Changes in cerebrospinal fluid IgG and apolipoprotein E indices in patients with multiple sclerosis during demyelination and remyelination.

Approximately 85% of patients with multiple sclerosis (MS) can be diagnosed by using magnetic resonance imaging and laboratory tests such as determination of the cerebrospinal fluid (CSF) IgG Index and electrophoresis to detect oligoclonal banding. However, these tests results are abnormal in MS patients whether they are in clinical remission or acute exacerbation. Because apolipoprotein E (apo E) is synthesized in the central and peripheral nervous system, particularly during remyelination, we propose that apo E might be a reliable marker of the remyelination that accompanies clinical remission in MS patients. We studied 33 patients with MS, 22 in remission and 11 in exacerbation, and 26 controls of comparable ages. The apo E Index, calculated from the concentrations of apo E and albumin in CSF and serum, allowed us to discriminate between MS patients in remission and MS patients in exacerbation (P less than 0.001); the IgG Index failed to show similar differences. However, combining the apo E and IgG indices gave maximum discrimination between controls, MS patients in remission, and those in exacerbation. This study suggests that apo E measurements should be included in the laboratory evaluation of MS patients.