The effect of anti-CD52 treatment on slowing-down neurodegeneration and microglia activation in multiple sclerosis (MS) is unknown.

Mice were infected with TMEV at 7 weeks of age and treatment with anti-muCD52 or vehicle placebo (VHPLC) was started at 3 months post-infection (pi). 36 mice were treated with anti-muCD52 and 36 with VHPLC. There were 3 groups of 24 mice treated with either anti-muCD52 (n=12) or VHPLC (n=12) that underwent different imaging protocols. Group 1 was scanned with brain imaging that evaluated regional volumes, quantitative susceptibility mapping, magnetic resonance spectroscopy metabolites and leptomeningeal enhancement, group 2 with spinal cord imaging that assessed number and volume of T2 lesions, while group 3 examined the detection of ultra-small particle iron oxide positive enhancing lesion number and volume in the brain, as biomarkers of microglia and macrophage activity. MRI, behavioral testing and blood collection for serum analysis was performed for Groups 1 and 2 at months 3, 5, 7 and 9 month pi, and for Group 3 at 4, 5 and 7 month pi, in addition to pre-treatment baseline assessments (month 3 pi). Histology, immunochemistry markers and viral TMEV transcript, were also assessed.