Treatment of acute inflammatory polyneuropathy

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.

Plasma Exchange in Five Patients with Acute Guillain Barré syndrome

During the last 3 years plasma exchanges were undertaken in 5 patients with acute Guillain Barré syndrome (G.B.S.). All the patients were admitted in the intensive respiratory care unit and had received six plasma exchange procedures over two weeks (each procedure consists of 2–3 L exchange). The first patient improved dramatically after the second exchange. Moderate success was obtained in two patients. One patient did not show any effect. The fifth patient received plasma exchange one day after her recovery phase had begun but the course of recovery remained uneffected.

The effect of plasma exchange was analysed as the patients’ response to motor activity, and compaired with a historical control group consisting of 50 acute G.B.S. patients admitted in the intensive respiratory care area over the last 25 years. Plasma exchange does not seem to have excerted any significant effect although at any given time the plasma exchange group had higher motor activity than that of the control group. A controlled clinical trial especially in the early phase of the disease is emphasized.

Analytic Reviews : Aspiration Pneumonitis: Patient Risk Factors, Prevention, and Management

Occurrence of aspiration pneumonitis, the morbid con dition that often follows aspiration of gastric contents, has been documented for over 40 years. A number of risk factors that predispose patients to acid aspiration have been identified. The acidity of the gastric fluid and the volume of the aspirate are high-risk factors that de termine the severity of the pneumonitis. In this review I discuss those conditions that predispose patients to as piration and subsequent development of pneumonitis as well as current strategies for prevention and treatment.

Corticosteroids for Guillain-Barré syndrome

BACKGROUND

Guillain-Barré syndrome (GBS) is an acute paralysing disease caused by inflammation of the peripheral nerves, which corticosteroids would be expected to benefit.

OBJECTIVES

To examine the ability of corticosteroids to hasten recovery and reduce the long-term morbidity from GBS.

SEARCH METHODS

On 12 January 2016, we searched the Cochrane Neuromuscular Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase. We also searched trials registries.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-RCTs of any form of corticosteroid or adrenocorticotrophic hormone versus placebo or supportive care alone in GBS. Our primary outcome was change in disability grade on a seven-point scale after four weeks. Secondary outcomes included time from randomisation until recovery of unaided walking, time from randomisation until discontinuation of ventilation (for those ventilated), death, death or disability (inability to walk without aid) after 12 months, relapse, and adverse events.

DATA COLLECTION AND ANALYSIS

The review authors used standard methods expected by Cochrane.

MAIN RESULTS

The review authors discovered no new trials in the new searches in June 2009, November 2011, or January 2016. Six trials with 587 participants provided data for the primary outcome. According to moderate quality evidence, the disability grade change after four weeks in the corticosteroid groups was not significantly different from that in the control groups, mean difference (MD) 0.36 less improvement (95% confidence intervals (CI) 0.16 more to 0.88 less improvement). In four trials of oral corticosteroids with 120 participants in total, there was very low quality evidence of less improvement after four weeks with corticosteroids than without corticosteroids, MD 0.82 disability grades less improvement (95% CI 0.17 to 1.47 grades less). In two trials with a combined total of 467 participants, there was moderate quality evidence of no significant difference of a disability grade more improvement after four weeks with intravenous corticosteroids (MD 0.17, 95% CI -0.06 to 0.39). According to moderate quality evidence, there was also no significant difference between the corticosteroid treated and control groups for improvement by one or more grades after four weeks (risk ratio (RR) 1.08, 95% CI 0.93 to 1.24) or for death or disability after one year (RR 1.51, 95% CI 0.91 to 2.5). We found high quality evidence that the occurrence of diabetes was more common (RR 2.21, 95% CI 1.19 to 4.12) and hypertension less common (RR 0.15, 95% CI 0.05 to 0.41) in the corticosteroid-treated participants.

AUTHORS' CONCLUSIONS

According to moderate quality evidence, corticosteroids given alone do not significantly hasten recovery from GBS or affect the long-term outcome. According to very low quality evidence, oral corticosteroids delay recovery. Diabetes requiring insulin was more common and hypertension less common with corticosteroids based on high quality evidence.

Corticosteroids for Guillain-Barré syndrome

BACKGROUND

Guillain-Barré syndrome (GBS) is an acute paralysing disease caused by inflammation of the peripheral nerves, which corticosteroids would be expected to benefit.

OBJECTIVES

To examine the ability of corticosteroids to hasten recovery and reduce the long-term morbidity from GBS.

SEARCH METHODS

We searched The Cochrane Neuromuscular Disease Group Specialized Register (1 November 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 4), CENTRAL (2011, Issue 4), MEDLINE (January 1966 to October 2011) and EMBASE (January 1980 to October 2011).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-RCTs of any form of corticosteroid or adrenocorticotrophic hormone in GBS. Our primary outcome was change in disability grade on a seven-point scale after four weeks. Secondary outcomes included time from randomisation until recovery of unaided walking, time from randomisation until discontinuation of ventilation (for those ventilated), death, death or disability (inability to walk without aid) after 12 months, relapse, and adverse events.

