Treatment of Guillain-Barré syndrome with interferon-beta

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.

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.

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.

Biological Drugs in Guillain-Barré Syndrome: An Update

Background:

Guillain-Barré Syndrome (GBS) is currently considered the most common global cause of acute flaccid paralysis. Currently, standard therapy for Guillain-Barré Syndrome includes intravenous immunoglobulin or plasma exchange. Despite medical advances regarding these treatments, many treated patients do not reach full recovery. Therefore several biological agents have attracted the attentions from researchers during the last decades, and various studies have investigated their role in Guillain-Barré Syndrome.

Objective:

The present study aims to address emerging biological approaches to GBS while considering their efficiency and safety in treating the disease.

Materials and Methods:

An extensive electronic literature search was conducted by two researchers from April 2016 to July 2016. Original articles, clinical trials, systematic reviews (with or without meta-analysis) and case reports were selected. Titles and abstracts of papers were screened by reviewers to determine whether they met the eligibility criteria, and full texts of the selected articles were retrieved.

Results:

Herein authors focused on the literature data concerning emerging biological therapeutic agents, namely anti-C5 monoclonal antibody (Eculizumab), anti-C1q monoclonal antibody, anti-T cell monoclonal antibody, anti-CD2 monoclonal antibody, anti L-selectin monoclonal antibody, anti-CD20 monoclonal antibody (Rituximab), anti-CD52 monoclonal antibody (Alemtuzumab) and cytokine targets. By far, none of these agents have been approved for the treatment of GBS by FDA.

Conclusion:

Literature findings represented in current review herald promising results for using these biological targets. Current review represents a summary of what is already in regards and what progress is required to improve the immunotherapeutic approach of treating GBS via future studies.

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 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 18 January 2016, we searched the Cochrane Neuromuscular Specialised Register, Cochrane Central Register of Controlled Trials, 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. We also identified a number of non-randomised studies during the search, the results of which we considered in the Discussion.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology.

MAIN RESULTS

We identified no new trials during this update of the review. In previous versions of this review we identified only very low quality evidence for four different interventions published in four studies. Each study had a high risk of bias in at least one respect. One RCT with 19 participants comparing interferon beta-1a and placebo showed no clinically important difference in any outcome between groups. Another with 10 participants comparing brain-derived neurotrophic factor and placebo showed no clinically important difference in any outcome between groups. A third with 37 participants comparing cerebrospinal fluid filtration and plasma exchange also showed no clinically important difference in any outcome between groups. In a fourth with 43 participants, the risk ratio for an improvement by one or more disability grade after eight weeks was greater with the Chinese herbal medicine tripterygium polyglycoside than with corticosteroids (risk ratio 1.47; 95% confidence interval 1.02 to 2.11); other outcomes in this trial showed no difference. Serious adverse events were uncommon with each of these treatments and in the control groups.

AUTHORS' CONCLUSIONS

The quality of the evidence was very low. Three small RCTs, comparing interferon beta-1a or brain-derived neurotrophic factor with placebo, and cerebrospinal fluid filtration with plasma exchange, showed no significant benefit or harm for any of the interventions. A fourth small trial showed that the Chinese herbal medicine, tripterygium polyglycoside, hastened recovery in people with GBS to a greater extent than corticosteroids, but this result needs confirmation. We were unable to draw any useful conclusions from the few observational studies we identified.

New strategies in the management of Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is an acute and usually monophasic, neurological, demyelinating disease. Although most patients have good outcomes without sequelae after conventional plasma exchange and intravenous immunoglobulin therapy, 20% of patients continue to have severe disease and 5% die of their disease. Therefore, there is an obvious need for more acceptable and efficacious therapies. Experimental autoimmune neuritis (EAN) is the classical animal model for GBS. As there is no specific drug for GBS, several drugs targeting the humoral and cellular components of the immune response have been used to treat EAN in the endeavour to find new treatment alternatives for GBS. This review focused on some new strategies for GBS, which have been reported but have not yet been widely used, and on the main drugs which have been investigated in EAN.

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 this update in 2013. 

