Autoimmune glial fibrillary acidic protein astrocytopathy mimicking acute disseminated encephalomyelitis: A case report

INTRODUCTION

Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is an increasingly recognized type of steroid-responsive autoimmune disease of the nervous system. Defined in 2016, it is associated with the presence of anti-GFAP immunoglobulinG in the serum or cerebrospinal fluid (CSF) of affected patients.

PATIENT CHARACTERISTICS

Herein, we report a case of acute neurological symptoms, including headache, fever, confusion, and paralysis of the lower extremities. CSF analysis revealed lymphocytic pleocytosis and elevated protein levels, indicating acute disseminated encephalomyelitis, and the patient was given immunotherapy. Cranial magnetic resonance imaging showed multifocal T2/fluid-attenuated inversion recovery hyperintense signal changes in the periventricular white matter, and electromyography testing showed changes consistent with severe sensorimotor neuropathy, indicating the involvement of the brain and peripheral nerves.

DIAGNOSES

Finally, a diagnosis of autoimmune GFAP astrocytopathy was confirmed due to the presence of GFAP-immunoglobulinG in the patient's CSF.

INTERVENTIONS

The patient was treated with one course of intravenous immunoglobulin therapy, then followed with intravenous methylprednisolone (1.0 g/d for 3 days) and oral prednisolone.

OUTCOMES

At 1 week after intravenous immunoglobulin therapy, his level of consciousness improved. However, flaccid paralysis persisted without substantial improvement.

CONCLUSION

In conclusion, the provision of an accurate early diagnosis and appropriate treatment are crucial for improving the prognosis of patients with autoimmune GFAP astrocytopathy. Further, this case highlights the importance of recognizing the role of peripheral nerve involvement in GFAP autoimmunity.

Acupuncture for HIV-associated distal symmetric peripheral neuropathy: A protocol for systematic review and meta-analysis

BACKGROUND

Human immunodeficiency virus (HIV)-associated distal symmetric peripheral neuropathy (DSPN) is one of the most frequent neurological complications of HIV infection, and causes pain and dysaesthesias in millions globally. Many individuals with this infection report using acupuncture to manage their symptoms, but evidence supporting the use of acupuncture is limited. This systematic review will assess the effectiveness and safety of acupuncture for patients with HIV-associated DSPN.

METHODS

Databases including MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, Scopus, Web of science, AMED (Allied and Complementary Medicine), the Chinese Biomedical Literature Database, the China National Knowledge Infrastructure, Wanfang Database, VIP Database and clinical trials registers (the WHO International Clinical Trials Registry Platform portal and www.ClinicalTrials.gov) will be electronically searched from inception to December 1, 2020. All randomized controlled trials in English or Chinese without restriction on publication status will be included. Selection of studies, extraction of data, and assessment of studies quality will be independently performed by 2 reviewers. The primary outcome measure will be the change in pain intensity assessed by validated scales. Secondary outcomes include change in neurologic summary scores, quality of life, physical function evaluated by admitted tools, and adverse events related to acupuncture reported in the included trials. If possible, a meta-analysis will be conducted to provide an estimate of the pooled treatment effect using Review Manager 5.3 statistical software. Otherwise, qualitative descriptive analysis will be given. The results will be presented as the risk ratio for binary data and the mean difference (MD) or standardized MD for continuous data.

RESULTS

The results of the systematic review will be disseminated via publication in a peer-reviewed journal and presented at a relevant conference.

CONCLUSION

This review will be the first review entirely focused on assessing the effectiveness and safety of acupuncture for HIV-associated DSPN.

PROSPERO REGISTRATION NUMBER

CRD42020210994.

Serum cytokine patterns in immunoglobulin m monoclonal gammopathy-associated polyneuropathy

INTRODUCTION

Polyneuropathy with immunoglobulin M monoclonal gammopathy (IgM-PNP) is associated with the presence of IgM antibodies against nerve constituents such as myelin associated glycoprotein (MAG) and gangliosides.

METHODS

To test whether B-cell-stimulating cytokines are increased in IgM-PNP, we measured serum concentrations of 11 cytokines in 81 patients with IgM-PNP and 113 controls.

RESULTS

Median interleukin (IL)-6 concentrations were higher in patients with IgM-PNP, and median IL-10 concentrations were higher in the subgroup with anti-MAG IgM antibodies. These serum concentrations were not increased in 110 patients with multifocal motor neuropathy.

