Oligoclonal Band Number Correlates with Relapses and Progression in Multiple Sclerosis
Objectives: The goal of this study was to examine relationships between the number of OCBs and markers of relapses as well as progression, both clinical and radiographic, in two-year follow-up.
Methods: In this retrospective study, 1270 patients on MS disease-modifying therapies (DMTs) were screened for OCB testing. Further selection criteria included a diagnosis of relapse-remitting MS and adherence to a DMT with two years of follow-up clinical visits and imaging, yielding 128 patients. The primary outcome measures were clinical relapses (number of steroid prescriptions) and radiographic relapses (number of new lesions on MRI) at two-year follow-up. Secondary outcome measures were clinical progression (categorized as independent, cane, walker, or wheelchair) and radiographic progression (net changes in third ventricular width, lateral ventricular width, and cortical width). Unpaired, two-tailed t-tests were used for comparative analyses. Significance was determined with p<0.05.
Results: In two years, clinical relapses were significantly greater in patients with ≥10 OCBs (μ=0.70) compared to patients with <10 OCBs (μ=0.27), p=0.006. Similarly, patients with ≥10 OCBs were more likely to have radiographic relapses with nearly twice the number of new lesions on MRI at two years compared to patients with <10 OCBs (μ=1.98 and μ=1.04, respectively), p=0.018. Furthermore, with no significant difference between groups at baseline with regard to an assistive device, within-subjects analysis demonstrated that use of a new assistive device was higher for patients with ≥10 OCBs, p=0.007. While lateral ventricular width increased to a greater extent in patients with ≥10 OCBs (p=0.015), changes in third ventricular width and cortical width were not significantly different between groups.
Conclusions: This study reveals significantly greater relapses, both clinical and radiographic, as well as clinical progression in patients with high levels (≥10) of OCBs in short-term follow-up. As OCBs may have greater diagnostic weight going forward, the quantity may be important in guiding selection of DMTs.