Absence of cerebrospinal fluid oligoclonal bands is associated with delayed disability progression in relapsing-remitting MS patients treated with interferon-β

To assess the role of CSF oligoclonal bands (OB) in determining the clinical outcome in patients with relapsing-remitting multiple sclerosis (RRMS) treated with IFN-β, we carried out a retrospective, multicentre, observational study recruiting 209 RRMS patients from six MS centres from northern, central and southern areas of Italy under treatment with IFN-β-1a i.m., IFN-β-1a s.c. and IFN-β-1b s.c. Twenty-two of 209 patients (10.6%) showed no OB in CSF. The patients without had, at disease onset, significantly higher frequency of visual disturbances (p = 0.02) and less sensory involvement (p = 0.04) than those with OB. A statistical trend (p = 0.056) towards a longer time to reach sustained disability progression during treatment was found in patients without compared to those with OB. Thirty-six of 187 (19%) patients with OB worsened by at least 1 EDSS point compared to none of 22 (0%) OB-negative patients (p = 0.017). The delaying of disability progression in OB-negative patients during treatment was significantly dependent only on the number of baseline MRI T2-weighted lesions (p = 0.012) that was found to be significantly lower in OB-negative than in OB-positive patients (p = 0.04). The absence of OB and low number of baseline T2-weighted lesions in this cohort of MS patients are favourable prognostic factors influencing the clinical response to IFN-β treatment in RRMS patients.