IVIg in myasthenia gravis, Lambert Eaton myasthenic syndrome and inflammatory myopathies: current status

Intravenous immunoglobulin (IVIg) is an effective tool for the treatment of diseases with immune pathogenesis. This article reviews the current knowledge of the benefits of treating with IVIg patients with myasthenia gravis (MG), Lambert Eaton myasthenic syndrome (LEMS), dermatomyositis (DM), polymyositis (PM) and inclusion body myositis (IBM). Myasthenia gravis: Treatment of MG with IVIg was reported to be beneficial in a number of case series and two randomised controlled trials, in which efficacy was measured by clinical improvement using myasthenic muscle score and decrease in anti-acetylcholine receptor antibodies (AchRAb). According to the results, IVIg could be recommended for crisis and severe exacerbation. In many other clinical conditions, such as response to treatment of mild or moderate exacerbation, changes in steroid dosage and before thymectomy, IVIg has also been reported to be helpful, but no controlled trials to confirm its efficacy have been performed. Lambert-Eaton myasthenic syndrome: A placebo-controlled crossover study reported a significant clinical improvement in the amplitude of the resting CMAP following IVIg treatment. Further experience from case reports also indicates that IVIg is useful in patients with LEMS, both as a short- and long-term treatment, especially when immunosuppressive drugs are not fully effective. Inflammatory myopathies/dermatomyositis: In a double-blind placebo-controlled crossover trial in patients with DM resistant to other treatments, IVIg was shown to produce a significant increase of muscle strength as well as a marked improvement in immunopathological parameters in repeated muscle biopsies (before and after IVIg). Thus, IVIg is an important therapy in patients with DM resistant to other conventional therapies. Polymyositis: No randomised trials have been undertaken. One study showed clinical improvement and a reduction in the need of prednisone in patients with chronic refractory PM. Inclusion body myositis: Three controlled trials showed some muscle strength improvement, although the changes did not reach statistical significance. However improvement in swallowing was repeatedly observed, suggesting that some patients with severe dysphagia may derive a modest benefit from IVIg therapy. CONCLUSION: Controlled trials indicate that in MG, LEMS, and DM, IVIg at a total dose of 2 g/kg is a highly useful therapy. Uncontrolled trials and case reports indicate benefit in many different clinical situations, but further clinical investigation is required.     

Intravenous immunoglobulin maintenance treatment in myasthenia gravis: A randomized,controlled trial sample size simulation

Introduction: In cases of exacerbation or crisis, myasthenia gravis (MG) patients can be treated with intravenous immunoglobulin (IVIg), plasmapheresis, or immunoadsorption. However, IVIg efficacy data in maintenance treatment are sparse. Methods: We prospectively observed 16 index patients with chronic and insufficiently controlled MG under standard immunosuppressant therapy and symptomatic treatment. The IVIg treatment response was measured using changes in quantitative myasthenia gravis (QMG) score and surrogates. Based on these results, a sample size calculation for a future randomized, controlled trial (RCT) was simulated. Results: There was an enduring decline in QMG score and other parameters of about 50% under IVIg maintenance treatment. RCT sample size calculation results in 73 or 33 patients per arm to detect at least a 20% vs. 30% clinical difference in QMG score. Conclusion: We recommend using the QMG score as a primary endpoint for an RCT of IVIg maintenance for chronic MG. Muscle Nerve 50: 999–1004, 2014     

