Long-term immunologic effects of thymectomy in patients with myasthenia gravis

Altered T cell development in an animal model of multiple sclerosis

Multiple sclerosis (MS) is a chronic autoimmune disease that affects the central nervous system (CNS), leading to demyelination and axonal degeneration. Experimental autoimmune encephalomyelitis (EAE) is an animal model of MS that has significantly improved our understanding of MS. Studies have observed early thymic involution in MS patients, suggesting the potential involvement of the thymus in CNS autoimmunity. However, our knowledge of the thymus's role in autoimmune disorders affecting the CNS remains limited. In this study, we examined the effects of EAE induction on thymopoiesis and observed alterations in T cell development. These changes were characterized by increased apoptosis and decreased proliferation of thymocytes at the EAE peak stage. We also identified a blockade in the transition from CD4-CD8- double-negative thymocytes to CD4+CD8+ double-positive cells, as evidenced by the accumulation of double-negative stage 1 thymocytes at both the EAE onset and peak stages. Furthermore, positive selection was disrupted in the thymus of EAE mice at both stages, leading to an elevated proportion and number of CD4+CD8- and CD4-CD8+ single-positive cells. Meanwhile, we observed an augmented production of regulatory T cells in the thymus of EAE mice. Moreover, peripheral blood analysis of EAE mice at the onset stage showed expanded T cell subsets but not at the peak stage. We also observed altered expression patterns in thymus-derived CD4+CD8- and CD4-CD8+ single-positive cells between MS patients and healthy controls. Our findings demonstrate a modified T cell development in EAE/MS, providing valuable insights into the potential of modulating thymic function as a targeted therapeutic approach to MS/EAE.

Insights from a Case of Good's Syndrome (Immunodeficiency with Thymoma)

Immunodeficiency with thymoma was described by R.A. Good in 1954 and is also named after him. The syndrome is characterized by hypogammaglobulinemia associated with thymoma and recurrent infections, bacterial but also viral, fungal and parasitic. Autoimmune diseases, mainly pure red cell aplasia, other hematological disorders and erosive lichen planus are a common finding. We describe here a typical case exhibiting all these clinical features and report a detailed immunophenotypic assessment, as well as the positivity for autoantibodies against three cytokines (IFN-alpha, IL-6 and GM-CSF), which may add to known immune abnormalities. A review of the published literature, based on case series and immunological studies, offers some hints on the still unsolved issues of this rare condition.

Anti-dsDNA Is Associated with Favorable Prognosis in Myasthenia Gravis: A Retrospective Study

Objectives. To investigate the presence of serum antinuclear antibody (ANA) and anti-double-stranded DNA antibody (anti-dsDNA) in patients with myasthenia gravis (MG) and analyze the clinical characteristics and prognostic factors associated with MG. Methods. We retrospectively enrolled 363 patients with MG and analyzed the clinical characteristics and follow-up data between patients positive and negative for ANA and anti-dsDNA. We defined a Myasthenia Gravis Activities of Daily Living (MG-ADL) reduction as a main prognosis predictor and used logistic regression to determine independent factors associated with prognosis. We built a nomogram to predict prognosis and evaluate the internal validity of the model. Results. Ninety-eight (27.0%) patients were positive for ANA, and 51 (14.0%) were positive for anti-dsDNA. Patients positive for ANA and anti-dsDNA antibodies tended to be female and positive for acetylcholine receptor antibody (AChR-Ab). The rate of thymoma was higher in anti-dsDNA-positive patients with MG (p-dsDNA-MG) than in patients negative for anti-dsDNA (49.0% vs. 26.0%, $p=0.001$ ), and p-dsDNA-MG was associated with reduced MG-ADL score. Regression analysis showed that except for age of onset ( $\text{OR}=0.986$ , $95\%\text{CI}=0.973–0.999$ , $p=0.037$ ), anti-dsDNA ( $\text{OR}=2.800$ , $95\%\text{CI}=1.381–5.679$ , $p=0.004$ ), ptosis ( $\text{OR}=2.930$ , $95\%\text{CI}=1.827–4.699$ , $p<0.001$ ), and eye movement disorder ( $\text{OR}=2.815$ , $95\%\text{CI}=1.672–4.741$ , $p<0.001$ ) were independent predictive factors of a favorable prognosis of MG. These predictors were used to generate a nomogram with an excellent predictive value. Conclusions. Being female and the presence of AChR-Ab were features of ANA- or anti-dsDNA-positive MG. The presence of anti-dsDNA was associated with a favorable prognosis of MG.

Concurrent de novo Thymoma-associated Paraneoplastic Type 1 Autoimmune Hepatitis and Pure Red Cell Aplasia after Thymectomy: A Case Report and Literature Review

The precise manipulation of immune tolerance is the holy grail of immunotherapies for both autoimmunity and cancer immunity. Thymomas are well known to be associated with autoimmune diseases. The exact mechanism by which autoreactivity is induced after thymectomy remains to be elucidated. We herein present the case of a 50-year-old lady with concurrent de novo type 1 autoimmune hepatitis (AIH) and pure red cell aplasia (PRCA), 1 month after undergoing a successful total thymectomy for combined squamous cell carcinoma and thymoma (Masaoka stage II). Corticosteroids yielded short-term effects for both AIH and PRCA. Literature on thymoma-associated AIH, an extremely rare immune-related comorbidity, was also reviewed.

Clinical characteristics of myasthenia gravis (MG) patients developing other autoimmune diseases after thymectomy from one single center cohort

BACKGROUND

Myasthenia gravis (MG) patients are reported to have a high risk of other autoimmune diseases (ADs), and thymectomy may increase the risk further. A cohort of MG patients in which thymectomy was performed were investigated to analyze the prevalence, types and features of the new onset ADs.

METHODS

Consecutive patients with MG who underwent thymectomy at Beijing Hospital between January 2012 and August 2021 were retrospectively enrolled. Patients with a postoperative follow-up period shorter than a year or incomplete clinical records were excluded. Clinical and follow-up data were collected. Statistical analyses were performed using SPSS version 22.0.

