Plasma exchange morbidity in Guillain-Barré syndrome: results from the French prospective, randomized, multicenter study. The French Cooperative Group

European Academy of Neurology/Peripheral Nerve Society Guideline on diagnosis and treatment of Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is an acute polyradiculoneuropathy. Symptoms may vary greatly in presentation and severity. Besides weakness and sensory disturbances, patients may have cranial nerve involvement, respiratory insufficiency, autonomic dysfunction and pain. To develop an evidence-based guideline for the diagnosis and treatment of GBS, using Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology a Task Force (TF) of the European Academy of Neurology (EAN) and the Peripheral Nerve Society (PNS) constructed 14 Population/Intervention/Comparison/Outcome questions (PICOs) covering diagnosis, treatment and prognosis of GBS, which guided the literature search. Data were extracted and summarised in GRADE Summaries of Findings (for treatment PICOs) or Evidence Tables (for diagnostic and prognostic PICOs). Statements were prepared according to GRADE Evidence-to-Decision (EtD) frameworks. For the six intervention PICOs, evidence-based recommendations are made. For other PICOs, good practice points (GPPs) are formulated. For diagnosis, the principal GPPs are: GBS is more likely if there is a history of recent diarrhoea or respiratory infection; CSF examination is valuable, particularly when the diagnosis is less certain; electrodiagnostic testing is advised to support the diagnosis; testing for anti-ganglioside antibodies is of limited clinical value in most patients with typical motor-sensory GBS, but anti-GQ1b antibody testing should be considered when Miller Fisher syndrome (MFS) is suspected; nodal-paranodal antibodies should be tested when autoimmune nodopathy is suspected; MRI or ultrasound imaging should be considered in atypical cases; and changing the diagnosis to acute-onset chronic inflammatory demyelinating polyradiculoneuropathy (A-CIDP) should be considered if progression continues after 8 weeks from onset, which occurs in around 5% of patients initially diagnosed with GBS. For treatment, the TF recommends intravenous immunoglobulin (IVIg) 0.4 g/kg for 5 days, in patients within 2 weeks (GPP also within 2-4 weeks) after onset of weakness if unable to walk unaided, or a course of plasma exchange (PE) 12-15 L in four to five exchanges over 1-2 weeks, in patients within 4 weeks after onset of weakness if unable to walk unaided. The TF recommends against a second IVIg course in GBS patients with a poor prognosis; recommends against using oral corticosteroids, and weakly recommends against using IV corticosteroids; does not recommend PE followed immediately by IVIg; weakly recommends gabapentinoids, tricyclic antidepressants or carbamazepine for treatment of pain; does not recommend a specific treatment for fatigue. To estimate the prognosis of individual patients, the TF advises using the modified Erasmus GBS outcome score (mEGOS) to assess outcome, and the modified Erasmus GBS Respiratory Insufficiency Score (mEGRIS) to assess the risk of requiring artificial ventilation. Based on the PICOs, available literature and additional discussions, we provide flow charts to assist making clinical decisions on diagnosis, treatment and the need for intensive care unit admission.

European Academy of Neurology/Peripheral Nerve Society Guideline on diagnosis and treatment of Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is an acute polyradiculoneuropathy. Symptoms may vary greatly in presentation and severity. Besides weakness and sensory disturbances, patients may have cranial nerve involvement, respiratory insufficiency, autonomic dysfunction and pain. To develop an evidence-based guideline for the diagnosis and treatment of GBS, using Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology, a Task Force (TF) of the European Academy of Neurology (EAN) and the Peripheral Nerve Society (PNS) constructed 14 Population/Intervention/Comparison/Outcome questions (PICOs) covering diagnosis, treatment and prognosis of GBS, which guided the literature search. Data were extracted and summarised in GRADE Summaries of Findings (for treatment PICOs) or Evidence Tables (for diagnostic and prognostic PICOs). Statements were prepared according to GRADE Evidence-to-Decision (EtD) frameworks. For the six intervention PICOs, evidence-based recommendations are made. For other PICOs, good practice points (GPPs) are formulated. For diagnosis, the principal GPPs are: GBS is more likely if there is a history of recent diarrhoea or respiratory infection; CSF examination is valuable, particularly when the diagnosis is less certain; electrodiagnostic testing is advised to support the diagnosis; testing for anti-ganglioside antibodies is of limited clinical value in most patients with typical motor-sensory GBS, but anti-GQ1b antibody testing should be considered when Miller Fisher syndrome (MFS) is suspected; nodal-paranodal antibodies should be tested when autoimmune nodopathy is suspected; MRI or ultrasound imaging should be considered in atypical cases; and changing the diagnosis to acute-onset chronic inflammatory demyelinating polyradiculoneuropathy (A-CIDP) should be considered if progression continues after 8 weeks from onset, which occurs in around 5% of patients initially diagnosed with GBS. For treatment, the TF recommends intravenous immunoglobulin (IVIg) 0.4 g/kg for 5 days, in patients within 2 weeks (GPP also within 2-4 weeks) after onset of weakness if unable to walk unaided, or a course of plasma exchange (PE) 12-15 L in four to five exchanges over 1-2 weeks, in patients within 4 weeks after onset of weakness if unable to walk unaided. The TF recommends against a second IVIg course in GBS patients with a poor prognosis; recommends against using oral corticosteroids, and weakly recommends against using IV corticosteroids; does not recommend PE followed immediately by IVIg; weakly recommends gabapentinoids, tricyclic antidepressants or carbamazepine for treatment of pain; does not recommend a specific treatment for fatigue. To estimate the prognosis of individual patients, the TF advises using the modified Erasmus GBS outcome score (mEGOS) to assess outcome, and the modified Erasmus GBS Respiratory Insufficiency Score (mEGRIS) to assess the risk of requiring artificial ventilation. Based on the PICOs, available literature and additional discussions, we provide flow charts to assist making clinical decisions on diagnosis, treatment and the need for intensive care unit admission.

