Not every patient with an initial clinical demyelinating event needs to be treated: a low CXCL13 index at the time of the ICDE has prognostic value for the absence of later activity

The management of persons with an initial clinical demyelinating event (PwICDE) is controversial. Frequently, patients with ICDE are often treated with an Multiple Sclerosis (MS) disease-modifying therapy (DMT), while in others, a “wait-and-see” approach is followed. Even in PwICDE who are prescribed a DMT, there are significant barriers to initiation of therapy. A reliable biomarker that can predict when it is safe to monitor patients rather than start a DMT would be highly beneficial. The CXCL13 index (I CXCL13 ), which measures the intrathecal production of CXCL13, a key chemokine for trafficking B cells and follicular helper T(Tfh) cells, is such a biomarker. In this study, low I CXCL13 is shown to predict the safety of remaining off DMTs.