Azathioprine as a single drug or in combination with steroids in the treatment of myasthenia gravis

Autoimmune myasthenia gravis: emerging clinical and biological heterogeneity

Acquired myasthenia gravis (MG) is an autoimmune disorder of the neuromuscular junction in which patients experience fluctuating skeletal muscle weakness that often affects selected muscle groups preferentially. The target of the autoimmune attack in most cases is the skeletal muscle acetylcholine receptor (AChR), but in others, non-AChR components of the neuromuscular junction, such as the muscle-specific receptor tyrosine kinase, are targeted. The pathophysiological result is muscle endplate dysfunction and consequent fatigable muscle weakness. Clinical presentations vary substantially, both for anti-AChR positive and negative MG, and accurate diagnosis and selection of effective treatment depends on recognition of less typical as well as classic disease phenotypes. Accumulating evidence suggests that clinical MG subgroups might respond differently to treatment. In this Review, we provide current information about the epidemiology, immunopathogenesis, clinical presentations, diagnosis, and treatment of MG, including emerging therapeutic strategies.

Ocular myasthenia: diagnostic and treatment recommendations and the evidence base

PURPOSE OF REVIEW

Increasing rigor is being applied to medical decision making, but myasthenia gravis, commonly considered the best understood autoimmune disorder from a pathophysiological basis, lags other disciplines in the evidence base used to make clinical decisions. The review attempts to provide a focused, practical guideline for the diagnosis and treatment of ocular myasthenia within the limits of largely retrospective case series and expert opinion.

RECENT FINDINGS

Confirmation of clinical diagnosis continues to be challenging for ocular myasthenia. Despite the recognition of a new autoantigen, the muscle-specific kinase protein in generalized myasthenia gravis, it has been found to be only rarely identified in ocular myasthenia patients and therefore the majority of patients lack detectable autoantibodies and confirmation of a neuromuscular transmission disorder relies on specialized testing of single-fiber electromyography. The visual compromise of ocular myasthenia responds poorly to nonpharmacological and cholinesterase inhibitor therapy, and although corticosteroids are thought to be extremely effective, their toxicity is poorly defined in ocular myasthenia patients and whether they reduce the risk of development of generalized disease is not known.

SUMMARY

Rigorous clinical trials or large databases with outcome assessments are necessary in order to allow development of rational treatment strategies.

Immunosuppressive agents for myasthenia gravis

BACKGROUND

The benefits of different immunosuppressants for myasthenia gravis (MG) are unclear.

OBJECTIVES

Assessment of immunosuppressant drug efficacy in MG.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Trials Register, MEDLINE (from January 1966 to July 2007), EMBASE (from January 1980 to July 2007), review and trial bibliographies and contacted trial authors.

SELECTION CRITERIA

Types of studies: Randomised and quasi-randomised controlled trials.

TYPES OF PARTICIPANTS

Any age, any type or severity of MG regardless of concomitant treatment. Types of interventions: Any immunosuppressive agent. Types of outcome measures: Primary: (1) Improvement or not at six months. Secondary: (1) Improvement or not at one year (2) Need for other treatment, for example corticosteroid dose, at six months (3) Number of exacerbations during the first year (4) Acetylcholine receptor antibody titre after at least six months (5) Occurrence of one or more adverse events at any time after the introduction of treatment.

DATA COLLECTION AND ANALYSIS

One author extracted and two checked the data.

MAIN RESULTS

Seven trials are included but few reported the outcomes selected for this review. A meta-analysis of ciclosporin versus placebo from two trials (59 participants) - one as monotherapy (20 participants) and the other with corticosteroids (39 participants) - showed that it resulted in improvement of participants in the ciclosporin group compared with those in the placebo group, with a relative rate of improvement of 2.44 (95% confidence interval (CI) 1.13 to 5.27). In addition the weighted mean difference in QMG score between the ciclosporin and placebo groups was -0.34 (95% CI -0.52 to -0.17). Azathioprine (plus prednisolone for first month) had no significant benefit over prednisolone alone (41 participants). The effects of azathioprine plus prednisolone versus prednisolone plus placebo were similar (34 participants). Cyclophosphamide was reported to be statistically more efficacious than placebo at 12 months in corticosteroid-dependent participants (23 participants), but no raw data were available. Trials of mycophenolate mofetil and tacrolimus did not provide relevant endpoint data for this review. All trials had low numbers of participants. Adverse event reporting was variable. Trial protocol heterogeneity prevented comparison of the different immunosuppressants.

