Myasthenia gravis: clinical, immunological, and therapeutic advances

Research progress of malignant peritoneal mesothelioma with paraneoplastic syndrome: A review

Malignant peritoneal mesothelioma (MPM) is a rare and invasive tumor, and some patients will develop paraneoplastic syndrome (PS) during the course of the disease. This review summarizes PS associated with MPM, focusing on the clinical characteristics and treatment progress in hematological, endocrine, rheumatic, neurological, urinary, and other systems to decrease missed diagnosis and misdiagnosis, help early diagnosis and prompt treatment, and provide guidance for the clinical decision-making of this kind of patients.

Social support and medication adherence among adult myasthenia gravis patients in China: the mediating role of mental health and self-efficacy

BACKGROUND

Myasthenia gravis (MG), a rare chronic neuromuscular disorder, is characterized by progressive physical decline and requires long-term pharmacological treatment. Due to the decline of physical and social abilities, MG patients are in great need of social support, including tangible and emotional support. This study aims to examine the association between social support and medication adherence and the possible mediating effects of mental health and self-efficacy among MG patients.

METHODS

A cross-sectional analysis of a nationwide MG registry was conducted on 865 patients under oral medication treatment in China between June and July 2022. Validated scales were used to measure the respondent's mental distress (Four-item Patient Health Questionnaire), social support (Modified Medical Outcomes Study Social Support Scale), self-efficacy for medication use (Self-efficacy for Appropriate Medication Use Scale), and medication adherence (Morisky Medication Adherence Scale, MMAS).

RESULTS

The association between social support and medication adherence and possible mediating effects of mental distress and self-efficacy were tested by structural equation model, with significant demographic and disease-related factors adjusted. The respondents showed a very low level of medication adherence (71.2% poor adherence; 1.4% high adherence; mean MMAS = 4.65). The level of social support was positively associated with medication adherence, and such association was fully mediated by two indirect pathways: through self-efficacy (β = 0.07, proportion mediated = 63.8%); and through mental distress and then self-efficacy (β = 0.01, proportion mediated = 6.7%).

CONCLUSION

Provision of social support and interventions on mental health with emphasis on improving self-efficacy for medication use may effectively improve medication adherence among MG patients.

Altered serum levels of cytokines in patients with myasthenia gravis

Background

Myasthenia gravis (MG) is an autoimmune disease characterized by generalized skeletal muscle contraction weakness due to autoantibodies targeting neural-muscular junctions. Here, we investigated the relationship between key cytokines and MG type, disease course, antibodies, and comorbidities.

Method

Cytokine levels in serum samples collected from MG (n = 45) and healthy control (HC, n = 38) patients from January 2020 to June 2022 were quantified via flow cytometry.

Results

Levels of IL-6 were higher in the MG group versus healthy individuals (p = 0.026) and in patients with generalized versus ocular MG (p = 0.019). IL-6 levels were positively correlated with QMG score. In patients with MG with both AChR and Titin antibodies, serum levels of sFas and granulysin were higher than in those with AChR alone (p = 0.036, and p = 0.028, respectively). LOMG had a reduction in serum levels of IL-2 compared to EOMG (p = 0.036). LOMG patients with diabetes had lower serum levels of IL-2, IL-4, and IFN-γ (p = 0.044, p = 0.038, and p = 0.047, respectively) versus those without diabetes. sFas in the MG with Abnormal thymus were reduced compared to those in MG with Normal thymus (p = 0.008).

Conclusions

This study revealed a positive correlation between IL-6 level and MG status. Serum cytokine levels of the AChR + Titin MG group differed from those of the AChR group. LOMG had a lower IL-2 level. Comorbidities affect some cytokines in peripheral blood in MG serum.

LncRNA OIP5-AS1 modulates the proliferation and apoptosis of Jurkat cells by sponging miR-181c-5p to regulate IL-7 expression in myasthenia gravis

Background

Myasthenia gravis (MG) is an antibody-mediated autoimmune disease. In recent years, accumulating evidence has indicated that long non-coding RNAs (lncRNAs) can function as competing endogenous RNAs (ceRNAs), contributing to the progression of various autoimmune diseases. Nevertheless, the regulatory roles of ceRNAs in MG pathogenesis remain unclear. In this study, we aimed to elucidate the role of lncRNA OIP5-AS1 as a ceRNA associated with MG progression.

Methods

Real-time PCR was used to detect OIP5-AS1 levels in peripheral blood mononuclear cells (PBMCs) from patients with MG. Luciferase reporter assays were performed to validate the relationship between OIP5-AS1 and miR-181c-5p. CCK-8 and flow cytometry were performed to test the proliferation and apoptotic abilities of OIP5-AS1 in Jurkat cells. Furthermore, real-time PCR and Western blot assays were performed to explore the interactions between OIP5-AS1, miR-181c-5p, and IL-7.

