Biological Drugs in Guillain-Barré Syndrome: An Update

Challenges in the Management of Acute Severe Ulcerative Colitis in a Patient With Guillain-Barré Syndrome Associated With Infliximab

Despite being a rare adverse event, Guillain-Barré syndrome should be a differential diagnosis in patients taking tumor necrosis factor alpha (TNF-α) inhibitors who develop neurological events. Ustekinumab seems to be a safe option after TNF-α inhibitors in these patients.

Animal models of immune-mediated demyelinating polyneuropathies

Immune-mediated demyelinating polyneuropathies (IMDPs) are rare disorders in which dysregulated adaptive immune responses cause peripheral nerve demyelinating inflammation and axonal injury in susceptible individuals. Despite significant advances in understanding IMDP pathogenesis guided by patient data and representative mammalian models, specific therapies are lacking. Significant knowledge gaps in IMDP pathogenesis still exist, e.g. precise antigen(s) and mechanisms that initially trigger immune system activation and identification of large population disease susceptibility factors. The initial directional cues for antigen-specific effector or autoreactive leukocyte trafficking into peripheral nerves are also unknown. An overview of current animal models, with emphasis on the experimental autoimmune neuritis and spontaneous autoimmune peripheral polyneuropathy models, is provided. Insights on the initial directional cues for peripheral nerve tissue specific autoimmunity using a novel Major Histocompatibility Complex class II conditional knockout mouse strain are also discussed, suggesting an essential research tool to study cell- and time-dependent adaptive immunity in autoimmune diseases.

Causal relationship between immune cells and Guillain-Barré syndrome: a Mendelian randomization study

Objective

The aim of this study was to investigate the causal effect of immune cell phenotype on GBS using two-sample Mendelian randomization (MR) approach.

Methods

This study used MR to investigate the causal relationship between 731 immune cell phenotypes and GBS. We used Inverse variance weighted, Weighted median, MR Egger, Simple mode, Weighted mode for MR analysis. We also used the Cochran Q test, MR-Egger intercept test, IVW regression and MR-PRESSO, leave-one-out analysis to assess the presence of horizontal pleiotropy, heterogeneity and stability, respectively.

Results

Our study revealed a causal relationship between 33 immune cell phenotypes and GBS. Twenty immunophenotypes were observed to be associated with GBS as risk factors. For example, CD20 on IgD+ CD38dim in the B cell group (OR = 1.313, 95%CI:1.042-1.654, p = 0.021), CD3 on CD4 Treg in Treg cell group (OR = 1.395, 95%CI:1.069-1.819, p = 0.014), CD3 on TD CD8br in Maturation stages of T cell group (OR = 1.486, 95%CI:1.025-2.154, p = 0.037), CD16 on CD14+ CD16+ monocyte in Monocyte group (OR = 1.285, 95%CI:1.018-1.621, p = 0.035), CD33dim HLA DR+ CD11b + %CD33dim HLA DR+ in Myeloid cell group (OR = 1.262, 95%CI:1.020-1.561, p = 0.032), HLA DR+ NK AC in TBNK cell group (OR = 1.568, 95%CI:1.100-2.237, p = 0.013). Thirteen immune phenotypes are associated with GBS as protective factors. For example, CD19 on PB/PC in the B cell group (OR = 0.577, 95%CI:0.370-0.902, p = 0.016), CD4 Treg AC in Treg cell group (OR = 0.727, 95%CI:0.538-0.983, p = 0.038), CD11c + monocyte %monocyte in cDC group (OR = 0.704, 95%CI:0.514-0.966, p = 0.030), CX3CR1 on CD14+ CD16- monocyte in Monocyte group (OR = 0.717, 95%CI:0.548-0.939, p = 0.016), Mo MDSC AC in Myeloid cell group (OR = 0.763, 95%CI:0.619-0.939, p = 0.011), CD45 on granulocyte in TBNK group (OR = 0.621, 95%CI:0.391-0.984, p = 0.042).