OBJECTIVES

To review systematically the evidence from randomised controlled trials (RCTs) for pharmacological agents other than plasma exchange, intravenous immunoglobulin and corticosteroids.

SEARCH METHODS

On 28 August 2012, we searched the Cochrane Neuromuscular Disease Group Specialized Register CENTRAL (2012, Issue 8 in The Cochrane Library), MEDLINE (January 1966 to August 2012) and EMBASE (January 1980 to August 2012) for treatments for GBS. We considered evidence from non-randomised studies in the Discussion.

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

Change in disability after four weeks was the primary outcome. Two authors checked references and extracted data independently. One author entered and another checked data in Review Manager (RevMan). We assessed risk of bias according to the Cochrane Handbook for Systematic Reviews of Interventions. We calculated mean differences and risk ratios with their 95% confidence intervals. We assessed strength of evidence with GradePro software.

MAIN RESULTS

Only very low quality evidence was found for four different interventions. This update of the review found no new trials. One RCT with 13 participants showed no significant difference in any outcome between interferon beta-1a and placebo. Another with 10 participants showed no significant difference in any outcome between brain-derived neurotrophic factor and placebo. A third with 37 participants showed no significant difference in any outcome between cerebrospinal fluid filtration and plasma exchange. In a fourth with 20 participants, the risk ratio of improving by one or more disability grades after eight weeks was significantly greater with the Chinese herbal medicine tripterygium polyglycoside than with corticosteroids (risk ratio 1.47; 95% confidence interval 1.02 to 2.11). Serious adverse events were uncommon with each of these treatments and not significantly commoner in the treated than the control groups.

AUTHORS' CONCLUSIONS

The quality of the evidence was very low. Three small RCTs, of interferon beta-1a, brain-derived neurotrophic factor and cerebrospinal fluid filtration, showed no significant benefit or harm. A fourth small trial showed that the Chinese herbal medicine tripterygium polyglycoside hastened recovery significantly more than corticosteroids but this result needs confirmation. It was not possible to draw useful conclusions from the few observational studies.

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.  

OBJECTIVES

To review systematically the evidence from randomised controlled trials for pharmacological agents other than plasma exchange, intravenous immunoglobulin and corticosteroids.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Specialized Register (5 July 2010), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 2), MEDLINE (January 1966 to June 2010) and EMBASE (January 1980 to June 2010) for treatments for GBS. We considered evidence from non-randomised studies in the Discussion.

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

Change in disability after four weeks was the primary outcome. Two authors checked references and extracted data independently. One author entered and another checked data in Review Manager (RevMan). We assessed risk of bias according to the Cochrane Handbook for Systematic Reviews of Interventions. We calculated mean differences and risk ratios with their 95% confidence intervals. We assessed strength of evidence with GradePro software.

MAIN RESULTS

Only very low quality evidence was found for four different interventions. One randomised controlled trial with 13 participants showed no significant difference in any outcome between interferon beta-1a and placebo. Another with 10 participants showed no significant difference in any outcome between brain-derived neurotrophic factor and placebo. A third with 37 participants showed no significant difference in any outcome between cerebrospinal fluid filtration and plasma exchange. In a fourth with 20 participants, the risk ratio of improving by one or more disability grades after eight weeks was significantly greater with the Chinese herbal medicine tripterygium polyglycoside than with corticosteroids (risk ratio 1.47; 95% confidence interval 1.02 to 2.11).

AUTHORS' CONCLUSIONS

The quality of the evidence was very low. Three small randomised controlled trials, of interferon beta-1a, brain-derived neurotrophic factor and cerebrospinal fluid filtration, showed no significant benefit or harm. A fourth small trial showed that the Chinese herbal medicine tripterygium polyglycoside hastened recovery significantly more than corticosteroids but this result needs confirmation. It was not possible to draw useful conclusions from the few observational studies.

A role for interferon-beta in Guillain-Barré Syndrome?