DATA COLLECTION AND ANALYSIS

Two authors extracted the data independently.

MAIN RESULTS

No new trials were discovered in the new searches in June 2009 or November 2011. Six trials with 587 participants provided data for the primary outcome. According to moderate quality evidence, the disability grade change after four weeks in the corticosteroid groups was not significantly different from that in the control groups, mean difference (MD) 0.36 less improvement (95% confidence intervals (CI) 0.16 more to 0.88 less improvement). In four trials of oral corticosteroids with 120 participants in total, there was significantly less improvement after four weeks with corticosteroids than without corticosteroids, MD 0.82 disability grades less improvement (95% CI 0.17 to 1.47). In two trials with a combined total of 467 participants, there was no significant difference, MD 0.17 (95% CI -0.06 to 0.39) of a disability grade more improvement after four weeks with intravenous corticosteroids. According to moderate to high quality evidence, there were no significant differences between the corticosteroid-treated and the control groups in any of the secondary efficacy outcomes. Diabetes was significantly more common and hypertension significantly much less common in the corticosteroid-treated participants.

AUTHORS' CONCLUSIONS

According to moderate quality evidence, corticosteroids given alone do not significantly hasten recovery from GBS or affect the long-term outcome. According to low quality evidence oral corticosteroids delay recovery. Diabetes requiring insulin was significantly more common and hypertension less common with corticosteroids.

Corticosteroids for Guillain-Barré syndrome

BACKGROUND

Guillain-Barré syndrome is caused by inflammation of the peripheral nerves, which corticosteroids should benefit.

OBJECTIVES

To examine the efficacy of corticosteroids.

SEARCH STRATEGY

We searched The Cochrane Neuromuscular Disease Group Trials Specialized Register (June 2009), MEDLINE (January 1966 to June 2009) and EMBASE from (January 1980 to June 2009).

SELECTION CRITERIA

We included quasi-randomised or randomised controlled trials of any form of corticosteroid or adrenocorticotrophic hormone. Our primary outcome was change in disability grade on a seven-point scale after four weeks. Secondary outcomes included time from randomisation until recovery of unaided walking, time from randomisation until discontinuation of ventilation (for those ventilated), death, death or disability (inability to walk without aid) after 12 months, relapse, and adverse events.

DATA COLLECTION AND ANALYSIS

Two authors extracted the data.

MAIN RESULTS

No new trials were discovered in the new search in June 2009. Six trials with 587 participants provided data for the primary outcome. According to moderate quality evidence, the disability grade change after four weeks in the corticosteroid groups was not significantly different from that in the control groups, weighted mean difference (WMD) 0.36 less improvement (95% confidence intervals (CI) 0.16 more to 0.88 less improvement). In four trials of oral corticosteroids with 120 participants in total, there was significantly less improvement after four weeks with corticosteroids than without corticosteroids, WMD 0.82 disability grades less improvement, 95% CI 0.17 to 1.47). In two trials with a combined total of 467 participants, there was no significant difference, WMD 0.17 (95% CI -0.06 to 0.39) of a disability grade more improvement after four weeks with intravenous corticosteroids. According to moderate to high quality evidence, there were no significant differences between the corticosteroid-treated and the control groups in any of the secondary efficacy outcomes. Diabetes was significantly more common and hypertension significantly much less common in the corticosteroid-treated participants.

AUTHORS' CONCLUSIONS

According to moderate quality evidence, corticosteroids given alone do not significantly hasten recovery from GBS or affect the long-term outcome. According to low quality evidence oral corticosteroids delay recovery. Diabetes requiring insulin was significantly more and hypertension less common with corticosteroids.

Corticosteroids for Guillain-Barré syndrome

BACKGROUND

The cause of Guillain-Barré syndrome is inflammation of the peripheral nerves, which corticosteroids would be expected to benefit.

OBJECTIVES

To examine the ability of corticosteroids to hasten recovery and reduce the long-term morbidity from Guillain-Barré syndrome.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Register (May 2005), MEDLINE (January 2000 to May 2005) and EMBASE (January 1980 to May 2005) and contacted trial authors and other experts.

SELECTION CRITERIA

We included quasi-randomised or randomised controlled trials of people of all ages and all degrees of severity of Guillain-Barré syndrome who were treated with any form of corticosteroid or adrenocorticotrophic hormone. Our primary outcome measure was change in disability grade on a commonly used, validated seven-point scale at four weeks after randomisation. Secondary outcome measures were: time from randomisation until recovery of unaided walking, time from randomisation until discontinuation of ventilation (for those ventilated), mortality, proportion of participants dead or disabled (unable to walk without aid) after 12 months, improvement in disability grade after six and 12 months, relapse, and adverse events related to corticosteroid treatment.

DATA COLLECTION AND ANALYSIS

Two authors extracted the data.