AUTHORS' CONCLUSIONS

In generalised MG, limited evidence from small RCTs suggests that ciclosporin, as monotherapy or with corticosteroids, or cyclophosphamide with corticosteroids, significantly improve MG.Limited evidence from RCTs shows no significant benefit from azathioprine (as monotherapy or with steroids), mycophenolate mofetil (as monotherapy or with either corticosteroids or ciclosporin) or tacrolimus (with corticosteroids or plasma exchange). Bigger, better-designed, longer trials are needed.

Ocular myasthenia: diagnosis, treatment, and pathogenesis

BACKGROUND

Although myasthenia gravis (MG) is often considered the best-understood autoimmune disorder and effective treatments have controlled life-threatening complications, the pathogenesis of ocular myasthenia (OM) remains enigmatic, and its clinical consequences offer therapeutic challenges.

REVIEW SUMMARY

About half of patients with MG present with visual complaints of droopy eyelids or double vision, and many will remain with purely ocular muscle weakness without generalized weakness, defined as OM. OM may be confused with disorders of the brainstem, ocular motor nerves, and eye muscles. Frustrating for the clinician, confirmatory tests such as the edrophonium test, serum acetylcholine receptor antibodies, and standard electrodiagnostic evaluations may fail to positively identify the clinical suspicion of OM. Patients may derive relief from nonpharmacologic interventions and cholinesterase inhibitors, but most will desire better symptom control with corticosteroids or need other immunosuppression. Early corticosteroid therapy may reduce the probability of generalization of the disease. The reasons for ocular muscle involvement by OM include physiologic and cellular properties of the ocular motor system and the unique immunology of OM, which, when better understood, will lead to novel treatments.

CONCLUSIONS

OM is a challenging disorder for the clinician and scientist, with both learning from the other for the betterment of the patient. The future requires answers to why the ocular muscles are so frequently involved by MG, whether the generalization of the disease may be limited by early corticosteroid treatment, and what treatment options may be developed which will improve symptoms without long-term complications.

Activation of humoral immunity and eosinophils in neuromyelitis optica

OBJECTIVE

To study immunologic alterations in patients with neuromyelitis optica (NMO).

METHODS

The authors studied 8 patients with NMO together with 16 healthy subjects, 16 patients with relapsing remitting multiple sclerosis (RRMS), and 16 patients with secondary progressive MS (SPMS), matched for age and sex, as controls. Because recent histopathologic studies have demonstrated that active NMO lesions consist of perivascular immunoglobulin (Ig) deposition and eosinophil infiltration, IL-5, IL-6, IL-12, IgG, and IgM production by anti-myelin oligodendrocyte glycoprotein (MOG) mononuclear cells in peripheral blood and CSF were selected for study using ELISPOT. Eotaxin-2 (Eo-2) and eotaxin-3 (Eo-3) levels were also assessed using ELISA and eosinophil cationic protein (ECP) levels by radioimmunoassay.

RESULTS

MOG-specific responses in CSF showed significant increase in IL-5, IL-6, IgG, and IgM secreting cells in NMO patients compared with patients with RRMS, SPMS and healthy subjects. Interestingly, numbers of IgM secreting cells were significantly higher than identical specificity IgG secreting ones. Moreover, CSF Eo-2, Eo-3, and ECP levels were also significantly higher in NMO patients compared to all three control populations. Anti-MOG IL-12 secreting cells were increased in CSF and peripheral blood from NMO, RRMS, and SPMS patients when compared to healthy subjects.