Indications and Outcomes of Patients Receiving Therapeutic Plasma Exchange under Critical Care Conditions: A Retrospective Eleven-Year Single-Center Study at a Tertiary Care Center

Background: Therapeutic plasma exchange (TPE) is frequently performed in critical care settings for heterogenous indications. However, specific intensive care unit (ICU) data regarding TPE indications, patient characteristics and technical details are sparse. Methods: We performed a retrospective, single-center study using data from January 2010 until August 2021 for patients treated with TPE in an ICU setting at the University Hospital Zurich. Data collected included patient characteristics and outcomes, ICU-specific parameters, as well as apheresis-specific technical parameters and complications. Results: We identified n = 105 patients receiving n = 408 TPEs for n = 24 indications during the study period. The most common was thrombotic microangiopathies (TMA) (38%), transplant-associated complications (16.3%) and vasculitis (14%). One-third of indications (35.2%) could not be classified according to ASFA. Anaphylaxis was the most common TPE-related complication (6.7%), while bleeding complications were rare (1%). The median duration of ICU stay was 8 ± 14 days. Ventilator support, renal replacement therapy or vasopressors were required in 59 (56.2%), 26 (24.8%), and 35 (33.3%) patients, respectively, and 6 (5.7%) patients required extracorporeal membrane oxygenation. The overall hospital survival rate was 88.6%. Conclusion: Our study provides valuable real-world data on heterogenous TPE indications for patients in the ICU setting, potentially supporting decision-making.

Removal Dynamics of Autoantibodies, Immunoglobulins, and Coagulation Factors by Selective Plasma Exchange on Three Consecutive Days

Selective plasma exchange has been shown to be effective in various diseases, but no studies have assessed the benefits of daily treatment. We aimed to investigate the removal dynamics of immunoglobulins, fibrinogen, and factor XIII on three consecutive days in three patients. For mean processed plasma volumes of 1.06 × plasma volume, reductions of 79.6%, 49.3%, and 8.6% were seen for immunoglobulins G, A, and M, respectively. The reductions for fibrinogen and factor XIII were 18.4% and 13.0%, respectively. Removal dynamics were similar for immunoglobulin G-related autoantibodies and immunoglobulin G when using daily selective plasma exchange. Moreover, daily use effectively removed the immunoglobulin G while retaining the coagulation factors. When disease-specific autoantibodies are limited to immunoglobulin G, daily selective plasma exchange may be a useful and safe method of intensive induction treatment for plasmapheresis. However, further study is required in larger cohorts to confirm these findings.

Plasma exchange for Guillain-Barré syndrome

BACKGROUND

Guillain-Barré syndrome (GBS) is an acute paralysing disease caused by peripheral nerve inflammation. This is an update of a review first published in 2001 and last updated in 2012.

OBJECTIVES

To assess the effects of plasma exchange for treating GBS.

SEARCH METHODS

On 18 January 2016 we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, and Embase. We also searched clinical trials registries.

SELECTION CRITERIA

Randomised and quasi-randomised trials of plasma exchange versus sham exchange or supportive treatment, or comparing different regimens or techniques of plasma exchange.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology.

MAIN RESULTS

In the first version of this review there were six eligible trials concerning 649 participants comparing plasma exchange with supportive treatment. No new eligible trials have been identified in subsequent updates. Two other studies compared different numbers of plasma exchanges. Overall the included trials had a moderate risk of bias (in general, the studies were at low risk but all had a high risk of bias from lack of blinding).In one trial with 220 severely affected participants, the median time to recover walking with aid was significantly shorter with plasma exchange (30 days) than without plasma exchange (44 days). In another trial with 91 mildly affected participants, the median time to onset of motor recovery was significantly shorter with plasma exchange (six days) than without plasma exchange (10 days). After four weeks, moderate-quality evidence from the combined data of three trials accounting for a total of 349 patients showed that plasma exchange significantly increased the proportion of patients who recovered the ability to walk with assistance (risk ratio (RR) 1.60, 95% confidence interval (CI) 1.19 to 2.15).In five trials with 623 participants in total, moderate-quality evidence showed that the RR for improvement by one or more disability grades after four weeks was 1.64 (95% CI 1.37 to 1.96) times greater with plasma exchange. Participants treated with plasma exchange also fared better, according to moderate-quality evidence, in time to recover walking without aid (three trials with 349 participants; RR 1.72, 95% CI 1.06 to 2.79) and requirement for artificial ventilation (five trials with 623 participants; RR 0.53, 95% CI 0.39 to 0.74). More participants had relapses by the end of follow-up in the plasma exchange group than in the control group (six trials with 649 participants; RR 2.89, 95% CI 1.05 to 7.93; moderate-quality evidence). Despite this, according to moderate-quality evidence, the likelihood of full muscle strength recovery at one year was greater with plasma exchange than without plasma exchange (five trials with 404 participants; RR 1.24, 95% CI 1.07 to 1.45), and the likelihood of severe motor sequelae was less (six trials with 649 participants; RR 0.65, 95% CI 0.44 to 0.96). High-quality evidence from six trials with 649 participants could not confirm or refute a lower risk of death following plasma exchange compared to control (RR 0.86, 95% CI 0.45 to 1.65).Three trials (N = 556) provided details of serious adverse events during the hospital stay; combined analyses found no increase in serious infectious events compared to the control group (RR 0.91, 95% CI 0.73 to 1.13), nor were there clear differences in blood pressure instability, cardiac arrhythmias or pulmonary emboli.