RESULTS

A total of 445 patients were included in this study. The median follow-up period was 72 months (range, 12-135 months). A total of 63 (14.2%) MG patients had concurrent ADs. The incidence rate was higher than the background prevalence of population (5%), and also higher than that of a former Chinese MG cohort (11.6%). A total of 47 patients (10.6%) were diagnosed with ADs before thymectomy, and 19 (4.3%) developed a new AD after thymectomy. The most common types of new onset ADs after thymectomy were Hashimoto's thyroiditis and rheumatoid arthritis (RA), which were different from those before thymectomy (hyperthyroidism and Hashimoto's thyroiditis). The incidence rate of new onset RA (1.35%) was higher than the frequency of RA before thymectomy (0.45%), and also higher than the incidence rate in a Chinese MG cohort (0.5%). There was a higher proportion of female patients (p = 0.026) with postoperative ADs. A younger age at operation may increase the risk of nonthymoma MG patients (p = 0.040) developing ADs. The postoperative treatment effect of MG was similar between patients with and without new onset ADs (p > 0.05).

CONCLUSIONS

We observed a higher incidence rate of autoimmune diseases, especially rheumatoid arthritis, in MG patients after thymectomy. The most common types of ADs after thymectomy were different from those before thymectomy. New onset ADs tended to occur in female and young nonthymoma MG patients. The postoperative effect of MG was not related with the new occurrence of ADs.

Poor responses and adverse outcomes of myasthenia gravis after thymectomy: Predicting factors and immunological implications

Myasthenia gravis (MG) has been recognized as a series of heterogeneous but treatable autoimmune conditions. As one of the indispensable therapies, thymectomy can achieve favorable prognosis especially in early-onset generalized MG patients with seropositive acetylcholine receptor antibody. However, poor outcomes, including worsening or relapse of MG, postoperative myasthenic crisis and even post-thymectomy MG, are also observed in certain scenarios. The responses to thymectomy may be associated with the general characteristics of patients, disease conditions of MG, autoantibody profiles, native or ectopic thymic pathologies, surgical-related factors, pharmacotherapy and other adjuvant modalities, and the presence of comorbidities and complications. However, in addition to these variations among individuals, pathological remnants and the abnormal immunological milieu and responses potentially represent major mechanisms that underlie the detrimental neurological outcomes after thymectomy. We underscore these plausible risk factors and discuss the immunological implications therein, which may be conducive to better managing the indications for thymectomy, to avoiding modifiable risk factors of poor responses and adverse outcomes, and to developing post-thymectomy preventive and therapeutic strategies for MG.

Early Thymectomy Is Associated With Long-Term Impairment of the Immune System: A Systematic Review

Background and Aims

Congenital heart diseases (CHDs) are diagnosed in approximately 9 in 1,000 newborns, and early cardiac corrective surgery often requires partial or complete thymectomy. As the long-term effect of early thymectomy on the subsequent development of the immune system in humans has not been completely elucidated, the present study aimed to evaluate the effects of thymus removal on the functional capacity of the immune system after different periods.

Methods

A systematic review of the literature was performed using MEDLINE, EMBASE, LILACS and Scopus. The inclusion criteria were original studies that analyzed any component of the immune system in patients with CHD who had undergone thymectomy during cardiac surgery in the first years of life. The results were evaluated for the quality of evidence.

Results

Twenty-three studies were selected and showed that patients who underwent a thymectomy in the first years of life tended to exhibit important alterations in the T cell compartment, such as fewer total T cells, CD4+, CD8+, naïve and CD31+ T cells, lower TRECs, decreased diversity of the TCR repertoire and higher peripheral proliferation (increased Ki-67 expression) than controls. However, the numbers of memory T cells and Treg cells differed across the selected studies.

Conclusions

Early thymectomy, either partial or complete, may be associated with a reduction in many T cell subpopulations and TCR diversity, and these alterations may persist during long-term follow-up. Alternative solutions should be studied, either in the operative technique with partial preservation of the thymus or through the autograft of fragments of the gland.

Systematic Review Registration

Prospero [157188].

Mixed connective tissue disease after thymectomy in refractory myasthenia gravis

Connective tissue diseases, including systemic lupus erythematosus (SLE) and systemic sclerosis are classic models of autoimmunity; diseases with large-scale loss of tolerance and subsequent development of pathogenic autoreactive lymphocytes and tissue targeting autoantibodies. Here we report a case of mixed connective tissue disease, with features of systemic lupus erythematosus and systemic sclerosis developing in a patient 10 years post thymectomy for myasthenia gravis. The patient developed acute cutaneous lupus, Raynaud's with digital ulcers, arthritis and lymphopenia. Her myasthenia continued to be resistant to treatment and her rheumatic disease progressed despite aggressive therapy. We performed a database search of MEDLINE, EMBASE, Scopus, and Web of Science for articles of similar cases post thymectomy from inception to August 2021, using the terms "systemic lupus erythematosus" (or systemic sclerosis, or connective tissue disease) and "myasthenia gravis" and "thymectomy". We identified 41 cases, 28 of SLE post thymectomy, 8 related to systemic sclerosis, 5 with mixed connective tissue disease and highlighted their different presentation and serology. We explore the role of the thymus, tolerance and myasthenia gravis in the development of connective tissue disease. This highlights the complexity of concurrent autoimmune diseases and their autoantibodies.