CONCLUSIONS

These observations suggest that neuromyelitis optica is associated with a major humoral immune response (particularly anti-MOG IgM production) and eosinophil activation present exclusively in CSF.

Mycophenolate mofetil and myasthenia gravis

Myasthenia gravis (MG) represents the prototypic autoimmune disorder with well characterized immunopathology. Advances in the diagnosis and treatment of this neuromuscular transmission disorder have significantly improved the management of myasthenic patients. Unfortunately the currently available immunomodulating treatments have significant side effects and some patients do not tolerate them or adequately respond to them. Therefore the possibility of a new immunosuppressant agent that is safe, effective and has steroid-sparing effect is very appealing. Mycophenolate mofetil (MMF) has shown promising effects in MG patients in preliminary studies and is currently being studied in two prospective, randomized, double-blind, placebo controlled, multicenter trials to better establish its role in the treatment of MG.

Treatment review and update for myasthenia gravis

Myasthenia gravis (MG) is the best understood autoimmune disease, with well-characterized humoral and cellular effector mechanisms. It is not surprising, therefore, that immunotherapies play a key role in the management of MG. Significant progress has been made over the last few decades in the treatment of patients with MG, and the number of effective avenues of therapy continue to increase. In this review, we provide an update on management options in MG, highlighting recent literature on both traditional and more novel approaches.

Increase of circulating CD4+CD25+ T cells in myasthenia gravis patients with stability and thymectomy

BACKGROUND

CD4(+)CD25(+) regulatory T cells are key controllers of peripheral immunological self-tolerance and suppress various autoimmune diseases in animal models, but few studies have been done to define their roles in myasthenia gravis (MG) so far.

OBJECTIVE

To investigate frequencies and dynamic changes of blood CD4(+)CD25(+) T cells from MG patients.

METHODS

The peripheral blood CD4(+)CD25(+) T cells of 29 MG patients and 23 healthy controls were detected by three-color flow cytometry.

RESULTS

Myasthenic patients with symptomatically uncontrollable disease showed slightly lower percentages of CD4(+)CD25(+) T cells (mean = 3.79 +/- 1.40%; P = 0.12), whereas MG patients with clinically stable disease had significantly increased CD4(+)CD25(+) T cells (mean = 8.45 +/- 1.96%, P = 0.0001), as compared with healthy controls (mean = 4.53 +/- 0.96%). In addition, thymectomized MG patients had significantly higher percentages of CD4(+)CD25(+) T cells (mean = 8.44 +/- 2.39%), as compared with both non-thymectomized MG patients (mean = 5.88 +/- 2.89%, P = 0.038) and healthy controls (P = 0.003).

CONCLUSIONS

Our observations indicate that increased percentages of CD4(+)CD25(+) T cells in MG patients may be related to disease stability and that thymectomy in patients with MG resulted in augmented CD4(+)CD25(+) T cells.

The molecular era of myology

This review covers, in general terms, the salient features and impact of molecular myology under the following headings: its role in providing clues for the understanding of molecular etiology and pathogenesis of genetic myopathies, its contribution to the modernization and rationalization of the classification of muscle diseases, providing means of precise diagnosis and prevention of myopathies, development of radically new cell and gene therapies, and determination of future research directions. Myology appears to be among the medical disciplines that have benefited a great deal from molecular science. This remarkable progress will hopefully translate into effective treatment capabilities in the near future.