AUTHORS' CONCLUSIONS

Moderate-quality evidence shows significantly more improvement with plasma exchange than with supportive care alone in adults with Guillain-Barré syndrome, without a significant increase in serious adverse events. According to moderate-quality evidence, there was a small but significant increase in the risk of relapse during the first six to 12 months after onset in people treated with plasma exchange compared with those who were not treated. Despite this, after one year, full recovery of muscle strength was more likely and severe residual weakness less likely with plasma exchange.

Use of Cellular and Plasma Apheresis in the Critically Ill Patient: Part II: Clinical Indications and Applications

Apheresis is the process of separating the blood and removing or manipulating a cellular or plasma component for therapeutic benefit. Such procedures may be indicated in the critical care setting as primary or adjunctive therapy for certain hematologic, neurologic, renal, and autoimmune/rheumatologic disorders. In part I of this series, the technical aspects of apheresis were described and the physiologic rationale and clinical considerations were discussed. This review highlights the pathophysiologic basis, specific clinical indications, and treatment parameters for disorders that more commonly require management in the intensive care unit. The choice of plasma or cellular apheresis in these cases is guided by wellaccepted, evidence-based clinical treatment guidelines. For some disorders, such as liver failure, severe sepsis, and multiple-organ dysfunction syndrome, apheresis treatment approaches remain experimental. Ongoing studies are investigating the potential utility of conventional plasma exchange, ex vivo plasma manipulation, and newer technologies for these and other disorders in severely ill patients.

Disease-modifying therapies and infectious risks in multiple sclerosis

Immunomodulatory and immunosuppressive treatments for multiple sclerosis (MS) are associated with an increased risk of infection, which makes treatment of this condition challenging in daily clinical practice. Use of the expanding range of available drugs to treat MS requires extensive knowledge of treatment-associated infections, risk-minimizing strategies and approaches to monitoring and treatment of such adverse events. An interdisciplinary approach to evaluate the infectious events associated with available MS treatments has become increasingly relevant. In addition, individual stratification of treatment-related infectious risks is necessary when choosing therapies for patients with MS, as well as during and after therapy. Determination of the individual risk of infection following serial administration of different immunotherapies is also crucial. Here, we review the modes of action of the available MS drugs, and relate this information to the current knowledge of drug-specific infectious risks and risk-minimizing strategies.

[Immunotherapy and infectious issues in multiple sclerosis. Self-injectable and oral drugs for immunotherapy]

Immunotherapy is generally associated with an increased risk for the development of infections. Due to the continuously expanding spectrum of new and potent immunotherapy treatment options for multiple sclerosis (MS), this article describes the currently known risks for treatment-related infections and the current recommendations for prevention of corresponding problems with drugs used in treatment strategies for MS and their mechanisms of action. The new treatment options in particular are linked to specific and severe infections; therefore, intensive and long-lasting monitoring is required before, during and after treatment and multidisciplinary surveillance of patients is needed. This article gives a detailed review of drug-specific red flags and current recommendations for the prophylaxis of infections associated with treatment of relapsing-remitting MS and when using self-injectable and oral disease-modifying immunotherapeutic drugs.

Plasmapheresis in neurological disorders: Experience from a tertiary care hospital in South India

BACKGROUND

Therapeutic plasma exchange (PE) or plasmapheresis is the treatment of choice in many neurological disorders. Even though it is safe in experienced hands, there is a major concern about its safety among physicians.

OBJECTIVES

To analyze our experience with 230 patients who underwent PE for various neurological disorders.

MATERIALS AND METHODS

Retrospective review of PE procedures done during a period of 48 months, from July 2007 to June 2011 in a tertiary care teaching hospital in South India. Indications, clinical results and technical factors are discussed.

RESULTS

The main indication for PE was GBS (203 patients; 88.3%). Age of patients ranged from 14-65 (mean = 42.3 years). The most common complications were paraesthesias and/or cramps (36.1%) and hypotension (32.2%). Four pregnant patients who underwent PE had good recovery with one intrauterine death. There was no mortality.

CONCLUSION

The analysis of 240 cases of PE done in our department shows that the procedure is safe, with only minimal procedure related complications and no mortality.

Multiple sclerosis treatment and infectious issues: update 2013

Immunomodulation and immunosuppression are generally linked to an increased risk of infection. In the growing field of new and potent drugs for multiple sclerosis (MS), we review the current data concerning infections and prevention of infectious diseases. This is of importance for recently licensed and future MS treatment options, but also for long-term established therapies for MS. Some of the disease-modifying therapies (DMT) go along with threats of specific severe infections or complications, which require a more intensive long-term monitoring and multi-disciplinary surveillance. We update the existing warning notices and infectious issues which have to be considered using drugs for multiple sclerosis.