Association Between Myasthenia Gravis and Systemic Lupus Erythematosus as a Comorbid State

Systemic lupus erythematosus (SLE) and myasthenia gravis (MG) are autoimmune states which have presentational similitude. Both conditions test serologically positive for anti-nuclear antibodies and require exceptional differential diagnostic acumen to segregate one from the other. The hypothesized factors provoking these diseases may be immunological, genetic, hormonal, or environmental and can be better understood by large-scale controlled epidemiological studies. Biochemical factors such as variation in CXC (an α chemokine subfamily), CXCL13, and granulocyte-macrophage colony-stimulating factor levels are assumed to play a pivotal role in the pathogenesis of SLE and MG; however, further studies are required to understand their exact mechanism and effect on the underlying autoimmune diseases. Following this, another precipitating factor for this overlap is believed to be thymectomy which is performed to eliminate MG symptoms. Although thymectomy is the effective treatment modality in MG patients, other findings and data support the view that this procedure may lead to the development of other autoimmune states such as SLE. It is evident from previously published data and case reports that patients with one autoimmune disease who underwent thymectomy contracted SLE and became more susceptible to other autoimmune diseases compared to the general population. Post-thymectomy follow-up of patients provides us with mechanistic clues for understanding the development of SLE-MG overlap; hence, in MG patients who have undergone thymectomy, any clinical and immune serological SLE suspicion should be carefully evaluated.

How I manage acquired pure red cell aplasia in adults

Pure red cell aplasia (PRCA) is a rare hematological disorder with multiple etiologies. The multifaceted nature of this disease is emphasized by the variety of concomitant clinical features. Classic idiopathic presentation aside, prompt recognition of pathogenetic clues is important because of their diagnostic and therapeutic implications. As a consequence, treatment of PRCA is diverse and strictly dependent on the presented clinical scenario. Here, we propose a series of clinical vignettes that showcase instructive representative situations derived from our routine clinical practice. Using these illustrative clinical cases, we review the diagnostic workup needed for a precise diagnosis and the currently available therapeutic options, discussing their applications in regard to the various PRCA-associated conditions and individual patients' characteristics. Finally, we propose a treatment algorithm that may offer guidance for personalized therapeutic recommendations.

[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.

Risk of incident autoimmune diseases in patients with thymectomy

OBJECTIVES

The data concerning the association between Tx and ADs remain unclear and are scarce. This study was undertaken to investigate whether people with Tx are more likely to develop ADs, compared to those without Tx.

METHODS

Individuals who received Tx between 2002 and 2015 were identified and matched on age and sex with individuals without Tx. We performed multivariate and stratified analysis using the Kaplan-Meier method and Cox proportional hazards models in order to estimate the association between Tx and the risk of developing ADs.

RESULTS

A total of 2550 thymectomized (Txd) patients and 24,664.941 non-Txd comparison subjects were selected from NHIRD. Tx-MG (myasthenia gravis) as compared with general population (nonTx-nonMG), adjusted hazard ratio (aHR) were higher for incident Addison disease (aHR = 10.40, 95% CI 1.01-107), autoimmune hemolytic anemia (aHR = 21.54, 95% CI 2.06-14.8), Hashmoto thyroiditis (aHR = 5.52, 95% CI 1.34-34.7), ankylosing spondylitis (aHR = 2.73, 95% CI 1.09-6.84), rheumatoid arthritis (aHR = 5.25, 95% CI 1.79-15.47), primary Sjogren syndrome (pSS) (aHR = 3.77, 95% CI 1.30-11.0), and systemic lupus erythemtoasus (aHR = 10.40). Tx-nonMG as compared with general population, aHR were higher for incident autoimmune hemolytic anemia (aHR = 25.50), Hashmoto thyroiditis (aHR = 6.75) and systemic lupus erythematosus (SLE) (aHR = 13.38). NonTx-MG as compared with general population, aHR were higher for incident Hashmoto thyroiditis (aHR = 6.57), pSS (aHR = 4.50), SLE (aHR = 17.29), and systemic vasculitis (aHR = 25.86).

INTERPRETATION

In conclusion, based on a retrospective cohort study throughout Taiwan, patients with Tx have a higher risk of new onset ADs than patients without Tx.

Neuromyelitis optica in patients with myasthenia gravis: Two case-reports

Neuromyelitis optica spectrum disorders (NMOSD) and myasthenia gravis (MG) are disorders that affect the central nervous system and the neuromuscular junction respectively. Although both conditions are rare, reports of the coexistence of these two pathologies are increasing worldwide. Rarely, patients with MG develop aggressive forms of neuromyelitis optica (NMO) after thymectomy. Here, we describe two Peruvian patients with the association of MG and NMO.

A tale of autoimmunity: thymoma, thymectomy, and systemic lupus erythematosus

The thymus plays an integral role in immune system regulation, modulating the development, diversity, and selection of T lymphocytes, a critical feature for the prevention of T cell-mediated autoimmunity. Thymoma is a rare tumor of the thymus. Autoimmune diseases and paraneoplastic syndromes such as myasthenia gravis, pure red blood cell aplasia, and systemic lupus erythematosus, although relatively uncommon, have been described in association with thymomas. Rare cases of post-thymectomy autoimmune related diseases, including systemic lupus erythematosus and pure red cell aplasia, have been reported in the literature. Here, we present the case of a 65-year-old male who developed systemic lupus erythematosus 2 years after thymectomy in the setting of thymoma-associated pure red cell aplasia.

Neonatal thymectomy in children-accelerating the immunologic clock?

The thymus is critical for central tolerance and diverse T-lymphocyte repertoire development, to provide lifelong defense against pathogens while maintaining self-tolerance. Peak thymic output occurs in utero, during infancy, and in early childhood, diminishing throughout life. Infants with congenital heart disease requiring sternotomy often undergo thymectomy to clear the surgical field. The long-term effects of early thymectomy are just being appreciated. Many patients remain asymptomatic despite immunologic findings mirroring those of immunosenescence. Few develop increased infection or lymphoreticular malignancy risk. When considering the effects of infant thymectomy, patients with partial DiGeorge syndrome or hypomorphic recombination-activating gene (RAG) mutations may be instructive. These patients are lymphocytopenic, with increased early-onset infection and autoimmunity risk that is not seen in most patients who underwent thymectomy during infancy. The thymic structure of patients with partial DiGeorge syndrome or hypomorphic RAG is abnormal, with disrupted architecture inclining to perturbation of central tolerance. Similar findings may be seen in patients with myasthenia gravis, although disrupted peripheral tolerance may play a greater role in autoimmunity development. In conclusion, thymectomy during infancy may increase future risk of infection or autoimmunity, with premature immunosenescence mediated through disruption of central and peripheral tolerance mechanisms initiated by early cessation or diminution of thymic output. Ideally, some thymic tissue should be preserved at the time of surgery.