Conclusion

The findings suggest that certain specific immune cell phenotypes, particularly B cell and Treg cell subpopulations, are causally associated with GBS, providing potential targets for the clinical treatment of GBS.

Guillain-Barré syndrome: immunopathogenesis and therapeutic targets

INTRODUCTION

Guillain-Barré syndrome (GBS) is a group of acute immune-mediated disorders in the peripheral nervous system. Both infectious and noninfectious factors are associated with GBS, which may act as triggers of autoimmune responses leading to neural damage and dysfunction.

AREAS COVERED

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its vaccines as well as flaviviruses have been associated with GBS, although a robust conclusion has yet to be reached. Immunomodulatory treatments, including intravenous immunoglobulins (IVIg) and plasma exchange (PE), have long been the first-line therapies for GBS. Depending on GBS subtype and severity at initial presentation, the efficacy of IVIg and PE can be variable. Several new therapies showing benefits to experimental animals merit further investigation before translation into clinical practice. We review the state-of-the-art knowledge on the immunopathogenesis of GBS in the context of coronavirus disease 2019 (COVID-19). Immunomodulatory therapies in GBS, including IVIg, PE, corticosteroids, and potential therapies, are summarized.

EXPERT OPINION

The association with SARS-CoV-2 remains uncertain, with geographical differences that are difficult to explain. Evidence and guidelines are lacking for the decision-making of initiating immunomodulatory therapies in mildly affected patients or patients with regional subtypes of GBS.

Case report: Resolution of Guillain-Barré syndrome in a patient with dual primary tumors after treatment with rituximab

Guillain-Barré syndrome (GBS) is a rare immune-related adverse event (irAE) that can occur in solid tumors such as hepatocellular carcinoma, gastric cancer, breast cancer, and colorectal cancer. It is characterized by progressive myasthenia and mild sensory abnormalities. The emergence of immune checkpoint inhibitors (ICIs) has significantly improved cancer patients' life expectancy but can also trigger various irAEs, including GBS. We report a rare case of GBS in a 64-year-old male patient with dual primary tumors of the colon and stomach who received toripalimab and chemotherapy for liver metastases. After five treatments, the patient experienced weakness and numbness in his limbs. Lumbar puncture, electromyography, and other tests confirmed the diagnosis of GBS. Intravenous immunoglobulin (IVIG) and methylprednisolone did not improve the patient's symptoms, but rituximab, which is not a standard regimen for GBS, was effective in eliminating B cells and improving symptoms. Following this, we effectively shifted from a regimen combining immunotherapy and chemotherapy to a targeted therapy regimen, resulting in prolonged patient survival. Currently, limited studies have been undertaken to evaluate the efficacy of rituximab in managing refractory neurological adverse events associated with ICI therapy. Using this case, we reviewed similar cases and formed our views.

C1q and central nervous system disorders

C1q is a crucial component of the complement system, which is activated through the classical pathway to perform non-specific immune functions, serving as the first line of defense against pathogens. C1q can also bind to specific receptors to carry out immune and other functions, playing a vital role in maintaining immune homeostasis and normal physiological functions. In the developing central nervous system (CNS), C1q functions in synapse formation and pruning, serving as a key player in the development and homeostasis of neuronal networks in the CNS. C1q has a close relationship with microglia and astrocytes, and under their influence, C1q may contribute to the development of CNS disorders. Furthermore, C1q can also have independent effects on neurological disorders, producing either beneficial or detrimental outcomes. Most of the evidence for these functions comes from animal models, with some also from human specimen studies. C1q is now emerging as a promising target for the treatment of a variety of diseases, and clinical trials are already underway for CNS disorders. This article highlights the role of C1q in CNS diseases, offering new directions for the diagnosis and treatment of these conditions.

Guillain-Barré syndrome in children - High occurrence of Miller Fisher syndrome in East Asian region

BACKGROUND

Guillain-Barré syndrome (GBS) is a rare acquired immune-mediated polyneuropathy. Updated population-based data concerning paediatric GBS is needed.

