The six year experience of plasmapheresis in patients with myasthenia gravis

Greater Number of Plasma Exchanges Does Not Improve Outcome in Myasthenic Crisis

OBJECTIVES

To determine the relationship between the number of plasma exchanges and clinical outcome in patients experiencing myasthenic crisis.

METHODS

We retrospectively reviewed all episodes of myasthenia gravis exacerbation/crisis who received plasmapheresis in patients admitted to a single-center tertiary care referral center from July 2008 to July 2017. We performed statistical analyses to determine whether the increased number of plasma exchanges improves the primary outcome (hospital length of stay) and the secondary outcome (disposition to home, skilled nursing facility, long-term acute care hospital, or death).

RESULTS

There is neither clinically observable nor statistically significant improvement in length of stay or disposition on discharge in patients who received 6 or greater sessions of plasmapheresis.

CONCLUSIONS

This study provides class IV evidence that extending the number of plasma exchanges beyond 5 does not correlate with decreased hospital length of stay or improved discharge disposition in patients experiencing myasthenic crisis.

Our Clinical Experience in the Treatment of Myasthenia Gravis Acute Exacerbations with a Novel Nanomembrane-Based Therapeutic Plasma Exchange Technology

According to the American Academy of Neurology 2011 guidelines, there is insufficient evidence to support or refute the use of therapeutic plasma exchange (TPE) for myasthenia gravis (MG). The goal of this study was to determine whether a novel nanomembrane-based TPE could be useful in the treatment of MG. Thirty-six adult patients, MGFA 4/4B and 5, with acute MG episodes were enrolled into a single-center retrospective before-and-after study to compare a conventional treatment group (n = 24) with a nanomembrane-based TPE group (n = 12). TPE or intravenous immunoglobulins (IVIG) infusions were used in impending/manifested myasthenic crises, especially in patients at high-risk for prolonged invasive ventilation (IMV) and in those tolerating non-invasive ventilation (NIV). The clinical improvement was assessed using the Myasthenia Muscle Score (0–100), with ≥20 increase for responders. The primary outcome measures included the rates of implemented TPE, IVIG, and corticosteroids immunotherapies, NIV/IMV, early tracheotomy, MMS scores, extubation time, neuro-ICU/hospital LOS, complications, and mortality rates. The univariate analysis found that IMV was lower in the nanomembrane-based group (42%) compared to the conventional treatment group (83%) (p = 0.02). The multivariate analysis using binary logistic regression revealed TPE and NIV as independent predictors for short-term (≤7 days) respiratory support (p = 0.014 for TPE; p = 0.002 for NIV). The novel TPE technology moved our clinical practice towards proactive rather than protective treatment in reducing prolonged IMV during MG acute exacerbations.

Treatment of refractory myasthenia gravis by double-filtration plasmapheresis and rituximab: A case series of nine patients and literature review

INTRODUCTION

Myasthenia gravis (MG) is an autoimmune disease mediated by circulating autoantibodies (anti-AchR, anti-MuSK, etc.). More than 20% of myasthenic patients are refractory to conventional treatments (plasma exchange, IVIg, steroids, azathioprine, mycophenolate mofetil). Rituximab (B-lymphocyte-depleting anti-CD20) and apheresis (double-filtration plasmapheresis [DFPP] and immunoadsorption [IA]) are interesting therapeutic alternatives.

METHODS

This monocentric pilot study included nine refractory myasthenic patients (March 2018 to May 2020) treated by DFPP and/or IA associated with rituximab (375 mg/m² ). Clinical responses were assessed using the Myasthenia Gravis Foundation of America (MGFA) score.

RESULTS

Average age of patients was 53 ± 17 years. Gender ratio (M/F) was 3:6. The combination of apheresis and rituximab reduced median MGFA score from IV to II after 12 months of follow-up. Clinical improvement assessed by MGFA score was sustained in the long-term for all patients, during an average follow-up of 14 ± 9 months, allowing them to be self-sufficient and out sick-leave. The median number of apheresis sessions was 7 (5-30). The dose of prednisolone was reduced in two patients from 40 mg/d and 30 mg/d to 7.5 mg/d and 10 mg/d, respectively. It was stopped in a patient who was taking 30 mg/d. No infectious, bleeding, or thrombosis complications were noted.

