The causal relationship between neuromyelitis optica spectrum disorder and other autoimmune diseases

Objectives

The coexistence of neuromyelitis optica spectrum disorder (NMOSD) with other autoimmune diseases has been well recognized. However, the causal association between these two conditions has not been fully studied. The etiology and therapies of NMOSD coexisting with autoimmune diseases also need to be elucidated.

Methods

We performed two-sample Mendelian randomization (MR) analysis to examine the causality. Genome-wide association (GWAS) summary data from NMOSD, autoimmune thyroid disease (AITD), systemic lupus erythematosus (SLE), and Sjogren’s syndrome (SS) were used to identify genetic instruments. Causal single-nucleotide polymorphisms (SNPs) were annotated and searched for cis-expression quantitative trait loci (cis-eQTL) data. Pathway enrichment analysis was performed to identify the mechanism of NMOSD coexisting with AITD, SLE, and SS. Potential therapeutic chemicals were searched using the Comparative Toxicogenomics Database.

Results

The MR analysis found that AITD, SLE, and SS were causally associated with NMOSD susceptibility, but not vice versa. Gene Ontology (GO) enrichment analysis revealed that MHC class I-related biological processes and the interferon-gamma-mediated signaling pathway may be involved in the pathogenesis of NMOSD coexisting with AITD, SLE, and SS. A total of 30 chemicals were found which could inhibit the biological function of cis-eQTL genes.

Conclusions

Our findings could help better understand the etiology of NMOSD and provide potential therapeutic targets for patients with coexisting conditions.

Neuromyelitis optica spectrum disorders and systemic lupus erythematosus: A case series from a university center

Neuromyelitis optica spectrum disorders (NMOSD) are immune-mediated inflammatory diseases of the central nervous system (CNS), which preferentially affect the optic nerves and the spinal cord. Anti-aquaporin 4 antibody is a specific serological marker. Systemic lupus erythematosus (SLE) is a rheumatologic disease that may affect the CNS. There are several reports about the coexistence of NMOSD and autoimmune diseases, mainly those of rheumatologic origin. We describe three different cases in which SLE and NMOSD subsequently occurred, drawing attention to the clinical heterogeneity, the challenge and the importance of recognizing this possible association.

[Transverse myelitis syndrom as a result of neuromyelitis optica spectrum disorders, systemic lupus erythematosus and myasthenia gravis combination]

Neuromyelitis optica spectrum disorders (NMOSD) - autoimmune condition characterized by an inflammatory lesions mainly of the spinal cord with the development of longitudinally extensive transverse myelitis (LETM) and/or involvement of the optic nerve with the development of usually bilateral optical neuritis (ON). In recent years, there has been increased awareness that NMOSD can be combined with other autoimmune diseases, including myasthenia gravis (MG), systemic lupus erythematosus (SLE) et al. The simultaneous presence of several autoimmune diseases in one patient can adversely affect the course of each of the diseases, causing the so-called mutual burden or «overlap syndrome». In this article, we describe our own clinical observation of a 51-year-old woman of European origin who developed acute relapsing TM seropositive for AQP4-IgG, by 23 years after the diagnosis of generalized MG seropositive for antibodies to acetylcholine receptors (AChR-Ab) and the occurrence of SLE, criterially confirmed, several months after the initial TM attack. During the fourth TM attack, partial positive dynamics was achieved only against the background of the combined use of intravenous methylprednisolone (pulse therapy), high-volume plasma exchange, rituximab and cyclophosphamide. The NMOSD is a rare disease leading to severe disability. In patients with MG, when symptoms of damage to the central nervous system appear, an analysis should be performed for AQP4-IgG and possibly for antibodies to myelin glycoprotein of oligodendrocytes (MOG-Ab), as well as markers characteristic of systemic connective tissue diseases (SCTD). In patients with STDD, when symptoms of involvement nervous systemappear, testing for AQP4-IgG (and, if necessary, for MOG-Ab) should be performed to exclude NMOSD, as well as AChR-Ab (and, if necessary, antibodies against muscle specific kinase (MuSK-Ab)) to exclude MG.

Systemic lupus erythematosus with the development of neuromyelitis optica (Devic's syndrome) is a rare combination of autoimmune diseases

Neuromyelitis optica ((NMO), Devic's syndrome) is an immune-mediated inflammatory demyelinating disease characterized by transverse myelitis and optic neuritis. Determination of the level of antibodies to aquaporin 4 (NMO-IgG) is presently one of the key methods for the diagnosis and assessment of the activity of ONM, which allows this disease to be differentiated from multiple sclerosis and other demyelinating CNS lesions. ONM can occur not only as an independent disease, but also as a syndrome in different systemic diseases, such as: systemic lupus erythematosus (SLE), antineutrophilic cytoplasmic antibody-associated vasculitides, Sjögren's disease, etc. (up to 50–70%). In such situations, the clinician is always confronted with a question as whether the patient can have two rare autoimmune diseases or develop ONM as a systemic manifestation of rheumatic disease.

The paper describes a clinical case of a young female patient with SLE concurrent with a CNS lesion, the manifestations of which corresponded to ONM. The patient had focal changes in the substance of the brain and spinal cord, as evidenced by magnetic resonance imaging, as well as high NMO-IgG titers. The development of ONM worsens SLE prognosis and requires active immunosuppressive therapy. The patient received three plasmapheresis sessions, ultrahigh-dose glucocorticoid and cyclophosphamide therapy, followed by replacement with azathioprine, causing a stable clinical and laboratory disease remission to be achieved.