Results

The expression of OIP5-AS1 was up-regulated in patients with MG. Luciferase reporter assay indicated that OIP5-AS1 targeted the miR-181c-5p. Functional assays showed that OIP5-AS1 suppressed Jurkat cell apoptosis and promoted cell proliferation by sponging miR-181c-5p. Mechanistically, knockdown of OIP5-AS1 inhibited IL-7 expression at both the mRNA and protein levels in Jurkat cells, whereas the miR-181c-5p inhibitor blocked the reduction of IL-7 expression induced by OIP5-AS1 suppression.

Conclusions

We confirmed that OIP5-AS1 serves as an endogenous sponge for miR-181c-5p to regulate the expression of IL-7. Our findings provide novel insights into MG processes and suggests potential therapeutic targets for patients with MG.

The Use of the Saccadometer to Identify Saccadic Characteristics in Myasthenia Gravis: A Pilot Study

BACKGROUND

Myasthenia gravis (MG) often presents with ocular signs that mimic other forms of ocular defects, such as isolated cranial nerve palsy. Normal velocity or even hyperfast saccadic eye movements in the presence of deficits of smooth pursuit have been well described in the literature in myasthenic patients. The reason for these paradoxical clinical findings has been reported to be due to increased postsynaptic folding of the fast-twitch fibers responsible for the execution of a saccade which is absent in those fibers responsible for slower, smooth eye movement. Saccadic characteristics therefore offer a point of differential diagnosis between patients suspected of having ocular motility deficits as a result of MG and those caused by other neuropathies. The advent of portable quantitative saccadic assessment means that previously laboratory-based assessments that require specialist equipment and training may now be undertaken clinically, providing a noninvasive test that can aid the differential diagnosis of the condition. The aim of this pilot study was to investigate the feasibility of the saccadometer (Ober Consulting, Poznan, Poland) in detecting the saccadic characteristics associated with myasthenia, specifically normal peak velocity (PV) in a group of patients confirmed with myasthenia.

METHODS

A group of 5 patients with a confirmed diagnosis of MG were recruited from a single site into the study along with 5 age-matched healthy volunteers. All myasthenic patients had ocular signs such as underaction or limitations of motility confirmed through ocular clinical examination. Healthy volunteers were screened for any underlying ocular motility or neurological defects before inclusion within the study. All participants undertook 100 trials of both 10 and 20° amplitude saccades, and mean PV, amplitude, and latency were recorded using the saccadometer for each individual. Overall, mean PV, amplitude, and latency were collated for both myasthenic and healthy control groups for each saccade size and compared.

RESULTS

The mean PV was significantly greater (481 ± 103.5 deg/seconds) for myasthenic patients compared with healthy controls (384 ± 42.8 deg/seconds) (P < 0.05) in 10° saccades. PV was also greater in myasthenics for 20° saccades; however, this difference did not reach statistical significance for patients with MG (547 ± 89.8 deg/seconds vs 477 ± 104.5 deg/seconds) (P = 0.14). The latency of participants with MG was not significantly different from those of age-matched healthy participants in 10° saccades but was significantly different for 20° saccades. There was no difference in amplitude measured between the groups.

CONCLUSIONS

PV for both 10 and 20° saccades was greater in myasthenic patients compared with healthy controls. All myasthenic patients produced normal velocity saccades in the presence of deficits of smooth ocular motility. The results from this small pilot study demonstrate the potential use of the saccadometer in a clinical setting to provide a noninvasive aid in the diagnosis of patients suspected with myasthenia.

Perioperative Approach in a Patient with Myasthenia Gravis

Background: Myasthenia gravis is an autoimmune neuromuscular disorder that causes the destruction and overall decrease in functional acetylcholine receptors at the neuromuscular junction. The resultant respiratory and cardiovascular implications are a primary cause of mortality; therefore, a complete and comprehensive understandings of this disorder is vital for the anesthesia provider. Anesthesia management in myasthenia gravis is a great challenge for all anesthesiologists. In this disease, even small doses of muscle relaxants could lead to delayed recovery for respiratory muscles. Case report: We present the case of a 38 years old woman (weight 87 kg) diagnosed with Myasthenia Gravis, which symptoms has worsened recently. The case demonstrates the anesthetic challenges involved, with a focus on the overall approach, pharmacologic considerations, physiological changes, and an emphasis on preoperative operative and post-operative optimization. Conclusion: Thymectomy is a common procedure performed in cases of myasthenia gravis (MG) with a thymoma or general MG that does not improve with medical therapy. During anesthesia the use of propofol or sevoflurane with opioids without the use of any neuromuscular blocking agents has been used with success.

Efficacy and safety of double-filtration plasmapheresis treatment of myasthenia gravis: A systematic review and meta-analysis

OBJECTIVES

To evaluate the efficacy of double-filtration plasmapheresis (DFPP) treatment of myasthenia gravis (MG) through a systematic review and meta-analysis.

METHODS

PubMed, Cochrane Library, Embase, China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals Database (VIP), and Wanfang databases were searched for randomized controlled trials (RCTs) and clinical controlled trials (CCTs) on DFPP for MG from database establishment to June 2019. Two researchers independently screened the articles, extracted the data, and cross checked the results. RevMan 5.3 was used for statistical analyses.