Myasthenia gravis (MG): epidemiological data and prognostic factors

Data from 756 myasthenic patients were analyzed for diagnostic criteria, clinical aspects, and therapeutic approaches. The patients were followed up at our institution from 1981 to 2001. Clinical evaluation was performed according to the myasthenia gravis score adopted at our clinic. Clinical features of each patient (comprising demographic, clinical, neurophysiological, immunological, radiological, and surgical data, as well as serial myasthenia gravis scores) were filed in a relational database containing more than 7000 records. Clinical efficacy and variables influencing outcome were assessed by life-table methods and Cox proportional hazards regression analysis. Complete stable remission, as defined by the Task Force of the Medical Scientific Advisory Board of the Myasthenia Gravis Foundation of America, was the end point for good prognosis. Four hundred and ninety-nine patients (66%) were female and 257 (34%) were male. Mean follow-up was 55.1 +/- 48.1 months. Onset of symptoms peaked in the third decade in females, whereas the male distribution was bimodal with peaks in the third and sixth decades. Modality of myasthenia gravis presentation was as follows: ocular, 39.3%; generalized, 28.5%; bulbar, 31.3%; and respiratory, 0.8%. Thymectomy was carried out on 63.7% of our patients by different approaches: (1) transcervical; (2) transsternal; (3) video-thoracoscopic mini-invasive surgery. The last approach has been preferentially used in more recent years and accounted for 62.4% of the thymectomized myasthenia gravis population. Univariate analysis and Kaplan-Meier analysis showed that variables such as sex (female), age at onset (below 40 years), thymectomy, and histological diagnosis of thymic hyperplasia were significantly associated with complete stable remission, whereas on multivariate analysis only age at onset below 40 years and thymectomy were confirmed.

Video-assisted thoracoscopic extended thymectomy and extended transsternal thymectomy (T-3b) in non-thymomatous myasthenia gravis patients: remission after 6 years of follow-up

The aims of this study were to assess the efficacy of video-assisted thoracoscopic extended thymectomy (VATET) as a treatment for myasthenia gravis (MG) and to identify prognostic factors for thymectomy success. Clinical efficacy and variables influencing outcome were assessed by life-table and Cox proportional hazards regression analysis. Complete stable remission (CSR), as defined by the MGFA Medical Task Force, was the end point for efficacy. VATET was performed in 159 MG patients and T-3b in 47 MG patients. At 6 years of follow-up, CSR, assessed by life-table analysis, was 50.6% in non-thymomatous VATET patients and 48.7% in non-thymomatous T-3b surgery. By univariate analysis, the presence of thymic hyperplasia (P=0.0002) and treatment only with anticholinesterases (P<0.0001) were positively associated with the probability of CSR. By multivariate analysis, the chance of complete remission was significantly increased by the use of anticholinesterases (odds ratio [OR] 2.45; 95% confidence interval [CI] 1.44-4.17; P=0.001) and the presence of thymic hyperplasia (OR 1.96; 95% CI 1.05-3.68; P=0.036). VATET seems to be effective in inducing CSR in MG with an efficiency similar to that of the T-3b transsternal (TS) approach; it is easy to perform in experienced hands and is associated with low morbidity and negligible esthetic sequelae.

Long-term follow-up of myasthenia gravis patients with hyperthyroidism

OBJECTIVE

To access clinical characteristics and treatment outcome of myasthenia gravis (MG) patients with hyperthyroidism (HT).

MATERIALS AND METHODS

The clinical characteristics of 51 MG patients with HT were studied. The treatment outcome was analysed in 34 patients, comparing high-dosage prednisolone (HDP) (group IS), HDP and/or immunosuppressants with antithyroid drugs (group IS + antiHThyr), antithyroid drugs (group antiHThyr), and thymectomy.

RESULTS

The prevalence of HT in MG was 17.5%. Group IS showed higher remission of both diseases compared with group antiHThyr, but not with group IS + antiHThyr. Remission of HT and relapse of both diseases showed no difference among the three groups. Ten patients who had thymectomies had a lower relapse of MG but not of HT, whilst remission of both diseases was no different to 24 non-thymectomy patients.

CONCLUSION

This study showed a high prevalence of HT in Thai MG. HDP alone can induce remission of both diseases without difference in relapse. Thymectomy lowers MG relapse further but has no influence on HT.