METHODS

Paediatric patients aged below 18 years diagnosed with GBS between 2009 and 2018 in all 11 paediatric departments in Hong Kong were identified from the Hong Kong Hospital Authority Clinical Data Analysis and Reporting System. The collected data from medical health records were reviewed by paediatric neurologist from each department. Estimated incidence of paediatric GBS was calculated. We also compared our findings with other paediatric GBS studies in Asia.

RESULTS

63 subjects of paediatric GBS were identified, giving an estimated annual incidence of 0.62 per 100,000 population. Half of the subjects had acute inflammatory demyelinating polyneuropathy (AIDP) (n = 31; 49.2%), one quarter had Miller Fisher Syndrome (MFS) (n = 16; 25.4%), one-fifth had axonal types of GBS (n = 12; 19.0%), and four were unclassified. Paediatric subjects with axonal subtypes of GBS compared to the other 2 subtypes, had significantly higher intensive care unit (ICU) admission rates (p = 0.001) and longest length of stay (p = 0.009). With immunomodulating therapy, complete recovery was highest in those with MFS (100%), followed by AIDP (87.1%) and axonal GBS (75%). Our study also confirms a higher MFS rate for paediatric GBS in East Asia region and our study has the highest MFS rate (25.4%).

CONCLUSION

Our population-based 10-year paediatric GBS study provides updated evidence on estimated incidence, healthcare burden and motor outcome of each subtype of paediatric GBS and confirmed a higher occurrence of paediatric MFS in East Asia.

SARS-CoV-2 and Guillain-Barré Syndrome: Lessons from Viral Infections

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for the COVID-19 pandemic. COVID-19 has a broad clinical spectrum from asymptomatic patients to multiorgan dysfunction and septic shock. Most of the common symptoms of COVID-19 are classified as respiratory disorders, but some reports show neurological involvements. During the COVID-19 pandemic, a case series of neurological complications, such as Guillain-Barré syndrome (GBS), were reported. GBS is a neuroimmune disorder with acute inflammatory radicular polyneuropathy in different parts of the peripheral nerve. Some studies have reported GBS as an inflammatory neuropathy related to various viral infections, such as cytomegalovirus (CMV), Epstein-Barr Virus (EBV), herpes simplex virus (HSV), human immunodeficiency virus (HIV), influenza, and Zika virus. There are some immunomodulation approaches for the management of GBS. Studies have evaluated the effects of the various therapeutic approaches, including intravenous immunoglobulin (IVIG), plasma exchange (PE), complement inhibitors, and corticosteroids to regulate overactivation of immune responses during GBS in experimental and clinical studies. In this regard, the possible association between GBS and SARS-CoV-2 infection during the outbreak of the current pandemic and also the mentioned therapeutic approaches were reviewed.

Development of a Trivalent Construct Omp18/AhpC/FlgH Multi Epitope Peptide Vaccine Against Campylobacter jejuni

Campylobacter jejuni (C. jejuni) is one of the major pathogens contributing to the enteritis in humans. Infection can lead to numerous complications, including but not limited to Guillain-Barre syndrome, reactive arthritis, and Reiter's syndrome. Over the past two decades, joint efforts have been made toward developing a proper strategy of limiting the transmission of C. jejuni to humans. Nevertheless, except for biosecurity measures, no available vaccine has been developed so far. Judging from the research findings, Omp18, AhpC outer membrane protein, and FlgH flagellin subunits of C. jejuni could be adopted as surface protein antigens of C. jejuni for screening dominant epitope thanks to their strong antigenicity, expression of varying strains, and conservative sequence. In this study, bioinformatics technology was adopted to analyze the T-B antigenic epitopes of Omp18, AhpC, and FlgH in C. jejuni strain NCTC11168. Both ELISA and Western Blot methods were adopted to screen the dominant T-B combined epitope. GGS (GGCGGTAGC) sequence was adopted to connect the dominant T-B combined epitope peptides and to construct the prokaryotic expression system of tandem repeats of antigenic epitope peptides. The mouse infection model was adopted to assess the immunoprotective effect imposed by the trivalent T-B combined with antigen epitope peptide based on Omp18/AhpC/FlgH. In this study, a tandem epitope AhpC-2/Omp18-1/FlgH-1 was developed, which was composed of three epitopes and could effectively enhance the stability and antigenicity of the epitope while preserving its structure. The immunization of BALB/c mice with a tandem epitope could induce protective immunity accompanied by the generation of IgG2a antibody response through the in vitro synthesis of IFN-γ cytokines. Judging from the results of immune protection experiments, the colonization of C. jejuni declined to a significant extent, and it was expected that AhpC-2/Omp18-1/FlgH-1 could be adopted as a candidate antigen for genetic engineering vaccine of C. jejuni MAP.