MAIN RESULTS

Six trials with 587 participants provided data for our primary outcome measure . The overall evidence showed no significant difference between the corticosteroid and non-corticosteroid treated patients in disability grade. In four trials of oral corticosteroids with 120 participants in total, there was significantly less improvement after four weeks with corticosteroids than without corticosteroids (weighted mean difference of 0.82 of a disability grade less improvement, 95% confidence intervals 0.17 to 1.47). In two trials with a combined total of 467 participants, there was a trend towards more benefit from intravenous corticosteroids which was not quite significant, weighted mean difference 0.17 (95% confidence intervals -0.06 to 0.39) of a disability grade more improvement after four weeks than with placebo. There were no important significant differences between the corticosteroid-treated participants and the control group in any of the secondary outcome measures. Diabetes was significantly more common and hypertension much less common in the corticosteroid-treated participants.

AUTHORS' CONCLUSIONS

Limited evidence shows that oral corticosteroids significantly slow recovery from Guillain-Barré syndrome. Substantial evidence shows that intravenous methylprednisolone alone does not produce significant benefit or harm. In combination with intravenous immunoglobulin, intravenous methylprednisolone may hasten recovery but does not significantly affect the long-term outcome. More research is needed and more effective treatments for Guillain-Barré syndrome should be sought.

Inhibition of Ras attenuates the course of experimental autoimmune neuritis

EAN induced in Lewis rats by immunization with peripheral bovine myelin was treated by the Ras inhibitor farnesylthiosalicylate (FTS). Treatment from day 0 with FTS (5 mg/kg intraperitoneally twice daily) attenuated peak clinical scores (mean+/-S.E., 2.5+/-0.5 compared to 4.1+/-0.5 in saline treated controls, p=0.018, t-test) but not recovery. Treatment from day 10 with FTS attenuated peak disability (2.5+/-0.6, p=0.032 compared to saline treated controls) and improved recovery (0.84+/-0.42, untreated controls 2.4+/-0.6, p=0.028 by repeated measures ANOVA). Effects were confirmed by rotarod and nerve conduction studies. An inactive analogue, geranylthiosalicylate, had no clinical effect. Inhibition of Ras is of potential use in the treatment of inflammatory neuropathies.

Corticosteroids for treating Guillain-Barré syndrome

BACKGROUND

The cause of Guillain-Barré syndrome (GBS) is inflammation of the peripheral nerves which corticosteroids would be expected to benefit.

OBJECTIVES

To examine the efficacy of corticosteroids in hastening recovery and reducing the long term morbidity from Guillain-Barré syndrome (GBS).

SEARCH STRATEGY

Search of the Cochrane Neuromuscular Disease Group register for randomised trials and enquiry from authors of trials and other experts in the field.

SELECTION CRITERIA

Types of studies: quasi-randomised or randomised controlled trials

TYPES OF PARTICIPANTS

patients with GBS of all ages and all degrees of severity Types of interventions: any form of corticosteroid or adrenocorticotrophic hormone Types of outcome measures: Primary: improvement in disability grade on a commonly used seven point scale four weeks after randomisation Secondary: time from randomisation until recovery of unaided walking, time from randomisation until discontinuation of ventilation (for those ventilated), mortality, proportion of patients dead or disabled (unable to walk without aid) after 12 months, improvement in disability grade after six months, improvement in disability grade after 12 months, proportion of patients who relapse, and proportion of patients with adverse events related to corticosteroid treatment

DATA COLLECTION AND ANALYSIS

We identified six randomised trials. One author extracted the data and the other checked them. We obtained some missing data from investigators.

MAIN RESULTS

The six eligible trials included a total of 195 corticosteroid treated patients and 187 control subjects. One trial of intravenous methylprednisolone accounted for 243 of the total 382 subjects studied (63%). This trial did not show a significant difference in any disability related outcome between the corticosteroid and placebo groups. There was no significant difference between the corticosteroid and control groups for the primary outcome measure, improvement in disability grade four weeks after randomisation. The weighted mean difference of the three trials for which this outcome was available showed no difference. The actual figure was 0.01 (95% CI -0.27 to 0.29) grade in favour of the corticosteroid group. There was also no significant difference between the groups for most of the secondary outcome measures. However in the largest trial hypertension developed less often in the intravenous methylprednisolone group (2/124, 1.6%) than in the control group (12/118, 10.2%), a significant difference in favour of corticosteroid treatment (relative risk 0.20, 95% CI 0.04 to 0.66).

REVIEWER'S CONCLUSIONS

Corticosteroids should not be used in the treatment of Guillain-Barré syndrome. If a patient with Guillain-Barré syndrome needs corticosteroid treatment for some other reason its use will probably not do harm. The effect of intravenous methylprednisolone combined with intravenous immunoglobulin in Guillain-Barré syndrome is being tested with a randomised trial.

