Anti-titin antibodies are associated with myocarditis in patients with myasthenia gravis

BACKGROUND

Myasthenia gravis (MG) can affect cardiac muscles with variable presentations. Myocarditis is a rare but potentially serious cardiac manifestation of MG. Although thymomas and anti-titin antibodies have been suggested as risk factors for myocarditis in patients with MG, their independent influence on myocarditis has rarely been assessed.

METHODS

A retrospective chart review was conducted on 247 patients diagnosed with MG who were tested for anti-titin antibodies. Myocarditis was diagnosed on the basis of the European Society of Cardiology 2013 Task Force criteria for clinically suspected myocarditis. Patients were classified into myocarditis-positive and myocarditis-negative groups. Multivariate analysis was performed to analyze the risk factors for myocarditis.

RESULTS

Of the 247 patients, 25 (10.1%) were myocarditis-positive and 222 (89.9%) were myocarditis-negative. Anti-titin antibody positivity was higher in the myocarditis-positive group than in the myocarditis-negative group (68.0% vs. 28.4%, p < 0.001). A history of MG crisis was more frequent in the myocarditis-positive group than in the myocarditis-negative group (64.0% vs. 10.4%, p < 0.001). The presence of anti-titin antibodies (odds ratio [OR] 7.906; confidence interval [CI] 2.460-25.401) and MG crisis (OR 24.807; CI 7.476-82.311) was significantly associated with myocarditis. The Cox regression model showed that the anti-titin antibody levels (hazard ratio [HR] 3.639; 95% CI 1.557-8.505) and MG crisis (HR 6.137; 95% CI 2.639-14.272) were significant risk factors for the development of myocarditis.

CONCLUSION

The presence of anti-titin antibody was associated with myocarditis in patients with MG, whereas thymoma was not. Although rare, early suspicion of myocarditis could be required, especially in patients with MG having anti-titin antibodies.

Clinical and Genetic Characteristics of Thymoma Patients With Autoimmune Hepatitis and Myocarditis

BACKGROUND

Our study investigated a special series of thymoma with autoimmune hepatitis and myocarditis and tried to reveal the gene expression profiles of this series of thymoma.

METHODS

From 2011 to 2019, a total of 13 special thymoma patients presented with autoimmune hepatitis and myocarditis, accounting for about 1.26% of thymoma patients undergoing surgery in Beijing TongRen Hospital. Clinical data were retrospectively collected. All samples were harvested during surgical procedures, and analyzed to identify changes in gene expression using the CapitalBio mRNA microarray analysis, the Whole exome sequencing analysis (WES), qPCR and immunohistochemistry (IHC) tools.

RESULTS

After surgery, patient symptoms were relieved gradually. Levels of lactate dehydrogenase (LDH), creatine kinase MB (CK-MB), aspartate transaminase (AST), and alanine amiotransferase (ALT) increased to some extent within 1 to 3 months after surgery, and fluctuated, and then, gradually decreased close to normal within 6 months after surgery. Enrichment analysis of Kyoto Genome and Genome Encyclopedia (KEGG) pathway was performed and enrichment results were visualized. It indicated that gene expression of 5 signaling pathways, including cell cycle and p53 signaling pathway, were generally abnormal. P53 expression was up-regulated in all tumor tissues. However, IHC and qPCR analysis showed that there was no significant difference in p21 expression between normal and tumor tissue. Results of WES showed that only one driver gene-MDM4 amplified 4 fold in 53.2% thymoma cells. Further qPCR and IHC analysis confirmed the up-regulation of the expression of p53 and mdm4 in 13 thymoma patients with autoimmune hepatitis and myocarditis.

CONCLUSION

Our study reveals the clinical and genetic characteristics of thymoma patients with autoimmune hepatitis and myocarditis. For this special category of thymoma, the up-regulation of p53 and mdm4 plays an important role in the occurrence of thymoma and autoimmune hepatitis/myocarditis.