CONCLUSION

The combination of rituximab and DFPP was effective to treat refractory MG.

Myasthaenia Gravis: Clinical management issues before, during and after pregnancy

Myasthaenia gravis (MG) is an autoimmune neuromuscular disorder which is twice as common among women, often presenting in the second and third decades of life. Typically, the first trimester of pregnancy and first month postpartum are considered high-risk periods for MG exacerbations. During pregnancy, treatment for MG is usually individualised, thus improving its management. Plasma exchange and immunoglobulin therapies can be safely used to treat severe manifestations of the disease or myasthaenic crises. However, thymectomies are not recommended because of the delayed beneficial effects and possible risks associated with the surgery. Assisted vaginal delivery-either vacuum-assisted or with forceps-may be required during labour, although a Caesarean section under epidural anaesthesia should be reserved only for standard obstetric indications. Myasthaenic women should not be discouraged from attempting to conceive, provided that they seek comprehensive counselling and ensure that the disease is under good control before the start of the pregnancy.

A comparison between IVIG and plasma exchange as preparations before thymectomy in myasthenia gravis patients

Myasthenia gravis (MG) is one of the curable neurologic disorders. Various pharmacological therapies are administered for these patients and a thymectomy plays an important role in the therapy of myasthenia gravis, which develops a permanent or relative remission. We investigated the efficacy of intravenous immunoglobulin (IVIG) and plasma exchange (PLEX) as a preparation before thymectomy in patients with MG. This randomized clinical trial was conducted on 24 patients with MG referred for thymectomy, which were randomized to two groups of IVIG and PLEX. The IVIG group received IVIG 1 g/kg/day for two consecutive days and the PLEX group underwent 1-L plasma exchange five times with 5 % albumin replacement fluid, every other day, 10-30 days before the procedure. The duration of hospitalization (day), length of intensive care unit (ICU) stay after surgery (day), length of intubation period (h), duration of surgery (h) and dose of steroid administered were compared between the two groups. Analysis was performed via SPSS version 20. In the PLEX group, post-operative outcomes (duration of hospitalization, ICU length of stay after surgery, intubation period and duration of surgery) were longer than those in the IVIG group. There was significant difference in intubation period (p value = 0.01) and duration of surgery (p value = 0.05) between the PLEX and IVIG groups. The administration of IVIG in comparison to PLEX can be more effective in the preparation before thymectomy in myasthenia gravis patients.

Current and future immunotherapy targets in autoimmune neurology

Randomized controlled treatment trials of autoimmune neurologic disorders are generally lacking and data pertaining to treatment are mostly derived from expert opinion, large case series, and anecdotal reports. The treatment of autoimmune neurologic disorders comprises oncologic therapy (where appropriate) and immunotherapy. In this chapter, we first describe the standard acute and chronic immunotherapies and provide a practical overview of their use in the clinic (mechanisms of action, dosing, monitoring, and side effects). Novel approaches to treatment of autoimmune neurologic disorders, through new drug discovery or repurposing, are dependent on improved mechanistic understanding of immunopathology. Such approaches, with emphasis on monoclonal antibodies, are discussed using the paradigm of three autoimmune neurologic disorders whose immunopathogenesis is better understood, specifically myasthenia gravis, neuromyelitis optica, and chronic inflammatory demyelinating polyradiculoneuropathy. It is important to realize that the treatment strategy and management plan must be individualized for each patient. In general these are influenced by the following: clinical severity, antibody type, presence or absence of cancer, and prior treatment response, if known.

Plasma exchange versus intravenous immunoglobulin for myasthenia gravis crisis: an acute hospital cost comparison study

OBJECTIVE

To compare the short-term financial costs of treating a patient in myasthenia gravis crisis with intravenous immunoglobulin (IVIG) versus plasma exchange.

METHODS

An itemized comparative cost-minimization analysis of IVIG versus plasma exchange for myasthenia gravis crisis was performed. Calculations were based on each therapy's implementation cost, associated hospitalization times, and predicted cost to treat known complications. A cost superiority determination was proposed based on the total cost profile of each therapy.

RESULTS

The difference in total cost favored IVIG over plasma exchange with an average savings of $22,326 per patient. Sensitivity analysis demonstrated that overall costs are highly dependent on IVIG dosing, hospital lengths of stay, and the number of plasma exchange days required.