Metabolic adaptation orchestrates tissue context-dependent behavior in regulatory T cells

The diverse distribution and functions of regulatory T cells (Tregs) ensure tissue and immune homeostasis; however, it remains unclear which factors can guide distribution, local differentiation, and tissue context-specific behavior in Tregs. Although the emerging concept that Tregs could re-adjust their transcriptome based on their habitations is supported by recent findings, the underlying mechanisms that reprogram transcriptome in Tregs are unknown. In the past decade, metabolic machineries have been revealed as a new regulatory circuit, known as immunometabolic regulation, to orchestrate activation, differentiation, and functions in a variety of immune cells, including Tregs. Given that systemic and local alterations of nutrient availability and metabolite profile associate with perturbation of Treg abundance and functions, it highlights that immunometabolic regulation may be one of the mechanisms that orchestrate tissue context-specific regulation in Tregs. The understanding on how metabolic program instructs Tregs in peripheral tissues not only represents a critical opportunity to delineate a new avenue in Treg biology but also provides a unique window to harness Treg-targeting approaches for treating cancer and autoimmunity with minimizing side effects. This review will highlight the metabolic features on guiding Treg formation and function in a disease-oriented perspective and aim to pave the foundation for future studies.

Thymectomy in patients with myasthenia gravis increases the risk of autoimmune rheumatic diseases: a nationwide cohort study

Objectives

Previous studies have shown myasthenia gravis (MG) and autoimmune rheumatic diseases (ARDs) share common pathogenetic mechanisms. Therefore, the present study investigated the possible relationship between MG and ARDs.

Methods

We analysed Taiwanese medical data from the Registry of Catastrophic Illness and identified patients with MG. From the entire general population data of the National Health Insurance Research Database, we randomly selected a comparison cohort that was frequency-matched by age (in 5-year increments), sex, and index date. We analysed the risk of ARDs by using a Cox proportional hazards regression model stratified by sex, age and treatment.

Results

In the present study, we enrolled 6478 patients with MG (58.03% women; mean age, 50.55 years) and 25 912 age- and sex-matched controls. The risk of total ARDs was 6.25 times higher in the MG cohort than in the non-MG cohort after adjustment for age and sex. Furthermore, the MG cohort was associated with a significantly higher risk of primary SS (pSS), SLE and other ARD types (adjusted hazard ratios: 15.84 [95% CI: 8.39, 23.91]; 11.32 [95% CI: 5.04, 25.429]; and 4.07 [95% CI: 1.31, 12.62], respectively). The MG cohort who underwent thymectomy had an increased risk of RA, pSS and SLE (adjusted hazard ratios: 4.41; 15.06; and 23.68, respectively).

Conclusion

The present nationwide cohort study revealed an association between MG and incident ARDs. The MG cohort who underwent thymectomy had an increased risk of RA, pSS and SLE. Future studies are needed to elucidate the underlying pathogenesis and to translate this into clinical therapeutic options.

Ischaemic stroke in a patient with myasthaenic crisis and antiphospholipid antibody syndrome

While autoimmune diseases have been frequently found to coexist in the same patients, the co-occurrence of myasthaeniagravis and antiphospholipid antibody syndrome (APAS) has only been reported in eight cases. We present a case of a 46-year-old Filipina who developed ischaemic stroke while admitted at the neurocritical unit for myasthaenic crisis. She was successfully thrombolysed with intravenous recombinant tissue plasminogen activator (rTPA), given a regimen of intravenous Ig and a dose of cyclophosphamide prior to discharge. Extensive workup revealed APAS to be the aetiology of her stroke. Twenty-one months into her follow-up, she is doing well with a modified Rankin Score of 0. Our case suggests that rTPA followed by immunomodulators may be given safely in myasthaenic crisis patients who develop ischaemic stroke. We emphasise the importance of doing a comprehensive neurological evaluation in agitated patients in the critical care unit.

Clinical characteristics of autoimmune disorders in the central nervous system associated with myasthenia gravis

Myasthenia gravis (MG) is occasionally associated with autoimmune diseases in the central nervous system (CNS), such as neuromyelitis optica spectrum disorder (NMOSD), multiple sclerosis (MS), Morvan syndrome, and anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. Here, we report five original cases associated with autoimmune disorders in the CNS among 42 patients with MG in a single tertiary hospital in Japan (11.9%). In four of these five cases, the second disease developed when the preceding disease was unstable. Accurate diagnosis of the newly developing disease may be difficult in such cases, because some neurological symptoms can be seen in both disorders. This implies the great importance of recognizing the possible co-occurrence of MG and disorders in the CNS. In addition, a comprehensive review of the literature revealed distinct clinical characteristics depending on the associated disease in the CNS, including thymic pathology and temporal relationship between MG and associated CNS disorders. Notably, NMOSD usually develops after the onset of MG and thymectomy, in clear contrast to MS. Thymoma is highly prevalent among patients with Morvan syndrome, in contract to cases with NMOSD and MS. The analysis of clinical characteristics, representing the first such investigation to the best of our knowledge, suggests different pathogeneses of these autoimmune diseases in the CNS, and provides significant implications for clinical practice.