Selective capture of anti-A antibodies from human blood using a novel integrated bead and hollow fiber module

Anti-A/B antibody removal from blood in the peritransplantation period facilitates ABO-incompatible transplantation and significantly increases the donor pool. We have been developing an anti-A/B immunoadsorption device (BSAF), compatible with whole blood perfusion. The BSAF is based on integrated microfiltration hollow fibers with antibody capturing beads uniformly distributed within the fiber interstitial space. In this study we fabricated BSAF prototypes, appropriately scaled down from a conceptual clinical scale device. We then, for the first time, measured the time course of anti-A capture from blood samples recirculating through the scaled down BSAF devices. We observed a significant reduction in IgM (96% ± 5%, n = 5, p < 0.001), and IgG (81% ± 18%, n = 5, p < 0.05) anti-A antibody titers within 2 h. We did not observe a significant change between the initial and final values of hematocrit, total plasma protein concentration, plasma free hemoglobin concentration, and anti-B antibody titer over five experiments. In conclusion we showed that the BSAF modules selectively removed anti-A antibodies from blood in a simple one step process, without requiring a separate plasmapheresis unit.

Plasma exchange for Guillain-Barré syndrome

BACKGROUND

Guillain-Barré syndrome is an acute paralysing disease caused by peripheral nerve inflammation. This is an update of a review first published in 2001 and last updated in 2008.

OBJECTIVES

To assess the effects of plasma exchange for treating Guillain-Barré syndrome.

SEARCH METHODS

We searched the Cochrane Neuromuscular Disease Group Specialized Register (14 June 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (2011, Issue 2), MEDLINE (January 1966 to June 2011) and EMBASE (January 1980 to June 2011).

SELECTION CRITERIA

Randomised and quasi-randomised trials of plasma exchange versus sham exchange or supportive treatment.

DATA COLLECTION AND ANALYSIS

Two review authors agreed the selection of eligible studies and independently assessed the risk of bias in included studies. Data were extracted by one review author and checked by a second review author. Likewise data for adverse events were extracted by one review author and checked by a second review author.

MAIN RESULTS

In the first version of this review there were six eligible trials concerning 649 participants comparing plasma exchange with supportive treatment. No new eligible trials have been identified in subsequent updates. Overall the included trials had a low risk of bias.Primary outcomes In one trial with 220 severely affected participants, the median time to recover walking with aid was significantly faster; with plasma exchange (30 days) than without (44 days). In another trial with 91 mildly affected participants, the median time to onset of motor recovery was significantly shorter with plasma exchange (six days) than without (10 days). After four weeks, combined data from three trials accounting for a total of 349 patients showed that plasma exchanged significantly increased the proportion of patients who recovered the ability to walk with assistance (risk ratio (RR) 1.60, 95% confidence interval (CI) 1.19 to 2.15).Secondary outcomes In five trials with 623 participants in total, the RR of being improved by one or more grades after four weeks was 1.64 (95% CI 1.37 to 1.96) in favour of plasma exchange. Participants treated with plasma exchange also fared significantly better in time to recover walking without aid (three trials with 349 participants, RR 1.72 (95% CI 1.06 to 2.79)) and requirement for artificial ventilation (five trials with 623 participants, RR 0.53 (95% CI 0.39 to 0.74)). There were significantly more participants with relapses by the end of follow-up in the plasma exchange than the control group (6 trials with 649 participants, RR 2.89 (95% CI 1.05 to 7.93)). Despite this, at one year the likelihood of full muscle strength recovery was significantly greater with plasma exchange than without (five trials with 404 participants, RR 1.24 (95% CI 1.07 to 1.45)) and the likelihood of severe motor sequelae was significantly less (six trials with 649 patients, RR 0.65 (95% CI 0.44 to 0.96)). There was no significant difference in deaths (six trials with 649 participants, RR 0.86 (95% CI 0.45 to 1.65)) or participants with adverse events (three trials with 556 participants), except fewer arrhythmias in plasma exchange treated participants (RR 0.75 (95% CI 0.56 to 1.00)).

AUTHORS' CONCLUSIONS

Moderate-quality evidence shows significantly more improvement with plasma exchange than supportive care alone in adults with Guillain-Barré syndrome without a significant increase in serious adverse events. There was a small but significant increase in the risk of relapse during the first six to 12 months after onset in people treated with plasma exchange compared with those that were not treated. Despite this, after one year, full recovery was significantly more likely and severe residual weakness less likely with plasma exchange.

Immune mediated diseases and immune modulation in the neurocritical care unit

This chapter will review the spectrum of immune-mediated diseases that affect the nervous system and may result in an admission to the neurological intensive care unit. Immunomodulatory strategies to treat acute exacerbations of neurological diseases caused by aberrant immune responses are discussed, but strategies for long-term immunosuppression are not presented. The recommendations for therapeutic intervention are based on a synthesis of the literature, and include recommendations by the Cochrane Collaborative, the American Academy of Neurology, and other key organizations. References from recent publications are provided for the disorders and therapies in which randomized clinical trials and large evidenced-based reviews do not exist. The chapter concludes with a brief review of the mechanisms of action, dosing, and side effects of commonly used immunosuppressive strategies in the neurocritical care unit.

Inpatient management of guillain-barré syndrome

Guillain-Barré syndrome (GBS) is the most common cause of acute flaccid paralysis in the developed world. Guillain-Barré syndrome typically presents with ascending paralysis and is usually severe enough to warrant hospital admission for management. In the United States alone, GBS results in more than 6000 hospitalizations each year. Although GBS patients were historically cared for at tertiary referral centers, changing treatment practices have broadened the number of neurologists who care for the disease. This article provides a review of key issues in the inpatient management of GBS. A survey of the evidence base for treatment with plasma exchange or intravenous immunoglobulins is presented. Although either of these treatments can limit the severity of GBS, patients are still at risk for a broad range of complications, including respiratory failure, autonomic dysfunction, thromboembolic disease, pain, and psychiatric disorders. Awareness of these complications, their detection and management, may help limit the morbidity of GBS.

