrosothiol concentrations were found both in relapsing-remitting and secondary-progressive MS. Further analysis demonstrated that S-nitrosothiol levels were selectively increased in patients with spinal cord injury. The data suggest that high S-nitrosothiol concentration may be a potential serum biomarker for spinal cord injury in MS.