DISCUSSION

Median IL-6 and IL-10 serum concentrations differ between patients with anti-MAG neuropathy and other patients with IgM-PNP compared with healthy and neuropathy controls. These differences may indicate differences in immune-mediated disease mechanisms. Muscle Nerve 59:694-698, 2019.

A Systemic Inflammatory Signature Reflecting Cross Talk Between Innate and Adaptive Immunity Is Associated With Incident Polyneuropathy: KORA F4/FF4 Study

Prospective analyses of biomarkers of inflammation and distal sensorimotor polyneuropathy (DSPN) are scarce and limited to innate immunity. We therefore aimed to assess associations between biomarkers reflecting multiple aspects of immune activation and DSPN. The study was based on 127 case subjects with incident DSPN and 386 noncase subjects from the population-based Cooperative Health Research in the Region of Augsburg (KORA) F4/FF4 cohort (follow-up 6.5 years). Proximity extension assay technology was used to measure serum levels of biomarkers of inflammation. Of 71 biomarkers assessed, 26 were associated with incident DSPN. After adjustment for multiple testing, higher levels of six biomarkers remained related to incident DSPN. Three of these proteins (MCP-3/CCL7, MIG/CXCL9, IP-10/CXCL10) were chemokines, and the other three (DNER, CD40, TNFRSF9) were soluble forms of transmembrane receptors. The chemokines had neurotoxic effects on neuroblastoma cells in vitro. Addition of all six biomarkers improved the C statistic of a clinical risk model from 0.748 to 0.783 (P = 0.011). Pathway analyses indicated that multiple cell types from innate and adaptive immunity are involved in the development of DSPN. We thus identified novel associations between biomarkers of inflammation and incident DSPN pointing to a complex cross talk between innate and adaptive immunity in the pathogenesis of the disease.

Immune Axonal Polyneuropathy

PURPOSE OF REVIEW

Immune axonal polyneuropathy is caused by a diverse group of disorders that share similar presentations and treatment regimens. This article focuses on the clinical findings, evaluation, and management of immune-mediated causes of axonal polyneuropathy, focusing primarily on large fiber sensorimotor polyneuropathy.

RECENT FINDINGS

Specific characteristics of an immune-mediated polyneuropathy have been incorporated in a new diagnostic screening tool that is highly sensitive and can easily be used in the outpatient clinic setting. New insights into autoantibodies may help identify the presence of an underlying autoimmune or paraneoplastic disease as the cause of a polyneuropathy.

SUMMARY

This article provides readers with further understanding into the autoimmune causes of axonal polyneuropathy and will help the clinician recognize key clinical features that may lead to timely diagnosis and treatment.

General Approach to Peripheral Nerve Disorders

PURPOSE OF REVIEW

This article provides a conceptual framework for the evaluation of patients with suspected polyneuropathy to enhance the clinician's ability to localize and confirm peripheral nervous system pathology and, when possible, identify an etiologic diagnosis through use of rational clinical and judicious testing strategies.

RECENT FINDINGS

Although these strategies are largely time-honored, recent insights pertaining to the pathophysiology of certain immune-mediated neuropathies and to evolving genetic testing strategies may modify the way that select causes of neuropathy are conceptualized, evaluated, and managed.

SUMMARY

The strategies suggested in this article are intended to facilitate accurate bedside diagnosis in patients with suspected polyneuropathy and allow efficient and judicious use of supplementary testing and application of rational treatment when indicated.

Chronic Demyelinating Polyneuropathies

PURPOSE OF REVIEW

This article reviews the chronic demyelinating neuropathies, with a focus on the diagnosis and treatment of immune-mediated neuropathies and the features that can help differentiate immune-mediated neuropathies from other chronic demyelinating peripheral nerve conditions.

RECENT FINDINGS

Advances in clinical phenotyping and outcomes assessment have enabled neurologists to improve disease recognition, treatment, and disease monitoring. Our understanding of the immunopathogenesis of demyelinating neuropathies is evolving. Identification of new antibodies and recognition that node of Ranvier dysfunction may be an early pathogenic feature may herald further diagnostic and treatment advancements.

SUMMARY

The chronic demyelinating polyneuropathies are heterogeneous. The clinical and diagnostic features are sometimes overlapping, and the specific disorders are variable in pathogenesis, treatment, and prognosis. This heterogeneity underscores the importance of achieving diagnostic accuracy and implementing disease-specific treatment approaches.