Treatment of inflammatory neuropathy

Experimental autoimmune neuritis (EAN) provides an accurate model for understanding the mechanism of acute and chronic inflammatory demyelinating polyradiculoneuropathy (AIDP and CIDP). Treatments aimed at every stage of the immune process in EAN have been effective in inhibiting or treating the disease, including antibodies directed against cell adhesion molecules on the endothelium, inhibition of T cells, removal or blockade of antibodies, depletion of complement, and interference with the release or action of macrophage effector molecules. In human disease the only proven treatments are plasma exchange and intravenous immunoglobulin (IVIg) in AIDP, and either of these regimens and also corticosteroids in CIDP. However the outcome from AIDP and CIDP remains unsatisfactory with existing immunosuppressive regimens. This problem arises from the fact that while demyelination appears to be effectively and promptly repaired by remyelination, it may be accompanied by axonal degeneration which can cause severe persistent disability. In addition to limiting demyelination, it will also be important to develop strategies to protect axons from degeneration and to enhance regeneration.

Childhood Guillain-Barré syndrome: clinical presentation, diagnosis, and therapy

A rapidly progressive, generally symmetric, ascending flaccid paraparesis or quadriparesis that develops in an infant or child constitutes an uncommon but important pediatric neurologic emergency that requires immediate evaluation and treatment. The differential diagnosis primarily includes acute neuropathies, most commonly the childhood Guillain-Barré syndrome and, rarely, acute transverse myelitis or infantile poliomyelitis. A clinical distinction may be difficult in the younger child in whom detailed sensory examination is not possible. Although most children with Guillain-Barré syndrome usually have a benign and relatively limited clinical illness, some become severely ill, requiring intubation and careful intensive monitoring. To date, no well-controlled multi-institutional studies of treatment with either plasmapheresis or intravenously administered immunoglobulin have been developed in children despite the success of these modalities in adults. A review of the data available using these therapies is included in this study.

Pilot trial of immunoglobulin versus plasma exchange in patients with Guillain-Barré syndrome

We compared intravenous immunoglobulin (IVIG) and plasma exchange (PLEX) in the treatment of 50 patients with Guillain-Barré syndrome (GBS). Standard outcome measures did not differ for the two groups. Sixty-one percent of the PLEX-treated group and 69% of the IVIG-treated group improved by one disability grade at 1 month. The complication rate was higher in the PLEX-treated group. We conclude that the efficacy of IVIG in the treatment of GBS is comparable with that of PLEX and that it can be used safely, although we had a small number of patients. We did not observe a higher relapse rate with IVIG. The usefulness of combination therapy is unknown at this time.

Pain in the Guillain-Barré syndrome: a clinical review

The Guillain-Barré syndrome, or acute inflammatory polyneuropathy, is often regarded as a predominantly motor neuropathy with few sensory features, which has a good prognosis in most cases. However, pain is a common symptom occurring in up to 72% of cases. The types of pain are protean including paraesthesiae, dysaesthesia, axial and radicular pain, meningism, myalgia, joint pain and visceral discomfort, etc., and patients may present in a variety of clinical settings such as intensive care units, acute medical wards or rehabilitation departments. These factors, combined with the fact that the condition is relatively uncommon, means that no controlled trial of pain management has been done and a range of treatments has been proposed. We review the various pains which may be associated with Guillain-Barré syndrome and discuss suggestions for their management.

Plasma exchange therapy reduces the nursing care needed in Guillain-Barré syndrome

The authors compared the effect of plasma exchange therapy on the need for nursing care for 26 patients with acute idiopathic Guillain-Barré syndrome. The patients were randomized either to a plasma exchange (PE) or conservative treatment group. The need for nursing care and the need for specialist nursing services was assessed daily by the nurses at the Department of Neurology. At first, the average need for care was the same for the two groups of patients, but the pattern of care over time was different, with the PE group needing more care at the beginning and then very much less care, whilst the conservative group needed a more uniform amount of care over the entire stay at hospital. In the PE group the need for specialist nursing services increased markedly, and the need for nursing care decreased rapidly after the first 2 weeks to a level lower than that needed by control group patients, probably because PE increased muscle forces of patients. This study suggests that PE treatment is useful in reducing patients' needs for nursing care, especially after the first 2 weeks following the treatment.

Activated T lymphocyte subsets in experimental allergic neuritis

Changes in activated T cell subsets in peripheral blood were examined during the course of experimental allergic neuritis (EAN), using two-color immunofluorescence flow cytometry. Both CD4+ and CD8+ activated T cells decreased transiently before the onset of clinical signs, and increased just around the time of onset of the disease. In contrast, during the recovery phase, the numbers of CD4+ activated T cells returned to the normal range, whereas CD8+ activated T cells continued to increase. These findings imply that activation of CD4+ helper/inducer cells contributes mainly to the evolution of EAN, and that of CD8+ suppressor cells are necessary for recovery.

