No evidence of disease activity (NEDA) in MS should include CSF biology - Towards a 'Disease-Free Status Score'

The concept of NEDA (no evidence of disease activity) was forged to describe relapse-free patients under treatment with recent drugs, but this goal is reached by less than half of all patients and not sustained over time. However a complete remission of disease is expected to be associated with the normalization of CSF biomarkers. On pathophysiological grounds, we propose to add the criterion of no evidence of biological activity in CSF to design a future 'disease-free status score'. This composite criterion, which should concern neurodegenerative and immune activation biomarkers, would be better suited for assessing the persistence of biological processes long before CNS atrophy occurs and should help in predicting long-term remission/progression of MS.