RESULTS

Seven RCTs and 2 CCTs were found comprising 329 patients. The results showed that clinical MG remission rate after DFPP treatment was significantly higher (OR = 4.33; 95% confidence interval [CI], 1.97-9.53; P < .001) and the serum levels of antititin antibody was significantly decreased (standardized mean difference [SMD] = 9.30; 95% CI, 7.51-11.08; P < .001). In addition, the quantitative MG (QMG) score, hospital stay and time to remission of MG symptoms, and acetylcholine receptor antibody (AchRAb) decreased in the DFPP treatment group; however, these outcomes had high heterogeneity among the studies. Only one study has reported on the adverse effects, including hypotension and hematoma.

CONCLUSION

This meta-analysis suggests that DFPP can be recommended for the short-term mitigation of MG. Because our review was limited by the quantity and quality of the included studies, the above conclusions should be verified by additional high-quality studies.

Case Series: Clinical Impact of Plasmapheresis and Thymectomy on Early-Onset Myasthenia Gravis

Thymectomy is a common procedure performed in cases of myasthenia gravis (MG) with a thymoma or general MG that does not improve with medical therapy. This procedure is usually preceded by plasmapheresis to prevent the occurrence of myasthenic crisis and improve clinical outcome after thymectomy. Early-onset MG has a different phenotype than late-onset MG. So far, the effectiveness of plasmapheresis followed by thymectomy in early-onset MG remains unclear because of the conflicting results of previous studies. We present 5 early-onset MG patients who underwent plasmapheresis followed by thymectomy in the 2007–2020 period. Follow-up was done 1 year after thymectomy. We describe clinical features and postoperative data and evaluate the clinical outcome after thymectomy. Muscle strength was assessed by the Medical Research Council scale. Evaluation of clinical stage before and after thymectomy were carried out with the modified Osserman classification. All patients showed improvement (100%) in the clinical grade of the modified Osserman classification: 3 patients were in the complete remission category and 2 patients were in the improved category. All patients with general weakness experienced improvement in muscle strength at the 1-year evaluation.

Prediction of generalization of ocular myasthenia gravis under immunosuppressive therapy in Northwest China

BACKGROUND

It is well demonstrated that immunosuppressants can reduce, but not eliminate the risk of generalized development in ocular myasthenia gravis (OMG). In this study, we aimed to explore the predictive factors of generalized conversion of OMG patients who received immunosuppressive treatments.

METHODS

OMG patients under immunosuppressive treatments in Tangdu Hospital from June 2008 to June 2012 were retrospectively reviewed. Baseline clinical characteristics were documented. Patients were followed up regularly by face-to-face interview and the main outcome measure was generalized conversion. The logistic regression analysis was performed to determine the predictive factors of generalization of OMG.

RESULTS

Two hundred twenty-three eligible OMG patients completed the final follow-up visit and 38 (17.0%) progressed to generalized MG (GMG) at a median time to generalization of 0.9 year. Patients with adult onset and positive repetitive nerve stimulation (RNS) of facial or axillary nerve had higher conversion rate than those with juvenile onset and negative RNS (p = 0.001; p = 0.019; p = 0.015, respectively). Adult-onset patients converted earlier than juvenile-onset OMG patients (p = 0.014). Upon multivariate logistic regression analysis, age of onset (Odds ratio [OR] 1.023, 95% confidence interval [CI] 1.006-1.041, p = 0.007) and positive facial nerve RNS (OR 2.826, 95%CI 1.045-5.460, p = 0.038) were found to be positively associated with generalized development. Moreover, an obviously negative association was found for disease duration (OR 0.603, 95%CI 0.365-0.850, p = 0.019).

CONCLUSIONS

Age of onset, disease duration and facial nerve RNS test can predict generalized conversion of OMG under immunosuppressive therapy. Adult-onset, shorter disease duration and facial nerve RNS-positive OMG patients have a higher risk of generalized development.

Occurrence of Guillain-Barré syndrome and Myasthenia Gravis in an elderly male

Introduction

The occurrence of both Guillain-Barré syndrome(GBS) and myasthenia gravis (MG) in the same individual is rare. The underlying pathophysiology was assumed to be autoimmune humoral mechanisms and molecular mimicry with a cross-reaction between autoantibodies and myelin sheath of peripheral nerves and acetylcholine receptors of the neuromuscular junction (NMJ).

Case description

A 68-year-old male known diabetic and hypertensive with good drug compliance presented with acute onset quadriparesis with bulbar involvement for 1 day. On examination, he had mild neck flexion weakness and bulbar weakness. He had flaccid quadriparesis with absent deep tendon reflexes and negative Babinski. The rest of the neurological examination was normal.

Discussion and evaluation

Blood and electrophysiological studies showed evidence of demyelinating polyradiculoneuropathy with temporal dispersion suggestive of Guillain-Barré syndrome. He was treated with intravenous immunoglobin and complete resolution of symptoms. Two months later, he presented with new-onset asymmetrical ptosis and bulbar symptoms for 3 days. On further evaluation, repetitive nerve stimulation showed postsynaptic neuromuscular disorder pattern typical of myasthenia gravis, which was further confirmed by positive acetylcholinesterase receptor antibodies (AChR). Thymoma was ruled out by imaging. He was treated with anticholinesterases, low dose steroids, and immunosuppressants (azathioprine) following which he had improvement of symptoms.

