Antidopaminergic antibodies in a patient with a complex autoimmune disorder and rapidly progressing Parkinson's disease

Causal relationships between rheumatoid arthritis and neurodegenerative diseases: a two-sample univariable and multivariable Mendelian randomization study

Background

Observational research has highlighted a potential relationship between rheumatoid arthritis (RA) and neurodegenerative diseases (NDs). However, the confirmation of a causal connection is impeded by the inherent limitations of such studies, including vulnerability to confounding factors and the possibility of reverse causality. This study employs a two-sample Mendelian randomization (MR) approach to assess the causal impact of RA on three NDs, including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS).

Methods

We aggregated data from genome-wide association studies (GWASs) targeting RA or NDs within populations of European descent. Single nucleotide polymorphisms (SNPs) with robust associations to RA were identified as instrumental variables (IVs). To estimate the association between RA and AD, PD, and ALS, we utilized the inverse variance weighted (IVW) method in our univariable MR (UVMR) analysis. Validation of the IVW results ensued through supplementary analyses using MR-Egger and weighted median methods. The multivariable MR (MVMR) analysis was conducted, adjusting for body mass index (BMI), alcohol drinking, and type 2 diabetes mellitus (T2DM).

Results

The UVMR analysis, based on the IVW method, revealed a significantly positive causal association between RA and late-onset (LO) AD (OR [95% CI] = 1.084 [1.020-1.153]; p = 9.980 × 10-3), while suggesting a possible inverse relationship with PD (OR [95% CI] = 0.727 [0.563-0.938]; p = 0.014). Our study did not detect any causal connections between RA and early-onset (EO) AD, atypical or mixed (AM) AD, and ALS (all p > 0.05). The MVMR analysis results indicated that after adjusting for alcohol drinking, RA remains a risk factor for LOAD (OR [95% CI] = 1.094 [1.024-1.169]; p = 0.008). However, MVMR analysis revealed no causal connections between RA and PD after adjustments for BMI, alcohol drinking, or T2DM (all p > 0.05). Sensitivity analyses showed no evidence of heterogeneity and horizontal pleiotropy.

Conclusions

This research provides genetic evidence indicating that RA potentially causes an increased risk of developing LOAD and PD. Such a revelation underscores the importance for individuals suffering from RA to be vigilant about the potential emergence of LOAD and PD. Ongoing monitoring and prompt detection are essential for successfully managing and intervening in this possible risk.

Systemic lupus erythematosus is associated with increased risk of Parkinson’s disease

Background:

A small number of studies have suggested an association between systemic lupus erythematosus (SLE) and Parkinson’s disease (PD).

Objectives:

This study aimed to determine the risk of incident PD among Korean patients with SLE.

Design:

A nationwide retrospective cohort study using the claims database of the National Health Insurance Service of Korea was conducted.

Methods:

Patients above 40 years of age diagnosed with SLE between 2010 and 2015 were included in the study. The primary outcome of the study was incident PD, defined by registration in the rare intractable diseases program for PD and an ICD-10 code of G20. Subjects were followed until PD diagnosis or the end of 2017. We estimated the cumulative incidence of PD among the SLE cohort and compared this to that in a 1:5 age- and sex-matched control group.

Results:

Totals of 11,615 SLE cases and 58,075 matched controls were identified. The cumulative incidence rate of PD was 0.7 per 1000 person-years in the SLE cohort. The crude hazard ratio (HR) of incident PD was 1.71 (95% CI: 1.25–2.36) among the SLE cohort compared to the control group. The HR was 1.59 (95% CI: 1.15–2.20) after adjustment for age, sex, income, and baseline comorbidities.

Conclusion:

This study demonstrated that patients with SLE had an increased risk of incident PD compared to non-SLE controls. Further research is required to determine the mechanism underlying this and to elucidate the precise role of systemic inflammation in the development of PD in patients with SLE.

Risk of dementia or Parkinson's disease in the presence of Sjögren's syndrome: A systematic review and meta-analysis

Objective

Evidence from observational studies suggests that Sjögren's syndrome (SS) may contribute to an elevated risk of Parkinson's disease (PD) and dementia. However, few studies have been undertaken to summarize and assess the consistency of the data quantitatively. Therefore, we evaluated the risk of dementia and PD in SS patients through a systematic review and meta-analysis approach.

Methods

Two reviewers independently conducted a systematic search of PubMed, Embase, and Web of Science databases (updated to February 14, 2022) to identify published literature on the association between SS and dementia or PD. The risk estimates of dementia or PD in patients with SS were pooled using fixed or random-effects models.

Results

Of the 631 studies initially searched, 10 were eventually included. Pooled results suggested that the risk of developing dementia significantly increased in patients with SS (HR = 1.24, 95% CI: 1.15-1.33, P < 0.001), and such risk in females with SS was similar to that in males. The risk of PD was 1.36 times higher in SS (HR = 1.36, 95% CI: 1.23-1.50, P < 0.001). The association between SS and PD risk appeared to occur primarily in female patients (female: HR = 1.28, 95% CI: 1.21-1.35; P < 0.001 vs. male: HR = 1.00, 95% CI: 0.87-1.16, P = 0.962, respectively). No significant effect of age was observed on the risk of developing PD and dementia in SS patients.

Conclusion

Our study supports that people with SS are at higher risk of PD and dementia than the general population. Further studies are needed to elucidate the underlying mechanisms and to assess whether interventions for SS have the potential to affect dementia and PD development.

