Guillain–Barré syndrome (GBS) is a rare heterogenous disorder of the peripheral nervous system, which is usually triggered by a preceding infection, and causes a potentially life-threatening progressive muscle weakness¹. Although GBS is considered an autoimmune disease, the mechanisms that underlie its distinct clinical subtypes remain largely unknown. Here, by combining in vitro T cell screening, single-cell RNA sequencing and T cell receptor (TCR) sequencing, we identify autoreactive memory CD4⁺ cells, that show a cytotoxic T helper 1 (T_H1)-like phenotype, and rare CD8⁺ T cells that target myelin antigens of the peripheral nerves in patients with the demyelinating disease variant. We characterized more than 1,000 autoreactive single T cell clones, which revealed a polyclonal TCR repertoire, short CDR3β lengths, preferential HLA-DR restrictions and recognition of immunodominant epitopes. We found that autoreactive TCRβ clonotypes were expanded in the blood of the same patient at distinct disease stages and, notably, that they were shared in the blood and the cerebrospinal fluid across different patients with GBS, but not in control individuals. Finally, we identified myelin-reactive T cells in the nerve biopsy from one patient, which indicates that these cells contribute directly to disease pathophysiology. Collectively, our data provide clear evidence of autoreactive T cell immunity in a subset of patients with GBS, and open new perspectives in the field of inflammatory peripheral neuropathies, with potential impact for biomedical applications.

Spinal magnetic resonance imaging (MRI) is currently not recommended for the routine monitoring of clinically stable multiple sclerosis (MS) patients. We aimed to investigate the occurrence of asymptomatic spinal lesions (a-SL) in clinically stable MS patients, and their association with clinical and radiological outcomes, including the recurrence of spinal lesions. The hospital MS registry was searched for clinically stable MS patients (no relapses, no disability progression) with spinal MRIs performed at T1 (baseline) and T2 (9–36 months after T1). Information on relapses, disability and new brain/spinal MRI lesions at T3 (≥6 months after T2) was collected and analyzed. Out of 300 MS patients, 45 showed a-SL between T1 and T2. The presence of a-SL was not associated with the subsequent occurrence of relapses or disability progression at T3, but did correlate with the risk of new brain (rate ratio (RR) = 1.63, 95% CI = 1.16−2.25, p = 0.003) and recurrent spinal lesions (RR = 7.28, 95% CI = 4.02–13.22, p < 0.0001). Accounting for asymptomatic brain lesions (a-BL), the presence of either a-BL or a-SL was associated with subsequent risk for new brain (OR = 1.81, 95% CI = 1.25–2.60, p = 0.001) or spinal (RR = 2.63, 95% CI = 1.27–5.45, p = 0.009) lesions. Asymptomatic spinal demyelinating lesions occurred in 15% of clinically stable MS patients within a median period of 14 months and conferred an increased risk of future radiological activity at the brain and spinal level.

Since marketing authorization, cases of neuralgic amyotrophy (NA), facial paralysis/Bell’s palsy (FP/BP), and Guillain-Barré syndrome (GBS) were reported with COVID-19 vaccines of different technologies. This study aimed to assess whether NA, FP/BP, and GBS were more frequently reported in VigiBase with COVID-19 vaccines (of any technologies) than with other viral vaccines, over the full database and across potential risk groups by sex and age. The reporting odds ratio (ROR) with 95% confidence interval (95% CI) was used as the measure of disproportionality and subgroup disproportionality analyses were performed by sex and age. Out of 808,906 safety reports with COVID-19 vaccines, 57 (0.01%) reported NA, 3320 (0.4%) FP/BP, and 632 (0.1%) GBS. There were not signals of disproportionate reporting for NA and GBS with COVID-19 vaccines against other viral vaccines. FP/BP was disproportionately more frequently reported with COVID-19 vaccines than with other viral vaccines over the full database (ROR 1.12, 95%CI 1.07–1.17), in males (ROR 1.65, 95%CI 1.54–1.78) and in age subgroups 65–74 years (ROR 1.21, 95%CI 1.05–1.39) and ≥75 years (ROR 1.84, 95%CI 1.52–2.22). Albeit not proving causation, these findings might support clinicians in decision-making for patients potentially at risk for developing an acute inflammatory neuropathy with COVID-19 vaccines.

Background and Aims: The clinical spectrum of human infection by HEV ranges from asymptomatic to severe acute hepatitis. Furthermore, HEV can cause diverse neurological manifestations, especially Parsonage-Turner syndrome. Here, we used a large-scale human genomic approach to search for genetic determinants of severe clinical presentations of HEV infection. Approach and Results: We performed whole genome sequencing in 3 groups of study participants with PCR-proven acute HEV infection: (1) 24 patients with symptomatic acute hepatitis E; (2) 12 patients with HEV-associated Parsonage-Turner syndrome; and (3) 16 asymptomatic blood donors (controls). For variant calling and annotation, we used GATK4 best practices followed by Variant Effect Predictor (VEP) and Annovar. For variant classification, we implemented the American College of Medical Genetics and Genomics/Association for Molecular Pathology Bayesian classification framework in R. Variants with a probability of pathogenicity >0.9 were considered damaging. We used all genes with at least 1 damaging variant as input for pathway enrichment analyses. We observed a significant enrichment of type I interferon response pathways in the symptomatic hepatitis group: 10 out of 24 patients carried a damaging variant in one of 9 genes encoding either intracellular viral sensors (IFIH1, DDX58, TLR3, POLR3B, POLR3C) or other molecules involved in type I interferon response [interferon regulatory factor 7 (IRF7), MYD88, OAS3, GAPDH]. We did not find any enriched pathway in the Parsonage-Turner syndrome group or in the controls. Conclusions: Our results highlight the essential role of type I interferon in preventing symptomatic acute hepatitis E.