Guillain-Barré syndrome (GBS) is an acute inflammatory demyelinating neuropathy that is associated with long-lasting morbidity and a substantial risk of mortality. The 2 reference treatments, plasma exchange and intravenous immunoglobulins (IVIg), do not change the functional prognosis for the most severely ill patients. The pathogenesis of GBS involves humoral and cellular immune dysfunctions that have only recently been characterised. Antibodies to nerve antigens may participate in complement activation, antibody-dependent macrophage cytotoxicity and reversible conduction failure. The cellular immune reaction is associated with increases in pro-inflammatory cytokines [such as tumour necrosis factor-alpha (TNFalpha)] and matrix metalloproteinases (MMPs; e.g. MMP-9), and a decrease in anti-inflammatory cytokines [such as transforming growth factor-beta1 (TGFbeta1)]. All the changes favour adhesion to and transmigration across the endothelium of immune cells, a key phenomenon associated with GBS. Recovery from GBS is characterised by the normalisation of these changes. Experimental allergic neuritis (EAN), the experimental model of GBS, has strikingly similar immunological characteristics. The usual treatment options for patients with GBS (plasma exchange and IVIg) mainly target the humoral component of the immune response. Interferon-beta (IFNbeta) is a cellular immunomodulator that inhibits antigen presentation and TNFalpha production and binding, and modulates macrophage properties. IFNbeta increases anti-inflammatory T cell functions and the production of anti-inflammatory cytokines, such as TGFbeta1. IFNbeta has important effects on leukodiapedesis, caused by modulating the expression of cell adhesion molecules and the MMP-9 proteinases. It has been used with success in EAN, in some patients with acute exacerbation of chronic inflammatory demyelinating polyneuropathy, and in 1 patient with GBS. The pathophysiology of patients with GBS, an understanding of IFNbeta properties and results of experimental studies support the investigation of IFNbeta in trials of patients with GBS.

From bench to bedside--experimental rationale for immune-specific therapies in the inflamed peripheral nerve

Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy are autoimmune-mediated inflammatory diseases of the PNS. In recent years, substantial progress has been made towards understanding the immune mechanisms that underlie these conditions, in large part through the study of experimental models. Here, we review the available animal models that partially mimic human Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy, and discuss the wide range of therapeutic approaches that have been successfully established in these models of inflammatory neuropathies. Transfer of this preclinical knowledge to patients has been far less successful, and inflammatory neuropathies are still associated with significant morbidity and mortality. We will summarize successful therapeutic trials in human autoimmune neuropathies to provide a vantage point for the transfer of experimental treatment strategies to clinical practice in immune-mediated diseases of the peripheral nerve.

Interferon and the central nervous system

Interferons (IFNs) were discovered as natural antiviral substances produced during viral infection and were initially characterized for their ability to "interfere" with viral replication, slow cell proliferation, and profound alteration of immunity. The IFNs are synthesized and secreted by monocytes, macrophages, T-lymphocytes, neurons, and glia cells. The different IFNs are classified into three classes: alpha, beta, and gamma. alpha-IFN produced in the brain exerts direct effects on the brain and endocrine system by activating the neurosecretory hypothalamic neurons and regulates the hypothalamic-pituitary-adrenocortical axis. IFNs modulate neurophysiological activities of many brain region involving in pain, temperature, and food intake regulation. alpha-IFN administration activates the sympathetic nerves innervating components of the immune system. IFNs may serve as regulatory mediators between the central nervous system, the immune system, and endocrine system. IFN is used as immunologic therapy to treat various hematologic malignancies and infectious ailments and autoimmune diseases.