Reducing neuroinflammation via therapeutic compounds and lifestyle to prevent or delay progression of Parkinson's disease

Parkinson's disease (PD) is the second most common age-associated neurodegenerative disorder and is characterised by progressive loss of dopamine neurons in the substantia nigra. Peripheral immune cell infiltration and activation of microglia and astrocytes are observed in PD, a process called neuroinflammation. Neuroinflammation is a fundamental response to protect the brain but, when chronic, it triggers neuronal damage. In the last decade, central and peripheral inflammation were suggested to occur at the prodromal stage of PD, sustained throughout disease progression, and may play a significant role in the pathology. Understanding the pathological mechanisms of PD has been a high priority in research, primarily to find effective treatments once symptoms are present. Evidence indicates that early life exposure to neuroinflammation as a consequence of life events, environmental or behaviour factors such as exposure to infections, pollution or a high fat diet increase the risk of developing PD. Many studies show healthy habits and products that decrease neuroinflammation also reduce the risk of PD. Here, we aim to stimulate discussion about the role of neuroinflammation in PD onset and progression. We highlight that reducing neuroinflammation throughout the lifespan is critical for preventing idiopathic PD, and present epidemiological studies that detail risk and protective factors. It is possible that introducing lifestyle changes that reduce neuroinflammation at the time of PD diagnosis may slow symptom progression. Finally, we discuss compounds and therapeutics to treat the neuroinflammation associated with PD.

Movement disorders in systemic autoimmune diseases: Clinical spectrum, ancillary investigations, pathophysiological considerations

With the advances in neuroimmunology especially due to the discovery of new neuronal antibodies, the recognition of treatable antibody-related movement disorders has recently received much attention. In contrast, the identification and characterisation of movement disorders associated with systemic autoimmune diseases remains a substantially unexplored area. Beyond the classic few associations such as chorea and antiphospholipid syndrome, or ataxia and coeliac disease, movement disorders have been reported in association with several systemic autoimmune diseases, however a clear image of clinical phenotypes, investigations, and treatment outcomes in these conditions has never been drawn. In this review, we analyse data from approximately 300 cases and summarise the epidemiological, clinical and diagnostic features of movement disorders associated with systemic autoimmune diseases, and the available knowledge about treatment and outcomes. We highlight that movement disorders in systemic autoimmune conditions are frequently the only or among a few presenting manifestations and are mostly treatable disorders responding to immunotherapy or dietary modifications. We point out the pertinent combination of clinical features and investigations which can suggest the underlying autoimmune nature of these movement disorders, and thus address the most appropriate treatment.

Rheumatoid arthritis decreases risk for Parkinson's disease: a Mendelian randomization study

Epidemiological and clinical studies have suggested comorbidity between rheumatoid arthritis and Parkinson’s disease (PD), but whether there exists a causal association and the effect direction of rheumatoid arthritis on PD is controversial and elusive. To evaluate the causal relationship, we first estimated the genetic correlation between rheumatoid arthritis and PD, and then performed a two-sample Mendelian randomization analysis based on summary statistics from large genome-wide association studies of rheumatoid arthritis (N = 47,580) and PD (N = 482,703). We identified negative and significant correlation between rheumatoid arthritis and PD (genetic correlation: −0.10, P = 0.0033). Meanwhile, one standard deviation increase in rheumatoid arthritis risk was associated with a lower risk of PD (OR: 0.904, 95% CI: 0.866–0.943, P: 2.95E–06). The result was robust under all sensitivity analyses. Our results provide evidence supporting a protective role of rheumatoid arthritis on PD. A deeper understanding of the inflammation and immune response is likely to elucidate the potential pathogenesis of PD and identify therapeutic targets for PD.

Restless Leg Syndrome and Sleep Disorders in Patients with Rheumatoid Arthritis and Its Relation with Anemia Parameters

OBJECTIVES

We aimed to investigate the prevalence of restless legs syndrome (RLS) and sleep disorders in patients with rheumatoid arthritis (RA), and the association of iron deficiency with them.

MATERIALS AND METHODS

The study included 72 patients with RA (59 females, 13 males), and 50 healthy control subjects (57 females, 15 males). Assessments were made using the International RLS Rating Scale, Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale, Fatigue Severity Scale (FSS), Beck anxiety and depression index and the SF-36 quality of life scores.

RESULTS

We found that the frequency of RLS in RA patients was 29.1% and 13.8% in healthy control (p = 0.021). RA patients had 44.4% iron deficiency and 5.5% anemia of chronic disease. We found that 52.3% of patients with iron deficiency had RLS. There was an independent relationship between present of RLS and FSS (Beta [β] = 0.317, p = 0.005) and total iron binding capacity (TIBC) (β = 0.244, p = 0.031). There was an independent relationship between RLS severity score and PSQI (β = 0.264, p = 0.025) and social functionality (β = 0.302, p = 0.009).

CONCLUSION

The prevalence of iron deficiency is high in RA in the developing countries. Analysis obtained in patients with RA is suggestive of an association between iron deficiency and increased frequency of RLS. The presence of RLS in patients with RA negatively affects sleep quality, psychiatric status, and quality of life of patients with RA. TIBC value may be a predictive marker for early detection of RLS in patients with RA.

