Related Experiment Videos
Terminal component of complement (C9) in cerebrospinal fluid of patients with multiple sclerosis
Insights
Cerebrospinal fluid (CSF) C9 levels are significantly lower in multiple sclerosis patients, suggesting C9 consumption and potential myelin damage. This finding may aid in diagnosing multiple sclerosis.
Area of Science:
- Neuroimmunology
- Complement System Biology
Background:
- Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system.
- The complement system, particularly the terminal component C9, plays a role in inflammatory and immune responses.
Purpose of the Study:
- To investigate the concentration of the terminal complement component C9 in cerebrospinal fluid (CSF) and plasma of patients with multiple sclerosis (MS).
- To evaluate the diagnostic utility of CSF C9 levels as a biomarker for MS compared to other neurological diseases.
Main Methods:
- An immunoradiometric assay was employed to quantify C9 concentrations.
- CSF and plasma samples were collected from 35 MS patients and 55 controls with other neurological diseases.
Main Results:
- CSF C9 concentrations were significantly reduced in MS patients (0.26 ± 0.02 µg/ml) compared to controls (1.52 ± 0.20 µg/ml; p < 0.0005).
- CSF C9 measurement demonstrated greater diagnostic utility than CSF IgG levels for distinguishing MS patients.
- The C9 index was a more effective discriminator between MS and control groups than the IgG index.
Conclusions:
- Reduced CSF C9 in MS patients suggests C9 consumption, likely via membrane attack complex formation.
- This consumption may contribute to myelin damage and reversible functional deficits characteristic of MS.
- CSF C9 serves as a potential biomarker aiding in the clinical diagnosis of multiple sclerosis.
Abstract:
An immunoradiometric assay was used to measure the concentration of the terminal component of complement (C9) in cerebrospinal fluid (CSF) and plasma from 35 patients with multiple sclerosis and 55 controls with other neurological diseases. There was a highly significant reduction in cerebrospinal fluid C9 concentration in patients with multiple sclerosis (0.26 +/- 0.02 microgram/ml) compared with controls (1.52 +/- 0.20 micrograms/ml; p less than 0.0005). As a single protein measurement C9 seemed to be more useful as an aid to clinical diagnosis than CSF IgG; the C9 index was also a better discriminator than IgG index between the two groups of patients. Reduced CSF C9 concentration in patients with multiple sclerosis implies C9 consumption due to formation of membrane attack complexes, which could mediate myelin damage and cause more widespread but reversible loss of function, accounting for the transient symptoms characteristic of the disease.