Upregulation of circ-FBL promotes myogenic proliferation in myasthenia gravis by regulation of miR-133/PAX7

Myasthenia gravis (MG) is a disease involving neuromuscular transmission that causes fatigue of skeletal muscles and fluctuating weakness. It has been shown that impairment of myogenic differentiation and myofiber maturation may be the underlying cause of MG. In this study, we detected the abnormal expression of circular RNA (circRNA) using next‐generation sequencing in patients with MG. We then investigated the regulatory mechanism and the relationship among circRNA, microRNA, and messenger RNA using quantitative reverse‐transcription polymerase chain reaction, bioinformatics analysis, and luciferase report analysis. The expression of inflammatory cytokines and regulatory T lymphocytes was shown to be increased. Circ‐FBL was significantly increased in MG patients. Bioinformatics and luciferase report analyses confirmed that miR‐133 and PAX7 were the downstream targets of circ‐FBL. Overexpression of circ‐FBL promoted myoblast proliferation by regulation of miR‐133/PAX7. Taken together, our study showed that upregulation of circ‐FBL promoted myogenic proliferation in patients with MG by regulating miR‐133/PAX7.

Peripheral blood hsa-circRNA5333-4: A novel biomarker for myasthenia gravis

In this study, the potential of specific Circular RNAs (circRNAs) as novel peripheral blood biomarkers for myasthenia gravis (MG) was explored. We analyzed circRNAs in the peripheral blood of three normal controls and three MG patients using RNA microarray. Candidate circRNAs were validated in three independent cohorts by Quantitative Real-time polymerase chain reaction (qPCR). Eleven differentially expressed circRNAs were initially identified and four were confirmed in the first independent cohort. Hsa_circ_0076490 and hsa-circ_5333-4 had the largest areas under the curve (AUCs) of the receiver operating characteristics (ROC) and were validated in the second cohort. In the third cohort, hsa-circRNA5333-4 had a larger AUC: 0.864 (95% confidence interval [CI] = 0.801-0.928, P < 0.001), a stronger correlation with the Quantitative Myasthenia Gravis Score (qMG): r = 0.505 (P < 0.001) and was correlated with gender and acetylcholine receptor antibody levels (P < 0.05). So hsa-circRNA5333-4 represents a novel biomarker for the diagnosis and monitoring of MG.

The epidemiology of myasthenia gravis

Neuromuscular junction (NMJ) disorders include several dysfunctions that ultimately lead to muscle weakness. Myasthenia gravis (MG) is the most prevalent NMJ disorder with a highly polymorphic clinical presentation and many different faces. Being an autoimmune disease, MG correlates with the presence of detectable antibodies directed against the acetylcholine receptor, muscle-specific kinase, lipoprotein-related protein 4, agrin, titin, and ryanodine in the postsynaptic membrane at the NMJ. MG has become a prototype serving to understand both autoimmunity and the function of the NMJ better. The aim of this review is to synthesize some of the epidemiological data available. Epidemiological data regarding MG are important for postulating hypotheses regarding its etiology and facilitating the description of MG subtypes. Thus, adequate documentation through broad databases is essential. The incidence and prevalence of MG reported around the globe have been rising steadily and consistently over the past decades. Ethnic aspects, gender-related differences, and environmental risk factors have been described, implying that these might contribute to a specific phenotype, further suggesting that MG may be considered an umbrella term that covers several clinical entities.

Clinical features and treatment status of antiacetylcholine receptor antibody-positive ocular myasthenia gravis

PURPOSE

To clarify the factors predictive of progression from ocular myasthenia gravis (OMG) to generalized MG (GMG) among patients with positive antiacetylcholine receptor antibodies (AChRAb) and to evaluate the efficacy of our OMG treatment protocol including tacrolimus (TAC).

STUDY DESIGN

Retrospective study.

METHODS

Fifty-two patients with AChRAb positivity and ptosis and/or eye movement disturbance showing diurnal fluctuation and fatigability were included. First, we compared the clinical characteristics of patients without OMG progression (p-OMG) with those of patients whose OMG transformed to GMG (TMG). Second, we subdivided the p-OMG patients according to the time of approval of TAC into the Before group and the After group. We compared the dosage and period of prednisolone administration (PSL) of the 2 groups. Third, we evaluated the responses to OMG treatment using the Myasthenia Gravis Foundation of America Postintervention Status (MGFA-PS) scale.