Myasthenia gravis

BACKGROUND

In myasthenia gravis (MG), the prototypic autoimmune disease, antibodies against acetylcholine receptors impair neuromuscular transmission and produce weakness. Although recognized for several hundred years, it has only been over the last three decades that effective treatments have become available for MG.

REVIEW SUMMARY

This review summarizes the principles of normal neuromuscular transmission, the clinical features of MG, and the tests available for its diagnosis. The current treatments for MG are discussed, including possible mechanisms of action and a discussion of potential adverse effects. When available, evidence-based justification for individual treatment options is given, and areas of controversy identified.

CONCLUSIONS

Significant improvements in the diagnosis and management of MG have been made over the last several decades. The available treatments either improve neuromuscular transmission directly, or suppress or modulate the pathogenic immune response in MG. Treatment is highly individualized and must take into account the severity of disease, the presence of other diseases, and the kinetics of response for the available treatments. This requires detailed knowledge of the mechanisms of action and possible adverse effects for each treatment. However, despite an optimistic outlook with modern treatment, the management of MG continues to be plagued by lack of efficacy in some, and significant adverse effects in most MG patients.

Myasthenia gravis: options and timing of immunomodulatory treatment

The autoimmune pathogenesis of myasthenia gravis is relatively well understood. The current options for treatment of this disease are acute and long term immunotherapies, acetylcholinesterase inhibitors and thymectomy. Many factors influence the timing of initiation of immunomodulatory therapy in myasthenia gravis and both disease factors, such as stage and severity, and patient factors, such as age, pregnancy and intercurrent illness, must be considered. Decisions regarding the choice of therapy can be difficult because of the limited number of randomised controlled trials that have been performed in myasthenic patients. In general, acetylcholinesterase inhibitors alone are used only in mild ocular disease, and in the majority of other patients immunomodulatory therapy is begun early. Corticosteroids are the most commonly used initial therapy, followed by azathioprine. In refractory cases, the available options include immunosuppressants such as cyclosporin, mycophenolate mofetil and cyclophosphamide. Plasmapheresis and intravenous immunoglobulin are important in the treatment of acute exacerbations and myasthenic crisis and in the perioperative setting. Despite many years of experience, the role of thymectomy in improving long term outcome in nonthymomatous myasthenia gravis remains controversial.

Immunosuppressive treatment of ocular myasthenia gravis

Myasthenia gravis (MG) is caused by autoantibodies against proteins at the neuromuscular junction. This autoimmune process leads to abnormal fatiguability and weakness of striated muscle. Ptosis and diplopia are among the most common manifestations of MG. The term "ocular MG" (OMG) as opposed to "generalised MG" (GMG) is used to define the clinical subtype of MG with isolated eye muscle weakness. Although OMG may appear to cause only moderate disability, it can significantly impair the patient's activities of daily living and progress to generalised myasthenia. Therefore, a clear management plan should be installed early in these patients. Since prospective treatment trials have not been performed, basic management strategies for OMG have to be deduced from retrospective studies, trials in GMG, and generally accepted clinical experience. Cholinesterase inhibitors are used in all types of MG, but are often less helpful in OMG. In the absence of thymoma, thymectomy is usually not considered in OMG, although a few studies have described histological abnormalities in thymuses from patients with OMG. Corticosteroids are of great short term benefit in most patients with OMG but potential adverse effects limit their long term use. Azathioprine is needed to reduce long term corticosteroid adverse effects, but this agent requires about 6 months to be effective. In summary, OMG has a good prognosis in most patients, with corticosteroids and azathioprine being the major treatment options. The challenges for the clinician are to recognise the condition despite the large number of differential diagnoses, to minimise the patient's symptoms using the therapies available and to carefully limit potentially hazardous therapeutic efforts, especially in mild or even uncertain cases.