Conclusion

Our patient, who was initially diagnosed with Guillain-Barré syndrome and recovered, presented 2 months later with a new-onset illness suggestive of myasthenia gravis. This existence of two different neurological entities in the same individual is a rarity, and early recognition is essential for treatment decision and prognostic strategies.

Autoantibodies in acquired myasthenia gravis: Clinical phenotype and immunological correlation

BACKGROUND

Data on antibody profile in myasthenia gravis (MG) from India are limited.

OBJECTIVES

To investigate antibody profile in patients with MG and their clinical correlates.

PATIENTS AND METHODS

Patients of MG (n = 85, M:F::1.1:1, mean age: 39.29 ± 17.3 years, mean symptom duration: 72.94 ± 91.8 months) were evaluated for clinical features, MG foundation of America (MGFA) score, response to treatment, and outcome at last follow-up. Antibodies to acetylcholine receptor (AChR), muscle-specific kinase (MUSK), titin and ryanodine receptor (RYR) were analysed using ELISA.

RESULTS

Based on the regional distribution of weakness, the cohort could be categorized as: generalized: 60, ocular: 16 and oculo-bulbar: 9. Sixty patients were followed up for a mean duration of 26.74 ± 13.8 months. Outcome at last follow-up was as follows: remission-22, no remission-33 and dead-5. AChR and MUSK antibodies were detected in 58 and 8 patients, respectively. Frequency of generalized MG, worse MGFA score during the disease course and thymomatous histology significantly correlated with presence of AChR-antibodies, though outcome at last follow-up was comparable between AChR-antibody positive and negative groups. Patients with MUSK antibodies had oculo-bulbar or generalized MG and frequent respiratory crisis, but majority improved or remitted with treatment. Titin antibodies were detected in 31.8% and RYR antibodies in 32.9%. Their presence did not correlate with age at onset of MG, severity or presence of thymoma.

CONCLUSION

This report highlights the spectrum of antibodies in MG in an Indian cohort. AChR-antibody positivity correlated with clinical severity. Outcome was good in majority of MUSK antibody-positive MG. The role of other antibodies, complementary vs epiphenomenon, remains open.

Assessment of pre and post-thymectomy myasthenia gravis

OBJECTIVE

To evaluate transcervical and transsternal thymectomy benefits in large myasthenia gravis (MG) cohort.

METHOD

We retrospectively evaluated MG patients (n = 184) who had undergone thymectomy between 2004 and 2015 at National Institute of Mental Health and Neurosciences, Bangalore (India). Myasthenia gravis foundation of America guidelines were followed to assess clinical outcome. Anti-acetylcholine receptors (AChR) antibodies, repetitive nerve stimulation (RNS) and Neostigmine tests were performed at pre and post-thymectomy stage.

RESULTS

Most of the patients were fell under MG grade IIA (82 of 184, 44.56%) and grade IIB (61 of 184, 33.15%). Thymoma and thymic hyperplasia was established in 64 (34.78%) and 89 (48.37%) patients respectively. Other thymic abnormalities such thymic atrophy, cysts and lipoma were established in 31 (16.85%) patients. MG patients were treated either with transcervical (n = 79) or (n = 105) transsternal thymectomy. At the pre-thymectomy stage, the majority of the patients were positive for anti-AChR antibodies (179 of 184, 97.28%), RNS (170 of 184, 92.4%), and Neostigmine (175 of 184, 95.11%). At the post-thymectomy stage, a significant reduction observed in anti-AChR antibodies positivity (p < 0.022) and RNS positivity (p < 0.015). Overall, benefits were observed in 61.41% (113 of 184) of patients. Clinical benefits (complete stable remission, pharmacological remission, minimal manifestation, and improvement) of transcervical and transsternal thymectomy observed in 69.62% (55 of 79) and 55.24% (58 of 105) of patients respectively. MG patients with thymoma showed the least improvement compared to thymic hyperplasia.

DISCUSSION

Transcervical and transsternal thymectomy showed clinical benefits, however, there was no significant difference between them.

The clinical features of patients concurrent with Guillain-Barre syndrome and myasthenia gravis

OBJECTIVE

To evaluate all the coincidence cases of Guillain-Barre syndrome (GBS) and myasthenia gravis (MG).

METHODS

We performed web-based research of the overlapping incidence of GBS and MG in studies occurring from 1982 to 2016 and restricted to the English language.

RESULTS

Among 15 cases, an elevated CSF protein level without pleocytosis was found in 10 cases (66.7%); reduced nerve conduction was found in 13 cases (86.6%); a positive repetitive nerve stimulation test occurred in 11 cases (73.3%); anti-AChR antibodies were found in 13 cases (86.6%); anti-GQ1b antibodies were found in 6 cases (40%); a positive edrophonium chloride test was present in 10 cases (66.7%); and a co-occurring thymoma or thymectomy occurred in 4 cases (26.6%). The MG co-occurred with acute inflammatory demyelinating polyneuropathy (AIDP) in 8 cases and with Miller Fisher Syndrome in 5 cases. Treatment in the assessed cases included pyridostigmine (10 cases), prednisolone (7 cases), intravenous immunoglobulin (9 cases), plasmapheresis (3 cases), combined intravenous immunoglobulin and plasmapheresis in one case, and immunosuppressive drugs in 2 cases (azathioprine). Functional outcome was mentioned in 13 patients. The prognosis was favorable in 8 of the 15 recorded patients (Hughes 0-1), and 2 cases resulted in death.

