New cord lesions at follow-up by CSF profile.

BackgroundControversy exists about the radiological follow-up of the spinal cord in MS, since cord lesions are mostly symptomatic, but there are also reports that 10% − 25% are asymptomatic. Therefore, a need exists for biomarkers to identify patients prone to future cord involvement where routine cord imaging at follow-up is warranted. Elevated intrathecal IgM has been shown to be cross-sectionally associated with more cord lesions. This study investigated whether there also is a longitudinal relation.MethodsRelapse-onset MS patients with baseline CSF and spinal MRI available were retrospectively identified. Cross-sectional associations between intrathecal immunoglobulin production and cord lesions were assessed. For the subgroup where follow-up spinal MRIs were available, Andersen–Gill time-to-event models were used to estimate the risk of new cord lesions based on CSF makers and important covariates.Results394 patients had baseline CSF and cord imaging available, of which 253 had CSF and serum IgG data available, 139 IgM data and 138 both IgG and IgM data. At baseline, patients with intrathecal IgG (IgG IF+; 175 out of 253) and IgM production (IgM IF+; 44 out of 139) had more cord lesions (IgG IF+, mean 1.30 vs. 0.85 spinal cord lesions, p ConclusionWhile intrathecal IgM production is cross-sectionally independently associated with spinal cord lesions, this study does not support a role for predicting new cord lesions at follow-up.