Micro-RNA-143 inhibits proliferation and promotes apoptosis of thymocytes by targeting CXCL13 in a myasthenia gravis mouse model

Myasthenia gravis (MG) is an autoimmune neuromuscular disorder, affecting the quality of life of millions of people worldwide. The present study aims to determine the relationship between micro-RNA-143 (miR-143) and C-X-C motif chemokine 13 (CXCL13) and whether it influences the pathogenesis of myasthenia gravis (MG). Thymus specimens were resected from patients with thymic hyperplasia combined with MG and then infused into normal mouse cavities to establish MG mouse models. Immunohistochemistry, reverse transcription-quantitative PCR, in situ hybridization detection, and Western blot analysis were employed to identify the expression of miR-143 and CXCL13 in MG and normal mice. The obtained thymocytes were cultured in vitro and transfected with a series of miR-143 mimic, miR-143 inhibitor, overexpression of CXCL13, or siRNA against CXCL13. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and flow cytometry assays were employed to assess cell viability, cycle entry, and apoptosis of the thymocytes. Dual-luciferase reporter assay provided verification, confirming that CXCL13 was the target gene of miR-143. Low miR-143 expression in the thymus tissues of the MG mice was detected, which presented with a reciprocal relationship with the expression rate of CLCX13. Observations in relation to the interactions between miR-143 mimic or siRNA-CXCL13 exposure showed reduced cell viability, with a greater number of cells arrested at the G0/G1 phase and a greater rate of induced apoptosis. Furthermore, overexpression of CXCL13 rescued miR-143 mimic-induced apoptosis. The findings have identified the potential role of miR-143 as a MG development mediator by targeting CXCL13. The key results obtained provide a promising experimental basis for targeted intervention treatment with miR-143.

Nephrotic Syndrome and a Retroperitoneal Mass: A Case Report of a Patient with Recurrent Invasive Thymoma

A 68-year-old man was admitted to our hospital to undergo an examination for nephrotic syndrome while concurrently complicated with recurrent thymoma in the parietal pleura and retroperitoneum. He had been diagnosed with invasive thymoma and had undergone thymo-thymectomy seven years previously. Based on the renal biopsy findings, his nephrotic syndrome was ascribed to minimal change disease. He was treated with corticosteroid monotherapy, which resulted in complete remission six months later, despite the fact that the recurrent thymoma remained. The role of thymoma in the pathogenesis of paraneoplastic glomerulopathy and the therapeutic concerns that emerged in this case are also discussed.

Bioactive Nutrients and Nutrigenomics in Age-Related Diseases

The increased life expectancy and the expansion of the elderly population are stimulating research into aging. Aging may be viewed as a multifactorial process that results from the interaction of genetic and environmental factors, which include lifestyle. Human molecular processes are influenced by physiological pathways as well as exogenous factors, which include the diet. Dietary components have substantive effects on metabolic health; for instance, bioactive molecules capable of selectively modulating specific metabolic pathways affect the development/progression of cardiovascular and neoplastic disease. As bioactive nutrients are increasingly identified, their clinical and molecular chemopreventive effects are being characterized and systematic analyses encompassing the "omics" technologies (transcriptomics, proteomics and metabolomics) are being conducted to explore their action. The evolving field of molecular pathological epidemiology has unique strength to investigate the effects of dietary and lifestyle exposure on clinical outcomes. The mounting body of knowledge regarding diet-related health status and disease risk is expected to lead in the near future to the development of improved diagnostic procedures and therapeutic strategies targeting processes relevant to nutrition. The state of the art of aging and nutrigenomics research and the molecular mechanisms underlying the beneficial effects of bioactive nutrients on the main aging-related disorders are reviewed herein.

Systemic Lupus Erythematosus and Secondary Antiphospholipid Syndrome after Thymectomy for Myasthenia Gravis - A Case Report

INTRODUCTION:

Systemic lupus erythematosus (SLE) and myasthenia gravis (MG) are autoimmune diseases that show some similarities: a higher incidence in young women, relapsing-remitting course and positive anti-nuclear antibodies (ANA). However, they are two different clinical syndromes, which can coexist or precede each other. Thymectomy is a therapeutic option for patients with severe MG or thymoma. There are many cases of SLE after thymectomy described in the literature, so the question arises whether thymectomy predisposes patients to SLE and what are imunopathogenetic mechanisms behind this process.

CASE REPORT:

We report a case of a patient who was diagnosed with SLE and secondary antiphospholipid syndrome (APS) 28 years after thymectomy for MG. Clinical picture of SLE was characterized by cutaneous and articular manifestations, polyserositis, lupus nephritis and immunological parameters showed positive ANA, anti-ds-DNA, excessive consumption of complement components, positive cryoglobulins. Clinical and laboratory immunological parameters for the diagnosis of secondary APS where also present. The patient was initially treated with glucocorticoids followed by mycophenolate mofetil. During one year follow-up patient was in a stable remission of SLE.

CONCLUSION:

Thymectomy for MG may predispose SLE development in some patients. Further studies are needed to better understand the connection between these two autoimmune diseases.

Complicating autoimmune diseases in myasthenia gravis: a review

Myasthenia gravis (MG) is a rare autoimmune disease of skeletal muscle endplates. MG subgroup is relevant for comorbidity, but usually not accounted for. MG patients have an increased risk for complicating autoimmune diseases, most commonly autoimmune thyroid disease, systemic lupus erythematosus and rheumatoid arthritis. In this review, we present concomitant autoimmune disorders associated with the different MG subgroups, and show how this influences treatment and prognosis. Concomitant MG should always be considered in patients with an autoimmune disorder and developing new neuromuscular weakness, fatigue or respiratory failure. When a second autoimmune disorder is suspected, MG should be included as a differential diagnosis.

Prolonged severe immunodeficiency following thymectomy and radiation: a case report

Introduction

Immunodeficiency can occur both in patients undergoing radiation therapy, as well as in patients who have had thymectomies. However, few studies have examined the immune recovery of a patient following both procedures. We aim to emphasize the need for assessment and consistent monitoring of patients with thymoma prior to and after combined treatment of thymectomy and radiation, both of which are likely to result in an increased risk for immunodeficiency.