CONCLUSION

Although comorbidity of GBS and MG is extremely rare, early recognition of this combination of inflammation of peripheral nerves and the neuromuscular junction is of great importance for both initial treatment and a better prognosis.

Myasthenia Gravis Complicated with Peripheral T-cell Lymphoma, Not Otherwise Specified (PTCL-NOS), Following Thymectomy and Longstanding Tacrolimus Therapy

Myasthenia gravis (MG), a neuromuscular junction autoimmune disease, sometimes complicates second malignancies; however, T-cell lymphoproliferative disorders have rarely been reported. A 55-year-old man, who received oral tacrolimus and prednisolone for MG for 16 years after thymectomy, presented with left abdominal pain, lymphadenopathy, and splenomegaly. A lymph node biopsy revealed peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS). This is the first report of oral tacrolimus leading to a T-cell lymphoproliferative disorder in patient without a history of transplantation. Physicians should be aware of the possibility of rare T-cell lymphoproliferative disorders, such as PTCL-NOS, occurring as complications in MG patients on immunosuppressive regimens after thymectomy.

Suppression of CHRN endocytosis by carbonic anhydrase CAR3 in the pathogenesis of myasthenia gravis

Myasthenia gravis is an autoimmune disorder of the neuromuscular junction manifested as fatigable muscle weakness, which is typically caused by pathogenic autoantibodies against postsynaptic CHRN/AChR (cholinergic receptor nicotinic) in the endplate of skeletal muscle. Our previous studies have identified CA3 (carbonic anhydrase 3) as a specific protein insufficient in skeletal muscle from myasthenia gravis patients. In this study, we investigated the underlying mechanism of how CA3 insufficiency might contribute to myasthenia gravis. Using an experimental autoimmune myasthenia gravis animal model and the skeletal muscle cell C2C12, we find that inhibition of CAR3 (the mouse homolog of CA3) promotes CHRN internalization via a lipid raft-mediated pathway, leading to accelerated degradation of postsynaptic CHRN. Activation of CAR3 reduces CHRN degradation by suppressing receptor endocytosis. CAR3 exerts this effect by suppressing chaperone-assisted selective autophagy via interaction with BAG3 (BCL2-associated athanogene 3) and by dampening endoplasmic reticulum stress. Collectively, our study illustrates that skeletal muscle cell CAR3 is critical for CHRN homeostasis in the neuromuscular junction, and its deficiency leads to accelerated degradation of CHRN and development of myasthenia gravis, potentially revealing a novel therapeutic approach for this disorder.

[A comparative analysis of the informative value of anti-AChR-antibody radioimmunoassay and laser correlation spectroscopy in myasthenia gravis]

AIM

An aim of the study was to compare informative value of traditional approach (anti-AChR antibody radioimmunoassay) and evaluation of metabolic shifts by laser correlation spectroscopy in myasthenia gravis.

MATERIAL AND METHODS

The search for the relationship between the disease severity in 77 patients, 12-80 years and the distribution pattern of subfraction serum components revealed three informative zones: 6-15, 27-67, and 127-223 nm.

RESULTS AND CONCLUSION

In patients without disturbances of vital functions, the contribution of the first zone particles into light scatter increases and that of the third zone particles decreases. Considerable differences attaining the level of statistical significance in zones 6 and 20 nm were revealed in the spectra of serum from patients with myasthenia gravis of the same severity with and without thymoma. This opens prospects for dynamic monitoring of the efficiency of therapy.

Clinical Profile and Outcome of Postthymectomy versus Non-Thymectomy Myasthenia Gravis Patients in the Philippine General Hospital: A 6-Year Retrospective Study

Background

Myasthenia gravis is an autoimmune neuromuscular disorder characterized by the production of abnormal autoantibodies directed against the receptors present in the neuromuscular junction. It has been the standard practice to offer thymectomy in all generalized myasthenia gravis patients despite the lack of robust evidence.

Objectives

The objectives of this study are to describe the clinical profile and differentiate the clinical outcomes of thymectomy versus non-thymectomy and thymomatous versus non-thymomatous myasthenia gravis patients in the Philippine General Hospital.

Methodology

Between 2009 and 2014, a total of 69 postthymectomy and 16 non-thymectomy patient records were successfully retrieved. The demographic characteristics, surgical approach, and histopathologic results were obtained. The clinical outcome after 6 months or 1 year-follow-up was also determined and grouped according to the following: (1) complete remission, (2) pharmacological remission, (3) no clinical change, (4) worsening symptoms, and (5) mortality.

