Serum anti-Glc(α1,4)Glc(α) antibodies as a biomarker for relapsing–remitting multiple sclerosis

There is an unmet need to develop specific biomarkers for multiple sclerosis (MS) to aid in the diagnosis, improve the management of patients and the monitoring of the effectiveness of treatment. We have screened serum from patients with relapsing–remitting MS (RRMS, n = 107) against a library of glycans on a glycan chip, and have found significantly higher levels of IgM anti-Glc(α1,4)Glc(α) antibodies (anti-Gα4Gα antibodies) than in patients suffering from other neurological diseases (OND, n = 50, p < 0.0001), and other autoimmune diseases (OAD, n = 27, p = 0.02). No significant differences were found relative to patients having primary progressive MS (n = 16). No significant differences were detected between the levels of IgM anti-Gα4Gα antibodies in sera from patients with RRMS in relapsing versus remitting state, and in patients treated with immunotherapy versus untreated patients. To test whether the highly significant difference in the levels of IgM anti-Gα4Gα between RRMS and OND group is due to general increase in IgM levels, we have measured total serum IgM in a subgroup of 62 MS and 48 OND patients. Although the total IgM was significantly lower in the OND than the RRMS group (p = 0.0007), analysis of covariance (ANCOVA) reveled no statistically significant relationship to the covariate (total IgM). Furthermore, following normalizing the values to total IgM the difference in the levels of IgM anti-Gα4Gα between the MS and OND groups was found highly significant (p ≪ 0.0001). The present findings support further assessment of serum anti-Gα4Gα antibodies as a potential biomarker for MS, which may confirm disease diagnosis and aid in its management.