Ganglionic Acetylcholine Receptor Antibodies and Autonomic Dysfunction in Autoimmune Rheumatic Diseases

Neurological and Psychiatric Clinical Manifestations of Sjögren Syndrome

PURPOSE OF REVIEW

Sjögren Syndrome is a systemic autoimmune disorder that presents mainly with sicca symptoms, but frequently affects other body systems which can lead to a wide variety of manifestations. Understanding the neurological and psychiatric manifestations of Sjögren Syndrome can help with an earlier diagnosis of this disease and leads to better clinical outcomes.

RECENT FINDINGS

We provide an updated overview of the central neurological manifestations, peripheral neurological manifestations and psychiatric manifestations and their diagnosis when associated with primary Sjögren Syndrome. The epidemiology and clinical features of the neurological and psychiatric manifestations are derived from different cohort studies and review articles that were selected from PubMed searches conducted between January 2024 and March 2024. The absence of diagnostic criteria and the scarcity of large, robust studies makes the recognition of the neurological and psychiatric manifestations of Sjögren Syndrome more difficult. Maintaining a high index of suspicion in clinical practice and a close collaboration between the Neurologist and the Rheumatologist will facilitate the diagnosis and management of these patients.

Autoimmune Autonomic Neuropathy: From Pathogenesis to Diagnosis

Autoimmune autonomic ganglionopathy (AAG) is a disease of autonomic failure caused by ganglionic acetylcholine receptor (gAChR) autoantibodies. Although the detection of autoantibodies is important for distinguishing the disease from other neuropathies that present with autonomic dysfunction, other factors are important for accurate diagnosis. Here, we provide a comprehensive review of the clinical features of AAG, highlighting differences in clinical course, clinical presentation, and laboratory findings from other neuropathies presenting with autonomic symptoms. The first step in diagnosing AAG is careful history taking, which should reveal whether the mode of onset is acute or chronic, followed by an examination of the time course of disease progression, including the presentation of autonomic and extra-autonomic symptoms. AAG is a neuropathy that should be differentiated from other neuropathies when the patient presents with autonomic dysfunction. Immune-mediated neuropathies, such as acute autonomic sensory neuropathy, are sometimes difficult to differentiate, and therefore, differences in clinical and laboratory findings should be well understood. Other non-neuropathic conditions, such as postural orthostatic tachycardia syndrome, chronic fatigue syndrome, and long COVID, also present with symptoms similar to those of AAG. Although often challenging, efforts should be made to differentiate among the disease candidates.

Immunotherapy Provides Electrophysiological Recovery and Excellent Clinical Response in Sjogren's Syndrome-Linked Quite Severe Autonomic Neuropathy

INTRODUCTION

The autonomic system is frequently affected in Sjogren's syndrome (SS), but presentation with severe autonomic neuropathy is infrequent. Herein, we present a patient with primary SS-linked autonomic neuropathy, which is significantly clinic and electrophysiological responsive to immunotherapy.

CASE REPORT

A 29-year-old female patient was admitted to our neurology department with recurrent syncope, postural light-headedness, and weight loss. Neurological examination revealed tonic pupils. The baseline composite autonomic symptom score-31 was 51 (0 to 75), and baseline functional ability score was 10 (0 to 100%). In the follow-up, syncope episodes that frequently develop during the day required the patient to lie in the supine position in bed all day and were triggered even by coming to a slightly sitting position. Neurophysiologic testing showed evidence of cardiovagal and sudomotor impairment. The patient was diagnosed with SS after detailed investigations. A 5-day course of intravenous immunoglobulin (IVIg) was given, and she continued IVIg once a month. After 6 months, she could walk long distances without support, and gastrointestinal complaints and syncopes had significantly decreased. After ~1.5 years, she had a composite autonomic symptom score-31 score of 11 and a functional ability score of 80%. Control heart rate variability analysis showed a significant improvement in the values of SD of the RR interval and root mean square of successive RR interval differences.