Myasthenic crisis: clinical features, complications and mortality

BACKGROUND AND OBJECTIVE: Myasthenic crisis is a life-threatening complication of myasthenia gravis (MG) and when treated aggressively is associated with good outcome. MATERIALS AND METHODS: Retrospective study of case records of patients with episodes of myasthenic crisis. RESULTS: Twenty-one (22%) of the 95 patients with MG (9 with thymoma), experienced 23 episodes of myasthenic crisis, 3 (33%) in patients with thymoma. The crisis episodes occurred within 2 years of disease onset in 11 (52%) patients. Infection was the most common primary precipitant of the crisis occurring in 65%. The median duration of the crisis episode was 11 days (7-39 days), and the median neurological intensive care unit stay was 15 days (range 9-47 days). Fifteen (65%) episodes were treated with small volume plasma exchange (PE) and 8 (35%) episodes received intravenous immunoglobulin (IVIg). The time taken for disease stabilization, the median number of days for extubation, was 8 days (range 7-12) in the PE group and 10 days (range 7-39) in the IVIg group. Disease stabilization could not be achieved in one patient in the IVIg group. Ventilator-associated pneumonia (VAP) was the commonest complication, seen in 30%. Two (8%) of the 23 episodes of crisis were fatal, one resulting from VAP and septicemia, and the other due to crisis itself. All the 19 patients who survived to discharge had complete resolution of admission symptoms. CONCLUSIONS: In patients with myasthenic crisis, both therapeutic options, PE and IVIg, are equally effective in disease stabilization. To achieve good outcomes all efforts should be directed at decreasing the duration of intubation and also aggressively treating the associated medical complications.     

Intravenous immunoglobulin in the preparation of thymectomy for myasthenia gravis

OBJECTIVES: A clinical trial including six patients was conducted to assess the effect of intravenous immunoglobulin (IVIg) in the preparation of thymectomy for patients with myasthenia gravis (MG). MATERIAL AND METHODS: Six consecutive patients of type IIB MG treated with IVIg at a dose 0.4 g/kg daily for 5 days before thymectomy were enrolled in this study. RESULTS: All patients responded positively to this treatment. Improvement began to occur 1-9 days after starting the injection (mean 3.33 days), and reached a maximum in 3-19 days (mean 6.50 days). Thymectomy was performed 9-13 days (mean 11.20 days) after starting the injection in five of the six patients with uneventful post-operative courses. CONCLUSION: IVIg might be an alternative to plasmapheresis (PE) in the prethymectomy preparation of MG patients, and thymectomy should be performed within 2 weeks after IVIg treatment to minimize the perioperative complications. Controlled trial vs PE enrolling more patients is needed to assess the significance of the IVIg in the preparation of thymectomy for patients of MG.     

Treatment of Myasthenia Gravis Based on Its Immunopathogenesis

The prognosis of myasthenia gravis (MG) has improved dramatically due to advances in critical-care medicine and symptomatic treatments. Its immunopathogenesis is fundamentally a T-cell-dependent autoimmune process resulting from loss of tolerance toward self-antigens in the thymus. Thymectomy is based on this immunological background. For MG patients who are inadequately controlled with sufficient symptomatic treatment or fail to achieve remission after thymectomy, remission is usually achieved through the addition of other immunotherapies. These immunotherapies can be classified into two groups: rapid induction and long-term maintenance. Rapid induction therapy includes intravenous immunoglobulin (IVIg) and plasma exchange (PE). These produce improvement within a few days after initiation, and so are useful for acute exacerbation including myasthenic crisis or in the perioperative period. High-dose prednisone has been more universally preferred for remission induction, but it acts more slowly than IVIg and PE, commonly only after a delay of several weeks. Slow tapering of steroids after a high-dose pulse offers a method of maintaining the state of remission. However, because of significant side effects, other immunosuppressants (ISs) are frequently added as "steroid-sparing agents". The currently available ISs exert their immunosuppressive effects by three mechanisms: 1) blocking the synthesis of DNA and RNA, 2) inhibiting T-cell activation and 3) depleting the B-cell population. In addition, newer drugs including antisense molecule, tumor necrosis factor alpha receptor blocker and complement inhibitors are currently under investigation to confirm their effectiveness. Until now, the treatment of MG has been based primarily on experience rather than gold-standard evidence from randomized controlled trials. It is hoped that well-organized studies and newer experimental trials will lead to improved treatments.     