Specific antibody filter (SAF) binding capacity enhancement to remove anti-A antibodies

Removal of Anti-A/B antibodies prior to ABO-incompatible transplantation can prevent hyperacute organ rejection. We are developing a specific antibody filter (SAF) device to selectively remove ABO blood group antibodies from the whole blood by utilizing immunoaffinity adsorption. The device consists of ultrafiltration hollow fiber membranes with synthetic antigens specific to bind blood group antibodies immobilized on the inner lumenal walls of the fibers. The aim of this study was to evaluate the effect of antigen molecular weight and surface activation process to increase the antibody binding capacity of the fiber membrane surface. A new higher molecular weight antigen Atri-pNSA-1000 compared with Atri-pNPA-30 (A-trisaccharide (Atri) conjugated to activated polymers of Mol. wt. 1000 kDa and 30 kDa, respectively) was employed to improve accessibility of the antigen to bind antibodies. Also, a cyanogen bromide (CNBr) based surface activation method mediated by TEA in neutral pH medium was used to enhance the number of active sites for antigen binding compared to a strong basic medium of NaOH. Using a CNBr/TEA activation method and by immobilizing Atri-pNSA-1000 antigen, an antibody binding capacity (∼0.01 monoclonal anti-A IgM nmol/cm(2)) was achieved on the fiber surface. This binding capacity was sufficient to reduce monoclonal antibody titer from 1:128 to final titer below 1:4 with a surface area to volume ratio that is similar to commercial dialysis device (∼1.1 m(2) surface area for an average body blood volume of 5 L).

High molecular weight blood group A trisaccharide-polyacrylamide glycoconjugates as synthetic blood group A antigens for anti-A antibody removal devices

Specific immunoadsorption of blood group antibodies by synthetic antigens immobilized on support matrices in the peri-transplantation period provides a promising solution to hyperacute rejection risk following ABO-incompatible transplantation. In this study, we investigated binding interactions between anti-A antibodies and synthetic blood group A trisaccharide conjugated with polyacrylamide of different molecular weights (30 and 1000 kDa). The glycopolymers were equipped with biotin tags and deposited on streptavidin-coated sensor chips. The affinity and kinetics of anti-A antibodies binding to glycoconjugates were studied using surface plasmon resonance (SPR). The high molecular weight conjugate (Atri-PAA(1000)-biotin) enhanced antibody binding capacity by two to three fold compared with the low molecular weight conjugate (Atri-PAA(30)-biotin), whereas varying the carbohydrate content in Atri-PAA(1000)-biotin (20 mol % or 50 mol %) did not affect antibody binding capacity of the glycoconjugate. The obtained results suggest that immunoadsorption devices, especially hollow fiber-based antibody filters which are limited in available surface area for antigen immobilization, may greatly benefit from the new synthetic high molecular weight polyacrylamide glycoconjugates.

Peripheral neuropathy

Patients presenting with symptoms of peripheral neuropathy are commonplace in the practice of generalist physicians, office based or hospitalists. Although there are at least a thousand different causes for peripheral neuropathy, the majority of patients can be properly diagnosed (and managed) based on framing the diagnostic possibilities within one of six typical scenarios. The case presentations in this article illustrate common and less common but essential presentations and the approach to evaluation and treatment. For these patients the key to success lies in the history and clinical examination findings.

Monoclonal anti-A antibody removal by synthetic A antigen immobilized on specific antibody filters

Removal of blood group anti-A and anti-B antibodies can prevent hyperacute organ rejection in ABO-incompatible transplantation. We are developing an extracorporeal-specific antibody filter (SAF) as an immunoadsorption device for direct removal of ABO blood group antibodies from whole blood, without the need for plasma separation and plasma exchange. A hollow fiber-based small scale SAF (mini-SAF) device was fabricated and synthetic A antigen, Atrisaccharide (Atri) conjugated to activated polyacrylic acid, was immobilized on the fiber lumen surface. Monoclonal antibody anti-A IgM were specifically removed up to 70% of initial antibodies using mini-SAF device. The monoclonal anti-A capture experiments on mini-SAF indicated that antibody removal relative to the initial concentration is independent of inlet concentration in the beginning; however, as the surface starts saturating with bound antibodies, removal becomes dependent on inlet concentration. No significant effect of flow rate on removal rate was observed. The radial diffusion and axial convection-based mathematical model developed for unsteady state antibody removal was in good agreement with the experimental data and showed that the antibody removal rate can be maximized by increasing the antibody-binding capacity of the SAF.

Synthetic blood group antigens for anti-A removal device and their interaction with monoclonal anti-A IgM

Removal of blood group antibodies against the donor organ prior to ABO-incompatible transplantation can prevent episodes of hyperacute rejection. We are developing a specific antibody filter (SAF) device consisting of immobilized synthetic Atrisaccharide antigens conjugated to polyacrylamide (Atri-PAA) to selectively remove anti-A antibodies directly from whole blood. In this study, we evaluated eight anti-A IgM monoclonal antibodies (mAbs) using Enzyme-Linked Immunosorbent Assay (ELISA) to determine their specificity for binding to Atri-PAA. Five of the eight mAbs met our criteria for specificity by binding to Atri-PAA with at least five times greater affinity compared to the negative controls. These selected mAbs will be studied for their binding characteristics to Atri-PAA which will aid in the development of the SAF. The study of kinetics of antibody removal and quantification of antibody removal will be used in our mathematical model to maximize the antibody removal rate and binding capacity of the SAF.