CONCLUSIONS

In SS-linked severe autonomic neuropathy, immunotherapy can provide electrophysiological recovery in addition to excellent clinical response.

Gastrointestinal Tract Considerations Part I

The upper gastrointestinal (GI) tract is frequently involved in systemic sclerosis (SSc) and may impact quality of life, physical function and survival. Although we are currently very proactive in terms of screening for heart and lung involvement, patients with SSc are not routinely screened for GI involvement. This review details the available investigations for common upper GI symptoms in SSc, including dysphagia, reflux and bloating and provides advice as to how to integrate these investigations into current clinical care.

Anti-ganglionic nicotinic acetylcholine receptor α3 subunit antibody as a potential biomarker associated with lupus enteritis

OBJECTIVES

We aimed to identify the clinical significance of anti-ganglionic nicotinic acetylcholine receptor α3 subunit (gAChRα3) antibodies (Abs) in patients with systemic lupus erythematosus (SLE).

METHODS

This retrospective study comprised adult patients with SLE who visited our hospital from 2006 through 2019. Anti-gAChRα3 Abs were measured in the sera of patients with SLE using a luciferase immunoprecipitation system assay. The clinical features of the patients with or without anti-gAChRα3 Abs were compared. We evaluated whether the Abs predict a specific manifestation and affect its development or relapse rate.

RESULTS

Among 144 patients, anti-gAChRα3 Abs were detected in 29 patients. Lupus enteritis (LE) was more frequently seen in anti-gAChRα3 Ab-positive patients than negative patients. The levels of anti-gAChRα3 Abs were significantly higher in patients with LE than those with other lupus manifestations. Logistic regression analysis revealed the anti-gAChRα3 Abs were independent predictors for LE (odds ratio 6.2, 95% confidence interval 1.9-20.3, p = .002). Kaplan-Meier analysis showed the rate of LE development or relapse from the time of sera collection was higher in anti-gAChRα3 Ab-positive patients than in negative patients (p < .001).

CONCLUSION

Anti-gAChRα3 Abs could be a predictive biomarker for the development or relapse of LE.

Gastrointestinal involvement in systemic sclerosis: pathogenesis, assessment and treatment

PURPOSE OF REVIEW

The majority of patients with systemic sclerosis (SSc) will experience involvement of their gastrointestinal over the course of their disease. Despite the high prevalence of gastrointestinal involvement in SSc, the strategies pertaining to the assessment and treatment for this clinical dimension of SSc have historically been limited. However, the present review highlights recent research contributions that enhance our understanding of SSc-GI patient subsets and provides updates on pathogenic mechanisms of disease, assessment and symptom-directed management.

RECENT FINDINGS

In the past few years, several studies have identified risk factors for more severe gastrointestinal disease in SSc and have provided insight to optimize diagnosis and management of SSc-GI symptoms. This article also provides a review of currently available investigations and therapies for individual SSc-GI disease manifestations and reflects on actively evolving areas of research, including our understanding the role of the gut microbiome in SSc.

SUMMARY

Here, we provide important updates pertaining to the risk stratification, assessment, diagnosis and management of SSc patients with gastrointestinal symptoms. These findings provide opportunities to enhance patient care and highlight exciting opportunities for future research.

Intimate intertwining of the pathogenesis of hypoxia and systemic sclerosis: A transcriptome integration analysis

OBJECTIVES

Systemic sclerosis (SSc) is an autoimmune disease caused by various pathogenic factors, including hypoxia. Hypoxia stimulates the production of the extracellular matrix to promote fibrosis. However, the integrated function and the underlying mechanism of hypoxia in SSc are unclear.