RESULTS

Forty-one patients were classified into the p-OMG group, and 11, into the TMG group. The AChRAb level (P = 0.0006) and prevalence of thymoma (P = 0.001) were significantly higher in the TMG group than in the p-OMG group. In the p-OMG group, the MG composite score (P ≤ 0.0001) and AChRAb level (P = 0.005) improved after treatment. The periods of PSL administration at ≥ 20 mg/day (P = 0.009) and at 10 to 19 mg/day (P = 0.002) were significantly shorter in the After group. At the last follow-up, 78.0% of the p-OMG group patients had achieved MGFA-PS minimal manifestations or better status with PSL ≤ 5 mg/day.

CONCLUSIONS

The TMG cases were characterized by higher AChRAb levels and presence of thymoma. The P-OMG patients could be managed with our treatment protocol. Combined use of TAC was efficacious in patients with steroid-dependent p-OMG.

Analysis of electrooculography signals for the detection of Myasthenia Gravis

OBJECTIVE

A precursor to more severe forms of Myasthenia Gravis (MG) is ocular MG (OMG) in which the MG symptoms are localized to the eyes. Current MG diagnostic methods are often invasive, painful, and not always specific. The objective of the proposed work was to extract quantifiable features from electrooculography (EOG) signals recorded around the eyes and develop an alternative non-invasive screening method for detecting MG.

METHODS

EOG signals acquired from MG and Control subjects were analyzed for eye movement characteristics and quantified using time and wavelet domain signal processing techniques. The ability of the proposed approaches to classify MG vs. control subjects was evaluated using a linear discriminant analysis (LDA) based classifier.

RESULTS

The range of overall classification accuracies achieved by the proposed time and wavelet domain approaches for different groupings were between 82.1-83.3% (Rise Rate feature: P < 0.01, AUC ≥ 0.87) and 82.1-87.2% (Mean Scale Band Energy feature: P < 0.01, AUC ≥ 0.89), respectively.

CONCLUSION

Our results demonstrate that an EOG-based signal analysis is a potentially viable non-invasive alternative for MG screening.

SIGNIFICANCE

The proposed approach could lead to early detection of MG and thereby improve clinical outcomes in this population.

Administering Neostigmine as a Subcutaneous Infusion: A Case Report of a Patient Dying With Myasthenia Gravis

BACKGROUND

Abrupt withdrawal of pharmacological therapies for myasthenia gravis can exacerbate muscle weakness and even trigger myasthenic crisis. Such medications should ideally be continued, but how this can be achieved in patients approaching the end of life, particularly when enteral administration is compromised, has not been defined.

CASE HISTORY

An 83-year-old man with a history of generalized myasthenia gravis and palliative metastatic anal adenocarcinoma was admitted to his local hospital with general decline, where he was considered by more than one physician to be actively dying from his cancer. In the days preceding admission, the patient had not taken his medications consistently, including the acetylcholinesterase inhibitor, pyridostigmine, for the management of his myasthenia gravis.

CASE MANAGEMENT AND OUTCOME

Reintroduction of the patient's usual myasthenia therapy improved his clinical condition to the point where he was no longer thought to be dying. When enteral administration of pyridostigmine was no longer possible, the patient was successfully converted to neostigmine, which was administered as a continuous subcutaneous infusion.

CONCLUSION

Undertreated myasthenia gravis can lead to a rapid deterioration in a patient's clinical condition, and such patients may be mistakenly diagnosed as dying. Undertreated myasthenia gravis should therefore be considered as a potentially reversible cause of acute deterioration, especially in patients with complex comorbidities. The use of neostigmine as a continuous subcutaneous infusion may have a role in the management of such patients, particularly when enteral administration of acetylcholinesterase inhibitors is no longer possible.

Hyperkalemia in a patient with myasthenia gravis: case presentation

BACKGROUND

Myasthenia gravis (MG) is the most common disorder of neuromuscular transmission, and it is typified by fluctuating degrees and variable combinations of weakness in the ocular, bulbar, limb, and respiratory muscles. Under rare circumstances, MG can be accompanied by Addison's disease.