Parkinson's disease is an autoimmune disease: A reappraisal

Parkinson's disease (PD) is a common, age-related, neurodegenerative disorder characterized by motor deficits and a cognitive decline. In the large majority of cases, it is associated with cytoplasmic aggregation of α-synuclein/SNCA and the formation of Lewy bodies in the dopamine neurons in the substantia nigra pars compacta. The etiopathogenesis of PD remains poorly understood. The disease results from an interplay of genetic and environmental factors, including pharmacological molecules, which destroy dopaminergic neurons. Recently, several notable data have highlighted various immune alterations underlying that PD is associated to autoimmune features and could be considered as an autoimmune disease. In this short article, we briefly review key elements participating to this emerging viewpoint.

Risk of Parkinson disease in Sjögren syndrome administered ineffective immunosuppressant therapies: A nationwide population-based study

To determine the incidence and risk of Parkinson disease (PD) in patients with Sjögren syndrome (SS) according to a nationwide population-based database.In total, 12,640 patients in the SS cohort and 50,560 in the non-SS cohort were enrolled from Taiwan's National Health Insurance Research Database from 2000 to 2010. We used the Cox multivariable proportional hazards model to determine the risk factors for PD in the SS cohort.We observed an increased incidence of PD in patients with SS, with a crude hazard ratio (HR) of 1.40 and an adjusted HR (aHR) of 1.23. The cumulative incidence of PD was 1.95% higher in the SS cohort than in the non-SS cohort. The SS cohort had an elevated HR under medication use, namely cevimeline and pilocarpine (crude HR, 1.28), hydroxychloroquine (crude HR, 1.43; aHR, 1.46), and methylprednisolone (crude HR, 2.21; aHR, 1.49). Patients receiving other non-hydroxychloroquine immunosuppressant therapies had a lower risk (aHR, 0.86) of PD. Furthermore, patients with SS aged 20 to 49 years had a 1.93-fold higher risk of PD than did those without SS (aHR, 1.93). The risk of PD was higher (aHR, 2.20) in patients with SS without comorbidities than in those with comorbidities. The aHR of PD significantly increased when the follow-up period exceeded 9 years (aHR, 1.93).We determined an increased risk of PD in patients with SS. Further investigation is warranted to determine the possible underlying mechanisms and the potential role of non-hydroxychloroquine immunosuppressants in ameliorating PD.

Autoimmune rheumatic diseases and the risk of Parkinson disease: a nationwide population-based cohort study in Taiwan

BACKGROUNDS

In autoimmune rheumatic diseases (ARDs), the levels of inflammatory mediators are increased and microglia may be activated, resulting in an inflammatory state and the degeneration of dopaminergic neurons. We investigated the association between ARDs and Parkinson disease (PD).

METHODS

We identified ARD patients through the Taiwan National Health Insurance Research Database from 2001 to 2012. From the general population, we randomly selected a comparison cohort that was frequency-matched by age (in 5-year increments), sex and index year. We analysed the risk of PD, stratified by sex, age and comorbidities, by using a Cox regression model.

RESULTS

The risk of PD was 1.37 times greater in ARD patients than in controls after adjustment for age, sex, and comorbidities. ARD subgroups, such as the rheumatoid arthritis and Sjogren syndrome (SS) cohorts, were associated with a significantly higher risk of PD (adjusted hazard ratio [HR], 1.14; 95% confidence interval [CI], 1.03-1.2 and adjusted HR, 1.56; 95% CI, 1.35-1.79, respectively). Furthermore, primary and secondary SS patients had significantly higher risks of PD (adjusted HR, 1.58; 95% CI, 1.32-1.88 and adjusted HR, 1.53, 95% CI, 1.23-1.90, respectively).

CONCLUSIONS

The risk of PD was significantly higher in the ARD patients. Prospective studies are needed to confirm whether ARDs indeed increase the risk of PD.

Autoimmune and paraneoplastic movement disorders: An update

Movement disorders (MDs) are common in patients with autoimmune disorders affecting the central and peripheral nervous system. They may be observed in autoimmune disorders triggered by an infectious agent, such as streptococcus in Sydenham's chorea, or in basal ganglia encephalitis with antibodies against the dopamine-D2 receptors. In these patients chorea or dystonia are usually the most prominent hyperkinetic MDs. MDs are also observed in patients with diffuse or limbic encephalitis with antibodies directed against neuronal cell-surface antigens. Anti-NMDA receptor encephalitis is one of the most common and may present with a variety of MDs, including: chorea, stereotypies, dystonia and myorhythmia. The recognition of other abnormal motor phenomena such as "faciobrachial dystonic seizures" and neuromyotonia, observed in patients with LGI1 and Caspr-2 antibodies, is important because they may herald the onset of overt limbic encephalitis. Autoimmunity directed against the intracellular enzyme glutamic acid decarboxylase usually presents with MDs, most commonly stiff-person syndrome or cerebellar ataxia. Chorea may be observed in rheumatologic disorders such as systemic lupus erythematosus or antiphospholipid syndrome. Disorders with uncertain autoimmune mechanisms such as Hashimoto's encephalitis and idiopathic opsoclonus-myoclonus syndrome commonly present with tremor, myoclonus and ataxia. A rapid diagnosis of an autoimmune disorder, which typically presents with subacute onset, is critical as early therapeutic intervention improves long-term prognosis and may be life-saving. Treatment usually involves some form of immunotherapy and symptomatic therapy of the abnormal movements with dopamine depleters, dopamine receptor antagonists, or GABAergic drugs. Detection and removal of an underlying tumor is essential for optimal outcome.

