CNS-compartmentalized complement activation contributes to MS progression and severity, according to data published in Neurology Journals. To investigate complement activation in MS in the context of an intrathecal IgM production and factors involved in the classical antibody-mediated pathway in different disease subtypes and stages, Johanna Oechtering, MD, and colleagues quantified complement components and complement activation products levels in the plasma and cerebrospinal fluid of patients with clinically isolated syndrome (n=112), MS (n=127), and inflammatory neuro- logic diseases (n=31), as well as symptomatic controls (n=44). Elevated levels of C3a, C4a, Ba, and Bb were seen in the cerebrospinal fluid (CSF) of patients with CIS/MS, particularly with intra- thecal IgM production. Increased CSF CC/CAP levels were associated with higher Expanded Disability Status Scale scores, MS Severity Score, and neurofilament light chain levels. The study suggests that CNS-compartmentalized complement activation contributes to MS progression and severity and advocates for the exploration of complement inhibition to mitigate MS-related tissue damage.