CASE PRESENTATION

Here, we reported the case of a 57-year-old Chinese woman with MG. She experienced progressive muscle weakness for 1 week. MG with acute exacerbation was initially suspected. However, further biochemistry tests found mild hyperkalemia (5.6 mEq/L) and a lower renal potassium excretion rate. Consequently, low aldosterone action was highly suspected. Further findings included a suppressed cortisol level, a higher adrenocorticotropic hormone concentration, and 21-hydroxylase antibody positivity, supporting a diagnosis of primary adrenal insufficiency due to autoimmune adrenalitis.

CONCLUSION

We successfully demonstrated that adrenal insufficiency could be diagnosed, due to the presence of hyperkalemia. This case suggested a need for clinicians to consider the possible coincidence of adrenal insufficiency in a patient with MG and hyperkalemia. Early hormone supplementation should be begun.

Oral corticosteroid dosing regimen and long-term prognosis in generalised myasthenia gravis: a multicentre cross-sectional study in Japan

OBJECTIVE

We examined the correlation between the dosing regimen of oral prednisolone (PSL) and the achievement of minimal manifestation status or better on PSL ≤5 mg/day lasting >6 months (the treatment target) in patients with generalised myasthenia gravis (MG).

METHODS

We classified 590 patients with generalised MG into high-dose (n=237), intermediate-dose (n=187) and low-dose (n=166) groups based on the oral PSL dosing regimen, and compared the clinical characteristics, previous treatments other than PSL and prognosis between three groups. The effect of oral PSL dosing regimen on the achievement of the treatment target was followed for 3 years of treatment.

RESULTS

To achieve the treatment target, ORs for low-dose versus high-dose regimen were 10.4 (P<0.0001) after 1 year of treatment, 2.75 (P=0.007) after 2 years and 1.86 (P=0.15) after 3 years; and those for low-dose versus intermediate-dose regimen were 13.4 (P<0.0001) after 1 year, 3.99 (P=0.0003) after 2 years and 4.92 (P=0.0004) after 3 years. Early combined use of fast-acting treatment (OR: 2.19 after 2 years, P=0.02; OR: 2.11 after 3 years, P=0.04) or calcineurin inhibitors (OR: 2.09 after 2 years, P=0.03; OR: 2.36 after 3 years, P=0.02) was associated positively with achievement of treatment target.

CONCLUSION

A low-dose PSL regimen with early combination of other treatment options may ensure earlier achievement of the treatment target in generalised MG.

Cancer chemotherapeutics in rheumatoid arthritis: A convoluted connection

Chemotherapy is one of the most popular therapeutic strategies to treat cancer. However, cancer chemotherapeutics have often been associated with impairment of the immune system, which might consequently lead to an augmented risk of autoimmune disorders, such as rheumatoid arthritis. Though the accurate mechanistic facets of rheumatoid arthritis induction have not been interpreted yet, a conglomeration of genetic and environmental factors might promote its etiology. What makes the scenario more challenging is that patients with rheumatoid arthritis are at a significantly elevated risk of developing various types of cancer. It is intriguing to note that diverse cancer chemotherapy drugs are also commonly used to treat symptoms of rheumatoid arthritis. However, a colossal multitude of such cancer therapeutics has demonstrated highly varied results in rheumatoid arthritis patients, including both beneficial and adverse effects. Herein, we attempt to present a holistic account of the variegated modalities of this complex tripartite cross-talk between cancer, rheumatoid arthritis and chemotherapy drugs in order to decode the sinuous correlation between these two appalling pathological conditions.

Social disadvantages associated with myasthenia gravis and its treatment: a multicentre cross-sectional study

OBJECTIVES

To clarify the social disadvantages associated with myasthenia gravis (MG) and examine associations with its disease and treatment.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

We evaluated 917 consecutive cases of established MG seen at 13 neurological centres in Japan over a short duration.

OUTCOME MEASURES

All patients completed a questionnaire on social disadvantages resulting from MG and its treatment and a 15-item MG-specific quality of life scale at study entry. Clinical severity at the worst condition was graded according to the MG Foundation of America classification, and that at the current condition was determined according to the quantitative MG score and MG composite. Maximum dose and duration of dose ≥20 mg/day of oral prednisolone during the disease course were obtained from the patients' medical records. Achievement of the treatment target (minimal manifestation status with prednisolone at ≤5 mg/day) was determined at 1, 2 and 4 years after starting treatment and at study entry.