Reduced Risk of Parkinson Disease in Patients With Rheumatoid Arthritis: A Nationwide Population-Based Study

OBJECTIVE

To investigate the association between rheumatoid arthritis (RA) and the risk of developing Parkinson disease (PD).

PATIENTS AND METHODS

This retrospective cohort study was conducted from January 1, 1998, through December 31, 2010, using data from the Taiwan National Health Insurance Research Database. We identified 33,221 patients with newly diagnosed RA and 132,884 randomly selected age- and sex-matched patients without RA. A multivariable Cox proportional hazards regression model was used to evaluate the risk of developing PD in the RA cohort.

RESULTS

The multivariable Cox proportional hazards regression analysis revealed an adjusted hazard ratio of 0.65 (95% CI, 0.58-0.73) for the development of PD in the RA cohort relative to the non-RA cohort. The cumulative incidence of PD was 2.42% lower in the RA cohort than in the non-RA cohort. The risk reduction of PD development in patients affected with RA was independent of treatment with disease-modifying antirheumatic drugs (DMARDs); subgroup analysis of patients treated with biologic DMARDs revealed further risk reduction (adjusted hazard ratio, 0.57; 95% CI, 0.41-0.79).

CONCLUSION

Patients with RA have a reduced risk of developing PD. This risk reduction was independent of treatment with DMARDs; however, biologic DMARDs appear to further reduce this risk. Further research is necessary to explore the underlying mechanism.

Dopamine and T cells: dopamine receptors and potent effects on T cells, dopamine production in T cells, and abnormalities in the dopaminergic system in T cells in autoimmune, neurological and psychiatric diseases

Dopamine, a principal neurotransmitter, deserves upgrading to 'NeuroImmunotransmitter' thanks to its multiple, direct and powerful effects on most/all immune cells. Dopamine by itself is a potent activator of resting effector T cells (Teffs), via two independent ways: direct Teffs activation, and indirect Teffs activation by suppression of regulatory T cells (Tregs). The review covers the following findings: (i) T cells express functional dopamine receptors (DRs) D1R-D5R, but their level and function are dynamic and context-sensitive, (ii) DR membranal protein levels do not necessarily correlate with DR mRNA levels, (iii) different T cell types/subtypes have different DR levels and composition and different responses to dopamine, (iv) autoimmune and pro-inflammatory T cells and T cell leukaemia/lymphoma also express functional DRs, (v) dopamine (~10(-8) M) activates resting/naive Teffs (CD8(+) >>>CD4(+) ), (vi) dopamine affects Th1/Th2/Th17 differentiation, (vii) dopamine inhibits already activated Teffs (i.e. T cells that have been already activated by either antigen, mitogen, anti-CD3 antibodies cytokines or other molecules), (viii) dopamine inhibits activated Tregs in an autocrine/paracrine manner. Thus, dopamine 'suppresses the suppressors' and releases the inhibition they exert on Teffs, (ix) dopamine affects intracellular signalling molecules and cascades in T cells (e.g. ERK, Lck, Fyn, NF-κB, KLF2), (x) T cells produce dopamine (Tregs>>>Teffs), can release dopamine, mainly after activation (by antigen, mitogen, anti-CD3 antibodies, PKC activators or other), uptake extracellular dopamine, and most probably need dopamine, (xi) dopamine is important for antigen-specific interactions between T cells and dendritic cells, (xii) in few autoimmune diseases (e.g. multiple sclerosis/SLE/rheumatoid arthritis), and neurological/psychiatric diseases (e.g. Parkinson disease, Alzheimer's disease, Schizophrenia and Tourette), patient's T cells seem to have abnormal DRs expression and/or responses to dopamine or production of dopamine, (xiii) drugs that affect the dopaminergic system have potent effects on T cells (e.g. dopamine=Intropin, L-dopa, bromocriptine, haloperidol, quinpirole, reserpine, pergolide, ecopipam, pimozide, amantadine, tetrabenazine, nomifensine, butaclamol). Dopamine-induced activation of resting Teffs and suppression of Tregs seem beneficial for health and may also be used for immunotherapy of cancer and infectious diseases. Independently, suppression of DRs in autoimmune and pro-inflammatory T cells, and also in cancerous T cells, may be advantageous. The review is relevant to Immunologists, Neurologists, Neuroimmunologists, Hematologists, Psychiatrists, Psychologists and Pharmacologists.

Inverse Association of Parkinson Disease With Systemic Lupus Erythematosus: A Nationwide Population-based Study

The effects of the inflammatory mediators involved in systemic lupus erythematous (SLE) on subsequent Parkinson disease have been reported, but no relevant studies have focused on the association between the 2 diseases. This nationwide population-based study evaluated the risk of Parkinson disease in patients with SLE.We identified 12,817 patients in the Taiwan National Health Insurance database diagnosed with SLE between 2000 and 2010 and compared the incidence rate of Parkinson disease among these patients with that among 51,268 randomly selected age and sex-matched non-SLE patients. A Cox multivariable proportional-hazards model was used to evaluate the risk factors of Parkinson disease in the SLE cohort.We observed an inverse association between a diagnosis of SLE and the risk of subsequent Parkinson disease, with the crude hazard ratio (HR) being 0.60 (95% confidence interval 0.45-0.79) and adjusted HR being 0.68 (95% confidence interval 0.51-0.90). The cumulative incidence of Parkinson disease was 0.83% lower in the SLE cohort than in the non-SLE cohort. The adjusted HR of Parkinson disease decreased as the follow-up duration increased and was decreased among older lupus patients with comorbidity.We determined that patients with SLE had a decreased risk of subsequent Parkinson disease. Further research is required to elucidate the underlying mechanism.

