Seroprevalence of neuronal antibodies in diseases mimicking autoimmune encephalitis.

Detection of neuronal antibodies for autoimmune encephalitis and paraneoplastic neurological syndromes relies on commercially available cell-based assays and lineblots. However, lineblots may reveal the presence of neuronal antibodies in patients with various non-autoimmune etiologies. Herein we describe patients with non-autoimmune etiologies (cohort B) and detectable neuronal antibodies and compare them to definite cases of autoimmune encephalitis (cohort A) for differences in clinical data. All patients positive for at least one neuronal antibody were retrospectively evaluated for autoimmune encephalitis and/or paraneoplastic neurological syndrome between 2016 and 2022. 39 cases in cohort B and 23 in cohort A were identified. In cohort B, most common diagnoses were neurodegenerative disorders in 9/39 (23.1%), brain tumors in 6/39 (15.4%) while most common detected antibodies were anti-titin (N10), anti-recoverin (N11), anti-Yo (N8) and all were detected in serum only. Differential aspects between cohort A and B were CSF pleocytosis (14/23 (60.8%) vs 11/35 (31.4%), p = 0.042, respectively), MRI features suggestive of encephalitis (6/23 (26.1%) vs 0 (0%), p = 0.002, respectively) and epilepsy restricted to temporal lobes (14/23 (60.9%) vs 2/30 (6.7%), p = 0.0003, respectively). A large proportion of lineblot results were non-specific when only serum was tested and were frequently found in non-autoimmune neurological conditions.

Autologous hematopoietic stem cell transplantation is superior to alemtuzumab in patients with highly active relapsing multiple sclerosis and severe disability.

OBJECTIVE: To assess the differences of treatment outcomes regarding disease activity in patients with highly active relapsing multiple sclerosis (RMS), treated with autologous hematopoietic stem cell transplantation (HSCT) or alemtuzumab (ATZ). METHODS: Open-label prospective single-center observational cohort study, enrolling patients with highly active RMS for treatment with ATZ or HSCT between 2014 and 2021. RESULTS: A total of 50 patients (31/50 (62 %) in HSCT vs 19/50 (38 %) in ATZ group) were included. There were no significant differences in relapse rate, MRI activity or disability worsening between the two study groups during the first two years after treatment onset. However, at 3 to 5 years follow-up, HSCT was superior to ATZ in all the aforementioned aspects. Kaplan-Meier analysis at 5 years post treatment revealed superiority of HSCT in relapse rate (69.6 % vs 95.7 %, p = 0.027), MRI activity (54.5 % vs 75.1 %, p = 0.038) and disability worsening (57.1 % vs 90.9 %, p =  0.031). CONCLUSIONS: ATZ may halt disability progression early in the course of highly active RMS, but the disability starts accumulating later, while in HSCT patients disability improvement is consistent both 3 and 5 years after treatment onset.