RESULTS

We found that 27.2% of the patients had experienced unemployment, 4.1% had been unwillingly transferred and 35.9% had experienced a decrease in income, 47.1% of whom reported that the decrease was ≥50% of their previous total income. In addition, 49.0% of the patients reported feeling reduced social positivity. Factors promoting social disadvantages were severity of illness, dose and duration of prednisolone, long-term treatment, and a depressive state and change in appearance after treatment with oral steroids. Early achievement of the treatment target was a major inhibiting factor.

CONCLUSIONS

Patients with MG often experience unemployment, unwilling job transfers and a decrease in income. In addition, many patients report feeling reduced social positivity. To inhibit the social disadvantages associated with MG and its treatment, greater focus needs to be placed on helping patients with MG resume a normal lifestyle as soon as possible by achieving the treatment target.

Early fast-acting treatment strategy against generalized myasthenia gravis

INTRODUCTION

In this study we sought to clarify the effects of early fast-acting treatment (EFT) strategies on the time course for achieving the treatment target in generalized myasthenia gravis (MG).

METHODS

This retrospective study of 923 consecutive MG patients analyzed 688 generalized MG patients who had received immunotherapy during the disease course. The time to first achieve minimal manifestations (MM) or better while receiving prednisolone at ≤5 mg/day for ≥6 months (MM-or-better-5mg) up to 120 months after starting immunotherapy was compared between EFT and non-EFT patients.

RESULTS

Achievement of MM-or-better-5mg was more frequent and earlier in the EFT group (P = 0.0004, Wilcoxon test; P = 0.0001, log-rank test). Multivariate Cox regression analysis calculated a hazard ratio of 1.98 (P < 0.0001) for utilization of EFT. Dosing regimens of oral steroids in EFT produced no differences in the time course.

CONCLUSIONS

EFT strategies are advantageous for early achievement of MM-or-better-5mg. Muscle Nerve 55: 794-801, 2017.

Response to treatment of myasthenia gravis according to clinical subtype

Background

We have previously reported using two-step cluster analysis to classify myasthenia gravis (MG) patients into the following five subtypes: ocular MG; thymoma-associated MG; MG with thymic hyperplasia; anti-acetylcholine receptor antibody (AChR-Ab)-negative MG; and AChR-Ab-positive MG without thymic abnormalities. The objectives of the present study were to examine the reproducibility of this five-subtype classification using a new data set of MG patients and to identify additional characteristics of these subtypes, particularly in regard to response to treatment.

Methods

A total of 923 consecutive MG patients underwent two-step cluster analysis for the classification of subtypes. The variables used for classification were sex, age of onset, disease duration, presence of thymoma or thymic hyperplasia, positivity for AChR-Ab or anti–muscle-specific tyrosine kinase antibody, positivity for other concurrent autoantibodies, and disease condition at worst and current. The period from the start of treatment until the achievement of minimal manifestation status (early-stage response) was determined and then compared between subtypes using Kaplan-Meier analysis and the log-rank test. In addition, between subtypes, the rate of the number of patients who maintained minimal manifestations during the study period/that of patients who only achieved the status once (stability of improved status) was compared.

Results

As a result of two-step cluster analysis, 923 MG patients were classified into five subtypes as follows: ocular MG (AChR-Ab-positivity, 77%; histogram of onset age, skewed to older age); thymoma-associated MG (100%; normal distribution); MG with thymic hyperplasia (89%; skewed to younger age); AChR-Ab-negative MG (0%; normal distribution); and AChR-Ab-positive MG without thymic abnormalities (100%, skewed to older age). Furthermore, patients classified as ocular MG showed the best early-stage response to treatment and stability of improved status, followed by those classified as thymoma-associated MG and AChR-Ab-positive MG without thymic abnormalities; by contrast, those classified as AChR-Ab-negative MG showed the worst early-stage response to treatment and stability of improved status.

Conclusions

Differences were seen between the five subtypes in demographic characteristics, clinical severity, and therapeutic response. Our five-subtype classification approach would be beneficial not only to elucidate disease subtypes, but also to plan treatment strategies for individual MG patients.

