Greenberg, Benjamin

Background: Rare genetic variants are emerging as important contributors to the heritability of multiple sclerosis (MS). Whether rare variants also contribute to pediatric-onset multiple sclerosis (POMS) is unknown. Objective: To test whether genes harboring rare variants associated with adult-onset MS risk ( PRF1, PRKRA, NLRP8 , and HDAC7 ) and 52 major histocompatibility complex (MHC) genes are associated with POMS. Methods: We analyzed DNA samples from 330 POMS cases and 306 controls from the US Network of Pediatric MS Centers and Kaiser Permanente Northern California for which Illumina ExomeChip genotypes were available. Using the gene-based method “SKAT-O,” we tested the association between candidate genes and POMS risk. Results: After correction for multiple comparisons, one adult-onset MS gene ( PRF1, p = 2.70 × 10 −3 ) and two MHC genes ( BRD2, p = 5.89 × 10 −5 and AGER, p = 7.96 × 10 −5 ) were significantly associated with POMS. Results suggest these are independent of HLA-DRB1*1501. Conclusion: Findings support a role for rare coding variants in POMS susceptibility. In particular, rare minor alleles within PRF1 were more common among individuals with POMS compared to controls while the opposite was true for rare variants within significant MHC genes, BRD2 and AGER . These genes would not have been identified by common variant studies, emphasizing the merits of investigating rare genetic variation in complex diseases.

Objective The purpose of this study was to determine the frequency of myelin oligodendrocyte glycoprotein (MOG)‐IgG and aquaporin‐4 (AQP4)‐IgG among patients with pediatric‐onset multiple sclerosis (POMS) and healthy controls, to determine whether seropositive cases fulfilled their respective diagnostic criteria, to compare characteristics and outcomes in children with POMS versus MOG‐IgG‐associated disease (MOGAD), and identify clinical features associated with final diagnosis. Methods Patients with POMS and healthy controls were enrolled at 14 US sites through a prospective case–control study on POMS risk factors. Serum AQP4‐IgG and MOG‐IgG were assessed using live cell‐based assays. Results AQP4‐IgG was negative among all 1,196 participants, 493 with POMS and 703 healthy controls. MOG‐IgG was positive in 30 of 493 cases (6%) and zero controls. Twenty‐five of 30 patients positive with MOG‐IgG (83%) had MOGAD, whereas 5 of 30 (17%) maintained a diagnosis of multiple sclerosis (MS) on re‐review of records. MOGAD cases were more commonly in female patients (21/25 [84%] vs 301/468 [64%]; p = 0.044), younger age (mean = 8.2 ± 4.2 vs 14.7 ± 2.6 years; p < 0.001), more commonly had initial optic nerve symptoms (16/25 [64%] vs 129/391 [33%]; p = 0.002), or acute disseminated encephalomyelitis (ADEM; 8/25 [32%] vs 9/468 [2%]; p < 0.001), and less commonly had initial spinal cord symptoms (3/20 [15%] vs 194/381 [51%]; p = 0.002), serum Epstein–Barr virus (EBV) positivity (11/25 [44%] vs 445/468 [95%]; p < 0.001), or cerebrospinal fluid oligoclonal bands (5/25 [20%] vs 243/352 [69%]; p < 0.001). Interpretation MOG‐IgG and AQP4‐IgG were not identified among healthy controls confirming their high specificity for pediatric central nervous system (CNS) demyelinating disease. Five percent of those with prior POMS diagnoses ultimately had MOGAD; and none had AQP4‐IgG positivity. Clinical features associated with a final diagnosis of MOGAD in those with suspected MS included initial ADEM phenotype, younger age at disease onset, and lack of EBV exposure. ANN NEUROL 2023;93:271–284

Background Recombinant human immunoglobulin M22 (rHIgM22) has promoted remyelination in animal models and was well tolerated in people with clinically stable multiple sclerosis. Objective Safety/tolerability of a single rHIgM22 dose was investigated following an acute relapse and to determine whether this enhanced CNS/CSF concentrations. Methods Adults (N = 27) with acute relapse were assigned to rHIgM22 (0.5 or 2.0 mg/kg) or placebo. Study included screening/steroid administration periods and 10 study visits over 6 months. rHIgM22 CSF concentrations were assessed on days 2 and 29. Pharmacokinetic and safety samples were taken for up to 60 days. Assessments included adverse events and other clinical measures. Brain magnetic resonance imaging was performed with/without gadolinium. Results rHIgM22 CSF levels were consistent with dose-dependent concentration on both days 2 and 29. Infusion was generally well tolerated during an acute relapse. Immunogenicity was mild. Most adverse events did not appear to be dose dependent, were mild/moderate, and were events often associated with multiple sclerosis. Conclusion Although limited by high variability and small sample size, the data suggest enhanced CNS uptake associated with a drop in CSF levels. This study demonstrated safety of an antibody directed to myelin and oligodendrocytes in the course of active demyelinating disease. Further research into rHIgM22 is warranted. ClinicalTrials.gov: NCT02398461 https://clinicaltrials.gov/ct2/show/NCT02398461