Long-term modifications of the peripheral immune repertoire after switching from sequestering disease-modifying treatments in multiple sclerosis.

BACKGROUND: Scarce data are available on the long-term immunological effects of multiple sclerosis (MS) disease-modifying treatments (DMTs). OBJECTIVES: This study aimed to investigate the long-term modifications of the peripheral immune repertoire on interruption of a sequestering DMT (natalizumab, fingolimod) and switch to another high-efficacy DMT. METHODS: Lymphocyte subpopulations were assessed, every 6 months up to 48 months, in patients switched from fingolimod or natalizumab to ocrelizumab, and in patients switched from fingolimod to natalizumab, compared to patients switched to ocrelizumab or natalizumab from a moderate-efficacy DMT and to naive patients. RESULTS: We included 389 MS patients (200 ocrelizumab and 189 natalizumab). After adjusting for baseline variables, patients switched from fingolimod to ocrelizumab showed lower CD3 + and CD4 + lymphocytes up to 48 months after switch (with lower percentage of naive CD4 +), and increased odds of total, CD3+, CD4+ lymphopenia. Patients switched from natalizumab to ocrelizumab showed higher CD3 + lymphocytes up to 36 months after switch, and higher CD4+, CD8+ lymphocytes up to 24 months. The frequency of infections was not influenced by previous treatment. CONCLUSIONS: A long-term persistence of the residual effects of the exposure to sequestering DMTs (fingolimod and less natalizumab) on the peripheral immune repertoire was observed after switching to another high-efficacy DMT.

Association of MRI leptomeningeal enhancement with disability worsening in progressive multiple sclerosis: A clinical and post-mortem study.

BACKGROUND: Leptomeningeal enhancement (LME) has been described as a biomarker of meningeal inflammation in multiple sclerosis (MS). OBJECTIVE: The aim of this study was to (1) assess if LME is predictive of disability worsening in progressive MS (pMS) patients and (2) investigate the pathological substrates of LME in an independent post-mortem MS series. METHODS: In total, 115 pMS patients were imaged yearly with 1.5T MRI, using post-contrast CUBE 3D FLAIR for LME detection. Endpoint: to identify the baseline variables predictive of confirmed disability worsening (CDW) at 24 months follow-up. Post-mortem, inflammation, and structural changes of the leptomeninges were assessed in 12 MS/8 control brains. RESULTS: LME (27% of patients at baseline) was associated with higher EDSS and lower brain volume (nBV). LME was unchanged in most patients over follow-up. LME at baseline MRI was independently associated with higher risk of 24 months CDW (HR 3.05, 95% CI 1.36-6.84, p = 0.007) in a Cox regression, including age, nBV, T2 lesion volume, high-efficacy treatments, and MRI disease activity. Post-mortem, focal structural changes (fibrosis) of the leptomeninges were observed in MS, usually associated with inflammation (Kendall's Tau 0.315, p < 0.0001). CONCLUSIONS: LME is frequently detected in pMS patients using 1.5T MRI and is independently predictive of disability progression. LME could result from both focal leptomeningeal post-inflammatory fibrosis and inflammation.