Patterns and severity of conduction abnormalities in Guillain-Barré syndrome

Whether the conduction abnormalities and lesions underlying them are randomly distributed throughout the peripheral nervous system (PNS) or certain regions are selectively more vulnerable to attack is an unresolved question in Guillain-Barré syndrome (GBS). To examine this question, 15 cases of GBS were comprehensively examined using electrophysiological techniques which allowed close examination, quantitation and comparison of conduction abnormalities in motor and sensory fibres of the upper limb between the spinal cord and the distal extremities of the nerve fibres. Comparison of these studies with results expected in a model where the chances of conduction failure were uniformly distributed led to the conclusion that conduction slowing and block were not uniformly distributed in most cases. Conduction block was maximal in the terminal segment distal to the wrist and to a lesser extent both conduction block and conduction slowing were disproportionately greater across the elbow and in the axillary to spinal root segments in over one half of the cases. These findings support the hypothesis that certain regions, perhaps because of relative deficiencies of the blood-nerve barrier, may be more vulnerable in GBS than other regions.

Prednisolone therapy of experimental allergic neuritis in Lewis rats does not induce relapsing or chronic disease

The effects of therapeutic prednisolone treatment on experimental allergic neuritis (EAN) in Lewis rats were evaluated in a controlled clinical and electrophysiological study. Since steroid therapy has been suspected to cause relapsing or chronic disease, monitoring was extended over 200 days. Short-term steroid treatment (5 days of 15 mg/kg prednisolone, n = 8) with sudden steroid withdrawal was compared with long-term application (30 days, beginning at 7.5 mg/kg) in descending dosage (n = 8). The experiment included saline-injected controls (n = 8) and controls for stress possibly exerted by the handling of the animals. Treatment was begun at the onset of clinical signs. The clinical and electrophysiological data indicated that deterioration, recovery and mild (insignificant) relapse (after day 30 and day 108) occurred in all groups at the same time. Both steroid application schemes significantly (p less than 0.03) attenuated the severity and shortened the duration of EAN. Relapse was not aggravated after steroid treatment. The clinical course and electrophysiological findings were unaltered by the experimental procedures and by mild experimental stress.

Gangliosides offer partial protection in experimental allergic neuritis

The effect of gangliosides on the clinical course of experimental allergic neuritis was tested in Lewis rats sensitized with bovine intradural root myelin in complete Freund's adjuvant. A mixture of bovine brain gangliosides (GM1, GD1a, GD1b, GT1b) was injected intramuscularly at a daily dose of 20 mg per kilogram of body weight, beginning 6 days after inoculation. The results from seven different experiments show that in most cases, the administered gangliosides were partially protective. Particularly striking was the reduction in mortality rate to half or less of saline-injected controls. Cumulative clinical index scores were also significantly lower with ganglioside treatment in five of the seven experiments. The cause of the wide variability is not known, but it was noted that better results were obtained when the animals were sensitized with freshly isolated myelin.

Ventilator dependence in acute severe asthma due to a variant presentation of Guillain-Barré syndrome

A 23-year-old white woman presented with severe status asthmaticus requiring prolonged ventilator support and subsequently developed a flaccid areflexic quadraparesis which resolved after plasmapheresis. This case represents a variant presentation of Guillain-Barré syndrome (GBS) that is difficult to distinguish from critical illness polyneuropathy (CIP).

IgG immunoadsorption in experimental allergic neuritis: effect on antibody levels and clinical course

The effect of IgG immunoadsorption upon the course of chronic experimental allergic neuritis (EAN) is described. Miniature membrane plasma separators coupled with a Protein A (PA)-Sepharose immunoadsorbent column were used to perform upon conscious rabbits 5 IgG immunoadsorption treatments over 6 days. Quantitation of anti-myelin IgG and IgM by ELISA revealed that 55-65% of plasma IgG was removed per treatment. Rapid post-treatment antibody rebound was observed for anti-myelin IgG although no antibody overshoot above control levels could be observed. Anti-myelin IgM levels remained relatively unaffected by PA immunoadsorption. Comparisons of clinical scores between control and treatment animals showed that IgG immunoadsorption was significantly beneficial (day 1 post-treatment p less than 0.001; day 2 post-treatment p less than 0.05). However, rapid relapse was observed in all treatment animals such that by day 3 post-treatment no significant clinical difference between control and treatment groups could be observed. IgG immunoadsorption suppresses the clinical progression of chronic EAN in a manner similar to that seen with plasma exchange. This finding suggests that antibody modulates early disease pathogenesis.

Suppression of P2-T cell line-mediated experimental autoimmune neuritis by interleukin-2 receptor targeted monoclonal antibody ART 18

The monoclonal antibody ART 18 directed to the rat interleukin-2 receptor (IL-2 R) was administered to Lewis rats immediately prior to and/or on consecutive days after adoptive transfer of autoreactive P2-T line lymphocytes. The effects of ART 18 and sham treatment on the development of adoptive transfer--experimental autoimmune neuritis (AT-EAN) were assessed by clinical inspection, serial electrophysiological monitoring, and semiquantitative histomorphological analysis. Early injection of ART 18 suppressed AT-EAN while treatment after appearance of clinical signs did not. Since the IL-2 R is expressed exclusively on proliferating T cells activated by antigen, the in vivo application of an IL-2 R-targeted monoclonal antibody allows for more selective immunosuppression of experimental autoimmune disease of the peripheral nervous system than has previously been achieved.