抗体阴性重症肌无力的短程血浆置换疗法初探

血浆置换(plasma exchange,PE)在重症肌无力(MG)上的疗效已有报道,但缺乏明确一致的置换方案。我们对12例MG患者进行了37人次的短程PE,各例均在10d内行3～4次置换术,术前和术后第7天按Mantegazza肌力评分表进行临床疗效评定,结果除1例外,均获得肯定疗效,仅1人次发生较严重的副反应。4例抗体阴性病人置换后均获显著疗效,提示抗体阴性MG血浆中存在某些未知的致病因子。短程PE可供选择作为MG危象的治疗方案。     

Clinical predictors of steroid-induced exacerbation in myasthenia gravis

Although oral corticosteroids are effective for the treatment of myasthenia gravis (MG), the possibility of steroid-induced exacerbation of symptoms, especially during the initial course of steroid therapy, has limited their use patients with severe MG. However, the factors influencing or predicting in exacerbation are not well understood. The purpose of this study was to identify the clinical factors that predict the initial paradoxical exacerbation of MG in response to steroid therapy. Fifty-five consecutive patients who were administered for the first time high doses of prednisone (40-80 mg) in a tertiary medical centre in Seoul, were included. Prednisone-induced exacerbation was defined as a significant reduction in a patient's Myasthenia Gravis Severity Scale (MSS) score within 4 weeks of prednisone administration. We divided the patients into two groups on the basis of whether or not they experienced prednisone-induced exacerbation, and investigated the differences between the two groups with respect to clinical, laboratory and electrophysiological features. Twenty-three patients (42%) experienced definite exacerbation after prednisone therapy. Older age, predominantly severe bulbar symptoms, and low MSS score were found to be significant clinical predictors of exacerbation by multivariate logistic regression analysis. A high daily dosage of prednisone relative to body weight was found to be neither a predictor of exacerbation nor a predictor of early improvement in bivariate correlation analysis. Steroid-induced exacerbation in MG is a frequently encountered and challenging problem. Clinicians should be aware of the possibility of exacerbation of MG when prescribing prednisone, especially when treating elderly, bulbar dominant, or severely myasthenic patients.     

Oral corticosteroid therapy and present disease status in myasthenia gravis

Introduction: The aim of this study was to elucidate the effectiveness of oral prednisolone (PSL) according to dosing regimen in 472 patients with myasthenia gravis (MG). Methods: We compared the clinical characteristics and PSL treatment between 226 patients who achieved minimal manifestations (MM) or better and 246 patients who remained improved (I) or worsened, according to the MG Foundation of America postintervention status. Results: Achievement of MM or better at peak PSL dose (odds ratio 12.25, P < 0.0001) and combined use of plasma exchange/plasmapheresis (PE/PP) and/or intravenous immunoglobulin (IVIg) (odds ratio 1.92, P = 0.04) were associated positively, and total PSL dose during the past year (odds ratio 0.17, P = 0.03) was associated negatively with present MM or better status. Conclusions: Higher PSL dose and longer PSL treatment do not ensure better outcome. In the absence of a good response, the PSL dose should be decreased by combining with modalities such as PE/PP or IVIg. Muscle Nerve 51 :692–696, 2015     

Topical naphazoline in the treatment of myasthenic blepharoptosis

Introduction. When treating ocular myasthenia gravis (MG), the risk/benefit profile of corticosteroids is unclear, and acetylcholinesterase inhibitors are not very effective. We examined the efficacy of topical naphazoline in the treatment of myasthenic blepharoptosis. Methods. Sixty MG patients with blepharoptosis (32 with ocular symptoms only and 28 with mild generalized symptoms) were enrolled in a multicenter open trial of topical naphazoline. The effects were reported by patients via a questionnaire and were also confirmed for each patient at the clinic. Results. Among 70 eyes of 60 patients, 20 eyes (28.6%) of 17 patients (28.3%) exhibited a marked response (full eye opening), and 24 eyes (34.3%) of 20 patients (33.3%) showed a good response (adequate but incomplete eye opening). Topical naphazoline was evaluated as useful in the treatment of myasthenic blepharoptosis by >70% of the patients. Conclusions. Topical naphazoline was found to be an effective supplementary symptomatic treatment for myasthenic blepharoptosis. Muscle Nerve 44: 41–44, 2011.     

