Gasperi C, et al. - In a cohort study of 673 patients with newly diagnosed relapsing-remitting multiple sclerosis or clinically isolated syndrome, researchers assessed if there is a correlation between intrathecal immunoglobulin G (IgG) synthesis and early disability worsening as estimated by Expanded Disability Status Scale (EDSS) scoring. Cerebrospinal fluid measurements and clinical data from the observational longitudinal German national multiple sclerosis cohort were examined. After 4 years, intrathecal IgG synthesis was correlated with a greater risk of EDSS worsening, independent of the occurrence of relapses and disease-modifying therapy. Moreover, intrathecal IgG synthesis was affiliated with earlier EDSS worsening. In those with and without intrathecal IgG synthesis, worsening was observed in 28.4% and 18.1%, respectively 4 years following study entry. No correlation of other routine cerebrospinal fluid parameters with EDSS worsening was seen. Since intrathecal IgG synthesis was a potentially beneficial marker for disability worsening in subjects with multiple sclerosis, it could be helpful for early treatment decisions.