High-dose steroid therapy in Guillain-Barré syndrome

In a pilot study, high-dose steroid therapy in acute Guillain-Barré syndrome (GBS) proved to be successful. The pharmacodynamic aspects of this approach appear interesting and worthy of further investigation. An initial dose of 1000 or 500 mg methylprednisolone is recommended which should be given in four divided doses per day. A very slow reduction in the dose is necessary to avoid a relapse. Lack of response correlated with late onset of therapy and high age of the patients.

Membrane plasma exchange in experimental allergic neuritis: effect on antibody levels and clinical course

The effect of membrane plasma exchange on the course of chronic experimental allergic neuritis in rabbits is described. Using miniature membrane plasma separators conscious animals were treated with 4 exchanges over 5 days removing one plasma volume per procedure and using a non-immunogenic gelatin plasma solution as replacement. Comparisons of clinical scores between control and treated groups indicated that treated animals received significant benefit from plasma exchange (day 1 post-treatment P less than 0.002; day 3 post-treatment P less than 0.01). However, relapse was observed in all plasma exchanged animals such that by day 8 post-treatment there was no significant difference in clinical scores between the two groups. Quantitation of anti-myelin IgG and IgM by ELISA assay showed that 55-60% of circulating antibody was removed per exchange. Rapid post-exchange antibody rebound was observed for both IgG and IgM so that pre-exchange levels were re-established within 24-48 h. However, no significant overshoot in circulating levels of anti-myelin IgG nor IgM could be observed. It is probable that long-term remission as a result of therapeutic plasma exchange is a function of effective circulating plasma removal and if present, the suppression of ongoing antigenic stimuli.

Immune responses in experimental allergic neuritis treated with corticosteroids

The preventive and suppressive effects of methylprednisolone (MP) were investigated in 22 rabbits immunized with peripheral nerve myelin. Cellular reactivity to bovine P2 protein (P2) and anti-P2 antibody were also examined serially in these animals, using the lymphocyte proliferation test or enzyme-linked immunosorbent assay. Seven animals (preventive group), given 15 mg/day of MP subcutaneously from Days 0-28, showed a significant reduction in maximal severity and a delay in onset in comparison with 8 control animals. The remaining 7 animals (suppressive group), given the same dose of MP from Days 11-28, also showed significantly milder clinical signs than those observed in the controls. However, cellular hypersensitivity to P2 were manifested at Day 14 (just after clinical onset) in the controls, as well as in the preventive or suppressive groups. Furthermore, anti-P2 antibody was detected in each group after Day 14. These results suggested that the interference of inflammatory processes of immune-mediated disease might respond to the preventive and suppressive effects of MP.

Chronic experimental allergic neuritis. An electrophysiological and histological study in the rabbit

Ten adult outbred New Zealand white rabbits were inoculated with a single multiportal dose of purified bovine peripheral nerve myelin and Freund's adjuvant containing 500 mg of nerve antigen. Seven animals developed chronic relapsing or progressive disease which was followed by clinical examination for 14 months. Electrophysiological studies showed marked slowing of motor conduction velocity, dispersion of the evoked muscle action potential (MAP) and reduction in amplitude of the MAP derived from distal stimulation. Histological examination of the peripheral nervous system showed at 12 months a marked hypertrophic neuropathy in the nerve roots with well developed onion bulbs, active demyelination and a moderate nerve fibre loss. It is suggested that these animals provide a reliable and predictable model for human chronic inflammatory demyelinating polyneuropathy (CIDP) which should prove valuable for therapeutic trials and studies of pathogenetic mechanisms.

Humoral factors in peripheral nerve disease

Humoral factors including soluble substances transported by the blood stream and factors released at a target tissue may play a role in diseases of the peripheral nervous system. Various criteria have to be met in order to accept humoral factors as potential pathogens. In this review these general criteria are discussed, including the evidence provided by plasma exchange therapy, demonstration of circulating or deposited autoantibodies and immune complexes, identification of antigenic molecules, animal model diseases, passive transfer experiments, and the demonstration of circulating factors not directed against specific targets. In acute, chronic, and chronic relapsing inflammatory polyneuropathies, and in the polyneuropathy associated with monoclonal gammopathy, humoral factors have been identified, but their exact pathogenic role is not fully understood. In the Lambert-Eaton myasthenic syndrome, a disorder of the motor nerve terminal, pathogenic IgG-antibodies have been demonstrated by passive transfer experiments. In the experimental animal model disorders, the acute and chronic variants of experimental allergic neuritis, humoral factors including antibodies to myelin basic proteins and galactocerebroside and nonspecific humoral factors may all contribute to the ultimate peripheral nerve damage, but their relative importance in relation to cell-mediated immune reactions is not yet clear.