Axonal variants of Guillain-Barré syndrome: an update

Axonal variants of Guillain-Barré syndrome (GBS) mainly include acute motor axonal neuropathy, acute motor and sensory axonal neuropathy, and pharyngeal-cervical-brachial weakness. Molecular mimicry of human gangliosides by a pathogen's lipooligosaccharides is a well-established mechanism for Campylobacter jejuni-associated GBS. New triggers of the axonal variants of GBS (axonal GBS), such as Zika virus, hepatitis viruses, intravenous administration of ganglioside, vaccination, and surgery, are being identified. However, the pathogenetic mechanisms of axonal GBS related to antecedent bacterial or viral infections other than Campylobacter jejuni remain unknown. Currently, autoantibody classification and serial electrophysiology are cardinal approaches to differentiate axonal GBS from the prototype of GBS, acute inflammatory demyelinating polyneuropathy. Newly developed technologies, including metabolite analysis, peripheral nerve ultrasound, and feature selection via artificial intelligence are facilitating more accurate diagnosis of axonal GBS. Nevertheless, some key issues, such as genetic susceptibilities, remain unanswered and moreover, current therapies bear limitations. Although several therapies have shown considerable benefits to experimental animals, randomized controlled trials are still needed to validate their efficacy.

B Cell Activation and Escape of Tolerance Checkpoints: Recent Insights from Studying Autoreactive B Cells

Autoreactive B cells are key drivers of pathogenic processes in autoimmune diseases by the production of autoantibodies, secretion of cytokines, and presentation of autoantigens to T cells. However, the mechanisms that underlie the development of autoreactive B cells are not well understood. Here, we review recent studies leveraging novel techniques to identify and characterize (auto)antigen-specific B cells. The insights gained from such studies pertaining to the mechanisms involved in the escape of tolerance checkpoints and the activation of autoreactive B cells are discussed. In addition, we briefly highlight potential therapeutic strategies to target and eliminate autoreactive B cells in autoimmune diseases.

Review of indications for immunoglobulin (IG) use: Narrowing the gap between supply and demand

Cellular blood components and plasma-derived medicinal products (PDMPs) are obtained from blood donated by volunteers. In a growing number of countries, in line with World Health Organization advice issued since the mid-1970s, donors are not remunerated. In recent decades, considerable efforts have been made to restrict the indications for labile blood components to those based on evidence, to ensure efficacy and safety. By contrast, the producers of PDMPs have developed pathogen reduction techniques for inactivating the microorganisms in (pooled) plasma, but little attention has been paid to the pertinence of the clinical indications for these products. The use of blood, and of erythrocytes in particular, has declined by almost 40%, but the use of immunoglobulins (IG) tripled between 2004 and 2018, making it necessary to pay donors to obtain sufficient blood to meet the market demand for these products. We analyzed the reasons for this increase to unsustainable levels of use, by investigating (practice) guidelines, recommendations, Cochrane data analyses and systematic reviews for clinical indications for IG over time. We found no new evidence explaining the huge increase up to 2018 or the predicted 5-7% yearly annual increase until 2024. For some former evidence-based indications, biologics have largely replaced IG, but the administration of IG for doubtful indications (up to 40%) has not decreased in recent decades. The main development since 2004 is that IG use in Europe has become market-driven rather than evidence-guided. As transfusion specialists and blood therapists, we must raise the alarm that this situation is likely to continue in the absence of good clinical studies determining the place of IG alongside other treatments, and for as long as market profitability remains the dominant driving force. We discuss here approaches for reversing this trend and moving towards European self-sufficiency through non-remunerated voluntary blood donation.