[Not Available]

Die Diagnose einer immunvermittelten Neuropathie ist eine der wichtigsten Differenzialdiagnosen bei Polyneuropathien. Chronisch inflammatorische Neuropathien haben oft eine schwere neurologische Beeinträchtigung zur Folge, weswegen eine frühzeitige Diagnose zur Einleitung einer antientzündlichen Therapie essenziell ist. Therapiekonzepte beinhalten je nach Pathologie Immunglobuline, Kortikosteroide oder Plasmaaustauschverfahren.

Home versus hospital immunoglobulin treatment for autoimmune neuropathies: A cost minimization analysis

Background

Prior clinical trials have suggested that home-based Ig treatment in multifocal motor neuropathy (MMN) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and its variant Lewis-Sumner syndrome (LSS) is safe and effective and is less costly than hospital-administered intravenous immunoglobulin (IVIg).

Methods

A French prospective, dual-center, cost minimization analysis was carried out to evaluate IVIg administration (5% concentrated) at home versus in hospital with regard to costs, patients' autonomy, and patients' quality of life. The primary endpoint was the overall cost of treatment, and we adopted the perspective of the payer (French Social Health Insurance).

Results

Twenty-four patients aged 52.3 (12.2) years were analyzed: nine patients with MMN, eight with CIDP, and seven with LSS. IVIg (g/kg) dosage was 1.51 ± 0.43 in hospital and 1.52 ± 0.4 at home. Nine-month total costs per patient extrapolated to 1 year of treatment were €48,189 ± 26,105 versus €91,798 ± 51,125 in the home and hospital groups, respectively (p < .0001). The most frequently reported factors for choosing home treatment were the good tolerance and absence of side effects of IVIg administration, as well as a good understanding of the advantages and drawbacks of home treatment (75% of respondents). The mRankin scores before and after switch to home treatment were 1.61 ± 0.72 and 1.36 ± 0.76, respectively (p = .027).

Discussion

The switch from hospital-based to home-based IVIg treatment for patients with immune neuropathy represents potentially significant savings in the management of the disease.

[Autoantibodies in Chronic Inflammatory Neuropathies]

Autoantibodies in chronic demyelinating neuropathies have been explored for several years. Recently, the peptides in the nodes of Ranvier have been the focus of attention in finding targets of autoantibodies. Until now, the most popular autoantibodies have been contactin-1 and neurofascin-155 for chronic demyelinating polyradiculoneuropathy (CIDP), GM1-ganglioside for multifocal motor neuropathy, and myelin-associated glycoprotein for polyneuropathy associated with monoclonal gammopathy of unknown significance. IgG is restricted to the IgG4 subtype in CIDP, indicating anti-inflammatory mechanisms related to the functional modification of the nodes of Ranvier. The clinical characteristics are also correlated with the presence of each of the autoantibodies, indicating the importance of auto-antibody screening in the development of suitable therapeutic strategies for each patient.

APECED syndrome in childhood: clinical spectrum is enlarging

Autoimmune polyendocrinopathy-candidiasis-ectodermal-distrophy (APECED) is a rare autosomal recessive disease, which is mainly characterized by the association of many autoimmune diseases, with a classic triad including chronic mucocutaneous candidiasis, hypoparathyroidism and adrenocortical failure. Its clinical spectrum has significantly enlarged in the last years and other non-classic components have been recently described. Aim of this review was to alert pediatricians to these novel clinical aspects of this syndrome, that have been recently included among the autoimmune APECED manifestations: a) chronic lung disease, that may evolve to cor pulmonale and terminal respiratory failure; b) chronic inflammatory demyelinating polineuropathy, with progressive muscular weakness of both arms and legs and sensory loss; c) gastrointestinal dysfunction, with recurrent diarrhea, malabsorption and steatorrhea or chronic constipation. For each of these novel components of APECED, specific autoantibodies against either lung autoantigens or peripheral nerves or tryptophan hydroxylase have been just recently identified.