Results

Majority of the patients were females (68.0%) with a mean age of 39.8 years and a mean duration of myasthenic symptoms of 21 months. Using the Myasthenia Gravis Foundation of America classification, 54.1% of patients fell under Class II and 48.2% of them presented with generalized weakness. In this study, 60.8% of postthymectomy myasthenia gravis patients had either complete remission or pharmacologic remission compared with 12.5% among non-thymectomy patients (p-value <0.001). No significant difference in the clinical outcome was found between thymomatous and non-thymomatous myasthenia gravis after thymectomy (p-value = 0.29).

Conclusion

This study showed that both thymomatous and non-thymomatous myasthenia gravis patients who underwent thymectomy had a higher incidence of complete stable remission and pharmacologic remission as compared with myasthenia gravis patients who did not undergo thymectomy.

Overlap of Myasthenia Gravis and Miller Fisher Syndrome

In this case report, we describe a patient with myasthenia gravis (MG) and Miller Fisher syndrome (MFS) overlap. A 69-year-old woman presented with acute bilateral ptosis, ophthalmoplegia, ataxic gait, and areflexia. The MFS diagnosis was confirmed with by a positive anti-GQ1b IgG antibody test result. MG was diagnosed from electrophysiological, edrophonium, and serological test results. Although intravenous immunoglobulin therapy is effective for both diseases, two courses of the therapy did not improve the patient's symptoms. However, steroid therapy was effective. Although the overlap of MG and MFS is very rare, it should be considered in the differential diagnosis of neuro-ophthalmic diseases.

Characterization of the interaction between acotiamide hydrochloride and human serum albumin: 1H STD NMR spectroscopy, electrochemical measurement, and docking investigations

The comprehensive investigation of acotiamide hydrochloride and HSA interaction provides a convictive explanation for its binding mechanism.

Diurnal and day-to-day variation of isometric muscle strength in myasthenia gravis

INTRODUCTION

In patients with myasthenia gravis (MG), muscle strength is expected to decrease gradually during the day due to physical activities.

METHODS

Isometric muscle strength at the shoulder, knee, and ankle was determined in 10 MG patients (MGFA class II-IV) who were receiving usual medical treatment and in 10 control subjects. To determine diurnal and day-to-day variation, muscle strength was measured 4 times during day 1 and once at day 2.

RESULTS

Knee extension strength decreased during the day in both patients and controls. Neither diurnal nor day-to-day variation of muscle strength was higher in patients compared with controls.

CONCLUSIONS

Patients with mild to moderate MG did not have increased variation of isometric muscle strength during the day or from day-to-day compared with controls. This suggests that isometric muscle performance can be determined with high reproducibility in similar groups of MG patients without regard to time of day.

A pilot study of acotiamide hydrochloride hydrate in patients with detrusor underactivity

AIM

To investigate the clinical efficacy of acotiamide hydrochloride hydrate in patients with detrusor underactivity.

METHODS

We measured the post-void residual urinary volume in 19 patients with underactive bladders. All these patients had been under treatment with distigmine bromide and were prescribed acotiamide hydrochloride hydrate at a dose of 100 mg three times daily for 2 weeks.

RESULTS

Compared with the post-void residual urinary volume value at baseline (161.4±90.0 mL) a statistically significant reduction was observed at the end of treatment (116.3±63.1 mL) (P=0.006). The drug was generally well tolerated by the majority of patients.

CONCLUSION

Maybe, acotiamide hydrochloride hydrate showed clinical efficacy in patients with underactive bladders and may, therefore, be used alternatively in patients who do not respond sufficiently to distigmine bromide.

A rare case of ocular myositis

We report the case of a 43 year old man who presented recurrent left abducens palsy. His medical history included arterial hypertension, ischemic cardiomiopathy, dyslipidemia, rhinitis, maxillary sinusitis. Physical examination revealed a overweight patient, horizontal gaze diplopia, left nerve VI paresis, mild left retro-orbital pain. The orbital MRI also didn’t offer new information: mild external edema on the left eye, with normal tendon aspect, no thickening or enhancement of the muscle belly and also normal aspect of the bony orbit. Recurrent palsy of EOMs can be caused in rare cases by ocular myositis.

Serological diagnostics in myasthenia gravis based on novel assays and recently identified antigens

Myasthenia gravis (MG) is the most common immune-mediated disorder of the neuromuscular junction with a prevalence of 200-300/million population and its study has established paradigms for exploring other antibody-mediated diseases. Most MG patients (~85%) have autoantibodies against the muscle acetylcholine receptor (AChR-MG), whereas about 6% of MG patients have autoantibodies against the muscle specific kinase (MuSK-MG). Until recently no autoantibodies could be detected in the remaining patients (seronegative MG). Probably, the most sensitive assays for the detection of the autoantibodies in MG sera have been the radioimmunoprecipitation assays (RIPA) for both types of MG. However, with recent novel methods, not yet used routinely, it has been shown that the "seronegative" MG group includes patients with low levels of autoantibodies or of low affinity, against the known autoantigens, or even with antibodies to recently identified autoantigens. Since MG is heterogeneous in terms of pathophysiology, depending on the autoantigen targeted and on other factors (e.g. presence of thymoma), the serological tests are crucial in verifying the initial clinical diagnosis, whereas frequent measurement of autoantibody levels is important in monitoring the course of the disease and the efficacy of treatment. In addition, in AChR-MG, autoantibodies against the muscle proteins titin and ryanodin receptor have been identified; these antibodies are useful for the classification of MG, indicating the concomitant presence of thymoma, and as prognostic markers.

