Immunoglobulin abnormalities in multiple sclerosis. Relation to clinical parameters: disability, duration and age of onset.

Cerebrospinal fluid (CSF) and serum from 35 pairs of multiple sclerosis (MS) patients were analysed as regards mononuclear pleocytosis, concentrations of total protein, immunoglobulin G and A and beta-trace protein, and kappa:lambda ratios, as well as the serum/CSF ratios of IgG and albumin. The disability of the patients differed, whereas the age and the duration of the disease were similar in each pair. Similar analyses were also performed on CSF and serum from 72 patients, who were subdivided according to age at onset and severity of the disease. The highest mean values of the CSF-IgG and the lowest mean values of the serum/CSF IgG ratios were found in the more disabled patients. CSF immunoglobulin abnormalities were encountered more often and were more pronounced in the patients with the most malignant course of the disease, i.e., in those with severe disability after a short duration of the disease (less than 10 yr) and in severely disabled patients with an early age at onset of the disease(less than 25 yr). Contrarily, normal mean values of CSF-IgG concentrations and serum/CFS/IgG ratios were found in the groups of patients without disability after a duration of the disease of 10 years or more, and patients without disability and an early age at onset of the disease (less than 25 yr). The observations indicate that the immune response is most vigorous in disabled patients with a short duration or with an early age at onset of the disease. MS patients with a late age at onset (greater than 35 yr) showed a less pronouced immune response within the CNS, irrespective of the occurrence of disability. The most disabled patients also showed the most severe blood-brain barrier damage as manifested by high mean values of total protein in CSF and low serum/CSF albumin ratios. The patients with severe disability and a long duration of the disease (greater than 10 yr) had the highest content of beta-trace protein in the CSF, probably as a sign of destruction of brain matter.