Neuromyelitis optica in a patient with an early onset demyelinating episode: clinical and autoantibody findings

Neuro-Ophthalmological Complications of the COVID-19 Vaccines: A Systematic Review

BACKGROUND

A worldwide mass vaccination campaign against the coronavirus disease 2019 (COVID-19) pandemic is currently underway. Although the safety data of the clinical trials did not report specific concerns regarding neuro-ophthalmological adverse events, they involved a limited number of individuals and were conducted over a relatively short time. The aim of the current review is to summarize the available postmarketing data regarding the occurrence of neuro-ophthalmological and other ocular complications of the COVID-19 vaccines.

EVIDENCE ACQUISITION

Electronic searches for published literature were conducted using Ovid MEDLINE, Embase, Web of Science, Google Scholar, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and ClinicalTrials.gov. The search strategy incorporated controlled vocabulary and free-text synonyms for the concepts of COVID, vaccines, and visual and neuro-ophthalmologic diseases and symptoms.

RESULTS

A total of 14 case reports and 2 case series have been selected for inclusion in the final report, reporting 76 cases of post-COVID-vaccination adverse events. The most common adverse event was optic neuritis (n = 61), followed by uveitis (n = 3), herpes zoster ophthalmicus (n = 2), acute macular neuroretinopathy (n = 2), optic disc edema as an atypical presentation of Guillain-Barré syndrome (n = 1), (arteritic anterior ischemic optic neuropathy; n = 1), abducens nerve palsy (n = 1), oculomotor nerve palsy (n = 1), Tolosa-Hunt syndrome (n = 1), central serous retinopathy (n = 1), acute zonal occult outer retinopathy (n = 1), and bilateral choroiditis (n = 1). Most cases were treated with high-dose steroids and had a favorable clinical outcome.

CONCLUSION

Since the implementation of the COVID-19 vaccination campaign in the past year, several post-COVID-vaccination neuro-ophthalmological complications have been described. However, considering the number of individuals that have been exposed to the vaccines, the risk seems very low, and the clinical outcome in most cases is favorable. Therefore, on a population level, the benefits of the vaccines far outweigh the risk of neuro-ophthalmological complications.

Cognitive impairment and cortical degeneration in neuromyelitis optica

OBJECTIVE

Neuromyelitis optica spectrum disorder (NMOsd) is an inflammatory and demyelinating syndrome characterized by optic neuritis and myelitis. Several magnetization transfer magnetic resonance imaging (MRI) studies have revealed abnormalities in normal-appearing gray matter in NMOsd. The aim of this study is to elucidate the characteristics and pathogenesis of cognitive impairment and neurodegeneration in NMOsd brains.

METHODS

Fourteen Japanese patients with serologically verified NMOsd, 17 patients with multiple sclerosis (MS), and 37 healthy controls were assessed with the Rao's Brief Repeatable Battery of Neuropsychological Tests (BRBN). Using 128 tissue blocks from 6 other cases of NMOsd, 3 cases of MS, and 4 controls without central nervous system involvement, we performed quantitative analysis of cortical neuronal loss and layer-specific changes in NMOsd.

RESULTS

In BRBN assessments, 57% of NMOsd patients and 47% of MS patients had impaired performance on at least 3 cognitive tests. Cognitive impairment in NMOsd was common even in the limited form of disease, indicating that NMOsd may progress insidiously from early stages of disease. Neuropathological assessments showed neuronal loss in cortical layers II, III, and IV, with nonlytic reaction of aquaporin-4 (AQP4)-negative astrocytes in layer I, massive activated microglia in layer II, and meningeal inflammation in NMOsd brains. All NMO cases showed no evidence of cortical demyelination.

INTERPRETATION

We demonstrate cognitive impairment and substantial cortical neuronal loss with unique AQP4 dynamics in astrocytes in NMOsd. These data indicate pathological processes consisting not only of inflammatory demyelinating events characterized by pattern-specific loss of AQP4 immunoreactivity but also cortical neurodegeneration in NMOsd brains.

Elderly-onset neuromyelitis optica which developed after the diagnosis of prostate adenocarcinoma and relapsed after a 23-valent pneumococcal polysaccharide vaccination

We report a case of elderly-onset neuromyelitis optica (NMO) positive for the anti-aquaporin-4 (AQP-4) antibody; symptoms developed after the diagnosis of prostate adenocarcinoma and relapsed after a 23-valent pneumococcal polysaccharide vaccination. We suggest that activation of CD4-positive T cells and secretion of interferon-gamma induced by adenocarcinoma and complement activation induced by vaccination are responsible for the onset and relapse of NMO, even if a patient is positive for the anti-AQP-4 antibody. This case supports the previous experimental finding that the anti-AQP-4 antibody does not cause NMO-like lesions when injected alone, but does so after the induction of T cell-mediated experimental autoimmune encephalomyelitis or when co-injected with human complement.

Intrathecal pathogenic anti-aquaporin-4 antibodies in early neuromyelitis optica

OBJECTIVE

The serum of most neuromyelitis optica (NMO) patients contains autoantibodies (NMO-IgGs) directed against the aquaporin-4 (AQP4) water channel located on astrocyte foot processes in the perivessel and subpial areas of the brain. Our objectives were to determine the source of central nervous system (CNS) NMO-IgGs and their role in disease pathogenesis.

METHODS

Fluorescence-activated cell sorting and single-cell reverse transcriptase polymerase chain reaction were used to identify overrepresented plasma cell immunoglobulin (Ig) sequences in the cerebrospinal fluid (CSF) of an NMO patient after a first clinical attack. Monoclonal recombinant antibodies (rAbs) were generated from the paired heavy and light chain sequences and tested for target specificity and Fc effector function. The effect of CSF rAbs on CNS immunopathology was investigated by delivering single rAbs to rats with experimental autoimmune encephalomyelitis (EAE).

RESULTS

Repertoire analysis revealed a dynamic, clonally expanded plasma cell population with features of an antigen-targeted response. Using multiple independent assays, 6 of 11 rAbs generated from CSF plasma cell clones specifically bound to AQP4. AQP4-specific rAbs recognized conformational epitopes and mediated both AQP4-directed antibody-dependent cellular cytotoxicity and complement-mediated lysis. When administered to rats with EAE, an AQP4-specific NMO CSF rAb induced NMO immunopathology: perivascular astrocyte depletion, myelinolysis, and complement and Ig deposition.

INTERPRETATION

Molecular characterization of the CSF plasma cell repertoire in an early NMO patient demonstrates that AQP4-specific Ig is synthesized intrathecally at disease onset and directly contributes to CNS pathology. AQP4 is now the first confirmed antigenic target in human demyelinating disease.