Movement and Other Neurodegenerative Syndromes in Patients with Systemic Rheumatic Diseases: A Case Series of 8 Patients and Review of the Literature

Patients with rheumatic diseases can present with movement and other neurodegenerative disorders. It may be underappreciated that movement and other neurodegenerative disorders can encompass a wide variety of disease entities. Such disorders are strikingly heterogeneous and lead to a wider spectrum of clinical injury than seen in Parkinson's disease. Therefore, we sought to stringently phenotype movement and other neurodegenerative disorders presenting in a case series of rheumatic disease patients. We integrated our findings with a review of the literature to understand mechanisms which may account for such a ubiquitous pattern of clinical injury.Seven rheumatic disease patients (5 Sjögren's syndrome patients, 2 undifferentiated connective tissue disease patients) were referred and could be misdiagnosed as having Parkinson's disease. However, all of these patients were ultimately diagnosed as having other movement or neurodegenerative disorders. Findings inconsistent with and more expansive than Parkinson's disease included cerebellar degeneration, dystonia with an alien-limb phenomenon, and nonfluent aphasias.A notable finding was that individual patients could be affected by cooccurring movement and other neurodegenerative disorders, each of which could be exceptionally rare (ie, prevalence of ∼1:1000), and therefore with the collective probability that such disorders were merely coincidental and causally unrelated being as low as ∼1-per-billion. Whereas our review of the literature revealed that ubiquitous patterns of clinical injury were frequently associated with magnetic resonance imaging (MRI) findings suggestive of a widespread vasculopathy, our patients did not have such neuroimaging findings. Instead, our patients could have syndromes which phenotypically resembled paraneoplastic and other inflammatory disorders which are known to be associated with antineuronal antibodies. We similarly identified immune-mediated and inflammatory markers of injury in a psoriatic arthritis patient who developed an amyotrophic lateral sclerosis (ALS)-plus syndrome after tumor necrosis factor (TNF)-inhibitor therapy.We have described a diverse spectrum of movement and other neurodegenerative disorders in our rheumatic disease patients. The widespread pattern of clinical injury, the propensity of our patients to present with co-occurring movement disorders, and the lack of MRI neuroimaging findings suggestive of a vasculopathy collectively suggest unique patterns of immune-mediated injury.

Insights into Neuroinflammation in Parkinson's Disease: From Biomarkers to Anti-Inflammatory Based Therapies

Parkinson's disease (PD) is the second most common neurodegenerative disorder worldwide, being characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta. Among several putative factors that may contribute to PD pathogenesis, inflammatory mechanisms may play a pivotal role. The involvement of microglial activation as well as of brain and peripheral immune mediators in PD pathophysiology has been reported by clinical and experimental studies. These inflammatory biomarkers evaluated by imaging techniques and/or by biological sample analysis have become valuable tools for PD diagnosis and prognosis. Regardless of the significant increase in the number of people suffering from PD, there are still no established disease-modifying or neuroprotective therapies for it. There is growing evidence of protective effect of anti-inflammatory drugs on PD development. Herein, we reviewed the current literature regarding the central nervous system and peripheral immune biomarkers in PD and advances in diagnostic and prognostic tools as well as the neuroprotective effects of anti-inflammatory therapies.

The dopaminergic system in autoimmune diseases

Bidirectional interactions between the immune and the nervous systems are of considerable interest both for deciphering their functioning and for designing novel therapeutic strategies. The past decade has brought a burst of insights into the molecular mechanisms involved in neuroimmune communications mediated by dopamine. Studies of dendritic cells (DCs) revealed that they express the whole machinery to synthesize and store dopamine, which may act in an autocrine manner to stimulate dopamine receptors (DARs). Depending on specific DARs stimulated on DCs and T cells, dopamine may differentially favor CD4⁺ T cell differentiation into Th1 or Th17 inflammatory cells. Regulatory T cells can also release high amounts of dopamine that acts in an autocrine DAR-mediated manner to inhibit their suppressive activity. These dopaminergic regulations could represent a driving force during autoimmunity. Indeed, dopamine levels are altered in the brain of mouse models of multiple sclerosis (MS) and lupus, and in inflamed tissues of patients with inflammatory bowel diseases or rheumatoid arthritis (RA). The distorted expression of DARs in peripheral lymphocytes of lupus and MS patients also supports the importance of dopaminergic regulations in autoimmunity. Moreover, dopamine analogs had beneficial therapeutic effects in animal models, and in patients with lupus or RA. We propose models that may underlie key roles of dopamine and its receptors in autoimmune diseases.