Treatment of dysimmune neuropathies

Several therapies are currently used in dys-immune neuropathies including steroids,plasma exchange (PE), high-dose intravenous immunoglobulins(IVIg), and immuno-suppressive agents (IS). Even if there is substantial evidence that these treatments may improve the course of the neuropathy, their effectiveness is far from being complete and is sometime hampered by the occurrence of associated side effects. In Guillain-Barré syndrome (GBS),IVIg and PE are similarly effective in accelerating the recovery but there is still little evidence that they can reduce mortality or long-term disability. Recent reports on the association of intravenous methylprednisolone or interferon-beta (IFN-beta) to IVIg did not result in significant further improvement. In chronic inflammatory demyelinating polyradiculoneuropathy(CIDP) steroids, PE, and IVIG are initially similarly effective. The short-term effect of PE and IVIgand the side effects associated with the long-term use of steroids have prompted the use of several IS, interferon and,more recently, the anti-CD20 monoclonal-antibody Rituximab, but their efficacy has still to be proved in controlled studies. The recent identification of multifocal motor neuropathy(MMN) was shortly followed by the finding of an effective therapy. Almost 80% of patients respond toIVIg whose effect needs to be maintained with periodic infusions for long periods of time, and tends to decrease after several years. Also in this condition a number of immune modulating agents have been used to reduce the frequency or improve the effectiveness of IVIg,but their efficacy has not been sofar confirmed in randomized trials. Similar conclusions can be drawn for neuropathies associated with monoclonal gammopathies where only PE and IVIg have proved to be effective in controlled studies,while the promising initial results obtained with Rituximab in neuropathy associated IgM monoclonal gammopathy awaits confirmation from controlled trials.

Advances in understanding and treatment of immune-mediated disorders of the peripheral nervous system

During recent years, novel insights in basic immunology and advances in biotechnology have contributed to an increased understanding of the pathogenetic mechanisms of immune-mediated disorders of the peripheral nervous system. This increased knowledge has an impact on the management of patients with this class of disorders. Current advances are outlined and their implication for therapeutic approaches addressed. As a prototypic immune-mediated neuropathy, special emphasis is placed on the pathogenesis and treatment of the Guillain-Barré syndrome and its variants. Moreover, neuropathies of the chronic inflammatory demyelinating, multifocal motor, and nonsystemic vasculitic types are discussed. This review summarizes recent progress with currently available therapies and--on the basis of present immunopathogenetic concepts--outlines future treatment strategies.

Ingested type I interferon: a potential treatment for autoimmunity

We have proposed a unifying hypothesis of the etiopathogenesis of autoimmunity that defines autoimmunity as a type I interferon (IFN) immunodeficiency syndrome. We have examined toxicity and potential efficacy in three phase I (type 1 diabetes, rheumatoid arthritis, multiple sclerosis) and one phase II clinical trials in multiple sclerosis (MS). In a phase I open-label trial in type 1 diabetes, ingested IFN-alpha preserved residual beta cell function in recent onset patients. In a second phase I trial, treatment of rheumatoid arthritis (RA) with ingested IFN-alpha reduced the secretion of interleukin-1 (IL-1), a proinflammatory cytokine. In a third phase I trial in MS, there was a significant decrease in peripheral blood mononuclear cell (PBMC) IL-2 and IFN-gamma production after ingesting IFN-alpha. In a phase II randomized, placebo-controlled, double-blind trial in MS, 10,000 IU ingested IFN-alpha significantly decreased gadolinium enhancements compared with the placebo group at month 5. Tumor necrosis factor-alpha (TNF-alpha) and IFN-gamma cytokine secretion in the 10,000 IU group at month 5 showed a significant decrease that corresponded with the effect of ingested IFN-alpha on decreasing gadolinium enhancements. Ingested IFN-alpha was not toxic in any of these clinical trials. These studies suggest that ingested IFN-alpha may have a potential role in the treatment of autoimmunity.