The management and outcome of patients with myasthenia gravis treated acutely in a neurological intensive care unit

The management and clinical course of patients with myasthenia gravis admitted to a neurological intensive therapy unit (ITU) over a 66 month period were reviewed. Twenty-seven patients were admitted in myasthenic crisis, eight of whom had multiple admissions. One patient had a cholinergic crisis and a further patient an acute myocardial infarction. A specific aetiological factor precipitating myasthenic crisis was identified in 19 instances: infection (8), reduction in medication (5), menstruation (4), and steroid administration (2). Thirteen patients with crisis had had a previous thymectomy, six with thymoma. Twenty-three out of 35 (66%) patients admitted in crisis required intubation; nine subsequently needed a tracheostomy. Twenty-nine patients received plasma exchange and seven intravenous immunoglobulin. Four patients in myasthenic crisis died in ITU [adult respiratory distress syndrome (1), disseminated intravascular coagulation and cytomegalovirus (CMV) pneumonitis (1), cardiac failure (1) and multiple organ failure (1)]. Appropriate management of myasthenia gravis requires the easy availability of specialised neuro-intensive care facilities. Copyright Rapid Science Ltd

Thymectomy: its role in the management of myasthenia gravis

The management and clinical course of patients with myasthenia gravis admitted to a neurological intensive therapy unit (ITU) for thymectomy over a 66 month period were reviewed. There were 53 patients, 20 male and 33 female, mean age 35.2 years (18-74) and median ITU stay of 5 days (2-30). Indications for thymectomy were thymic enlargement on computed tomography (34%), persistence of generalized symptoms (38%), a combination of both (20%), steroid side effects or dependency (4%) and progressive bulbar symptoms (4%). Following thymectomy, thymic histology revealed thymic follicular hyperplasia (26/53; 49%), atrophy (11/53; 21%), thymoma (12/53; 23%) and normal thymus (4/53; 8%). Post-operatively 23% required prolonged intubation (> 48 hrs); two patients required a tracheostomy 10 and 13 days post-operatively. Plasma exchange was required for two patients (3.8%) due to persistent severe myasthenic weakness. Three patients (6%) developed a post-operative chest infection and one pseudomembranous colitis. There were no post-operative mortalities during the study period. After 2 years, 35% of patients were in remission and 46% had ocular or mild generalized symptoms only. Thymectomy for myasthenia gravis is followed by sustained clinical improvement in the majority of patients. The appropriate post-operative management of these patients is best undertaken in a specialized neuro-intensive care setting. Copyright Rapid Science Ltd

Alpha interferon treatment in myasthenia gravis: effects on natural killer cell activity

The efficacy of recombinant interferon-alpha (rIFN alpha), on natural killer (NK) cell cytotoxic activity, CD3+, CD4+, CD8+, CD56+, HLA-DR+ lymphocyte counts, anti-acetylcholine receptor antibody (AChR Ab) levels, single fibre electromyography findings (SFEMG) and clinical course were evaluated in patients with myasthenia gravis (MG). During the IFN alpha treatment (3 mu, subcutaneous, 3 times a week), NK cell cytotoxicity and CD4+/8+ ratio increased, NK cell count remarkably decreased, and no significant clinical or SFEMG changes were observed. This preliminary open study in MG patients has demonstrated enhanced NK activity per unit NK cell after IFN alpha therapy. Although lymphocyte phenotypes and NK function approached normal levels during therapy, a higher dose of IFN alpha may be required for a significant clinical response. It has been also concluded that 6 months of IFN alpha therapy seems to be safe in MG, though in patients with malignancy, IFN alpha may cause increased autoimmunity, AChR positivity and MG.

