BAFF serum and CSF levels in patients with multiple sclerosis and infectious nervous system diseases

Abstract

Purpose

Multiple sclerosis (MS) is the most common immune-mediated CNS disease, characterised by demyelination and progressive neurological disability. The B-cell activating factor BAFF has been described as one important factor in the pathophysiology of different autoimmune diseases.

Methods

We measured BAFF levels in the serum and cerebrospinal fluid (CSF) in 50 consecutive patients with MS and 35 patients with infectious CNS disease (ID). 52 patients with other, non-inflammatory disorders (OND), served as controls.

Results

BAFF-serum levels in ID patients were higher than in patients diagnosed with MS (ID 0.55 ± 0.24 ng/ml, MS 0.43 ± 0.14 ng/ml, OND 0.45 ± 0.24 ng/ml; p = 0.09). Interestingly, MS patients had lower BAFF CSF levels compared to the controls and ID patients, and the CSF levels in the latter were elevated compared to those of the controls (MS 0.17 ± 0.11 ng/ml, OND 0.25 ± 0.14 ng/ml, ID 0.97 ± 0.78 ng/ml; p < 0.001).

Conclusions

The ID patients’ having higher absolute BAFF levels in the CSF than in the serum indicates that the increased BAFF CSF levels were caused by intrathecal synthesis rather than passive transfer via a disturbed blood-brain-barrier. The significantly decreased BAFF CSF levels in MS patients were a surprising result of our study. Although it has been reported that astrocytes in active MS lesions can express BAFF, the soluble form was not increased in the CSF of MS patients. It remains unclear whether the inflammatory features of active MS plaques are truly represented by the CSF compartment.

Keywords:

• B-cell activating factor
• multiple sclerosis
• autoimmunity
• cerebrospinal fluid

Data availability statement

The authors declare that the data supporting the findings of this study are available within the article.

Disclosure statement

M. Tschernatsch received consultancy fees from Novartis, Merck, Genzyme, Roche, TEVA. T.Braun received travel grantto cover the cost of participation in a conference from Bayer. F. Blaes receivedhonoraria and travel grants from MerckSerono, Novartis, Grifols, and UCB, andresearch grants from Grifols, Bayer, MerckSerono.

Trial registration

Because of the observational character without intervention, the study was not previously registered.

Additional information

Funding

The research project was supported by BayerHealthCare and MerckSerono. The funding had no impact on the results of the present study.