Intrathecal IgM synthesis in neurologic diseases: relationship with disability in MS.

The authors studied the intrathecal IgM synthesis (ITMS) in paired sera and CSF samples from 65 patients with MS, 28 with CNS infection, 40 with other neurologic diseases and eight control subjects. ITMS was found in 30 patients with MS and in 20 with CNS infection, but not in patients with other neurologic diseases or in control subjects. In infectious samples, the ITMS is likely a primary response. In MS group, it was associated with higher Expanded Disability Status Scale index (p = 0.017).