Chronic inflammatory demyelinating polyneuropathy and respiratory failure

Neuromuscular respiratory failure is not considered to be a clinical feature of chronic inflammatory demyelinating polyneuropathy (CIDP). We present 4 patients with CIDP who required respiratory assistance and mechanical ventilation. Two patients needed emergent intubation and one patient lapsed in a stupor from hypercapnia. Respiratory failure in CIDP should be considered exceptional, but more formal studies in CIDP may be needed to assess its prevalence.

Neuromuscular disorders in the intensive care unit

Neuromuscular disorders encountered in the ICU can be categorized as muscular diseases that lead to ICU admission and those that are acquired in the ICU. This article discusses three neuromuscular disorders can lead to ICU admission and have a putative immune-mediated pathogenesis: the Guillian-Barré syndrome, myasthenia gravis, and dermatomyositis/polymyositis. It also reviews critical care polyneuropathy and ICU acquired myopathy, two disorders that, alone or in combination, are responsible for nearly all cases of severe ICU acquired muscle weakness.

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 Guillain-Barré syndrome

BACKGROUND

Guillain-Barré syndrome is an acute symmetric, usually ascending and usually paralysing illness, due to inflammation of peripheral nerves. It is thought to be caused by autoimmune factors, such as antibodies. Plasma exchange removes antibodies and other potentially injurious factors from the blood stream. It involves connecting the patient's blood circulation to a machine which exchanges the plasma for a substitute solution, usually albumin. Several studies have evaluated plasma exchange for Guillain-Barré syndrome.

OBJECTIVES

To systematically review the evidence concerning the efficacy of plasma exchange for treating Guillain-Barré syndrome.

SEARCH STRATEGY

Search of the Cochrane Neuromuscular Disease Trial Register for randomised trials concerning plasma exchange in Guillain-Barré syndrome, search of the bibliographies of identified papers and enquiry from the authors of the papers.

SELECTION CRITERIA

Randomised and quasi-randomised trials of plasma exchange versus sham exchange or supportive treatment.

DATA COLLECTION AND ANALYSIS

Potentially relevant papers were scrutinised by two reviewers and the selection of eligible studies was agreed by them and a third reviewer. Data were extracted by one reviewer and checked by a second reviewer. Some missing data were obtained from the authors of studies.

MAIN RESULTS

Six eligible trials concerning 649 patients were identified, all comparing plasma exchange versus supportive treatment alone. Primary outcome measures ~bullet~Time to recover walking with aid In the only two trials for which this measure was reported, the median time to recover this ability was faster in the plasma exchange than the control group. ~bullet~Time to onset of motor recovery in mildly affected patients In the one trial for which this measure was available, the time was significantly shortened in the plasma exchange group. Secondary outcome measures ~bullet~Improvement in disability grade at four weeks In five trials, there were significantly more patients who had improved by one disability grade or more in the plasma exchange group as compared to the control group. Patients treated with plasma exchange fared significantly better in the following secondary outcome measures: time to recover walking without aid, percentage of patients requiring artificial ventilation, duration of ventilation, full muscle strength recovery after one year, and severe sequelae after one year. There were less patients with infectious events and cardiac arrhythmias in the plasma exchange than the control group. Subgroup analyses Plasma exchange was beneficial in patients with mild, moderate and severe (needing ventilation) Guillain-Barré syndrome. It was beneficial in patients with a disease duration of seven or less days and also in those with disease lasting more than seven days. However, in the only trial that enrolled patients up to 30 days from disease onset, the benefit of plasma exchange in patients treated after seven days was less apparent. Type of treatment Single studies showed that two plasma exchanges were significantly superior to none for mild Guillain-Barré syndrome and four to two for moderate Guillain-Barré syndrome, but that six were not superior to four for severe Guillain-Barré syndrome requiring ventilation. One study suggested that continuous flow plasma exchange was significantly superior to intermittent flow. Another study found no significant difference between the two techniques. The same study found a significantly higher rate of adverse events with fresh frozen plasma as the replacement fluid than albumin. Plasma exchange compared with cerebrospinal fluid filtration A single trial comparing these two treatments did not show any difference in outcomes but was too small to demonstrate equivalence.

REVIEWER'S CONCLUSIONS

Plasma exchange is the first and only treatment that has been proven to be superior to supportive treatment alone in Guillain-Barré syndrome. Consequently, plasma exchange should be regarded as the treatment against which new treatments, such as intravenous immunoglobulin, should be judged. In mild Guillain-Barré syndrome two sessions of plasma exchange are superior to none. In moderate Guillain-Barré syndrome four sessions are superior to two. In severe Guillain-Barré syndrome six sessions are no better than four. Continuous flow plasma exchange machines may be superior to intermittent flow machines and albumin to fresh frozen plasma as the exchange fluid. Plasma exchange is more beneficial when started within seven days after disease onset rather than later, but was still beneficial in patients treated up to 30 days after disease onset. The value of plasma exchange in children less than 12 years old is not known. There is insufficient evidence to determine whether cerebrospinal fluid filtration is equivalent to plasma exchange.