Plasmapheresis in severe forms of myasthenia gravis

In this study we introduce a new combination treatment of plasma exchange (PE) and high daily doses of prednisone for severe forms of myasthenia gravis (MG). The clinical efficacy of the combined therapy has been tested in 18 patients suffering from severe forms of MG. The protocol included 5 sessions of PE, performed in a range of 15 days, 1 session every 3 days, with concurrent administration of oral prednisone (1 mg/kg of body weight), starting at the first session of PE and given daily for at least 3 months. At the end of the entire cycle of PE, almost complete recovery (more than 90% of the initial clinical score) was obtained in 8 of 18 patients while an improvement between 60 and 90% of the initial score was achieved in 9 of 18 patients. An early improvement was noted 24 h after the beginning of plasmapheresis in 11 of 18 patients. No recurrence of symptoms was reported after 36 months of follow-up for 17 patients. The administration of steroid therapy was never followed by an early exacerbation of myasthenic symptoms as reported when it is administered in the absence of concomitant PE. According to our results, we can conclude that high doses of oral prednisone therapy in simultaneous association with PE lead to successful control of severe forms of MG, significantly superior to the therapeutic strategies until now adopted and reported in literature.

Detection of antibody classes and subpopulations in myasthenia gravis patients using a new nonradioactive enzyme immunoassay

To investigate the presence of antibodies in myasthenia gravis (MG) patients, we have developed a new reproducible and sensitive enzyme immunoassay (EIA-AChR), in which a beta subunit-specific monoclonal antibody (mAb 73) immobilizes fetal calf acetylcholine receptors (AChRs). We tested 92 MG patients (42 with positive and 50 with negative antibody titers), 60 healthy controls, and 40 controls with other autoimmune diseases. EIA-AChR detected immunoglobulin G (IgG) titers in all of the seropositive samples, with a significant correlation between these and those obtained using the traditional immunoprecipitation method. Moreover, 5 seronegative patients at immunoprecipitation assay were positive at EIA-AChR. EIA-AChR was also useful in revealing: (1) a seropositive patient subpopulation with generalized MG who had Abs directed against alpha-Bungarotoxin binding sites; and (2) patients with IgM directed against fetal calf AChR (detected in 13 seronegative and 16 seropositive MG patients, and in 6 of the patients with other autoimmune diseases).

Reliable disability scale for myasthenia gravis sensitive to clinical changes

INTRODUCTION

we developed a disability scale to monitor myasthenia gravis (MG) patients, based on degree of function impairment and daily frequency of each symptom.

MATERIAL & METHODS

the scale was based on standardized questions and clinical examination. The scale was administered to 12 patients, one or more times, for a total of 22 interviews. Each observation was recorded on videotape and reviewed by five independent observers. The ability of our scale to discriminate clinical changes was also compared with the Osserman classification.

RESULTS

our scale showed from substantial to almost perfect inter and intraobserver agreement. Our findings showed that clinically relevant changes not detected by Osserman staging were disclosed by our scale.

CONCLUSION

our scale is simple and easy to use in clinical practice. It offers an accurate means of evaluating disability in MG patients and may detect clinically relevant changes in disability. It would therefore be useful to monitor the effects of therapy.

Changes in peripheral blood lymphocyte subset frequencies in myasthenia gravis patients are related to immunosuppression

Surface antigens on peripheral blood lymphocytes from myasthenia gravis patients were investigated. The expression of DR+ and CD8+/DR+ T lymphocytes was increased and the expression of CD4+ T cells reduced. Neither thymectomy, clinical condition nor anti-acetylcholine receptor antibody titre correlated with any of the changes in peripheral blood lymphocyte subsets observed. However, immunosuppressive therapy correlated with the significant reduction in CD4+ and CD2+/CD4+ T cells in these patients.

Efficacy of intranasal administration of neostigmine in myasthenic patients

The efficacy of intranasally administered neostigmine was tested in 22 patients with generalized myasthenia gravis (MG). Topical therapy to the highly vascularized oropharynx proved to be quickly effective in 5-15 min both clinically and electrophysiologically. Twenty-eight MG patients were then recruited from different centres and their morning doses of oral pyridostigmine were substituted with intranasal neostigmine over a period of 2 or 3 weeks. Intranasal neostigmine proved to be equally efficacious in this regimen. No side-effect was noted even in 4 patients treated in this way for 1 year. Intranasal administration of anti-acetylcholinesterase may be very beneficial: (1) for patients with irregular absorption of oral doses; (2) early in the morning and every time a fast and temporary effect is needed; (3) in bulbar impairment and emergencies, in which a handy atomizer may be life-saving.