Intravenous immunoglobulin in the treatment of autoimmune neuromuscular diseases: present status and practical therapeutic guidelines.

This review summarizes the current status of intravenous immunoglobulin (IVIg) in the treatment of autoimmune neuromuscular disorders and the possible mechanisms of action of the drug based on work in vivo, in vitro, and in animal models. Supply of idiotypic antibodies, suppression of antibody production, or acceleration of catabolism of immunoglobulin G (IgG) are relevant in explaining the efficacy of IVIg in myasthenia gravis (MG), Lambert-Eaton myasthenic syndrome (LEMS), and antibody-mediated neuropathies. Suppression of pathogenic cytokines has putative relevance in inflammatory myopathies and demyelinating neuropathies. Inhibition of complement binding and prevention of membranolytic attack complex (MAC) formation are relevant in dermatomyositis (DM), Guillain-Barré syndrome (GBS), and MG. Modulation of Fc receptors or T-cell function is relevant in chronic inflammatory demyelinating polyneuropathy (CIDP), GBS, and inflammatory myopathies. The clinical efficacy of IVIg, based on controlled clinical trials conducted in patients with GBS, CIDP, multifocal motor neuropathy (MMN), DM, MG, LEMS, paraproteinemic IgM anti-myelin-associated glycoprotein (anti-MAG) demyelinating polyneuropathies, and inclusion body myositis is summarized and practical issues related to each disorder are addressed. The present role of IVIg therapy in other disorders based on small controlled or uncontrolled trials is also summarized. Finally, safety issues, risk factors, adverse reactions, spurious results or serological tests, and practical guidelines associated with the administration of IVIg in the treatment of neuromuscular disorders are presented.     

静脉注射人免疫球蛋白治疗全身型重症肌无力的短期疗效观察

目的观察静脉注射人免疫球蛋白(intravenous immunoglobulin, IVIg)治疗全身型重症肌无力(myasthenia gravis, MG)的短期临床疗效、安全性。方法纳入2016年1月至2019年9月期间北京医院就诊的58例Osserman分型Ⅱb及以上的全身型MG患者。收集患者一般信息、入院诊断、治疗用药情况,采用许氏绝对与相对评分法(the absolute and relative score of MG,ARS-MG)评估患者IVIg治疗前及治疗后7、14 d临床症状的改善情况,并比较不同年龄(<60岁和≥60岁)、病程(≤1年和>1年)以及有无构音障碍、咀嚼障碍、呼吸困难者间IVIg疗效的差异。结果 58例MG患者IVIg治疗后第7天许氏评分较治疗前降低[(17.21±10.52)分比(23.22±10.45)分,P<0.01]。IVIg治疗7 d时其总有效率为48.28%(n=58),治疗后14 d其总有效率为59.46%(n=37)。不同年龄、病程以及有无构音障碍、咀嚼障碍、呼吸困难者间IVIg疗效比较无统计学差异(均P>0...     

High-dose intravenous immunoglobulin therapy for myasthenia gravis

The objective of this open, retrospective study was to investigate whether intravenous immunoglobulin (IVIg) could induce a clinically obvious improvement in patients with generalized myasthenia gravis (MG), as judged by MG functional status. Fourteen patients with generalized MG were treated during at least one episode with 0.4 g IVIg per kilogram body weight per day for 5 consecutive days. Patients with confounding variables were excluded; this left 11 patients (16 episodes) to be further analysed. We defined improvement as at least a one-step improvement in MG functional status (according to the University of Virginia’s Modification of Osserman’s classification). Of the treatment episodes, 56% were classified as positive responses. If improvement occurred, onset of improvement started after 3 (1–12) days and peak effect was reached after 7 (4– 30) days (median and range). All four patients who required artificial ventilation could be weaned from it 8.5 (6–11) days after the start of IVIg (median and range). Of the patients treated on two occasions, only one patient had a positive response during both. In MG functional status 5, improvement was observed during five of seven episodes. None of the patients with MG functional status 3 responded. Patients with an acute relapse of MG seemed to respond equally well to IVIg compared with patients with subacute deterioration/ chronic-static state (50% versus 60%). The MG functional status at the start of IVIg and on the day of maximal improvement was compared for all episodes together, and significant improvement was noted (P = 0.0052). We did not see any serious side-effects after IVIg treatment. This retrospective analysis suggests that high-dose IVIg is an effective therapy in some patients with deterioration of generalized MG. If improvement occurs, it starts within a few days of the onset of IVIg and the effect seems to peak within 2 weeks. Received: 4 March 1997 Received in revised form: 28 August 1997 Accepted: 1 September 1997     