CONCLUSIONS

The use of IVIG for myasthenia gravis crisis may be a short-term cost minimizing therapy compared with plasma exchange. Additional prospective studies are required to evaluate the extended cost profile and efficacy of these therapies.

In vivo adsorption of autoantibodies in myasthenia gravis using Nanodisc-incorporated acetylcholine receptor

Autoantibodies directed against the skeletal muscle acetylcholine receptor (AChR) play a critical role in the pathogenesis of the autoimmune disease, myasthenia gravis (MG). The pathogenic importance of anti-AChR antibodies is substantiated clinically by the often dramatic clinical improvement that follows removal of circulating antibodies utilizing extracorporeal plasma exchange (PE). Unfortunately, the effects of PE are non-specific as immunoglobulins (IgG) and other plasma proteins are removed in addition to anti-AChR IgG. In this study, we have successfully incorporated the AChR protein purified from Torpedo californicus into a Nanodisc (ND) membrane scaffold protein/phospholipid structure. We go on to demonstrate the effectiveness of this ND-AChR complex, administered intravenously, in the in vivo down-modulation of anti-AChR antibodies and subsequent amelioration of clinical disease in the experimental murine model of MG. These results provide proof-of-principle for the in vivo antigen-specific reduction of pathogenic anti-AChR antibodies utilizing ND-AChR particles. Further development of this strategy may provide an effective, antigen-specific, and readily accessible acute therapy for exacerbating MG or myasthenic crisis.

Current and future immunotherapy in myasthenia gravis

Current therapy for myasthenia gravis is directed towards generalized modulation and suppression of the immune system. These approaches have been extensively studied and are effective in many patients with myasthenia, but at the cost of significant adverse effects due to the global effects on the immune system. Future directions in therapy are geared towards focused immunotherapies that aim to improve outcomes while lessening the burden of side effects. This paper reviews both the current accepted treatments for myasthenia gravis as well as promising targeted therapies in development.

Towards antigen-specific apheresis of pathogenic autoantibodies as a further step in the treatment of myasthenia gravis by plasmapheresis

Myasthenia gravis (MG), a prototypic antibody-mediated autoimmune disease, presents an excellent target for scientific research aimed at a better understanding of the disease itself and the source that triggers an autoimmune reaction in an organism. MG is a neuromuscular disease caused mainly by an autoimmune response against the nicotinic acetylcholine receptor (AChR) which interferes with neuromuscular transmission. This review focuses on our studies on the extracellular domains of human muscle AChR subunits in an effort to develop an approach for the specific therapeutic apheresis of autoantibodies from patients' sera using the immobilized subunits as immunoadsorbents. The ability of the anti-AChR antibodies isolated by this technique, but not of the depleted sera, to induce disease is also described. This review is dedicated to the late Prof. John Newsom-Davis, who was the first to introduce the use of plasmapheresis for MG.

Comparative efficacy of low dose, daily versus alternate day plasma exchange in severe myasthenia gravis

OBJECTIVE

To evaluate the comparative efficacy of low dose daily versus alternate day plasma exchange in patients with severe myasthenia.

METHODS

Thirty three patients with myasthenia gravis (Osserman's stage II b and III) were randomized to receive alternate day (n = 17) or daily low dose plasma exchange (n = 16). Plasma exchange were carried on each patient, number of exchanges varying subject to their requirements and 20-25 ml/kg plasma was removed during each session. Myasthenia gravis disease scale (MGDS) score was evaluated before and after the procedure. Time to wean off ventilator, removal of nasogastric tube and total duration of hospital stay were also assessed.

RESULTS

There was no statistically significant difference between daily vs. alternate day group with regards to change in MGDS score, percentage change in MGDS score, and complication rates. A decreased hospital stay was observed in patients on daily plasma exchange which almost reached statistical significance.

CONCLUSION

We conclude from our study that daily and alternate day plasma exchange are similar in their efficacy and complication rates, however the daily schedule could be a preferred modality due to decreased hospital stay.

A Controlled Study of Double Filtration Plasmapheresis in the Treatment of Active Rheumatoid Arthritis

BACKGROUND

Double-filtration plasmapheresis with a plasma fractionator pore size of 20 nm should selectively remove large molecular weight substances like rheumatoid factor and IgM. This was proposed to be more likely to be helpful for rheumatoid arthritis than standard plasma exchange.

