Intrathecal Immunoglobulin G Synthesis and Brain Injury by Quantitative MRI in Multiple Sclerosis

Abstract

Objectives: It was the aim of this study to evaluate if the quantitative intrathecal immunoglobulin G (IgG) synthesis correlates with the brain atrophy and the total lesion volume (TLV) in brain magnetic resonance imaging (MRI) of multiple sclerosis (MS) patients. Methods: A total of 50 patients with relapsing-remitting MS were included in this study. MRIs were performed and cerebrospinal fluid samples were collected during the diagnostic determination when patients were in remission without treatment. Results: At study baseline, IgG index values were elevated in 36 patients (72%), and oligoclonal IgG bands were positive in 42 of 50 patients (84%). Brain MRI was abnormal in 94% of patients, and, compared with healthy controls, brain atrophy was observed in MS patients. A positive correlation among IgG index, cerebrospinal fluid leukocyte count and TLV was observed; the Expanded Disability Status Scale correlated positively with TLV and the number of lesions, although a significant relationship between disability and brain atrophy was not demonstrated. Conclusions: Although new parameters will be necessary in longitudinal studies to characterize the axonal injury in various stages of the disease, the data suggest that the high intrathecal IgG synthesis may predict a greater brain lesion burden.