Case presentation

We describe the longitudinal progress of a 59-year-old Asian male who underwent thymectomy followed by radiation therapy and subsequently presented with generalized urticaria. Revelation of a low absolute lymphocyte count (615 cells/mcL) on initial evaluation prompted further analysis of his immunoglobulin levels and antigen response to a polysaccharide pneumococcal vaccine (PneumoVax-23). Although his immunoglobulin levels were unremarkable, he failed to respond to 11 of 12 serotypes of the pneumococcal vaccine. As a result, he was placed on Bactrim^® (trimethoprim-sulfamethoxazole) prophylaxis to prevent opportunistic infections, and his CD4+ and CD8+ counts were monitored over the course of 8 years. His lymphocyte counts 87 months after thymectomy and 85 months after radiation therapy were as follows: absolute lymphocyte count 956 cells/mcL, absolute CD3+/CD4+ 164/mm³ (16%) and absolute CD3+/CD8+ 257/mm³ (25%). The patient was able to discontinue Bactrim^® (trimethoprim-sulfamethoxazole) prophylaxis after 9 years of treatment.

Conclusions

The lymphocytopenia, low CD4+ count, and failed response to pneumococcal vaccination that presented in our patient are consistent with immunodeficiency. After radiation alone, a recovery of T-lymphocytes is usually observed after approximately 3 weeks. Over the course of 8 years, he has still not made a full recovery according to laboratory markers, which seem to have stabilized at chronically low levels. To prevent serious complications, we suggest that patients who have undergone both thymectomy and radiation therapy be monitored for immunodeficiency. This case report informs the practices of allergists, oncologists, and neurologists in the continuing care of patients with thymoma.

The course of myasthenia gravis with systemic lupus erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is one of the autoimmune diseases, which is rarely reported with Myasthenia Gravis (MG). In the literature, the clinical features of MG in these patients were not mentioned in detail. Here, we want to present our five patients with MG and SLE.

METHODS

Between 2000 and 2010, 132 MG patients were evaluated and have been followed up in our institution. Five patients had MG with SLE and eleven patients had antinuclear antibody (ANA) positivity without SLE symptoms. The clinical, laboratory findings and treatment responses were reviewed.

RESULTS

All patients had generalized MG and four of five patients experienced at least one myasthenic crisis. The response to corticosteroid was poor; consequently, they needed immunosuppressive treatments, IVIg or plasmapheresis. Although in the literature thymectomy was accused of the precipitation of SLE, in our series SLE symptoms preceded thymectomy.

CONCLUSION

We would like to point out that MG and SLE being two autoimmune diseases may coexist. This coexistence might cause a more severe myasthenic course compared to MG alone; therefore, these patients need a close and frequent follow-up.

Elevated preoperative neutrophil/lymphocyte ratio as a predictor of increased long-term survival in minimal invasive coronary artery bypass surgery compared to sternotomy

Background

Neutrophil lymphocyte ratio (NLR) is a predictor of major adverse cardiovascular outcomes. Our study explores the value of NLR in predicting long-term mortality after minimally invasive coronary artery bypass surgery (MICS) via lateral left-thoracotomy versus conventional sternotomy coronary artery bypass grafting (CABG) surgery.

Methods

A total of 1126 consecutive patients (729 sternotomy CABG and 397 MICS) from a single tertiary center between 2005 and 2008 were followed until 2011. We stratified the patients into equal tertiles according to preoperative NLR. The primary outcome, all-cause mortality, was compared among the NLR tertiles.

Results

Out of the 1126 patients included in the study, 1030 (91%) patients underwent off-pump CABG . The first (NLR <2.3) tertile had a significantly lower 5-year mortality (30/371 =8%) in comparison to the second (NLR =2.3-3.4) and third (NLR ≥3.5) tertiles (49/375 =13% and 75/380 =20%), respectively with p < 0.0001. After multivariate adjustment, NLR was a significant independent predictor of mortality (hazard ratio [HR] per each unit increase of NLR was 1.05, 95% confidence interval [CI] 1.01-1.10, p = 0.008). MICS and sternotomy CABG groups with NLR <3 had similar mortality (21/221 =9.5% and 40/403 =9.9%), p = 1. However among patients with NLR ≥3, MICS had a significantly lower mortality (23/176 = 13.1%) compared to the sternotomy CABG (70/326 =21.5%), p = 0.02. According to the multivariate analysis of patients with NLR ≥3, MICS had a significantly lower mortality compared to sternotomy CABG (HR = 0.44, 95% CI 0.24-0.78, p = 0.005).

Conclusion

Elevated preoperative NLR is an independent predictor of long-term mortality after CABG. Among the patients with NLR ≥ 3, MICS was associated with a significantly improved survival compared with sternotomy CABG.

Myasthenia gravis and neuromyelitis opica: A causal link

Neuromyelitis Optica (NMO) and Myasthenia Gravis (MG) are rare antibody mediated disorders of the central nervous system (CNS) and neuromuscular junction (NMJ) respectively. Both diseases are predominantly mediated by IgG1 antibodies that activate complement. There have been increasing reports of patients who develop both disorders. Given the rarity of both diseases it would seem that these occurrences are not purely coincidental. There is heterogeneity between the cases described in the literature but common trends are observed in patients who develop both disorders. Most patients described are female. Typically the MG precedes the NMO and the majority of patients have undergone thymectomy. Generally, the symptoms of MG are mild but the NMO tends to follow a more aggressive clinical course. The pathogenesis of NMO in combination with MG is unknown, but thymectomy has been implicated in a subset of patients. We present the case of a female patient who developed NMO on a background of sero-positive MG and discuss the relevant literature.

Anti-aquaporin-4 antibody-positive definite neuromyelitis optica in a patient with thymectomy for myasthenia gravis

BACKGROUND

Since serum anti-aquaporin-4 (AQP4) antibody/neuromyelitis optica (NMO)-IgG has been detected as a specific biomarker for NMO), new diagnostic criteria have been proposed. Recently, a rare coexistence of NMO and myasthenia gravis (MG) has been documented. Here, we provide further evidence of the association of these 2 immunologic disorders and review the literature.