OBJECTIVE

To evaluate the efficacy of double-filtration plasmapheresis (DFPP) in the treatment of patients with active rheumatoid arthritis.

METHODS

Eighty-two patients were randomly assigned, 42 to the DFPP group and 40 to the no-DFPP group. All patients received sulfasalazine (0.75 g 3 times daily) plus methotrexate (10 mg orally once weekly). All patients had been on stable doses for more than 3 months. DFPP was performed once a week for 2 to 3 sessions. A total of 121 plasmapheresis procedures were performed in 42 patients. Control patients did not receive sham DFPP. The efficacy measures recorded 1 day after the final treatment and every month in follow-up for 4 to 22 months included the American College of Rheumatology (ACR) 20%, 50%, and 70% improvement criteria (ACR20, ACR50, and ACR70), the Health Assessment Questionnaire estimate of disability and the disease activity index.

RESULTS

Patients in the DFPP group had ACR20, ACR 50, and ACR70 improvements immediately after the last treatment of 100%, 92.9%, and 81.0%, when compared with the patients in no-DFPP group 17.5%, 0%, and 0% (P < 0.001). Significant change from baseline was observed in Health Assessment Questionnaire scores in the DFPP group, but not in the no-DFPP group (P < 0.001). The changes from baseline in the disease activity scores were significantly greater than in the no-DFPP group (P < 0.001). Improvements were maintained during follow-up of 7 to 22 months.

CONCLUSION

This open trial showed that DFPP therapy significantly altered the signs and symptoms of active rheumatoid arthritis. There were increases in physical function and improvement in quality of life. This is proposed as an approach that merits further investigation.

[Plasma exchange as a therapeutic option in neurological disorders]

Plasma exchange is a therapeutic procedure commonly used in various neurological disorders. Here we review its current role as a treatment option in diseases of the central and peripheral nervous system.

Preparation of an immunoadsorbent coupled with a recombinant antigen to remove anti-acetylcholine receptor antibodies in abnormal serum

An immunoadsorbent that removes anti-acetylcholine receptor antibodies (AChRAb) in abnormal serum of myasthenia gravis (MG) patient was efficiently prepared by an expression product, the functional fragment of AChR(alpha205) fused with maltose binding protein (MBP). The ligand can then covalently bind to amylose resin through MBP fusion protein. It was shown from the result of this study with anti-AChR mice sera that the removal rate of AChRAb on this immunoadsorbent reached 87+/-10% (mean value of 10 mice) and the maximally binding capacity of AChRAb was approximately 260 microg/g immunoadsorbent (wet weight). Moreover, the immunoadsorption test of sera in two MG patients indicated that about 90% and 96% of abnormal AChRAb could be eliminated, while other serum components such as albumin, IgG, IgM and IgA only dropped 18%, 35%, 22%, 15% and 24%, 27%, 15%, 12%, respectively, for two MG patient sera. It is anticipated from this study that the immunoadsorbent reported here could, with further development, find its clinical application for removal of AChRAb from patient serum.

Update on myasthenia gravis

Myasthenia gravis is an autoimmune disorder caused by autoantibodies against the nicotinic acetylcholine receptor on the postsynaptic membrane at the neuromuscular junction and characterised by weakness and fatigability of the voluntary muscles. It has a bimodal peak of incidence with first peak in the third decade and the second peak in the sixth decade. It is probably underdiagnosed in the very old population. Our understanding of the pathogenesis, immunology, and molecular biology of myasthenia gravis has greatly improved in last three decades. It is almost always possible to establish the diagnosis of myasthenia gravis with the current tests. The modern treatment is highly successful and the mortality of treated myasthenia gravis is practically zero. However, there are still important gaps in our knowledge of the origin of myasthenia gravis, the factors that contribute to chronic disease, and the way to cure the disease. In this article the current knowledge of the various aspects of myasthenia gravis are outlined.

Successful treatment of refractory myasthenia gravis using rituximab: a pediatric case report

We report the successful use of anti-CD20 therapy in a child with refractory myasthenia gravis (MG), an antibody-mediated autoimmune disease, who did not respond to conventional therapy. After initiation of anti-CD20 therapy, clinical improvement (muscular strength, pulmonary function) was observed.