Optimizing IgG therapy in chronic autoimmune neuropathies: a hypothesis driven approach

Prolonged intravenous immunoglobulin (IVIG) therapy is used for the chronic autoimmune neuropathies chronic idiopathic demyelinating polyneuropathy and multifocal motor neuropathy, but the doses and treatment intervals are usually chosen empirically due to a paucity of data from dose-response studies. Recent studies of the electrophysiology and immunology of these diseases suggest that antibody-induced reversible dysfunction of nodes of Ranvier may play a role in conduction block and disability which responds to immunotherapy more rapidly than would be expected for demyelination or axonal damage per se. Clinical reports suggest that in some cases, the effects of each dose of IVIG may be transient, wearing-off before the next dose is due. These observations lead us to hypothesize that that therapeutic IgG acts by competing with pathologic autoantibodies and that individual patients may require different IgG levels for optimal therapeutic effects. Frequent IVIG dosing and weekly subcutaneous IgG have been tried as ways of continuously maintaining high serum IgG levels, resulting in stabilization of neuromuscular function in small case series. Frequent grip strength and disability measurements, performed by the patient at home and reported electronically, can be used to assess the extent and duration of responses to IgG doses. Individualization of IgG treatment regimens may optimize efficacy, minimize disability, and identify nonresponders.

[Oropharyngeal dysphagia associated with Chiari I malformation and syringomyelia J]

BACKGROUND

Dysphagia associated with neurological disease is an important clinical manifestation in the diagnosis of injury that justifies the compression of the brainstem and lower cranial nerves.

OBJECTIVE

To emphasize the study of dysphagia in a patient with Chiari I malformation associated with syringomyelia in the absence of primary gastroenterological symptoms.

CLINICAL CASE

We describe the case of a 62 year-old woman with oropharyngeal dysphagia of six years of evolution, cervicobrachialgia, ptosis and facial diplexia.

CONCLUSIONS

Magnetic resonance imaging is an essential element for establishing the etiologic diagnosis of neurogenic dysphagia.

[A case of IgM paraproteinemic neuropathy associated with anti-sulfated glucuronic paragloboside (SGPG) IgG antibody without anti-myelin-associated glycoprotein (MAG) activity]

We report a case of IgM paraproteinemic neuropathy associated with anti-sulfated glucuronic paragloboside (SGPG) IgG antibody. An 84-year old man complained of numbness on the left side of the face and in the distal portions of the limbs. Neurological examination showed mild sensory ataxia. The laboratory tests revealed the presence of IgM lambda paraproteinemia and anti-SGPG IgG antibody without anti-myelin-associated glycoprotein (MAG) activity and anti-MAG/SGPG IgM antibody. Results of nerve conduction study showed decreased sensory nerve action potential (SNAP) amplitude, indicating the presence of sensory-dominant axonal polyneuropathy, and the prolongation of distal latency was not observed. Treatment with corticosteroids resulted in a rapid improvement in neurological abnormalities. In IgM paraproteinemic neuropathy associated with anti-MAG/SGPG antibody, distal acquired demyelinating sensory neuropathy and resistance to immunological treatments are the characteristic pathologic and clinical features, respectively. On the other hand our rare case of IgM paraproteinemic neuropathy positive for anti-SGPG IgG antibody presented with axonal sensory polyneuropathy and a good responsiveness to corticosteroids.

[A syndrome of chronic ataxic polyneuropathy, ophtalmoplegia, IgM paraprotein, cold agglutinins and anti-disialosyl antibodies can cause diplopia in patients with chronic sensory polyneuropathy]

CANOMAD is a rare syndrome of chronic ataxic polyneuropathy, ophtalmoplegia, IgM paraprotein, cold agglutinins and anti-disialosyl antibodies. We present a case of a 65-year-old woman with clinical and electrophysiological features of chronic sensory polyneuropathy and diplopia. Serum samples from the patient contained IgM paraprotein and anti-GM2-antibodies. Treatment with intravenous immunoglobulins resulted in an improvement of the patient's diplopia and polyneuropathy. The case shows the importance of considering CANOMAD as a cause of diplopia in patients with chronic sensory polyneuropathy.

Erythropoietin enhances nerve repair in anti-ganglioside antibody-mediated models of immune neuropathy