Plasma exchange versus intravenous immunoglobulin treatment in myasthenic crisis

We performed a retrospective multicenter chart review to compare the efficacy and tolerance of plasma exchange (PE) and intravenous immunoglobulin (i.v.Ig) in treatment of 54 episodes of myasthenic crisis. After adjustment for other variables, PE (compared with i.v.Ig) was associated with a superior ventilatory status at 2 weeks (partial F = 6.2, p = 0.02) and 1 month functional outcome (partial F = 4.5, p = 0.04). However, the complication rate was higher with PE compared with i.v.Ig (13 versus 5 episodes, p = 0.07).     

Plasma exchange in Guillain-Barré syndrome: One-year follow-up

We report the one-year assessment of plasma exchange (PE) versus control in Guillain-Barré syndrome (GBS), based on a randomized multicenter clinical trial of 220 patients with GBS. Treated patients received four PEs, with either albumin or fresh frozen plasma (FFP) as replacement fluid. This study completes the short-term analysis previously published (Ann Neurol 1987;22:753–761). Long-term benefit from PE was observed, as demonstrated by full muscular strength recovery at one year: 71% in the PE group versus 52% in the control group (p = 0.007), confirmed after adjustment for four prognostic factors. FFP showed no additional benefit compared with albumin (77% full recovery in the FFP group versus 65% in the albumin group; p = 0.22). PE did not affect the incidence of severe motor disability (11% in both groups).     

Treatment of myasthenia gravis exacerbation with intravenous immunoglobulin: a randomized double-blind clinical trial

BACKGROUND: The optimal dose of intravenous immunoglobulin (IVIG) in acute exacerbation of myasthenia gravis remains unknown. Increasing the treatment duration might provide added efficacy. OBJECTIVE: To determine the optimal dose of IVIG for treating myasthenia gravis exacerbation. DESIGN: Randomized double-blind placebo-controlled multicenter trial designed to demonstrate superiority of the 2 g/kg dose over the 1 g/kg dose of IVIG, conducted between November 13, 1996, and October 26, 2002. PARTICIPANTS: One hundred seventy-three patients aged 15 to 85 years with acute exacerbation of myasthenia gravis. INTERVENTION: Participants were randomly assigned to receive 1 g/kg of IVIG on day 1 and placebo on day 2 (group 1) vs 1 g/kg of IVIG on 2 consecutive days (group 2). MAIN OUTCOME MEASURE: Improvement in the myasthenic muscular score after 2 weeks. RESULTS: The mean improvements in the myasthenic muscular scores after 2 weeks were 15.49 points (95% confidence interval, 12.09-18.90 points) in group 1 and 19.33 points (95% confidence interval, 15.82-22.85 points) in group 2. However, the difference between the 2 groups was not significant (effect size, 3.84 [95% confidence interval, -1.03 to 8.71]; P = .12). CONCLUSION: This trial found no significant superiority of 2 g/kg over 1 g/kg of IVIG in the treatment of myasthenia gravis exacerbation.     