Plasma exchange versus double filtration plasmapheresis in the treatment of Guillain-Barré syndrome

Previous studies have shown that both plasma exchange (PE) and double filtration plasmapheresis (DFPP) are effective treatments in Guillain-Barré syndrome (GBS). Whether PE and DFPP have similar effects in GBS is not clear. This report compares the therapeutic effectiveness of PE and DFPP in GBS patients treated in 3 major hospitals in northern Taiwan. A total of 102 patients were included in this survey, including 39 with PE (hereafter PE group) and 63 with DFPP (hereafter DFPP group). Both groups showed significant improvement of disability scores after treatment. However, time to onset of effect was shorter (5.6 +/- 3.5 versus 7 +/- 3.4 days, p < 0.05), and changes of disability scores were more prominent (1.3 +/- 0.8 versus 0.8 +/- 0.8, p < 0.05) in the PE group than the DFPP group. Mortality and outcome after 6 months were not different between the 2 groups. In conclusion, both PE and DFPP are effective treatments in GBS. PE was superior to DFPP in short-term effectiveness. The long-term effectiveness was not different.

Plasma exchange for myasthenia gravis

BACKGROUND

Myasthenia gravis is an autoimmune disease mediated by auto-antibodies direct against the nicotinic receptor for acetylcholine. Patients would be expected to benefit from plasma exchange. Non-randomised studies suggest that plasma exchange is beneficial in the short term.

OBJECTIVES

To examine the efficacy of plasma exchange in the short and long term treatment of myasthenia gravis.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group register (searched 17 July 2002) and MEDLINE (January 1966 to June 2002) for randomised controlled trials using myasthenia gravis as the search term. We checked the bibliographies in reports of randomised trials and contacted one author to identify additional published or unpublished data.

SELECTION CRITERIA

Types of studies: All randomised or quasi-randomised studies.

TYPES OF PARTICIPANTS

All patients with myasthenia gravis who were diagnosed by an internationally accepted definition. Types of intervention: Treatment with plasma exchange alone or combined with steroids or immunosuppressive drugs. Types of outcome measures:

PRIMARY OUTCOME MEASURE

~bullet~patients treated for exacerbation: change in a specific muscle score after plasma exchange; ~bullet~patients treated for chronic myasthenia gravis: change in a functional scale.

SECONDARY OUTCOME MEASURES

~bullet~patients treated for exacerbation: change in a functional scale and percentage weaned from mechanical ventilation; ~bullet~patients treated for chronic myasthenia gravis: percentage in remission by the end of one year after first plasma exchange; ~bullet~adverse events.

DATA COLLECTION AND ANALYSIS

One author extracted the data and the two others checked them. Since there was only one trial no formal meta-analysis was required.

MAIN RESULTS

We identified one randomised controlled trial. Improvement in a quantitative muscle score was not significantly greater in patients treated with plasma exchange and prednisone than in patients treated with prednisone alone one month after onset of treatment. More relapses were observed in the plasma exchange and prednisone group in the first year as compared with the prednisone alone group. Problems in recruitment and matching of patients entered into this trial limit the conclusions that can be drawn. On the other hand,experience from many non-randomised studies suggests that plasma exchange is beneficial in myasthenia gravis. Consequently the relative benefits of plasma exchange are still unconfirmed.

REVIEWER'S CONCLUSIONS

There are no adequate randomised controlled trials but many case series report short-term benefit from plasma exchange in myasthenia gravis, especially in myasthenic crisis. There are no adequate randomised controlled trials to determine whether plasma exchange improves the long-term outcome for myasthenia gravis. Further research is need to compare plasma exchange with alternative short-term treatments for myasthenic crisis and to determine the value of long-term plasma exchange for treating myasthenia gravis.

Myasthenia gravis: diagnostic and management dilemmas

This review focuses on the diagnostic tests that may help to confirm myasthenia in patients without acetylcholine receptor antibodies, including the newly discovered anti-muscle-specific receptor tyrosine kinase antibody and other investigations. We discuss management dilemmas, particularly those that revolve around treatments whose efficacy is questionable or unproved, such as thymectomy. We review the important issue of how treatments are assessed, and examine future treatment trial designs.