The risk of relapse after a clinically isolated syndrome is related to the pattern of oligoclonal bands.

We prospectively assessed the risk of second relapse in 192 patients with clinically isolated syndromes (CIS) divided into three groups: patients lacking oligoclonal IgG bands (OC-IgG, 25.7%), those showing OC-IgG (52.4%), and those with both OC-IgG and lipid-specific IgM bands (LS-OC-IgM, 22%). OC-IgG increased 9.3-fold the risk compared to lacking OC-IgG; OC-IgG+LS-OC-IgM increased the risk 39.6-fold compared to not having OC-IgG and 4.4-fold compared to having only OC-IgG. Median time to second relapse was 0.7 years for patients with OC-IgG+LS-OC-IgM and 3.3 years for those with only OC-IgG. Therefore, CSF analysis identifies CIS patients at risk of second relapse.