Plasma exchange and intravenous immunoglobulin in autoimmune myasthenia gravis

Immunoglobulin Treatment in Neuromuscular Medicine

Intravenous immunoglobulin (IVIg) is used in the treatment of autoimmune diseases, including immune-mediated central and peripheral nervous system disorders. This article will review the indications, proposed mechanism of actions, and administration of immunoglobulin treatment in various neuropathies, neuromuscular junction disorders, and myopathies. IVIg may have more than one mechanism of action to alter the pathogenesis of underlying neuromuscular disease. IVIg treatment has been used as a first-line treatment in Guillain-Barre syndrome, chronic inflammatory demyelinating polyradiculoneuropathy, multifocal motor neuropathy, and second-line off-label treatment in medically refractory cases of polymyositis, dermatomyositis, and myasthenia gravis. IVIg is a well-tolerated and effective treatment for these neuromuscular diseases. With this review article, we hope to increase clinicians' awareness of the indications and efficiencies of IVIg in a broad spectrum of neuromuscular diseases.

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.

What are the indications for plasma exchanges in autoimmune diseases?: The registry of the Société Française d’Hémaphérèse

The use of plasma exchange (PE) in the autoimmune diseases is encouraged in France. Since 1990, the national registry of PE allows an analysis of the evolution of the coverage of these pathologies. The variation of the number of patients treated by PE is correlated in respect to the results of the therapeutic studies. After a decrease of PE activity in these indications during the 90s, one observes a new increase of the patients treated because of the validation of new indications. Autoimmune diseases represent the third cause of morbidity in developed countries, with a global prevalence of 5%, and concerns four groups of pathologies of organs or systems (neurology, haematology, nephrology and vasculitis). In 1976, Lockwood demonstrated the place of plasma exchanges (PE) in Goodpasture's syndrome [Lockwood CM, Rees AJ, Pearson TA, Evans DJ, Peters DK, Wilson CB. Immunosuppression and plasma exchange in the treatment of Goopasture's syndrome. Lancet 1976;1(7962):723-6. [1]], with a significant decrease of antibodies during large volume exchanges. In the 80s, several prospective studies began to estimate the efficiency of PE in other autoimmune diseases. The national registry of the Société Française d' Hémaphérèse, has collected the epidemiological and technical data of PE since 1985. This work analyses the evolution of the validated indications, between 1990 and 2005 in France.

Myasthenia Gravis

Myasthenia gravis is a disorder of neuromuscular transmission, manifest by variable weakness of skeletal muscle. The disorder has a range of therapies that differ with respect to efficacy, timing, and side effects. The physician treating myasthenia gravis must be well versed in understanding the evidence basis for using these agents, as well as the trade-offs between persistent disease manifestations and their costs and expected benefits. Diagnosis of myasthenia gravis depends on recognizing the pattern of weakness, which typically involves some combination of extraocular, bulbar, facial, limb, and neck muscles. Management relies on some combination of medications that influence the function of the neuromuscular junction and treatments that alter the immune response. Thymectomy is commonly used, although trends in evidence-based medicine are leading expert clinicians to look closely at its efficacy. Plasma exchange is useful for patients in crisis, who require rapid improvement. The exact role for high-dose intravenous immunoglobulin in this setting is still being studied, although the agent is gaining popularity. Knowing that the treatments are effective is not enough. It is still important to determine the treatment that has a more rapid onset, because these patients often require intensive care or respiratory assistance.

Plasma exchange in France: Epidemiology 2001

The French plasma exchange registry created in 1985 lists the indications, techniques and complications of the French therapeutic haemapheresis. In 2001 it contains the data of more than 16,700 patients for a total of 153,641 sessions. The indications concern five groups of pathologies (neurology, haematology, nephrology, vasculitis, and endocrinology). Until 2000, the neurology represented the most important group but the use of the high dose IgIV for Guillain-Barre and myasthenia gravis decreased the indications. The haematology became most important group treated because of the increase of the TTP and HUS number treated. The endocrinology (familial hypercholesterolemia) represents at present 10% of the patients treated for 18.7% of the sessions. The vascular access little changed since 1985, the peripheral venous access being the most used. The plasma substitution initially based on the albumin alone was gradually replaced by an association albumin macromolecules, in particular hydroxyethylstarch since 1990. After the observation of the side effects due to starches we observed an increase of the albumin alone use. The immediate complications decreased in half in 15 years. The French plasma exchange registry is the largest world database of haemapheresis with the cooperation of about 80 centres, allowing numerous scientific studies.

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.

Predictable recovery from myasthenia gravis crisis with plasma exchange: thirty-six cases and review of current management

Adult, acquired, idiopathic, autoimmune myasthenia gravis has a well-characterized IgG anti-acetylcholine striated-muscle receptor antibody. Removal by plasma exchange is effective, established therapy to augment anti-cholinesterase and immunosuppressive therapy and is the treatment of choice for myasthenia gravis crisis. We report 36 consecutive patients referred and accepted for plasma exchange, 32 of whom were in or entering myasthenia crisis, over a 10 year period. An average of 7.8 (range 1 to 16) plasma exchange procedures were done, with uniform, significant improvement, including extubation of 13 in myasthenic crisis and discharge from hospital in all. We conclude that this is the best treatment for myasthenia gravis crisis in hospital. From recent cases, most, if not all, crises can be prevented by IVIgG or plasma exchange as out-patients with use of corticosteroid and or azathioprine.