[Co-existence of Guillain-Barré syndrome and Behcet syndrome: A case report]

A 40-year-old male patient was referred to our department with complains of recurrent oral ulcer for more than 20 years and vulvar ulcer for more than 10 years. He presented with a 3-month history of right external ophthalmoplegia. More than 10 days ago, the patient received ganglioside infusion. And one week ago, he developed numbness and pain of his lambs, and progressive myasthenia, accompanied by right blepharoptosis and dysuria. On exam, motor strength was graded 0/5 in the lower and the upper extremities. Deep tendon reflexes were diminished in extremities. His admission medical examination: hemoglobin (HGB), white cell and platelet counts were normal. C-reactive protein (CRP) was negative. Erythrocyte sedimentation rate (ESR) 53 mm/h. Antinuclear antibody (ANA), anti-dsDNA antibody, anti-Smith antibody, anti-cardiolipin antibody and human leucocyte antigen B51 were all within normal range. The etiological tests of influenza A pathogen, influenza B pathogen, parainfluenza virus, enterovirus and parvovirus were all negative. He tested positive for serum anti-GM1 IgG. Cerebrospinal fluid had a normal white cell count, an elevated protein content. Gram staining, culture and PCR detection for varicella-zoster virus, cytomegalovirus and herpes simplex virus were all negative. Antibodies associated with autoimmune encephalitis and paraneoplastic syndrome were negative in cerebrospinal fluid. Electromyography and nerve conduction studies showed a severe axonal damage affecting motor nerves. No obvious abnormalities were observed in his magnetic resonance imaging of brain and cavernous sinus. The patient was diagnosed with Behcet syndrome complicated with acute Guillain-Barré syndrome. He received intravenous methylprednisolone, intravenous immunoglobulin (IVIg) therapy, plasma exchange and rituximab treatment. After treatment, the patient's muscle strength of limbs was restored to grade 1, blepharoptosis and pain disappeared. The nervous system involvement of Behcet syndrome is relatively rare, especially combined with Guillain-Barré syndrome, which is easy to cause misdiagnosis. The treatment of Behcet syndrome complicated with acute Guillain-Barré syndrome includes the treatment of primary disease, plasma exchange and IVIg therapy. In addition, supportive treatment is very important for such patients. The focus of treatment is to avoid respiratory insufficiency, prevent deep vein thrombosis, monitor cardiac function and hemodynamics. Pain-relieving, physical exercise and psychological support are often under-recognized. The rehabilitation treatment is very important to improve the prognosis and quality of life of patients. What we need to learn is that when the symptoms and signs of the nervous system are difficult to be explained by neuro-Behcet syndrome alone, we should be alert to the possibility of other nervous system diseases.

[Co-existence of Guillain-Barré syndrome and Behcet syndrome: A case report]

