Analysis of antibodies against MOG and MBP in patients with a clinically isolated syndrome is a rapid, inexpensive, and precise method for the prediction of early conversion to clinically definite multiple sclerosis. This finding may be important for the counseling and care of patients with a first demyelinating event suggestive of multiple sclerosis.

IFNbeta-1b induces higher levels of the above markers of IFNbeta bioactivity than either of the two IFNbeta-1a preparations. Moreover, there is a less striking difference between the two IFNbeta-1a preparations in favor of subcutaneous IFNbeta-1a.

Intrathecal immunoglobulin synthesis can be assessed by different approaches. It can be measured quantitatively by the IgG index or qualitatively by isoelectric focusing (IEF) to detect oligoclonal bands (OCB). In this study we investigated if there is a correlation between the frequency of OCB and the IgG index and if the IgG index predicts the diagnosis of a demyelinating CNS disease (DMD). We found a positive correlation between the IgG index and the frequency of OCB as well as the probability of DMD. We conclude that quantitative assessment of CSF-IgG can be useful because it is easier and quicker to perform than IEF but cannot replace IEF in general because this is the most sensitive method to detect abnormal IgG in CSF.

Interferon beta (IFNbeta) is a first-line therapy for multiple sclerosis (MS). However, some patients experience a decline in efficacy with continued therapy due to the development of anti-IFNbeta neutralizing antibodies (NAb). We investigated the frequency of NAb cross-sectionally in 846 MS patients who were receiving IFNbeta-1b, IFNbeta-1a im, or IFNbeta-1a sc. The frequency of NAb in patients receiving IFNbeta-1a im was lower (5%) than in patients treated with any other form of IFNbeta (22-35%) (P < 0.0001). Binding antibodies (BAb) were measured in 808 patients. The frequency differed significantly between treatment groups, ranging from 45% (IFNbeta-1a im) to 88% (IFNbeta-1b). The proportion of NAb-positive patients within the BAb-positive group differed significantly among treatment groups, ranging between 12% (IFNbeta-1a im) and 51% (IFNbeta-1a sc). The median NAb titer from all IFNbeta-1a-treated patients was higher than from IFNbeta-1b-treated patients (446 versus 171 NU/ mL, P = 0.04). Among NAb-positive patients, the frequency of NAb titers > 100 NU/mL was 71% for IFNbeta-1a compared with 58% for IFNbeta-1b (P = 0.04). Except for conflicting data regarding IFNbeta-1a sc, the results are generally consistent with the literature and together with the differing proportion of NAb-positive patients within the BAb-positive group, provide further insight into the immunogenicity of the IFNbeta preparations.