Guillain-Barré Syndrome

Guillain-Barré syndrome (GBS) is an acute immune-mediated polyneuropathy. Two thirds of GBS patients are unable to walk at their most severe state of disease. Respiratory insufficiency and autonomic failure are probably the main causes of death. Optimal general care, physiotherapy and the availability of intensive care facilities at short distance are of great importance. Randomized controlled trials show that intravenous immune globulin (IVIg) and plasma exchange (PE) are equally effective in reducing the time to functional recovery. The combination of PE followed by IVIg, is not significantly better than IVIg or PE alone. Corticosteroids alone are not effective in GBS. Approximately 10% of GBS patients deteriorate after initial improvement or stabilization following IVIg or PE treatment, and often require repeated treatment. These "treatment related clinical fluctuations" are more frequently seen in relatively young patients with severe motor and sensory involvement associated with a preceding and possibly ongoing cytomegalovirus infection. Predominantly motor GBS is frequently preceded by a Campylobacter jejeuni infection. Diarrhea prior to GBS is associated with a worse predicted outcome. Further confirmation is needed to determine whether this is especially the case in those patients treated with PE. GBS patients who are unable to walk without assistance, and who are still within their first 2 weeks of the disease, need to be treated. One PE study showed that patients who are only mildly disabled showed positive progress from two plasma exchange sessions. Presently, due to its wide availability, ease of administration, and favorable side-effect profile, IVIg is considered to be the first-line treatment for patients with GBS. Current investigations are trying to determine if IVIg used in combination with methylprednisolone is even more effective in treating GBS.

Treatment of immune-mediated inflammatory neuropathies

Experimental models have suggested potential new treatments for human inflammatory neuropathy, but current practice is largely based on empirical trials. Evidence from randomized trials supports the use of intravenous immunoglobulin in Guillain-Barré syndrome, chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy with conduction block (MMNCB). In Guillain-Barré syndrome and CIDP intravenous immunoglobulin is equivalent to but more convenient than plasma exchange. In MMNCB adequate comparative studies of intravenous immunoglobulin and plasma exchange have not been performed. Corticosteroid treatment is beneficial in CIDP, but not in Guillain-Barré syndrome and may worsen MMNCB. More randomized trials and systematic reviews are needed to improve the evidence base for clinical practice.

Autoimmunity is a type I interferon-deficiency syndrome corrected by ingested type I IFN via the GALT system

Type I interferons (IFN-alpha/beta), products of the innate immune system, can modulate immune function whereas proinflammatory IFN-gamma (type II IFN), a product of the acquired immune system upregulates inflammation and enhances cell mediated immunity. We have proposed a unifying hypothesis of the origin of autoimmunity as a type I IFN immunodeficiency syndrome involving inadequate regulation of the acquired immune system product IFN-gamma by the IFN-alpha/beta innate immune system. The common theme of ingested type I IFNs in autoimmunity is inhibition of proinflammatory type II IFN systemically or at the target organ. In multiple sclerosis (MS) and insulin-dependent diabetes mellitus (IDDM) at the target organ, and in rheumatoid arthritis (RA) as a regulator of other proinflammatory cytokines, IFN-gamma is the nexus of inflammation in autoimmunity. Ingested type I IFNs counteract type II IFN, overcome the relative lack of type I IFN activity, and ameliorate autoimmunity. The administration of type I IFNs (IFN-alpha/beta) via the gut offers an exciting alternative to systemic application for overcoming the type I IFN immunodeficiency in autoimmunity. Successful use of ingested type I IFN in three separate prototypical autoimmune diseases suggests a broad antiinflammatory therapeutic profile for this technology.

IFN-beta suppresses experimental autoimmune neuritis in Lewis rats by inhibiting the migration of inflammatory cells into peripheral nervous tissue

The putative prophylactic and therapeutic effect of interferon-beta (IFN-beta) on autoimmune inflammation of the peripheral nervous system was evaluated in experimental autoimmune neuritis (EAN), a well-known animal model of the human Guillain-Barré syndrome (GBS). We report that treatment of rats with 300,000 U of recombinant rat IFN-beta (rrIFN-beta) given every other day starting at the day of immunization prevented clinical signs of EAN. When treatment was started at the onset of disease development, the cytokine clearly ameliorated EAN. Both B- and T-cell responses towards peripheral myelin were suppressed by the IFN-beta, and immunohistochemical analyses revealed a strong decrease in the numbers of infiltrating CD4(+) T cells, macrophages, and other inflammatory cells as well as a significant reduction in MHC class II antigen expression and monocyte chemotactic protein-1 (MCP-1) production, which induces chemotaxis and chemokinesis of leukocytes from blood. It is concluded that the observed suppression of EAN by rrIFN-beta is associated with a decrease in the migration of inflammatory cells into peripheral nervous tissue.