Diffuse leukoencephalopathy and subacute parkinsonism as an early manifestation of systemic lupus erythematosus

Parkinsonism in SLE is rare. Diffuse leukoencephalopathy is equally uncommon and is associated with a poor prognosis. We present a single case of a 50-year-old Filipino man who presented with a generalized discoid rash after starting lisinopril. The rash persisted despite discontinuation of lisinopril, and over the next three months, he developed rapidly progressive parkinsonism. Brain MRI showed symmetric confluent T2-hyperintensities involving the white matter and basal ganglia. Four of the 11 American College of Rheumatology criteria for the classification of SLE were met. A rheumatologist made a diagnosis of SLE with cutaneous and central nervous system involvement. Significant neurologic and radiologic improvement occurred following treatment with IV steroids followed by a prolonged taper. This report highlights a case of subacute parkinsonism with a diffuse leukoencephalopathy as an early manifestation of SLE which resulted in a good recovery following treatment with only immunosuppressive therapy.

Inflammation and adaptive immunity in Parkinson's disease

The immune system is designed to protect the host from infection and injury. However, when an adaptive immune response continues unchecked in the brain, the proinflammatory innate microglial response leads to the accumulation of neurotoxins and eventual neurodegeneration. What drives such responses are misfolded and nitrated proteins. Indeed, the antigen in Parkinson's disease (PD) is an aberrant self-protein, although the adaptive immune responses are remarkably similar in a range of diseases. Ingress of lymphocytes and chronic activation of glial cells directly affect neurodegeneration. With this understanding, new therapies aimed at modulating the immune system's response during PD could lead to decreased neuronal loss and improved clinical outcomes for disease.

Movement disorders in systemic lupus erythematosus and the antiphospholipid syndrome

Movement disorders (MDs), particularly chorea, may be the presenting neurological complication of systemic lupus erythematosus (SLE) and the antiphospholipid syndrome (APS), but the association is not often initially recognized. Current evidence suggests an autoimmune mechanism related to antiphospholipid antibodies in these two conditions, although the antigenic target within the central nervous system has not yet been identified. Based on a comprehensive review of the literature, this article summarizes the current knowledge on MDs in SLE and APS. A high index of suspicion is required to make an early diagnosis and initiate appropriate treatment to provide symptomatic relief and to prevent other systemic complications related to the autoimmune process.

Autoimmune basal ganglia disorders

The basal ganglia are deep nuclei in the brain that include the caudate, putamen, globus pallidus, and substantia nigra. Pathological processes involving the basal ganglia often result in disorders of movement and behavior. A number of different autoimmune disorders predominantly involve the basal ganglia and can result in movement and psychiatric disorders. The classic basal ganglia autoimmune disorder is Sydenham chorea, a poststreptococcal neuropsychiatric disorder. Resurgence in the interest in Sydenham chorea is the result of the descriptions of other poststreptococcal neuropsychiatric disorders including tics and obsessive-compulsive disorder, broadly termed pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection. Encephalitic processes affecting the basal ganglia are also described including the syndromes basal ganglia encephalitis, encephalitis lethargica, and bilateral striatal necrosis. Last, systemic autoimmune disorders such as systemic lupus erythematosus and antiphospholipid syndrome can result in chorea or parkinsonism. Using paradigms learned from other autoantibody associated disorders, the authors discuss the autoantibody hypothesis and the role of systemic inflammation in autoimmune basal ganglia disorders. Identification of these entities is important as the clinician has an increasing therapeutic repertoire to modulate or suppress the aberrant immune system.

Risk of restless legs syndrome in low socioeconomic rheumatoid arthritis patients

OBJECTIVES

Our aim was to determine the frequency of restless leg syndrome (RLS) in rheumatoid arthritis (RA) patients from a low socioeconomic area of Pakistan and compare results with a control group to evaluate the effect of variables on RLS patients.

METHODS

A clinical observational study was carried out on 240 RA patients form low socioeconomic group. Controls (n = 210) were frequency-matched by age group to the RA patients. We evaluated the presence of RLS and collected information on characteristics believed to be correlated with RLS in the general population. Multiple logistic regression models were used to study the association between RLS and other risk factors such as age, smoking status, and obesity.

RESULTS

Among all rheumatic patients seen at our rheumatology clinic, 70.8% were women. Our study shows that 20% of RA patients were suffering from RLS compared with 10% of the control group with other rheumatic diseases. Multivariate logistic regression adjusted for age, obesity, and smoking also showed that women with RA were more likely to have RLS than control patients. RLS was also significantly associated with increasing age, high body mass index, and smoking status.

CONCLUSIONS

Approximately 20% of RA patients were suffering from RLS. Hence, there is need of increase awareness of RLS among rheumatologists to enhance early RLS diagnosis and appropriate management of this treatable condition.

[Neuropsychiatric systemic lupus erythematosus (1st part). Cases definitions and diagnosis and treatment of central nervous system and psychiatric manifestations of systemic lupus erythematosus]

Systemic lupus erythematosus (SLE) is an autoimmune disease, which primarily affects skin and joints. Peripheral neurologic syndrome and central nervous system (CNS) manifestations are common in lupus patients but are not always attributable to lupus itself. A classification, published in 1999 by the American College of Rheumatology (ACR) research committee, described 12 CNS syndromes and seven peripheral neurologic syndromes compatible with "neuropsychiatric systemic lupus erythematosus" (NPSLE). Despite this consensus, studies which have been published since 1999 have reported a prevalence of NPSLE varying from 20 to 97 %, which shows the diagnosis difficulty and the heterogeneity of neuropsychiatric manifestations in SLE. In order to understand the limits of this classification, we propose in this first part an exhaustive review of publications describing neuropsychiatric manifestations according to the ACR 1999 classification. We also detail case definitions, prevalence and risk factors, clinical characteristics and diagnosis of each lupus-related psychiatric and CNS manifestation.