Treatment of the adult Guillain-Barré syndrome: indications for plasma exchange

The Guillain-Barré syndrome is the most common cause of acute flaccid paralysis. Currently, 5% of patients die and 10% are left with severe motor sequelae at one year. Multidisciplinary teams, trained to specific treatments, are required to manage these patients. Oral and intravenous steroid treatment of GBS has been disappointing. Two large randomized clinical trials comparing plasma exchange (PE) to standard supportive treatment have shown a short-term and a one-year benefit of PE. Appropriate number of exchanges and indications of PE are now more precisely known. Patients with mild forms of the disease (able to walk) should receive two PEs, while a further two exchanges should be done in case of deterioration or in advanced forms (loss of walking ability, mechanical ventilation). A greater number of exchanges does not appeared beneficial. More recently, two randomized trials produced some evidence that intravenous immune globulin (IVIg, 0.4 g/kg daily for five days) and PE had equivalent efficiency in advanced forms. The combination of PE with IVIg did not yield a significant advantage, but did increase cost and risk. In advanced forms, the choice between PE and IVIg depends on the contraindications of each treatment.

[Treatment of Guillain-Barré syndrome in adults: role of plasma exchange]

PURPOSE

To review recent data on treatment of Guillain-Barré syndrome, especially indications of plasma exchange.

DATA SYNTHESIS

Guillain-Barré syndrome is the most common cause of acute flaccid paralysis. The current mortality is 5%, sever motor sequelae persist after 1 year in 10% of cases. Multidisciplinary teams are required to treat these patients, trained to all specific treatments. Oral and intravenous steroids have proven ineffective. Two large randomized clinical trials comparing plasma exchange (PE) with no treatment have shown a short-term and a 1-year benefit. Appropriate number of exchanges and indications are now more precisely known. In mild form (walking possible), patients should receive two PEs. A further two exchanges should be done in case of deterioration or in advanced forms (loss of walking ability, mechanical ventilation). More exchanges are not beneficial. Recently two new randomized trials have produced evidence that intravenous immune globulin (IVIg) (0.4 g/kg/d for 5 days) were as effective as five PEs in advanced forms. The combination of PE with IVIg did not confer a significant advantage, while increasing cost and risks.

CONCLUSION

The combination of PE with IVIg did not confer, in advanced forms, the choice between PE and IVIg depends of the contra-indications of each treatment.

Acute peripheral neuropathy in adults. Guillain-Barré syndrome and related disorders

Acute paralysis in adults has an extensive assortment of etiologies. Guillian-Barré syndrome is the most common cause of acute neuropathy in adults. This review emphasizes pathophysiology, clinical features, differential diagnosis, and a practical approach to the laboratory work-up for patients with suspected Guillian-Barré syndrome. The current status of immunotherapy is reviewed.

Clinical trial of plasma exchange and high-dose intravenous immunoglobulin in myasthenia gravis. Myasthenia Gravis Clinical Study Group

We have conducted a trial to randomly assess the efficacy and tolerance of intravenous immunoglobulin (i.v.Ig) or plasma exchange (PE) in myasthenia gravis (MG) exacerbation and to compare two doses of i.v.Ig. Eighty-seven patients with MG exacerbation were randomized to receive either three PE (n = 41), or i.v.Ig (n = 46) 0.4 gm/kg daily further allocated to 3 (n = 23) or 5 days (n = 23). The main end point was the variation of a myasthenic muscular score (MSS) between randomization and day 15. The MSS variation was similar in both groups (median value, +18 in the PE group and +15.5 in the i.v.Ig group, p = 0.65). Similar efficacy, although slightly reduced in the 5-day group was observed with both i.v.Ig schedules. The tolerance of i.v.Ig was better than that of PE with a total of 14 side effects observed in 9 patients, 8 in the PE group and 1 in the i.v.Ig group (p = 0.01). Although our trial failed to show a pronounced difference in the efficacy of both treatments, it exhibited a very limited risk for i.v.Ig. i.v.Ig is an alternative for the treatment of myasthenic crisis. The small sample sizes in our trial, however, could explain why a difference in efficacy was not observed. Further studies are needed to compare PE with i.v.Ig and to determine the optimal dosage of i.v.Ig.

Treatment of acute pandysautonomia with intravenous immunoglobulin

Acute pandysautonomia has been suggested to be an uncommon variant of Guillain-Barre syndrome. Acute pandysautonomia does not seem to have been treated with intravenous immunoglobulin or other therapies proved efficacious in Guillain-Barre syndrome. A patient is reported with severe acute pandysautonomia who responded dramatically to intravenous immunoglobulin. The findings are consistent with a dysimmune pathogenesis for this syndrome and suggest a possible treatment for future cases.

Appropriate number of plasma exchanges in Guillain-Barré syndrome. The French Cooperative Group on Plasma Exchange in Guillain-Barré Syndrome

Plasma exchange (PE) is the standard treatment in Guillain-Barré syndrome (GBS) patients who have lost the ability to walk. The effect of exchanges before this stage and the optimal number of exchanges for the other patients are still unknown. We randomized 556 GBS patients according to severity and number of exchanges as follows: Zero versus 2 PEs for patients who could walk-with or without aid-but not run, or who could stand up unaided (mild group); 2 versus 4 PEs for patients who could not stand up unaided (moderate group); and 4 versus 6 PEs for mechanically ventilated patients (severe group). In the mild group, 2 PEs were more effective than none for time to onset of motor recovery (median, 4 vs 8 days, respectively). In the moderate group, 4 PEs were more beneficial than 2 for time to walk with assistance (median, 20 vs 24 days) and for 1-year full muscle-strength recovery rate (64% vs 46%). Six PEs were no more beneficial than 4 in the severe cases. Patients with mild GBS on admission should receive 2 PEs. Patients with moderate and severe forms should benefit from 2 further exchanges.