A critical review of therapies in acute and chronic inflammatory demyelinating polyneuropathies

Acute and chronic inflammatory demyelinating neuropathies are among the most common treatable neuropathies seen by neurologists. Evidence for effective therapy has only recently been provided by randomized or controlled trials. In the Guillain-Barré syndrome such evidence does not support the use of corticosteroids or immunosuppressive agents. However, when used early in the course, plasma exchange (PE) has been shown to lessen the severity and shorten the duration of the disease; it is indicated only in severely paralyzed patients or those whose rapid deterioration suggests the imminent need for ventilatory support. Some patients with chronic inflammatory demyelinating polyneuropathy (CIDP) respond to corticosteroid therapy or other immunosuppressive agents. PE is also effective in certain patients, but there is no sound evidence to date concerning combined immunosuppression and PE. The rationale of PE in these conditions and whether it is the removal of a toxic factor or the replacement fluid used that is beneficial remains to be clarified.

[Comparative study between the use and the non-use of steroids in Guillain-Barré syndrome]

We studied 21 patients admitted at Servidores do Estado do Rio de Janeiro Hospital with clinical and laboratorial diagnosis of Guillain-Barré syndrome from May 1966 to December 1983. It was not observed any prevalence of symptoms at any special season of the year; 14 male patients and 7 female at the 2nd. and 4th. decades were analysed. The average time of hospitalization for patients without steroids was 52.6 days and for patients taking steroids was of 63.6 days. We discussed the therapeutic value of steroids and our conclusion is that improvement was shorter and better in patients without steroids. They acquired less time of hospitalization. Besides this, side effects on patients with steroids was greater.

Appearance of Guillain-Barré syndrome in patients during corticosteroid treatment

Three patients developed acute Guillain-Barré syndrome while on steroid treatment. The first patient suffered from ulcerative colitis and developed Guillain-Barré syndrome when the steroid dosage was being tapered. Another patient with long-standing multiple sclerosis received steroids during relapse and the Guillain-Barré syndrome appeared while treatment was reduced. The third patient, with aqueductal stenosis and ventriculoatrial shunt, who received steroids when malfunction of the shunt was suspected, developed Guillain-Barré syndrome while steroids were being tapered. Based on the putative immune pathogenesis of inflammatory demyelinating polyneuropathy, the occurrence of the syndrome in these patients could have been due to a selective effect of low-dose steroids on a specific, maybe suppressor lymphocyte subpopulation.

[The use of corticosteroids in Guillain-Barré syndrome: study of 51 cases]

This is a retrospective analysis of 51 patients admitted to the Hospital de Base do Distrito Federal (Brasília, Brazil), with the Guillain-Barré syndrome, from 1974 to 1984. Eighteen patients were treated with corticosteroids (prednisone or dexamethasone), whereas 33 did not receive such treatment. The clinical course (degree of recovery, sequelae, complications, causa mortis) and the length of the hospital stay were compared in these two groups. It is concluded that the use of corticosteroids did not have a major effect on the clinical course of the illness. Moreover, the only two cases of relapses occurred in patients that had been treated with corticosteroids.

Adult-onset muscle weakness. How to identify the underlying cause

When adults present with muscle weakness as the predominant symptom and sign, the causes can usually be narrowed down to four disorders: amyotrophic lateral sclerosis, Guillain-Barré syndrome, myasthenia gravis, and inflammatory myopathy. Perhaps the most difficult task for the clinician is identifying which of these patients are actually weak and which are describing generalized fatigue. This task should be made easier by keeping in mind the definition of muscle weakness--a loss of power resulting in reduction of motor function--and by performing careful functional muscle testing.

Rare association of herpes simplex virus IgM-specific antibodies and Guillain-Barré syndrome successfully treated with plasma exchange and immunosuppression

Herpes simplex virus (HSV) has been associated with various neurological disorders. In contrast, HSV infection is very rarely found in acute polyneuroradiculitis. In this report, a patient is described with a severe course of Guillain-Barr¿ syndrome (GBS). HSV IgM-specific antibodies and a rise of complement-fixation antibodies were detected. During the acute phase of neurologic syndrome, a nerve biopsy showed myelin damage and IgM deposits on the inner layer of the perineurium. Plasma exchange, in combination with immunosuppression, was successfully applied as a treatment in the relapsing course of GBS. Finally, after recovery, HSV-specific IgM antibodies disappeared.

Effects of glucocorticoids on experimental allergic neuritis

Corticosteroids were administered to rats and guinea pigs with experimental allergic neuritis, from the time of inoculation with antigen or from the onset of signs of disease. No statistically significant effects were observed in guinea pigs. In rats, to which large doses of corticosteroids were administered, disease severity was slightly but significantly reduced in both groups and recovery was more rapid in the animals treated from the time of induction of disease. These results were comparable with those obtained in trials of corticosteroids in acute inflammatory polyneuropathy in man, which have also not demonstrated any striking effects.