A new treatment regimen with high-dose and fractioned immunoglobulin in a special subgroup of severe and dependent CIDP patients

Background: Chronic inflammatory demyelinating polyneuropathy (CIDP) is treated with intravenous immunoglobulins (IVIg), corticosteroids or plasma exchange (PE). IVIg dosage is not universal and markers for treatment management are needed. Methods: We report the response to high-dose and fractioned IVIg in a subgroup of definite CIDP patients, resistant to corticosteroids and PE, responders to IVIg but with an efficacy window <15 d. Results: Four patients were included with similar predominantly clinical motor form and conduction abnormalities. Treatment management consisted of fractioning IVIg and increasing the monthly cumulated dose (mean: 3 g/kg/month). Serum IgG concentration was measured and correlated to the clinical state. Monitoring of serum IgG helped to guide IVIg administration dosage and frequency. A mean of 10 months was required to improve symptoms; therapy was then switched to subcutaneous (SC) route (maintenance dose: 3.5 g/kg/month). The mean Overall Neuropathy Limitations Scale was improved from 11 to 3.2 and the mean Medical Research Council scale from 26 to 90. Conclusion: It is important to distinguish patients with short IVIg efficacy window from those with classical resistance since the former may benefit from fractioning and increasing the IVIg dose. The monitoring of serum IgG level and its correlation to the clinical response could be of help in monitoring each individual's dosage.     

High dose intravenous immune globulins and plasma exchange in Guillain-Barré Syndrome

We report the effects of treatment with plasma-exchange (PE) and intravenous immune globulins (IVIg) in 36 out of 50 patients with Guillain-Barré syndrome (GBS) recruited by an incidence study in the Emilia-Romagna region of Italy. Comparison of the patients treated with PE and IVIg showed no significant differences in terms of effectiveness in improving the clinical course of GBS: at one month, respectively 11.1% and 25% had recovered, and 55.5% and 58.3% had improved by at least one grade. These results are in agreement with those of the Dutch GBS trial. No relapses were observed in either group. Moreover, our results showed no difference in clinical outcome at 1 and 3 months between the patients receiving only one therapy and those receiving two; a second cycle of therapy did not seem to improve the clinical course of the disease significantly. We conclude that PE and IVIg are both safe and effective therapies for GBS.     

Burden of illness in patients with treatment refractory myasthenia gravis

Introduction: This study assessed the clinical burden of refractory myasthenia gravis (MG), relative to nonrefractory MG. Methods: Rates of myasthenic crises, exacerbations, inpatient hospitalizations, and emergency room (ER) visits over a 1‐year period were measured for 403 refractory, 3,811 nonrefractory, and 403 non‐MG control patients from two administrative health plan databases. Results: Compared with nonrefractory patients, a significantly greater percentage of refractory patients had at least one myasthenic crisis (21.3% vs. 6.1%; P < 0.001) and at least one exacerbation (71.2% vs. 32.4%; P < 0.001) over a 1‐year period. Refractory patients were also significantly more likely to be hospitalized and/or have an ER visit than nonrefractory patients and non‐MG controls (P < 0.001 for all). Discussion: Refractory MG patients have significantly greater clinical burden and are more likely to utilize intensive healthcare resources than nonrefractory patients. Furthermore, refractory patients may be at greater risk of crises throughout the disease course than previous studies have suggested. Muscle Nerve 58 : 99–105, 2018     

静脉注射免疫球蛋白与血浆置换治疗重症肌无力的meta分析

目的系统评价静脉注射免疫球蛋白(IVIg)与血浆置换(PLEX)治疗重症肌无力(MG)的有效性和安全性。方法计算机检索Cochrane图书馆、Pubmed、Embase、CNKI及万方数据库,系统收集国内外有关这两种方式治疗MG的相关文献。按系统评价的方法,由2名研究员独立对文献进行质量评价和资料提取后,采用Rev Man 5.2软件进行Meta分析。结果共纳入9篇文献,合计2132例MG患者。Meta分析结果显示,IVIG与PLEX治疗MG的有效性无明显差异[OR=0.94,95%CI(0.57,1.32),P=0.79];IVIg与PLEX的治疗相关不良反应发生率也无明显差异[OR=0.91,95%CI(-0.37,2.21),P=0.83]。结论 IVIG与PLEX对MG的治疗效果以及治疗相关的不良反应发生率均无明显差异,因此,临床上可根据具体情况选择合适的治疗方式。