Genetic heterogeneity within the HLA region in three distinct clinical subgroups of myasthenia gravis

This study aims to investigate genetic susceptibility to early-onset and late-onset anti-acetylcholine receptor antibody positive myasthenia gravis (EOMG and LOMG) and anti-muscle specific kinase antibody positive MG (MuSK-MG) at genome-wide level in a single population. Using a custom-designed array and imputing additional variants and the classical HLA alleles in 398 patients, we detected distinct associations. In EOMG, rs113519545 in the HLA class I region (OR=5.71 [3.77-8.66], P=2.24×10(-16)), HLA-B*08:01 (OR=7.04 [3.95-12.52], P=3.34×10(-11)) and HLA-C*07:01 (OR=2.74 [1.97-3.81], P=2.07(-9)), in LOMG, rs111256513 in the HLA class II region (OR=2.22 [1.59-3.09], P=2.48×10(-6)) and in MuSK-MG, an intronic variant within HLA-DQB1 (rs68081734, OR=5.86, P=2.25×10(-14)) and HLA-DQB1*05:02 (OR=8.56, P=6.88×10(-13)) revealed the most significant associations for genome-wide significance. Differential genetic susceptibility within the HLA to EOMG, LOMG and MuSK-MG has been established in a population from Turkey.

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.

Myasthenia gravis epidemiology in a national cohort; combining multiple disease registries

OBJECTIVES

There is a wide variation in reported prevalence and incidence of myasthenia gravis (MG). In this study, we aimed to evaluate the validity of two nationwide databases by comparing prevalence and incidence rates reported from three recent studies using the two databases as case-finding method.

MATERIALS AND METHODS

Two different Norwegian nationwide databases were used: the acetylcholine receptor antibody database (reference cohort) and the Norwegian Prescription Database (NorPD) (study cohort). Presence of acetylcholine receptor antibodies (AChR) is specific for MG. Up to 85% of MG patients are AChR antibody-positive. All samples from the whole country were tested at one laboratory. NorPD contains patient information on all prescriptions of pyridostigmine.

RESULTS

Prevalence was 131 per million in the study cohort and 145 per million estimated from the reference cohort (Jan 1, 2008). No significant difference in prevalence between the study cohort and the reference cohort was found (SIR 1.1, 95% CI 1.0-1.2). The annual incidence rate was 16.0 per million in the study cohort and 8.8 per million estimated from the reference cohort, twofold more new MG patients were found in the study cohort compared to estimated figures from the reference cohort (SIR 1.8; 1.4-2.3).

CONCLUSIONS

This study confirms an optimal and unbiased case finding in both databases. Our calculated prevalence and incidence rates are in line with previous population-based studies. There was good agreement in prevalence reported from the two databases. The discrepancy in incidence is expected to diminish as years of study are increasing in NorPD.

Shenqi fuzheng injection alleviates the transient worsening caused by steroids pulse therapy in treating myasthenia gravis

Purpose. To evaluate the treatment effect and side effect of Shenqi Fuzheng Injection (SFI) on alleviating transient worsening of myasthenia gravis (MG) symptoms caused by high-dose steroids pulse therapy. Methods. Sixty-six consecutive patients with MG were randomly divided into two groups: the treatment group treated with SFI and methylprednisolone pulse therapy (MPT) and the control group treated with MPT alone. The severity of MG before, during, and after MPT and the duration of transient worsening (TW) were evaluated and compared with the clinical absolute scoring (AS) and relative scoring (RS) system. Results. Twenty-nine patients experienced TW in each group. At TW, the AS was significantly increased (P < 0.000) in both groups compared with baseline data, with the AS increase in the treatment group (16.8 ± 2) significantly smaller (P < 0.05) than in the control group (24.9 ± 2.5). At the end of the treatment course, the AS for the treatment group was significantly decreased (7.5 ± 0.9) compared with at TW, although no significant difference compared with the control (9.7 ± 1.1). The TW lasted 1-6 days (mean 3.7) for the treatment group, significantly shorter (P < 0.05) than 2-12 days (mean 7.8) for the control. The RS for the treatment group at the end of treatment was 43.8%-100% (mean 76.8% ± 2.6%), significantly better than the control group: 33.3%-100% (mean 67.2 ± 3.6%). Slight side effects (18.75%) included maldigestion and rash in the treatment group. Conclusion. SFI has a better treatment effect and few side effects and can alleviate the severity and shorten the duration of the transient worsening of MG during steroids pulse therapy.