Attempts to suppress experimental allergic neuritis in the rat by pretreatment with antigen

The injection of bovine dorsal root antigen in complete Freund's adjuvant can be used to produce experimental allergic neuritis (EAN) in rats. In this study attempts were made to prevent the development of the disease by prior injections of antigen. It was found that eight intradermal (i.d.) injections of antigen in either incomplete Freund's adjuvant or in saline failed to suppress EAN. A single intraperitoneal (i.p.) injection of antigen in saline produced only minimal protection against the disease. However, it was found that rats which had been given a primary course of EAN were subsequently completely unresponsive to a second injection of antigen.

Therapeutic apheresis. Applications and future directions

The past 10-15 years have been witness to major technological achievements in the field of therapeutic apheresis. Concurrently, a large number of diseases, primarily with an immunological basis, have been treated with apheresis. In this paper, we review the various applications of therapeutic apheresis, adverse reactions associated with the mode of therapy, and future research directions. Several representative diseases are also discussed in detail.

Cholinesterase activities in the autonomic nervous system of rabbits with experimental allergic neuritis: a biochemical study

Utilizing a colorimetric method with acetylthiocholine iodide (AThCh) as substrate and eserine and ethopropazine as inhibitors, the activities of AThCh-splitting enzymes, acetylcholinesterase (AChE) and non-specific esterase (psi ChE) were determined in different structures of the autonomic nervous system (ANS) from the left and from the right sides of rabbits with experimental allergic neuritis (EAN) and controls. The total activity of AThCh-splitting enzymes showed a highly significant decrease in the ganglion nodosum and in the ganglia of the thoracal and abdominal paravertebral sympathetic chain in rabbits with clinical symptoms of ANS-involvement. Lesser but still significant changes were found in EAN-rabbits with motor symptoms but without ANS symptoms. No definite changes could be found in the superior cervical ganglia, the cervical sympathetic trunk or the interganglionic portions of the abdominal and thoracal paravertebral sympathetic chains. In samples with decreased total enzyme activities, both AChE and psi ChE appeared to decrease to approximately the same extent. This study demonstrates that the activities of AThCh-splitting enzymes are decreased in EAN in parts of ANS innervating the heart, abdominal and pelvic organs, and suggests that enzyme activities not derived from the myelin sheath may be involved in the pathogenesis of this demyelinating disease.

Plasma-exchange in neurological diseases

This paper summarizes experience with plasma-exchange therapy for neurological diseases at the Saronno hospital. Most treatments were performed by discontinuous flow centrifugation, but membrane plasma separation and cascade filtration were also employed. Eighty-five patients with demyelinating diseases of the peripheral nervous system (Guillain-Barré syndrome, immune complex polyneuropathies, paraneoplastic polyneuropathies), demyelinating diseases of the central nervous system (multiple sclerosis, subacute sclerosing panencephalitis), dermatopolymyositis and myasthenia gravis have been treated so far. Particular attention is paid to the combination of plasmapheresis with lymphocytapheresis and immunosuppressive drugs. This therapeutic approach appears to bring about dramatic and sustained improvement in most patients with neurological diseases, thus altering their natural course.

A clinical study of the Guillain-Barré Syndrome

60 consecutive patients (age 15-77 years) with the Guillain-Barré syndrome were studied. 37 subjects had an antecedent infection. Onset occurred with motor and/or sensory limb symptoms in 56 cases; 4 subjects experienced onsets with pain, diplopia or bladder disturbances. The motor symptoms reached a maximum within 42 days in all cases, 87% within less than 20 days. All patients had limb-muscle weakness at the symptomatic maximum: 50% exhibited cranial-nerve affections and 10 subjects has respiratory insufficiency. Signs of a remission appeared within 60 days after onset in all cases surviving the maximal phase, 81% within less than 40 days. The CSF protein concentration was elevated (0.6-7.8 g/l) in 95% of the patients; an increased mononuclear cells count 6-60 X 10(6)/l) occurred in 27% of cases. Electrophysiological abnormalities were detected in 42 out of 43 examined cases. Totally there were 4 deaths, all caused by cardiac or thrombo-embolic events. Surviving patients had restitutions without functionally significant sequelae within less than 6 months after onset in 73% of cases; all but 2 of the remaining patients recovered within 18 months. The degree of muscle weakness at maximum was the predominant prognostic factor.

Plasma exchange in chronic inflammatory polyneuropathy: evidence suggestive of a pathogenic humoral factor

Chronic progressive of relapsing inflammatory polyneuropathy (CRIP) can be treated effectively with immunosuppressive drugs and/or plasma exchange (PE). This report describes a patient who responded dramatically and reproducibly to PE during four successive relapses and remained in remission while on medical immunosuppression with azathioprine and corticosteroids. The clinical course was closely correlated with electrophysiologic parameters such as compound muscle action potential amplitudes and distal latencies. The purified IgG fraction of PE filtrate bound to rat and human sciatic nerve on immunohistochemistry. Furthermore, a similar staining pattern was achieved by purified Fab fragments, which was absent in all control preparations. These findings support the hypothesis that circulating plasma factors may play a role in CRIP and that one of these factors may be an IgG antibody to peripheral nerve components.