Guillain-Barré syndrome (GBS) is a monophasic immune neuropathic disorder in which a significant proportion of patients have incomplete recovery. The patients with incomplete recovery almost always have some degree of failure of axon regeneration and target reinnervation. Anti-ganglioside antibodies (Abs) are the most commonly recognized autoimmune markers in all forms of GBS and specific Abs are associated with the slow/poor recovery. We recently demonstrated that specific anti-ganglioside Abs inhibit axonal regeneration and nerve repair in preclinical models by activation of small GTPase RhoA and its downstream effectors. The objective of this study was to determine whether erythropoietin (EPO), a pleiotropic cytokine with neuroprotective and neurotrophic properties, enhances nerve regeneration in preclinical cell culture and animal models of autoimmune neuropathy/nerve repair generated with monoclonal and patient derived Abs. Primary neuronal cultures and a standardized sciatic crush nerve model were used to assess the efficacy of EPO in reversing inhibitory effects of anti-ganglioside Abs on nerve repair. We found that EPO completely reversed the inhibitory effects of anti-ganglioside Abs on axon regeneration in cell culture models and significantly improved nerve regeneration/repair in an animal model. Moreover, EPO-induced proregenerative effects in nerve cells are through EPO receptors and Janus kinase 2/Signal transducer and activator of transcription 5 pathway and not via early direct modulation of small GTPase RhoA. These preclinical studies indicate that EPO is a viable candidate drug to develop further for neuroprotection and enhancing nerve repair in patients with GBS.

[Rapid improvement by rituximab treatment in a case of demyelinating polyneuropathy with anti-myelin-associated glycoprotein antibody]

Polyneuropathy associated with antibodies directed against myelin-associated glycoprotein (MAG) is a chronic symmetric sensorimotor demyelinating neuropathy caused by monoclonal IgM against MAG (anti-MAG neuropathy). Intravenous immunoglobulin therapy (IVIg) has been partially successful in patients with anti-MAG neuropathy. A placebo-controlled trial of rituximab in patients with anti-MAG neuropathy has been reported. We report rapid improvement in a patient with anti-MAG neuropathy using rituximab. A 58-year-old man presented with abnormal sensation, weakness of the limbs, and unsteadiness. He was previously diagnosed with chronic inflammatory demyelinating neuropathy and was treated with steroid pulse therapy and IVIg. However, these treatments were not effective. On examination at our hospital, he showed areflexia in all limbs, mild weakness in distal portions of upper and lower extremities, sensory ataxia, and hypesthesia/hypalgesia except for his face. He showed high serum IgM levels (323mg/dl). He did not show M protein on immunoelectrophoresis; however, anti-MAG and anti-sulfoglucuronyl paragloboside (SGPG) antibodies were detected by immunoblot and enzyme-linked immunosorbent assay, respectively. He was diagnosed with anti MAG neuropathy and was administered four cycles of intravenous rituximab at a dose of 375mg/m(2)/week. After the first cycle of rituximab administration, he showed improvement in two-point discrimination of middle fingers (10/13 before therapy to 7/7mm after administration). Two-point discrimination and vibration markedly improved after four cycles of rituximab administration. Romberg sign became negative after 7 months. Anti-SGPG antibody titers reduced from 0.554 before rituximab administration to 0.307 (OD) at 1,600 dilution, 4 months after administration. We concluded that rituximab was effective for the treatment of anti-MAG neuropathy. We suggested that rapid and long-term improvement in our patient might be caused not only by preventing the formation of new antibody-secreting cells and antibody-titer reduction but also affecting the balance of proinflammatory cytokines and regulatory cytokines production.

[Dynamics of blood concentration of neurospecific proteins and risk of neuropathy development in the conditions of 105-day confinement]

Six male volunteers (aged 25 to 40 years) were subjects in all-round psychophysiological, hormonal and immunological studies before, in and after 105-day isolation and confinement. Blood was drawn and the 16-factorial Cattell personality inventory was filled out every 30 days. Concentrations of blood hormones, neurospecific proteins and cytokines point to a close interrelation between antibody titers to myelin-associated glycoprotein and changes in the parameters of metabolism and reproduction-related hormones, as well as cytokines and individual psychophysiology (extra-introversion, dominance, intropunitiveness, social contact selectivity, etc.), and suggest a minimum risk of demyelinizing neuropathy due to exposure to the conditions of isolation and confinement.

Acute transverse myelitis and acute motor axonal neuropathy developed after vaccinations against seasonal and 2009 A/H1N1 influenza

Acute transverse myelitis (ATM) has been described as an uncommon complication of vaccinations and is rarely accompanied by inflammatory peripheral neuropathy. We report a case of a 77-year-old woman who developed ATM and acute motor axonal neuropathy (AMAN) following vaccinations against seasonal and 2009 A/H1N1 influenza. She manifested ophthalmoplegia, quadriparesis and sensory impairment. MR imaging showed a longitudinally-extensive spinal cord lesion, and nerve conduction study revealed motor axonal polyneuropathy. Despite prompt treatment, her symptoms poorly recovered. While concurrent ATM and AMAN may suggest the presence of a common antigen, their scarcity indicates the importance of other factors causing immunologic disruptions.