[Clinical factors affecting quality of life and treatment targets in patients with myasthenia gravis]

Presently, myasthenia gravis (MG) is seldom lethal. However, full remission without immune treatment is not common, and many patients still find it difficult to maintain daily activities. To both determine factors affecting health-related quality of life (QOL) and propose an appropriate treatment target for patients with MG, we evaluated 640 consecutive patients with MG seen at 11 neurological centers. Two-year follow-up data were obtained for 282 patients. Correlations between detailed clinical facotrs and the Japanese version of the 15-item MG-specific QOL scale were analyzed.In the cross-sectional analysis of 640 MG patients, multivariate regression revealed that disease severity as evaluated by MG Composite (p < 0.0001), but not quantitative MG score, total dose of oral prednisolone (p = 0.002), but not current dose, and Cushingoid appearance index (p = 0.0004) showed significant negative effects on QOL. Achieving status of Minimal Manifestations or better with prednisolone ≤ 5 mg/day was found to exert a major positive impact on QOL in both the cross-sectional and 2-year follow-up patient samples and can be recommended as a treatment target.

Considerations for subgroups and phenocopies in complex disease genetics

The number of identified genetic variants associated to complex disease cannot fully explain heritability. This may be partially due to more complicated patterns of predisposition than previously suspected. Diseases such as multiple sclerosis (MS) may consist of multiple disease causing mechanisms, each comprised of several elements. We describe how the effect of subgroups can be calculated using the standard association measurement odds ratio, which is then manipulated to provide a formula for the true underlying association present within the subgroup. This is sensitive to the initial minor allele frequencies present in both cases and the subgroup of patients. The methodology is then extended to the χ² statistic, for two related scenarios. First, to determine the true χ² when phenocopies or disease subtypes reduce association and are reclassified as controls when calculating statistics. Here, the χ² is given by, or for equal numbers of cases and controls. Second, when subgroups corresponding to heterogeneity mask the true effect size, but no reclassification is made. Here, the proportion increase in total sample size required to attain the same χ² statistic as the subgroup is given as , and a python script to calculate and plot this value is provided at kirc.se. Practical examples show how in a study of modest size (1000 cases and 1000 controls), a non-significant SNP may exceed genome-wide significance when corresponding to a subgroup of 20% of cases, and may occur in heterozygous form in all cases. This methodology may explain the modest association found in diseases such as MS wherein heterogeneity confounds straightforward measurement of association.

Advances in the treatment of myasthenia gravis

Myasthenia gravis (MG) should be classified according to antibody status (acetylcholine, MuSK, LRP4, titin), thymus (hyperplasia, neoplasia, atrophy), age at debut (< or >50 years), symptom localization (generalized, ocular) and severity. With optimal treatment, the prognosis is good in terms of daily functions, quality of life and survival. Symptomatic treatment with acetylcholine esterase is usually combined with immunosuppression. A combination of prednisolone and azathioprine remains the first choice alternative, whereas rituximab is a promising second choice drug for severe generalized MG. Thymectomy is recommended for early-onset, generalized MG and for thymoma MG. In acute exacerbations including MG crisis, intravenous immunoglobulin and plasma exchange have good and similar effects. MG in young females needs therapeutic considerations regarding potential pregnancy.

Myasthenia gravis: a review of available treatment approaches

Patients with autoimmune myasthenia gravis (MG) should be further classified before initiating therapy, as treatment response varies for ocular versus generalised, early onset versus late onset, and acetylcholine receptor antibody positive versus MuSK antibody positive disease. Most patients need immunosuppression in addition to symptomatic therapy. Prednisolone and azathioprine represent first choice drugs, whereas several second choice options are recommended and should be considered. Thymectomy should be undertaken in MG with thymoma and in generalised, early-onset MG. For MG crises and other acute exacerbations, intravenous immunoglobulin (IvIg) and plasma exchange are equally effective and safe treatments. Children and females in child bearing age need special attention regarding potential side effects of immunosuppressive therapy. MG pathogenesis is known in detail, but the immune therapy is still surprisingly unspecific, without a pin-pointed attack on the defined disease-inducing antigen-antibody reaction being available.