Movement disorders in autoimmune diseases

Movement disorders have been known to be associated with a variety of autoimmune diseases, including Sydenham's chorea, pediatric autoimmune neuropsychiatric disorders associated with streptococcus, systemic lupus erythematosus, antiphospholipid syndrome, gluten sensitivity, paraneoplastic and autoimmune encephalopathies. Tremors, dystonia, chorea, ballism, myoclonus, parkinsonism, and ataxia may be the initial and even the only presentation of these autoimmune diseases. Although antibodies directed against various cellular components of the central nervous system have been implicated, the pathogenic mechanisms of these autoimmune movement disorders have not yet been fully elucidated. Clinical recognition of these autoimmune movement disorders is critically important as many improve with immunotherapy or dietary modifications, particularly when diagnosed early. We discuss here the clinical features, pathogenic mechanisms, and treatments of movement disorders associated with autoimmune diseases, based on our own experience and on a systematic review of the literature.

Antibody binding to neuronal surface in movement disorders associated with lupus and antiphospholipid antibodies

AIM

Systemic lupus erythematosus is a multi-organ autoimmune disorder associated with autoantibodies of complex diversity. Antiphospholipid antibodies (aPL), which are commonly associated with lupus, create a pro-thrombotic tendency, but are also associated with non-thrombotic neurological features. Movement disorders are rare neuropsychiatric complications of lupus and antiphospholipid syndrome, and autoimmune and thromboembolic disease mechanisms have been proposed.

METHOD

We describe the clinical features, investigation findings, treatment, and outcome of six paediatric participants with movement disorders associated with lupus and/or aPL (six females, median age 13 y, range 8-15). To examine the autoantibody hypothesis, we used a neuronal cell line with dopaminergic characteristics and measured serum antibody binding to neuronal cell-surface antigens using flow cytometry. For comparison with the six participants, we used serum from healthy individuals (n=12, six females, median age 11 y, range 9-13) and children with other neurological diseases (n=13, seven females, median age 7 y, range 2-15).

RESULTS

Of the six participants, two had lupus only, two had lupus with aPL, and two had aPL only. The movement disorder was chorea in four and parkinsonism in two. All four participants with chorea had aPL and movement disorder relapses. The two participants with parkinsonism did not have aPL, but had a progressive course until rituximab or plasma exchange resulted in neuropsychiatric remission. All six participants demonstrated elevated serum antibody binding to neuronal cell-surface antigens compared with healthy individuals and those with other neurological diseases.

INTERPRETATION

This report supports the association of chorea with aPL, but suggests a different autoimmune mechanism operates in lupus parkinsonism. The presence of antibody binding to neuronal cell-surface antigens supports a possible direct action of autoantibodies on neurons in patients with movement disorders associated with lupus and aPL.

Systemic Lupus and Risk of Restless Legs Syndrome

Objective.

To determine the prevalence of restless legs syndrome (RLS) in women with systemic lupus erthythematosus (SLE), and to compare this to a rheumatic disease sample without SLE.

Methods.

Unselected consecutive female patients were SLE were recruited from a lupus clinic. A RLS questionnaire based on 4 criteria, validated by the International Restless Legs Syndrome Study Group, was administered during a face-to-face interview. Smoking history and height and weight data were collected. Similar methods were used to determine RLS prevalence in a comparator group of women with rheumatic diseases other than SLE. Controls were frequency-matched by age group (in 5-year age bands) to SLE subjects. Controls were otherwise unselected.

Results.

We recruited 33 women with SLE and 32 controls. Twelve of 33 female SLE subjects scored positively for RLS (37.5%; 95% CI 22.9, 54.7) compared to 4 of 32 controls (12.5%; 95% CI 5.0, 28.1). Multivariate logistic regression showed that adjusted for age, obesity, and smoking, women with SLE were more likely to have RLS than the female controls (adjusted odds ratio 6.61, 95% CI 1.52, 28.77). In our multivariate analyses of all rheumatic patients, including SLE, the adjusted OR for obesity and RLS was 5.14 (95% CI 1.07, 24.6).

Conclusion.

These novel data indicate that RLS is more prevalent in women with SLE than in controls. Although obesity was a significant risk factor for RLS in our sample, the predictive covariates examined were limited.

Autoimmune disease and risk for Parkinson disease: a population-based case-control study

OBJECTIVE

Inflammatory mediators are increased in autoimmune diseases and may activate microglia and might cause an inflammatory state and degeneration of dopaminergic neurons in the brain. Thus, we evaluated whether having an autoimmune disease increases the risk for developing Parkinson disease (PD).

METHODS

A population based case-control study was conducted in Denmark of 13,695 patients with a primary diagnosis of PD recorded in the Danish National Hospital Register during the period 1986-2006. Each case was matched on year of birth and sex to 5 population controls selected at random from among inhabitants of Denmark who were alive at the date of the patient's diagnosis. The main exposure measure was a hospital diagnosis of 1 of 32 selected autoimmune diseases recorded 5 or more years before the index date in the files of the Danish Hospital Register.

RESULTS

We observed no overall association between a diagnosis of autoimmune disease and risk for subsequent PD (odds ratio 0.96, 95% confidence interval 0.85-1.08). In a subgroup of patients with autoimmune diseases with systemic involvement, primarily rheumatoid arthritis, we saw a decrease in risk for PD of 30%.

