Glutamate and multiple sclerosis.

Multiple sclerosis (MS) has been considered for a long time a typical inflammatory demyelinating disease of the central nervous system due to autoimmunity targeting oligodendrocytes with sparing of axons until advanced stages of the disease. For this reason, most of the earliest experimental studies focused on the role of cytokines and chemokines at the site of oligodendrocytes loss and on the importance in MS pathogenesis of classical inflammatory mechanisms. As a result, several attempts to treat MS through reduction of the local inflammatory milieau have been performed, leading to the current "immunomodulatory" treatment of the disease. However, more recently the importance of axonal loss and neurodegeneration even in the earliest stages of MS has been also recognized, and additional or concomitant players have been therefore searched. Evidence is now increasing that excessive glutamate is released at the site of demyelination and axonal degeneration in MS plaques, and the most probable candidates for this cellular release are infiltrating leukocytes and activated microglia. These observations are no longer simply preclinical results obtained in the MS animal model, i.e. experimental allergic encephalomyelitis, but have already been partially confirmed by post-mortem studies and in vivo analysis in MS patients, thus raising the possibility that modulation of glutamate release and transport as well as receptors blockade might be relevant targets for the development of future therapeutic interventions.

Cerebrospinal fluid levels of BAFF and APRIL in untreated multiple sclerosis.

OBJECTIVE AND SUBJECTS: To examine in vivo levels of BAFF (B-cell activating factor of the tumor necrosis factor family) and APRIL (a proliferation-inducing ligand) in both the cerebrospinal fluid (CSF) and serum of 30 naïve MS patients and 79 subjects affected by acute or chronic inflammatory or non-inflammatory neurological diseases. DESIGN: Case-control study. RESULTS: No difference among groups was evidenced in serum BAFF or APRIL levels. By contrast, CSF levels of BAFF in MS (mean 144.3 pg/ml+/-141.2), although not significantly different from those observed in NIND (164.2 pg/ml+/-92.0), acute peripheral OIND (243.1 pg/ml+/-139.0) or chronic OIND (240.2 pg/ml+/-122.5), were significantly higher in acute central OIND patients (1274.0 pg/ml+/-803.8; p<0.001 vs. all groups). Similarly, CSF APRIL levels in MS (1541.0 pg/ml+/-1071.0), NIND (2629.0 pg/ml+/-1669.0), acute peripheral OIND (2834.0 pg/ml+/-1118.) or chronic OIND (2764.0 pg/ml+/-659.7) were not significantly different, while they were significantly higher in acute central OIND (6218.0 pg/ml+/-3790.0; p<0.001 vs. MS and NIND; and p<0.05 vs. acute peripheral OIND). CONCLUSIONS: Our results strongly suggest that further investigation is warranted to elucidate the role of BAFF and APRIL in MS and that serum levels of BAFF and APRIL do not reflect CSF levels.