The effect of early prednisolone treatment on the generalization rate in ocular myasthenia gravis

BACKGROUND AND PURPOSE

Several small retrospective studies have observed that patients with a purely ocular manifestation of myasthenia gravis (MG) are significantly less likely to convert to a generalized disease when treated early on with corticosteroids. However, given the limited number of reported patients in the literature these findings still remain controversial.

METHODS

In order to increase the number of published cases, we performed a retrospective analysis on 44 patients with newly diagnosed ocular MG who were subsequently either treated with corticosteroids or received no immunosuppressive therapy at all. The generalization rate was assessed at the end of a 2-year follow-up period.

RESULTS

Whereas none of 17 treated patients generalized, 11 of 27 (41%) untreated patients developed generalized symptoms. The difference between the groups was significant (P=0.003).

CONCLUSIONS

Our results agree well with previous studies on this issue. Taken together, published data indicate risk ratios for generalization of below 0.32 under corticosteroid treatment in comparison to untreated patients.

Myasthenia gravis: two case reports and review of the literature

BACKGROUND AND OBJECTIVES

Myasthenia gravis (MG) is an autoimmune neurologic disease that affects the postsynaptic portion of the neuromuscular junction. It represents a challenge for anesthesiologists due to the diversity of disease manifestations and possibility of postoperative respiratory complications. The objective of this study was to demonstrate the importance of adequate monitoring of the neuromuscular blockade (NMB) due to the multiple presentations of MG.

CONTENTS

In this paper we report two cases of patients with MG. The first patient presented with the classical sensitivity to the neuromuscular blocker (NMB) and the second had a similar response to that of a normal patient. The literature review will be restricted to disease characteristics, while the description of its pathophysiology will focus on its reactions to NMB.

CONCLUSIONS

We suggest that, due to the multiple presentation and treatment of MG, neuromuscular transmission monitors are fundamental when using NMB.

Thymoma in myasthenia gravis: from diagnosis to treatment

One half of cortical thymoma patients develop myasthenia gravis (MG), while 15% of MG patients have thymomas. MG is a neuromuscular junction disease caused in 85% of the cases by acetylcholine receptor (AChR) antibodies. Titin and ryanodine receptor (RyR) antibodies are found in 95% of thymoma MG and 50% of late-onset MG (MG onset ≥50 years), are associated with severe disease, and may predict thymoma MG outcome. Nonlimb symptom profile at MG onset with bulbar, ocular, neck, and respiratory symptoms should raise the suspicion about the presence of thymoma in MG. The presence of titin and RyR antibodies in an MG patient younger than 60 years strongly suggests a thymoma, while their absence at any age strongly excludes thymoma. Thymoma should be removed surgically. Prethymectomy plasmapheresis/iv-IgG should be considered before thymectomy. The pharmacological treatment does not differ from nonthymoma MG, except for tacrolimus which is an option in difficult thymoma and nonthymoma MG cases with RyR antibodies.

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.

Airway limitation and exercise intolerance in well-regulated myasthenia gravis patients

OBJECTIVES

Myasthenia gravis (MG) is an autoimmune disease of neuromuscular synapses, characterized by muscular weakness and reduced endurance. Remission can be obtained in many patients. However, some of these patients complain of fatigue. The aim of this study was to assess exercise capacity and lung function in well-regulated MG patients.

PATIENTS AND METHODS

Ten otherwise healthy MG patients and 10 matched controls underwent dynamic spirometry, and a ramped symptom-limited bicycle exercise test. Spirometric variables included forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and maximum voluntary ventilation (MVV). Exercise variables included maximal oxygen uptake (VO(2) max), anaerobic threshold (VO(2) AT) maximum work load (W), maximum ventilation (VE max), and limiting symptom.

RESULTS

Myasthenia gravis patients had significantly lower FEV1/FVC ratio than controls. This was more marked in patients on acetylcholine esterase inhibitors. On the contrary, patients not using acetylcholine esterase inhibitors had a significantly lower exercise endurance time.

CONCLUSION

Well-regulated MG patients, especially those using pyridostigmine, tend to have an airway obstruction. The modest airway limitation might be a contributing factor to their fatigue. Patients who are not using acetylcholinesterase inhibitor seem to have diminished exercise endurance in spite of their clinically complete remission.

