Cerebrospinal fluid complement proteins in neurological disease

CSF levels of C3 and C4 were similar in patients with no neurological disease, minor non-inflammatory conditions, degenerative disease and MS during relapse, but slightly lower in MS during remission and higher in patients with inflammation. All MS patients had low CSF levels of alpha 1-antitrypsin and high levels of IgG. The roles of local production and consumption of complement protein and damage to the blood-brain barrier are discussed.