CASE REPORT

A 60-year-old woman, who had a history of optic neuritis at age 43, developed longitudinally extended transverse myelitis (LETM). She had repeated optic neuritis and longitudinally extended transverse myelitis attacks, which have been treated by corticosteroid pulse therapy. She was diagnosed as having definite NMO, because serum anti-aquaporin-4 antibody was positive. She had also been suffering from generalized MG since age 30 and underwent thymectomy at age 40. There have been 14 patients with NMO associated with MG, most of whom developed NMO years after thymectomy. Our patient is the seventh patient with seropositive NMO who underwent thymectomy for MG.

CONCLUSIONS

The coexistence of MG with thymectomy and seropositive NMO suggests an etiopathogenic link between these 2 disorders but remains underrecognized by neurologists. Neurologists should consider this possible association when encountering atypical presentations of either MG or NMO.

End-point effector stress mediators in neuroimmune interactions: their role in immune system homeostasis and autoimmune pathology

Much evidence has identified a direct anatomical and functional link between the brain and the immune system, with glucocorticoids (GCs), catecholamines (CAs), and neuropeptide Y (NPY) as its end-point mediators. This suggests the important role of these mediators in immune system homeostasis and the pathogenesis of inflammatory autoimmune diseases. However, although it is clear that these mediators can modulate lymphocyte maturation and the activity of distinct immune cell types, their putative role in the pathogenesis of autoimmune disease is not yet completely understood. We have contributed to this field by discovering the influence of CAs and GCs on fine-tuning thymocyte negative selection and, in particular, by pointing to the putative CA-mediated mechanisms underlying this influence. Furthermore, we have shown that CAs are implicated in the regulation of regulatory T-cell development in the thymus. Moreover, our investigations related to macrophage biology emphasize the complex interaction between GCs, CAs and NPY in the modulation of macrophage functions and their putative significance for the pathogenesis of autoimmune inflammatory diseases.

Isolated adrenocorticotropin deficiency associated with painless thyroiditis: a case report and review of the literature

A 53-year-old Japanese man was admitted with a 3-month history of transient headache followed by general fatigue and weight loss. He had a history of ocular myasthenia gravis which had been in remission following thymectomy 30 years ago. He had a small diffuse goiter without tenderness, and was diagnosed as having painless thyroiditis with mild thyrotoxicosis on admission. Endocrinological studies showed he had isolated adrenocorticotropin deficiency. Magnetic resonance imaging of the pituitary gland revealed no abnormalities. His symptoms improved soon after replacement of glucocorticoid. After an episode of hypothyroidism, he spontaneously became euthyroid. It is likely that thyrotoxicosis uncovered adrenal insufficiency that had developed insidiously, and hypoadrenocorticism-induced immunological changes may have triggered the development of painless thyroiditis. Moreover, thymectomy might have facilitated the development of pituitary and thyroid autoimmunity.

Neuromyelitis optica spectrum disorders in patients with myasthenia gravis: ten new aquaporin-4 antibody positive cases and a review of the literature

BACKGROUND

Neuromyelitis optica (NMO, Devic syndrome) and myasthenia gravis (MG) are rare antibody-mediated autoimmune disorders. Concurrent incidence has been reported in only few patients, mostly non-Caucasians.

OBJECTIVE

To report on ten Caucasian patients with NMO spectrum disorders (NMOSD) and MG and to provide a comprehensive review of the literature.

METHOD

Retrospective study.

RESULTS

In total, 26 patients (m:f = 1:12; Caucasian in 12) with MG (generalized in 17) and NMOSD (NMO in 21, longitudinally extensive transverse myelitis in five) were identified from the authors' own files (n = 10) and the previous literature (n = 16). MG preceded NMOSD in 24/25 cases (96%). AQP4-Ab were tested in 20 patients and were positive in 17 (85%). Twenty out of 25 patients (80%) had been treated with thymectomy or thymic irradiation, which preceded NMOSD in all cases (median latency, 12 years; range, 0.3-32). At last follow-up, complete remission of MG was reported in 15/22 (68%), and MG was well controlled with pyridostigmine in three. Co-existing autoimmune disorders or autoimmune antibodies were reported in 17 patients.

CONCLUSION

Our study demonstrates that i) AQP4-Ab-positive NMOSD are more commonly associated with MG in Caucasians than previously thought; ii) MG precedes NMOSD in most cases, often by more than a decade; iii) NMOSD almost exclusively occur in females with juvenile or early-onset MG; and iv) MG frequently takes an unusually mild course in patients with NMOSD. A history of thymectomy could be a possible risk factor for the later development of NMOSD. We recommend testing for AQP4-Ab in MG patients presenting with atypical motor or optic symptoms.

The association of systemic lupus erythematosus and myasthenia gravis: a series of 17 cases, with a special focus on hydroxychloroquine use and a review of the literature

The coexistence of systemic lupus erythematosus (SLE) and myasthenia gravis (MG) is rarely reported, and most of the published studies are case reports. Hydroxychloroquine, an antimalarial agent, is an essential treatment in patients with SLE but special caution is recommended when used in MG patients. We retrospectively analyzed the clinical features, laboratory findings, and outcome of 17 patients with both diseases with a special focus regarding hydroxychloroquine use and with a review of the literature. All patients were women. The mean age at MG onset and SLE diagnosis was 34.5 [14-64] and 37.8 [18-72] years, respectively. The presenting symptoms of MG were limb weakness (94%), ocular (88%) and bulbar involvement (53%). Autoantibodies against the acetylcholine receptor were positive in 94% of cases. The main manifestations of SLE included arthritis (88%), cytopenias (53%) and skin rash (41%). Treatment of SLE required hydroxychloroquine (94%), steroids (47%) and immunosuppressive drugs (18%). Among eight patients (47%) who developed MG after initiation of hydroxychloroquine, the question of induction of MG by hydroxychloroquine was raised in one patient. On the other hand, an exacerbation of myasthenic symptoms was only seen in one of the eight patients who received hydroxychloroquine after the diagnosis of MG. Including our cases, we reviewed a total of 70 patients with SLE and MG. Compared with a large series of 1,000 unselected SLE patients, those with associated MG were older, had lower incidence of cutaneous, renal, and neurological manifestations, and higher frequency of anticardiolipin antibodies and lupus anticoagulant. In conclusion, the clinical pattern of patients with SLE and MG seems to be characterized by a less severe course of SLE and higher frequency of antiphospholipid antibodies. Hydroxychloroquine treatment appears to be safe in this setting.