Extracorporeal immunoglobulin elimination for the treatment of severe myasthenia gravis

Myasthenia gravis (MG) is a neuromuscular disorder leading to fluctuating muscle weakness and fatigue. Rarely, long-term stabilization is not possible through the use of thymectomy or any known drug therapy. We present our experience with extracorporeal immunoglobulin (Ig) elimination by immunoadsorption (adsorbers with human Ig antibodies). Acetylcholine receptor antibodies (AChRAs) were measured during long-term monitoring (4.7 +/- 2.9 years; range 1.1-8.0). A total of 474 samples (232 pairs) were analyzed, and a drop in AChRA levels was observed (P = .025). The clinical status of patients improved and stabilized. Roughly 6.8% of patients experienced clinically irrelevant side effects. The method of Ig elimination by extracorporeal immunoadsorption (IA) is a clinical application of the recent biotechnological advances. It offers an effective and safe therapy for severe MG even when the disease is resistant to standard therapy.

The challenge of pain management in patients with myasthenia gravis

Myasthenia gravis (MG) is an autoimmune disorder of the neuromuscular junction. The complexity of the disease and its treatments make MG patients particularly susceptible to adverse effects of drugs. MG is not a painful condition; however, as pain management armamentarium includes drugs from diverse pharmacological groups and with potential for drug-drug interactions, managing pain in patients with MG can be challenging. The underlying disease and the concomitant medications of each patient must be considered and the analgesic treatment individualized. This review presents an update on the various aspects of pain pharmacotherapy in patients with MG, focusing primarily on medications used to treat chronic pain. Drugs discussed are opioids, nonsteroidal anti-inflammatory drugs, antidepressants, anticonvulsants, muscle relaxants, benzodiazepines, intravenous magnesium, and local anesthetics. Drug interactions with agents used for MG treatment (acethylcholinesterase inhibitors, corticosteroids, immunosuppressants) and plasmapheresis are discussed. The clinical usefulness and limitations of each of the drug classes and agents are described.

[Paraneoplastic neurological syndromes]

BACKGROUND

Paraneoplastic neurological syndromes constitute a heterogenous group of diseases, which often cause severe neurological symptoms. Extensive research during the last 20 years has led to identification of new antigenic targets and inclusion of additional clinical conditions into this group of syndromes.

MATERIAL AND METHODS

The article is based on a non-systematic search of PubMed and the author's own experience with antibody analysis, treatment of patients and research within the field.

RESULTS AND INTERPRETATION

Paraneoplastic neurological syndromes affect less than 1 % of all patients with cancer. The etiology is probably autoimmune, and involves immune responses (cellular and humoral) against antigens shared by tumor cells and normal neurons. Many, but not all patients harbour onconeural antibodies (in serum and spinal fluid), which are highly useful diagnostic markers for a paraneoplastic etiology. The cornerstone of therapy is treatment of the underlying tumor, but additional immunosuppressive therapy is often administered.

Atrophy of type II fibres in myasthenia gravis muscle in thymectomized patients: steroid-induced change with prognostic impact

Selective atrophy of type II muscle fibres has been long recognized as an enigmatic but consistent feature of myasthenia gravis (MG) muscle; however, the pathophysiology and the mechanism of that change have remained obscure. In the present study, the results of histomorphometric analysis performed on muscle biopsies from 207 thymectomized seropositive MG patients were correlated with clinical features of MG to demonstrate possible pathophysiological associations and potential prognostic impact. The atrophy of type II fibres was verified in 35 cases (16.9%), being more pronounced in fibres of IIB subtype. It was neither significantly associated with the duration and severity of MG nor with the age of the patients. On the other hand, we demonstrated that the atrophy associated with long-term treatment with corticosteroids, and correlated with increasing doses. Thus, we suppose that the atrophy of type II muscle fibres in seropositive MG is steroid induced rather than MG-associated event. Although the MG patients with atrophy of type II fibres did not differ from the remaining MG cases in terms of improvement in the disease during the follow-up period, our analysis provides clear evidence that they presented a significantly slower tendency to reach an asymptomatic state after thymectomy. Therefore, the steroid-induced atrophy of type II fibres in MG muscle might be considered to be an unfavourable prognostic factor.

Haptoglobin study in myasthenia gravis

OBJECTIVE: A cross-sectional study of haptoglobin (Hp) in myasthenia gravis (MG) was designed, with the objective to identify its values and correlate them with different disease status. METHOD: 46 patients were enrolled in the study, all having disease severity established according to the quantitative myasthenia gravis strength scores (QMGSS). Based on the functional scale determined by Myasthenia Gravis Foundation of America (MGFA) recommendations, patients were classified as having: complete stable remission (CSR; n=10); minimal manifestations-0 (MM0; n=6), minimal manifestations-1 (MM1; n=4); pharmacological remission (PR; n=6). Two other groups participated: thymomatous patients (T; n=10) and patients without imunosuppression or thymectomy, until the assessment for Hp (WIT; n=10). Hp dosage was done by immunonephelometry, blindly to clinical data. Student's t-test, Anova test and linear regression were employed for statistical analyses. RESULTS: Statistically significant differences occurred between CSR+MM0xWIT groups (86.62x157.57, p<0.001) and PR+MM1xWIT groups (73.93x157.57, p<0.001). Linear regression showed correlation between Hp levels and QMGSS (r=0.759, p<0.001). CONCLUSION: Our results suggest that Hp may be useful in clinical practice as a disease severity marker in MG.