Acute treatment of myasthenia gravis with intranasal neostigmine: clinical and electromyographic evaluation

The effectiveness of intranasal neostigmine (9.3-13.8 mg) was tested in 20 subjects with myasthenia gravis, classified as Osserman grades 2A and 2B. In all cases the drug produced significant clinical and electromyographic improvement. No side effects were reported during the treatment.

Effect of thymectomy and immunosuppressive therapy on anti-neuroblastoma antibody levels in patients with myasthenia gravis

Antibodies reacting with human neuroblastoma cells (NBL) are distinct from the "classical" anti-acetylcholine receptor (AChR) antibodies in myasthenia gravis (MG). The influence of therapeutic interventions on serum anti-NBL antibody levels was followed in 42 MG patients. Thymectomy alone was performed in 28 patients while immunosuppressive medication was given to 14 patients out of whom 10 also had a thymectomy. In most patients serum anti-NBL antibody titers declined after thymectomy and/or during immunosuppressive treatment, though individual variations in the antibody response could be observed. Sequential examinations of individual patients revealed an association between the clinical severity of MG and anti-NBL antibody levels. No correlation between the treatment-induced changes of anti-NBL and anti-acetylcholine receptor (AChR) antibody titers could be observed during the follow-up period in MG patients positive for both types of antibodies. These findings further emphasize the immunological complexity of MG. Anti-NBL antibodies represent a pathogenic marker of the disease and display a regulation different from that of the anti-AChR antibodies.

A short plasma exchange protocol is effective in severe myasthenia gravis

Plasma exchange has been reported to be a successful therapeutic procedure for the treatment of severely compromised myasthenic patients, but the optimal regimen in terms of costs or clinical benefit has not so far been determined. We have investigated the efficacy of a short plasmapheresis protocol of two exchanges 1 day apart in a series of 70 patients with severe forms of myasthenia gravis. Patients were evaluated before and 7 days after the first exchange. A positive outcome was observed in 70% of the plasma exchange cycles performed. Disease severity did not seem to be a negative prognostic factor for the efficacy of this short protocol, which was well tolerated by patients. In only 1 case were major side-effects observed. In spite of its short duration, the exchange treatment plus concomitant immunosuppressive drug therapy was not followed by early clinical deterioration.

Azathioprine in myasthenia gravis: observations in 41 patients and a review of literature

We report azathioprine treatment of 41 patients with myasthenia gravis, with a follow-up of more than 3 yr. The data show that azathioprine is effective in controlling the disease, both as a single drug as well as in combination with prednisone. In addition it may be steroid sparing. Older patients derived more benefit from the medicament. Side-effects could be managed fairly well, except for one patient who developed a non-Hodgkin lymphoma. Data from this study do not support the supposition that the therapeutic effect of azathioprine is dependent on macrocytosis. Fluctuations of serum levels of antibodies to the acetylcholine receptor were simultaneous with clinical changes and thus were not of predictive volume for the clinical course.

Myasthenia gravis

Myasthenia Gravis is a disorder of neuromuscular function resulting from an immunologically based premature destruction of acetylcholine receptors. The disease is characterized clinically by variable weakness accentuated by repetitive muscular activity and usually responding to the administration of acetylcholinesterase inhibitors. Myasthenia Gravis is a complex disease and requires understanding of the many facets of its natural history and immunological basis to ensure optimal individual patient management. The long-term goal is control of the immunological imbalance; treatment regimens include thymectomy, corticosteroids, azathioprine, and plasmapheresis. The common use of acetylcholinesterase inhibitors provides symptomatic relief during variable daily muscular activity. Disability due to myasthenia gravis is to a large extent reversible and death is preventable. Early recognition of myasthenia gravis and appropriate treatment are often rewarded by remission that may be permanent.