The current place of high-dose immunoglobulins in the treatment of neuromuscular disorders

High-dose immunoglobulins for intravenous administration (IVIg) have originally been developed for substitution therapy in hypogammaglobulinemia. Over the last decade they are increasingly used in the treatment of immune-mediated diseases. In this review the results in immune-mediated neuromuscular diseases are summarized. Positive effects are demonstrated in open studies in dermato- and polymyositis, myasthenia gravis, and inflammatory neuropathies. Properly conducted randomized clinical trials demonstrating the effect of IVIg are available in dermatomyositis, Guillain-Barré syndrome, and chronic inflammatory demyelinating polyneuropathy, and smaller ones in multifocal motor neuropathy. In myasthenia gravis a trial is at present underway and only interim results are available. The results of a trial in the Lambert-Eaton myasthenic syndrome are in the process of publication. The therapeutic approach in individual patients is discussed, but often appears to be difficult. Considering chronic treatment with IVIg, proper long-term studies including cost-benefit studies are needed. Future developments aim for combination therapies, since IVIg and immune suppressants like prednisone are suggested to have a synergistic effect.

Inflammatory neuropathies--pathogenesis and the role of intravenous immune globulin

The inflammatory neuropathies may be subdivided into an acute form, Guillain-Barré syndrome, and a chronic form referred to as chronic inflammatory demyelinating polyneuropathy. More recently a chronic, asymmetrical pure motor neuropathy with multifocal conduction blocks has been described. All three neuropathies are considered to be immune-mediated. Their response to therapy is discussed, with special emphasis on high-dose intravenous immune globulin. For Guillain-Barré syndrome the efficacy of intravenous immune globulin has been proven in a randomized clinical trial. In chronic inflammatory demyelinating polyneuropathy a response rate of over 60% in newly diagnosed patients is suggested. Clinical prognostic criteria, however, seem to be very important to predict the effect of intravenous immune globulin. In multifocal motor neuropathy intravenous immune globulin is at present the only alternative to cyclophosphamide.

Biodistribution of monoclonal antibody Po66 in a human lung tumour-bearing mouse model: effect of blood exchange on tumour antibody uptake

We report a method designed to improve the specificity of tumour uptake after intravenous injection of an anti-tumour monoclonal antibody (MAb). It consists in increasing the blood clearance of the MAb injected in order to diminish its tissue activity, without altering tumour binding. Po66, an MAb directed against lung squamous cell carcinoma, was radiolabelled with 125I and injected i.v. into tumour-bearing nude mice. Radioactivity uptake by the tumour reached a plateau on days 3-5 which persisted up to day 14 after antibody injection. The radiolabelled Po66 remaining in the circulation on day 5 after injection was removed by means of exsanguination and blood transfusion. This blood exchange technique depleted circulating radiolabelled MAb by 60%, whenever mice had been injected with Po66 or an unrelated control IgG1. The proportion of radiolabelled Po66 taken up by the tumour 5 days after blood exchange did not differ substantially from that of non-exsanguinated controls (96.1% of controls). In contrast, there was a significant decrease in blood radioactivity (46% of control values on day 5). Blood exchange provoked a 1.8 fold increase in the tumour/blood and a 1.5-1.8 fold increase of the tumour/organ radioactivity ratios. After injection of unrelated radiolabelled IgG1, blood exchange reduced by 50% both blood and tumour radioactivity, and did not increase the tumour/blood or tumour/organ ratios. Hence, removal of 60% of circulating Po66, 5 days after its injection, did not affect the binding or retention of the antibody by the tumour, but would probably constitute a marked improvement if the antibody is used for two-phase radioimmunotherapy.

Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy: immune mechanisms and update on current therapies

The relation between Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy is discussed. Most likely they represent parts of a continuum, arbitrarily separated by their time course. Within the concept of chronic inflammatory demyelinating polyneuropathy the presence of a monoclonal gammopathy of undetermined significance is discussed. The pathogenesis of inflammatory demyelinating polyneuropathies has not been elucidated yet, but involvement of the immune system has been firmly established. Preceding infections, especially with Campylobacter jejuni, and the analysis of antiganglioside antibodies lend new support to the hypothesis of molecular mimicry between epitopes on infectious agents and peripheral nerve constituents as one of the mechanisms in Guillain-Barré syndrome. In the future, a further classification of individual patients based on clinical, epidemiological, electrophysiological, pathological, microbiological, and immunological criteria may give a basis for more individualized treatment strategies. In Guillain-Barré syndrome the efficacy of high-dose intravenous immune globulin treatment was established after earlier positive findings with plasma exchange; immune globulins are easier to administer and may be superior. Even with these treatments it should be anticipated that one fourth of patients after immune globulin treatment and one third of patients after plasma exchange will show further deterioration in the first 2 weeks after onset of treatment. Despite this, just one treatment course usually is indicated in the individual patient, and no valid arguments were found to switch to the other treatment modality. In chronic inflammatory demyelinating polyneuropathy, prednisone, plasma exchange, and immune globulins are effective in a proportion of patients. The last two are equally effective. Patients may respond to one of these if a previous treatment failed, and here switching therapy may be effective due to the chronic course of the disease. Complexity and costs make plasma exchange the last choice. Whether prednisone or immune globulin is the first choice depends on the speed of recovery and the estimation of long-term loss of quality of life due to side effects of prednisone versus the costs of immune globulins. The mechanism of immune globulins in inflammatory polyneuropathies is discussed. There is evidence that idiotypic-antiidiotypic interaction may play a role, but several other mechanisms also may be involved.