A 40-year-old male patient was referred to our department with complains of recurrent oral ulcer for more than 20 years and vulvar ulcer for more than 10 years. He presented with a 3-month history of right external ophthalmoplegia. More than 10 days ago, the patient received ganglioside infusion. And one week ago, he developed numbness and pain of his lambs, and progressive myasthenia, accompanied by right blepharoptosis and dysuria. On exam, motor strength was graded 0/5 in the lower and the upper extremities. Deep tendon reflexes were diminished in extremities. His admission medical examination: hemoglobin (HGB), white cell and platelet counts were normal. C-reactive protein (CRP) was negative. Erythrocyte sedimentation rate (ESR) 53 mm/h. Antinuclear antibody (ANA), anti-dsDNA antibody, anti-Smith antibody, anti-cardiolipin antibody and human leucocyte antigen B51 were all within normal range. The etiological tests of influenza A pathogen, influenza B pathogen, parainfluenza virus, enterovirus and parvovirus were all negative. He tested positive for serum anti-GM1 IgG. Cerebrospinal fluid had a normal white cell count, an elevated protein content. Gram staining, culture and PCR detection for varicella-zoster virus, cytomegalovirus and herpes simplex virus were all negative. Antibodies associated with autoimmune encephalitis and paraneoplastic syndrome were negative in cerebrospinal fluid. Electromyography and nerve conduction studies showed a severe axonal damage affecting motor nerves. No obvious abnormalities were observed in his magnetic resonance imaging of brain and cavernous sinus. The patient was diagnosed with Behcet syndrome complicated with acute Guillain-Barré syndrome. He received intravenous methylprednisolone, intravenous immunoglobulin (IVIg) therapy, plasma exchange and rituximab treatment. After treatment, the patient's muscle strength of limbs was restored to grade 1, blepharoptosis and pain disappeared. The nervous system involvement of Behcet syndrome is relatively rare, especially combined with Guillain-Barré syndrome, which is easy to cause misdiagnosis. The treatment of Behcet syndrome complicated with acute Guillain-Barré syndrome includes the treatment of primary disease, plasma exchange and IVIg therapy. In addition, supportive treatment is very important for such patients. The focus of treatment is to avoid respiratory insufficiency, prevent deep vein thrombosis, monitor cardiac function and hemodynamics. Pain-relieving, physical exercise and psychological support are often under-recognized. The rehabilitation treatment is very important to improve the prognosis and quality of life of patients. What we need to learn is that when the symptoms and signs of the nervous system are difficult to be explained by neuro-Behcet syndrome alone, we should be alert to the possibility of other nervous system diseases.

Pharmacological treatment other than corticosteroids, intravenous immunoglobulin and plasma exchange for Guillain-Barré syndrome

BACKGROUND

Plasma exchange and intravenous immunoglobulin, but not corticosteroids, are beneficial in Guillain-Barré syndrome (GBS). The efficacy of other pharmacological agents is unknown. This review was first published in 2011 and previously updated in 2013, and 2016.

OBJECTIVES

To assess the effects of pharmacological agents other than plasma exchange, intravenous immunoglobulin and corticosteroids for GBS.

SEARCH METHODS

On 28 October 2019, we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, and Embase for treatments for GBS. We also searched clinical trials registries.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) or quasi-RCTs of acute GBS (within four weeks from onset) of all types and degrees of severity, and in individuals of all ages. We discarded trials that investigated only corticosteroids, intravenous immunoglobulin or plasma exchange. We included other pharmacological treatments or combinations of treatments compared with no treatment, placebo or another treatment.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology.

MAIN RESULTS

We found six trials of five different interventions eligible for inclusion in this review. The trials were conducted in hospitals in Canada, China, Germany, Japan and the UK, and included 151 participants in total. All trials randomised participants aged 16 years and older (mean or median age in the trials ranged from 36 to 57 years in the intervention groups and 34 to 60 years in the control groups) with severe GBS, defined by the inability to walk unaided. One trial also randomised patients with mild GBS who were still able to walk unaided. We identified two new trials at this update.The primary outcome measure for this review was improvement in disability grade four weeks after randomisation. Four of six trials had a high risk of bias in at least one respect. We assessed all evidence for the outcome mean improvement in disability grade as very low certainty, which means that we were unable to draw any conclusions from the data. One RCT with 19 participants compared interferon beta-1a (IFNb-1a) and placebo. It is uncertain whether IFNb-1a improves disability after four weeks (mean difference (MD) -0.1; 95% CI -1.58 to 1.38; very low-certainty evidence). A trial with 10 participants compared brain-derived neurotrophic factor (BNDF) and placebo. It is uncertain whether BDNF improves disability after four weeks (MD 0.75; 95% CI -1.14 to 2.64; very low-certainty evidence). A trial with 37 participants compared cerebrospinal fluid (CSF) filtration and plasma exchange. It is uncertain whether CSF filtration improves disability after four weeks (MD 0.02; 95% CI -0.62 to 0.66; very low-certainty evidence). One trial that compared the Chinese herbal medicine tripterygium polyglycoside with corticosteroids with 43 participants did not report the risk ratio (RR) for an improvement by one or more disability grade after four weeks, but did report improvement after eight weeks. It is uncertain whether tripterygium polyglycoside improves disability after eight weeks (RR 1.47; 95% CI 1.02 to 2.11; very low-certainty evidence). We performed a meta-analysis of two trials comparing eculizumab and placebo with 41 participants. It is uncertain whether eculizumab improves disability after four weeks (MD -0.23; 95% CI -1.79 to 1.34; very low-certainty evidence). Serious adverse events were uncommon in each of the trials and evidence was graded as either low or very low. It is uncertain whether serious adverse events were more common with IFNb-1a versus placebo (RR 0.92, 95% CI 0.23 to 3.72; 19 participants), BNDF versus placebo (RR 1.00, 95% CI 0.28 to 3.54; 10 participants) or CSF filtration versus plasma exchange (RR 0.13, 95% CI 0.01 to 2.25; 37 participants). The trial of tripterygium polyglycoside did not report serious adverse events. There may be no clear difference in the number of serious adverse events after eculizumab compared to placebo (RR 1.90, 0.34 to 10.50; 41 participants). We found no clinically important differences in any of the outcome measures selected for this review in any of the six trials. However, sample sizes were small and therefore clinically important benefit or harm cannot be excluded.