The auto-antigen repertoire in myasthenia gravis

Myasthenia Gravis (MG) is an antibody-mediated autoimmune disorder affecting the postsynaptic membrane of the neuromuscular junction (NMJ). MG is characterized by an impaired signal transmission between the motor neuron and the skeletal muscle cell, caused by auto-antibodies directed against NMJ proteins. The auto-antibodies target the nicotinic acetylcholine receptor (nAChR) in about 90% of MG patients. In approximately 5% of MG patients, the muscle specific kinase (MuSK) is the auto-antigen. In the remaining 5% of MG patients, however, antibodies against the nAChR or MuSK are not detectable (idiopathic MG, iMG). Although only the anti-nAChR and anti-MuSK auto-antibodies have been demonstrated to be pathogenic, several other antibodies recognizing self-antigens can also be found in MG patients. Various auto-antibodies associated with thymic abnormalities have been reported, as well as many non-MG-specific auto-antibodies. However, their contribution to the cause, pathology and severity of the disease is still poorly understood. Here, we comprehensively review the reported auto-antibodies in MG patients and discuss their role in the pathology of this autoimmune disease.

Lack of association of the CIITA -168A→G promoter SNP with myasthenia gravis and its role in autoimmunity

Background

The major histocompatibility complex class II transactivator (CIITA) regulates MHC class II gene expression. A promoter SNP -168A→G (rs3087456) has previously been shown to be associated with susceptibility to several immune mediated disorders, including rheumatoid arthritis (RA), multiple sclerosis (MS) and myocardial infarction (MI). Myasthenia gravis (MG) is an autoimmune disorder which has previously been shown to be associated with polymorphisms of several autoimmune predisposing genes, including IL-1, PTPN22, TNF-α and the MHC. In order to determine if allelic variants of rs3087456 increase predisposition to MG, we analyzed this SNP in our Swedish cohort of 446 MG patients and 1866 controls.

Results

No significant association of the SNP with MG was detected, neither in the patient group as a whole, nor in any clinical subgroup. The vast majority of previous replication studies have also not found an association of the SNP with autoimmune disorders.

Conclusions

We thus conclude that previous findings with regard to the role of the CIITA -168A→G SNP in autoimmunity may have to be reconsidered.

Central and peripheral fatigue: exemplified by multiple sclerosis and myasthenia gravis

Fatigue is a feature of several chronic diseases of the central and peripheral nervous system. The pathophysiology of central fatigue is complex and often not well-defined. In contrast, peripheral fatigue is more objectively defined and measured. Fatigue can be part of the primary disease process, but there are often contributions from comorbid factors such as depression, sleep disturbance, medication, or deconditioning. Multiple sclerosis (MS) offers an example of central fatigue. More than 40% of MS patients complain of fatigue. Validated questionnaires are used to assess fatigue severity and comorbid factors. Although fatigue is believed to be a primary process in MS, depression and sleep disturbance are often comorbid problems. Magnetic resonance imaging (MRI), positron emission tomography, and functional MRI studies suggest that fatigue is related to gray matter disease, particularly of the cerebral cortex, but also of the thalamus and caudate. Disruption of impulse propagation from demyelination is also a likely factor. It is uncertain if pro-inflammatory cytokines have a specific effect on the genesis of MS fatigue. Several medications have been reported to alleviate fatigue in MS, but controlled studies show contradictory results. Treatment of depression and sleep disturbance, use of exercise programs and rehabilitation therapies as well as treatment of other comorbid conditions is necessary for optimal alleviation of fatigue. Myasthenia gravis (MG) patients exhibit peripheral fatigue. In contrast to MS, the mechanism of weakness and fatigue in MG is well-defined. Antibodies to the postsynaptic acetylcholine receptor at the myoneural junction cause diminution of the force of muscle contractions. This leads to a feeling of fatigue. MG treatments increase the availability of acetylcholine and reduce antibody formation. Evaluation for comorbid conditions, especially thymoma and hyperthyroidism, are mandatory in patients with MG.