Myasthenia Gravis during the Course of Neuromyelitis Optica

Neuromyelitis optica (NMO) is an inflammatory demyelinating disorder of the central nervous system that has been thought to be a severe subtype of multiple sclerosis for a long time. The discovery of aquaporin-4 (AQP4) antibody as a highly specific marker responsible for the pathogenesis of NMO, not only has made a revolutionary pace in establishing a serologic distinction between the two diseases, but it has also classified NMO as an antibody-mediated disorder. Similarly, myasthenia gravis (MG) is a well-known antibody-mediated disorder. In this report, we describe the case of a middle-aged female patient who experienced definite MG with an unclear clinical picture of chronic demyelinating disease that initially reflected the diagnosis of MS, but further imaging and paraclinical workup (e.g. positive AQP4 antibody test) revealed NMO. The coexistence of NMO and MG is previously described. However, this is the first case with NMO symptoms preceding the onset of MG. Of note, the development of MG occurred after a 2-year period of interferon β-1b (IFN β-1b) administration. This calls the question to mind of whether in our case MG is induced by the administration of interferon, instead of an original pathogenic link between MG and NMO. In other words, immunomodulatory treatments can slip the immunity towards T-helper II predominant pathways that can trigger MG. However, if we assume that such an explanation (i.e. increased susceptibility to autoantibody-mediated disorders) is true, our case can be considered the first case of NMO who developed MG following IFN β-1b treatment.

Immune dysregulation after cardiothoracic surgery and incidental thymectomy: maintenance of regulatory T cells despite impaired thymopoiesis

Thymectomy is performed in infants during cardiothoracic surgery leaving many patients with reduced thympopoiesis. An association between immune disorders and regulatory T cells (Treg) after incidental thymectomy has not been investigated. Questionnaires soliciting symptoms of atopic or autoimmune disease and biomarkers were measured in children and adults with congenital heart disease and either reduced or preserved thymopoiesis. Tregs were examined. Atopic or autoimmune-like symptoms and elevated anti-dsDNA antibodies were common after surgery in individuals with low thymopoiesis. Total Treg number and function were maintained but with fewer naïve Treg. TCR spectratypes were similar to other memory T cells. These data suggest that thymectomy does not reduce total Treg number but homeostasis is affected with reduced naïve Treg. Prevalence of autoimmune or atopic symptoms after surgery is not associated with total number or proportion of Tregs but appears to be due to otherwise unknown factors that may include altered Treg homeostasis.

Concomitant autoimmunity in myasthenia gravis--lack of association with IgA deficiency

A marked increase in concomitant autoimmune diseases has previously been noted in patients with myasthenia gravis (MG). We show that these diseases occur both before and after the onset of MG and that the process is not influenced by thymectomy. IgA deficiency (IgAD), which is strongly associated with the same HLA haplotype as early onset MG, has recently been suggested to be an autoimmune disease. However, there was no increase in the prevalence of IgAD in a large cohort of Swedish MG patients.

Myasthenia gravis development and crisis subsequent to multiple sclerosis

During the last decade, sporadic combination of multiple sclerosis (MS) and myasthenia gravis (MG) has been reported repeatedly. Although these are anecdotal, they are important enough to raise concerns about co-occurrence of MG and MS. Here, we present a case of an MS patient who developed an MG crisis. She had received interferon for relapsing remitting MS. Interestingly, she developed an MG crisis 4 years after the diagnosis of MS. MS and MG have relatively the same distribution for age, corresponding to the younger peak of the bimodal age distribution in MG. They also share some HLA typing characteristics. Furthermore, some evidences support the role of systemic immune dysregulation due to a genetic susceptibility that is common to these two diseases. The association may be underdiagnosed because of the possible overlap of symptoms especially bulbar manifestations in which either MG or MS can mimic each other, leading to underestimating incidence of the combination. The evidence warrants physicians, especially neurologists, to always consider the possibility of the other disease when encountering any patients either with MS or MG. Anecdotal and sporadic reports of combination of multiple sclerosis (MS) and myasthenia gravis (MG) have been raised concerns about co-occurrence of them.

Aquaporin-4 water channel expression by thymoma of patients with and without myasthenia gravis

BACKGROUND

Neuromyelitis optica (NMO) is a serious idiopathic inflammatory demyelinating disorder characterized by acute transverse myelitis and optic neuritis. A significant proportion of NMO patients are seropositive for NMO-IgG, an autoantibody targeting aquaporin-4 (AQP4) water channel. Paraneoplastic NMO associated various tumors were recently reported.

AIM

We studied the expression of AQP4 by thymoma from patients with and without myasthenia gravis (MG).

METHODS

Thymoma obtained from thymomectomy in patients with and without MG were studied by immunohistochemistry and western blot.

RESULTS

Ten thymoma patients (9 with MG) and two control patients without thymoma or MG were studied. Immunohistochemistry revealed AQP4 immunoreactivity in cell membrane of thymoma cells from all ten thymoma specimens whereas thymic tissues from patients without thymoma or MG were negative for AQP4 immunoreactivity. Western blot revealed that lysates of nine of the ten thymoma specimens reacted with anti-human AQP4 antibody with a band of ~30 kDa compatible with the molecular weight of AQP4. Interestingly, immunofluorescence revealed that IgG isolated from 2 NMO patients seropositive for NMO-IgG bound to cell membrane of thymoma cells from all ten thymoma specimens while IgG from healthy control subject did not.

CONCLUSION

Thymoma cells of patients with and without MG express AQP4. AQP4 autoantibodies from serum of NMO patients bound to AQP4 expressed on thymoma cell membrane.