CONCLUSIONS

Our results do not support the hypothesis that autoimmune diseases increase the risk for Parkinson disease. The decreased risk observed among patients with rheumatoid arthritis might be explained by underdiagnosis of movement disorders such as Parkinson disease in this patient group or by a protective effect of the treatment with anti-inflammatory drugs over prolonged periods.

Unusual neurologic manifestations (I): Parkinsonism in juvenile SLE

A girl with neuropsychiatric lupus demonstrated Parkinsonian features soon after commencing risperidone. The single photon emission computed tomography scan showed hyperperfusion of the basal ganglia. Symptoms abated with the addition of dopaminergic agents to immunosuppressive therapy. The literature on juvenile Parkinsonism in lupus has been reviewed.

Autoimmune-induced damage of the midbrain dopaminergic system in lupus-prone mice

Spontaneous development of lupus-like disease is accompanied by impaired dopamine catabolism and degenerating axon terminals in the mesencephalon of MRL-lpr mice. We presently examine the hypothesis that systemic autoimmunity affects the central dopaminergic system in behaviorally impaired animals. The functional damage of the nigrostriatal pathway was assessed from rotational behavior after a single injection of the D1/D2-receptor agonist apomorphine. Neurodegeneration in the midbrain was estimated by Fluoro Jade B (FJB) staining. The causal role of autoimmunity was tested by comparing asymptomatic and diseased MRL-lpr mice, and by employing the immunosuppressive drug cyclophosphamide. Damage of dopaminergic neurons was assessed by tyrosine-hydroxylase (TH) staining of the midbrain. Apomorphine induced significant asymmetry in limb use, which lead to increased circling in the diseased MRL-lpr group. While FJB-positive somas were not seen in the striatum, increased staining in the substantia nigra (SN) and ventral tegmental area (VTA) were detected in behaviorally impaired MRL-lpr mice, but not in age-matched controls. Reduced brain mass and increased levels of TNF-alpha in their cerebrospinal fluid (CSF) suggested cerebral atrophy and inflammation. In addition, CSF was neurotoxic to a dopaminergic progenitor cell line. Immunosuppression attenuated CSF cytotoxicity, TNF-alpha levels, and midbrain neurodegeneration. Supportive of the notion that dying neurons were dopaminergic, the SN of autoimmune mice showed approximately a 35% reduction in the number of TH-positive cells. A three-fold increase in serum brain-reactive antibodies accompanied this loss. Although the source of toxic mediator(s) remains unknown, present results are consistent with the hypothesis that autoimmunity-induced destruction of mesonigral and mesolimbic dopaminergic pathways contributes to the etiology of aberrant behavior in an animal model of neuropsychiatric lupus.

Juvenile parkinsonism as a manifestation of systemic lupus erythematosus: case report and review of the literature

Involvement of the central nervous system in systemic lupus erythematosus (SLE) has been well described. It usually includes psychiatric disturbance, seizures, and cranial nerve disorders. Movement disorders are less common, chorea being the one most frequently described. A parkinsonian syndrome may be an extremely rare manifestation of cerebral lupus. We report on a case of juvenile parkinsonism as a manifestation of SLE and review the literature.

Reversible parkinsonism in systemic lupus erythematosus

Parkinsonism as a manifestation of central nervous system (CNS) lupus is extremely rare. We report the first patient with systemic lupus erythematosus (SLE) who developed a reversible parkinsonian syndrome associated with enhancing subcortical lesions on magnetic resonance imaging (MRI). Following treatment with prednisolone and cyclophosphamide, her bradyphrenia, bradykinesia, hypophonia, rigidity, and abnormal gait progressively improved. Three months after she commenced treatment, repeat MRI scanning demonstrated resolution of the abnormal subcortical white matter enhancement. Our case illustrates unusual clinico-radiologic correlates of reversible parkinsonism in a SLE patient; these findings suggest that disruption of the subcortical frontal pathways may be a possible pathophysiologic mechanism for parkinsonism in cerebral lupus.

Cholinergic-drug induced sicca syndrome in Parkinson's disease: a case report and a review of the literature

A 67-year-old woman developed severe sicca manifestations after initial treatment of Parkinson's disease with an anti-cholinergic drug, which prompted us to look for the presence of Sjögren's syndrome. The results of sialography, labial salivary gland biopsy, Rose-Bengal test as well as the presence of antinuclear antibody were consistent with the diagnosis of Sjögren's syndrome. The sicca symptoms diminished by cessation of the anti-cholinergic drug, and the parkinsonian features were controlled by levodopa. We suggest that Sjögren's syndrome should be considered, if patients with Parkinson's disease complain severe xerostomia.

Systemic lupus erythematosus associated with transverse myelitis and parkinsonian symptoms

A 31-year old woman developed transverse myelitis after 10 years remission since she was first diagnosed as systemic lupus erythematosus. Although pulse methyl prednisolone resolved her myelitis, Parkinson-like symptoms developed subsequently after reduction of steroid. Treatments including apheresis did not improve her Parkinson-like symptoms such as rigidity, akinesia, impairment of speech and mask-like facial expression. Levodopa was effective as a symptomatic therapy. Orally administered cyclophosphamide eventually led her to remission and withdrawal from levodopa. Her clinical course and the absence of other possible causes prompted us to conclude that Parkinsonian symptoms as well as transverse myelitis may have developed as manifestations of central nervous system lupus.