AUTHORS' CONCLUSIONS

All six RCTs were too small to exclude clinically important benefit or harm from the assessed interventions. The certainty of the evidence was low or very low for all interventions and outcomes.

Advances in management of Guillain-Barré syndrome

PURPOSE OF REVIEW

The clinical presentation of Guillain-Barré syndrome (GBS) is highly variable, which can make the diagnosis challenging. Intravenous immunoglobulin (IVIg) and plasma exchange are the cornerstones of treatment since decades. But despite these treatments, 25% initially progress in muscle weakness, 25% require artificial ventilation, 20% is still not able to walk independently after 6 months, and 2-5% die, emphasizing the need for better treatment. We summarize new developments regarding the diagnosis, prognosis, and management of GBS.

RECENT FINDINGS

GBS is a clinical diagnosis that can be supported by cerebrospinal fluid examination and nerve conduction studies. Nerve ultrasound and MRI are potentially useful techniques to diagnose inflammatory neuropathies. Several novel infections have recently been associated to GBS. Evidence from experimental studies and recent phase 2 clinical trials suggests that complement inhibition combined with IVIg might improve outcome in GBS, but further studies are warranted. Prognostic models could guide the selection of patients with a relatively poor prognosis that might benefit most from additional IVIg or otherwise intensified treatment.

SUMMARY

New diagnostic tools may help to have early and accurate diagnosis in difficult GBS cases. Increased knowledge on the pathophysiology of GBS forms the basis for development of new, targeted, and personalized treatments that hopefully improve outcome.

Immunotherapy of Guillain-Barré syndrome

Guillain-Barré syndrome (GBS), the most common cause of acute neuromuscular weakness and paralysis worldwide, encompasses a group of acute immune-mediated disorders restricted to peripheral nerves and roots. Immune-mediated attack of peripheral nervous system myelin, axons or both is presumed to be triggered by molecular mimicry, with both cell- and humoral-dependent mechanisms implicated in disease pathogenesis. Good circumstantial evidence exists for a pathogenic role for molecular mimicry in GBS pathogenesis, especially with its axonal forms, providing insights that could guide future immunotherapy. Intravenous immunoglobulin (IVIg) and plasma exchange (PE) are the most commonly prescribed immunotherapies for GBS with variable efficacy dependent on GBS subtype, severity at initial presentation and other clinical and electrophysiologic prognostic factors. The mechanisms of action of IVIg and PE are not known definitely. Despite recent significant advances in molecular biology that provide insights into GBS pathogenesis, no advances in therapeutics or significant improvements in patient outcomes have occurred over the past three decades. We summarize the clinical aspects of GBS, its current pathogenesis and immunotherapy, and highlight the potential of leukocyte trafficking inhibitors as novel disease-specific immunotherapeutic drugs.