Apoptosis in neurones exposed to cerebrospinal fluid from patients with multiple sclerosis or acute polyradiculoneuropathy.

Primary cultures of murine cerebellar granule neurones were exposed to cerebrospinal fluid from patients with subtypes of multiple sclerosis or acute polyradiculoneuropathy (Guillain-Barré syndrome) for 2 days. Cells were then stained with Hoechst 33342 or terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) to detect apoptotic bodies. The results were compared with control cultures exposed to cerebrospinal fluid from patients with no known neurological disease or deficit. There was no significant difference in the level of apoptosis induced between these controls and cultures not exposed to cerebrospinal fluid at all. Cultures exposed to cerebrospinal fluid samples from patients with relapsing-remitting multiple sclerosis did not have higher levels of apoptosis than cells exposed to controls, regardless of whether the sample was taken during relapse or remission. However, a significant increase in apoptosis was observed in cultures exposed to cerebrospinal fluid from patients with primary progressive multiple sclerosis, and apoptosis correlated with disease severity. This supports the existence of biochemical differences between subgroups of multiple sclerosis. A significant increase in apoptosis was also induced by cerebrospinal fluid samples from patients with acute polyradiculoneuropathy, suggesting the presence of neurotoxic factor(s) here also. The relevance to disease pathology is unclear.