METHODS

In the present study, we used Agilent SurePrint G3 Human Gene Expression v3 for the transcriptional sequencing of fibroblasts with and without hypoxia to detect differentially expressed genes (DEGs) in hypoxia. We analyzed the results with the transcriptome data of SSc lesions (GSE95065) to select the co-DEGs. Then, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed on the basis of the co-DEGs using the R package ClusterProfiler, which showed that hypoxia and cross talk of hypoxia with other pathogenic factors are involved in the pathogenesis of SSc. Furthermore, we constructed a protein-protein interaction (PPI) network of co-DEGs and screened two significant functional expression modules.

RESULTS

We identified nine hub genes (ALDH1A1, EGF, NOX4, LYN, DNTT, PTGS2, TKT, ACAA2, and ALDH3A1). These genes affect the pentose phosphate pathway, oxidative stress, and lipolysis.

CONCLUSION

Our study provides insights into the mechanisms underlying the effects of hypoxia on SSc pathogenesis, which will help to better understand SSc pathogenesis and develop new therapeutic strategies for SSc.

The role of the cholinergic anti-inflammatory pathway in autoimmune rheumatic diseases

The cholinergic anti-inflammatory pathway (CAP) is a classic neuroimmune pathway, consisting of the vagus nerve, acetylcholine (ACh)-the pivotal neurotransmitter of the vagus nerve-and its receptors. This pathway can activate and regulate the activities of immune cells, inhibit cell proliferation and differentiation, as well as suppress cytokine release, thereby playing an anti-inflammatory role, and widely involved in the occurrence and development of various diseases; recent studies have demonstrated that the CAP may be a new target for the treatment of autoimmune rheumatic diseases. In this review, we will summarize the latest progress with the view of figuring out the role of the cholinergic pathway and how it interacts with inflammatory reactions in several autoimmune rheumatic diseases, and many advances are results from a wide range of experiments performed in vitro and in vivo.

Drug-resistance in rheumatoid arthritis: the role of p53 gene mutations, ABC family transporters and personal factors

Rheumatoid arthritis (RA) is an autoimmune disease that is associated with chronic inflammation in joints, which contribute to synovial membrane hyperplasia and cartilage damage. Conventional disease-modifying antirheumatic drugs (DMARDs), such as methotrexate (MTX) and leflunomide (LEF), are the common RA therapy to reduce inflammation and disease progression. Recently, drug-resistance in RA with conventional treatment has become an issue. Mutations in p53 tumor suppressor gene and overexpression of ABCB1/MDR-1/P-gp transporters may contribute to antirheumatic drug-resistance in RA. Biologic DMARDs (bDMARDs) are often prescribed, when conventional DMARDs fail to treat RA, by targeting proinflammatory mediators such as tumor necrosis factor-α (TNF-α) and interleukin (IL)-6. The efficacy of bDMARDs is affected by personal factors, for example, age, smoking, body mass index (BMI), immunogenicity, and genetic polymorphisms. This review highlights the role of p53 gene mutations, ABC family transporters and personal factors in antirheumatic drug-resistance, which may lead to new personalized therapies against RA with an increased drug-sensitivity.

Acute severe sensory ganglionopathy in systemic lupus erythematous

Sensory ganglionopathies (or neuronopathies) are a rare subgroup of neuropathies characterized by involvement of sensory neurons in the dorsal root ganglion. Although much less common than central nervous system involvement, patients with systemic lupus erythematous (SLE) can develop peripheral nervous system involvement (PNS) and most commonly a chronic length dependent symmetric sensorimotor axonal polyneuropathy as a late complication of the disease. Unlike in Sjogren's syndrome, SLE-associated sensory ganglionopathy is extremely rare and usually manifests in a chronic insidious fashion. We report a 24-year-old man with SLE-associated sensory ganglionopathy manifesting an unusually acute and severe disabling clinical course with a good response to immunosuppressive therapies. Timely recognition of this rare association and early targeted immunosuppression prevented severe neurological sequelae and preserved patient's ambulation. We demonstrate videos on the evolution of patient's neurological impairment and response to treatment, contributing to the current knowledge of the natural history of PNS involvement in SLE.