**13. Conclusion**

A distinctive feature of MS is a long‐lasting intrathecal inflammatory response, unlike chronic CNS infections in which intrathecal inflammation abates after antibiotherapy. The next step will be to decipher the factors promoting the sustainment of the intrathecal inflammatory response and to identify specific antibody targets. Understanding the role of long‐lived plasma cells that produce OCB during the chronic CNS surge could open up new prospects for progressive MS therapies. As Tourtellotte stated long ago, one of the goals of an effective MS treatment could be the eradication of ITS. Therapies targeting CNS B‐cells to disrupt B‐cell traffic on both sides of the BBB are under development and eradication of resident CNS plasma cells remains an ultimate goal.
