Archeological neuroimmunology: resurrection of a pathogenic immune response from a historical case sheds light on human autoimmune encephalomyelitis and multiple sclerosis

Aim of our study was to identify the target auto-antigen in the central nervous system recognized by the immune system of a unique patient, who died more than 60 years ago from a disease with pathological changes closely resembling multiple sclerosis (MS), following a misguided immunization with lyophilized calf brain tissue. Total mRNA was isolated from formaldehyde fixed and paraffin embedded archival brain tissue containing chronic active inflammatory demyelinating lesions with inflammatory infiltrates rich in B-lymphocytes and plasma cells. Analysis of the transcriptome by next generation sequencing and reconstruction of the dominant antibody by bioinformatic tools revealed the presence of one strongly expanded B-cell clone, producing an autoantibody against a conformational epitope of myelin oligodendrocytes glycoprotein (MOG), similar to that recognized by the well characterized monoclonal anti-MOG antibody 8-18C5. The reconstructed antibody induced demyelination after systemic or intrathecal injection into animals with T-cell mediated encephalomyelitis. Our study suggests that immunization with bovine brain tissue in humans may-in a small subset of patients-induce a disease with an intermediate clinical and pathological presentation between MS and MOG-antibody associated inflammatory demyelinating disease (MOGAD).

[Analysis of magnetic resonance imaging characteristics in Chinese patients with myelin oligodendrocyte glycoprotein antibody associated disorders]

Objective: To investigate the magnetic resonance imaging (MRI) characteristics in the brain and spinal cord of Chinese patients with myelin oligodendrocyte glycoprotein antibodies associated diseases (MOGAD). Methods: Forty nine MOGAD patients with seropositive MOG-IgG and 58 AQP4-IgG positive patients were enrolled in this study. The characteristics of brain and spinal cord MRI were retrospectively analyzed. Results: There was no significant difference in the proportion of abnormal brain MRI of the two groups (69.4% vs 65.5%, P=0.177) , while the proportion of abnormal spinal cord MRI of the AQP4-IgG positive group was significantly higher than that in the MOG-IgG positive group (84.5% vs 36.7%, P=0.001) . The proportion of MOG-IgG positive patients with subcortical white matter lesions and large lesions in the brain MRI was significantly higher than that in AQP4-IgG positive group (48.9% vs 13.8%, P=0.003, 46.9% vs 12.1%, P=0.000) . The longitudinally extensive transverse myelitis in spinal cord MRI of AQP4-IgG positive group was significantly higher than that in the MOG-IgG group (70.7% vs 24.5%, P=0.002) . In addition, the proportion of MOG-IgG positive child patients with large lesions in the brain was significantly higher than that in AQP4-IgG positive child patients (76.9% vs 20.0%, P=0.047) . Conclusion: Demyelinating MRI lesions caused by MOG-IgG are heterogeneous, and could lead to a wide range of clinical phenotypes which is significantly different from those with AQP4-IgG.

What proportion of AQP4-IgG-negative NMO spectrum disorder patients are MOG-IgG positive? A cross sectional study of 132 patients

Antibodies to myelin oligodendrocyte glycoprotein (MOG-IgG) have been described in patients with neuromyelitis optica spectrum disorders (NMOSD) without aquaporin-4 antibodies (AQP4-IgG). We aimed to identify the proportion of AQP4-IgG-negative NMOSD patients who are seropositive for MOG-IgG. In a cross sectional study, we reviewed all patients seen in the National NMO clinic over the last 4 years (after the availability of MOG-IgG testing), including clinical information, MRI, and antibody tests. 261 unique patients were identified. 132 cases satisfied the 2015 NMOSD diagnostic criteria. Of these, 96 (73%) were AQP4-IgG positive and 36 (27%) were AQP4-IgG negative. These 36 patients were tested for MOG-IgG and 15/36 (42%) tested positive. 20% (25/125) of the patients who did not satisfy NMOSD criteria had MOG-IgG. Approximately half of seronegative NMOSD is MOG-Ig seropositive and one in five of non-NMOSD/non-MS demyelination is MOG-IgG positive. Since MOG-associated demyelinating disease is likely different from AQP4-IgG disease in terms of underlying disease mechanisms, relapse risk and possibly treatment, testing for MOG-IgG in patients with AQP4-IgG-negative NMOSD and other non-MS demyelination may have significant implications to management and clinical trials.