Neuropathy with predominant small fiber involvement associated with abnormal anti-MAG titer

We describe a patient with painful neuropathy associated with an abnormal anti-MAG titer in which predominant involvement of intra-epidermal nerve fiber was documented. Electrophysiological studies revealed low-borderline amplitude of sensory and compound motor action potentials registering from lower limbs and normal conduction velocity. Sural nerve biopsy disclosed only a slight loss of myelinated fiber. Skin biopsy performed at the proximal thigh and at the distal leg was consistent with a non-length-dependent small fiber neuropathy. It is likely that in this case anti-MAG antibodies played a role in the pathogenesis of small fiber neuropathy.

Molecularly targeted therapies for dysimmune neuropathies

Conventional treatment options, including corticosteroids, intravenous immunoglobulin, or plasma exchange, often fail to treat dysimmune neuropathies, such as chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, and monoclonal gammopathy with its subtypes. Therefore, a significant percentage of patients require adjunctive immunosuppressive therapies. Considering that even immunosuppressive agents often are ineffective and/or associated with significant toxicities, the need for the development of safe and effective new treatment options is rising. Currently, several monoclonal antibodies (MAbs) have been tested in open-label small-sized studies or even in single cases so as to establish future directions in the therapy of diseases of the peripheral nervous system (PNS). Rituximab, an MAb targeting against the B cell surface membrane protein CD20, is the most widely used and promising MAb for the treatment of dysimmune neuropathies, especially for those in which immunoglobulin M (IgM) autoantibodies are pathogenetically involved. The efficacy of alemtuzumab, bevacizumab, and etanercept to treat various forms of dysimmune neuropathies is currently under investigation. This review looks critically at recent developments in molecularly targeted therapies for dysimmune neuropathies and also highlights areas of future research to pursue.

[The significance of intravenous immunoglobulin in treatment of immune-mediated polyneuropathies]

Long-term treatment of immune-mediated polyneuropathies remains difficult. For acute polyneuritis, or Guillain-Barré syndrome, the established standard therapy utilizes high doses of polyvalent intravenous immunoglobulins (IVIG). A recently published randomized placebo-controlled study of patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) showed IVIG to be clinically effective also for this disorder in both short and long term. This survey presents data of this so-called ICE study ("Intravenous immune globulin for the treatment of chronic inflammatory demyelinating polyradiculoneuropathy"). It also discusses the value of IVIG in the treatment of immune-mediated polyneuropathies.

[Dysimmune neuropathies: current diagnosis and therapy]

Dysimmune neuropathies encompass an acute form, Guillain-Barré syndrome (GBS), and mainly 3 chronic forms: chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), multifocal motor neuropathy, and polyneuropathy associated with anti-MAG (myelin-associated-glycoprotein) IgM monoclonal gammopathy. Recent concepts have concerned both incidence and mortality rates, and better scoring system for predict outcome in GBS, but new therapeutical strategy is needed for the so-called "benign" forms and for relapsing forms after first-line IVIg therapy. In chronic forms, criteria for diagnosis and guidelines for management have been edited in the recent years, together with recommendations for outcome measures. However, there is still a need for knowing the better outcome measures, and to elaborate new trials, mainly focusing on the long-term management of the patients.

Antibodies against GM1 in demented patients

The aim of this study was to evaluate the levels of anti-GM1 in demented patients, correlating them with the type and severity of dementia as well as with the eventually coexistent polyneuropathy. Anti-GM1 concentrations were measured in the sera of 33 demented patients with a male-to-female ratio of 1:2.7 (the mean age was 69.7 years for males and 70.1 years for females). Eighty-two percent of the patients revealed increased values of anti-GM1, but only 18.2% demonstrated polyneuropathies. Fifty-nine percent of the patients suffered from vascular dementia. The most severely demented patients demonstrated a Mini-Mental State Examination score of 5 to 23 out of 30 and revealed the most increased levels of anti-GM1 (>40 EU/mL). The findings of this study are indicative of a possible correlation between the levels of anti-GM1 and the severity of dementia, mainly of the vascular type.

Predictors of response to rituximab in patients with neuropathy and anti-myelin associated glycoprotein immunoglobulin M

We evaluated the efficacy and safety of rituximab in an open-label, uncontrolled study of 13 patients with polyneuropathy associated with antibodies to myelin-associated glycoprotein (MAG) and correlated the response to therapy with clinical and laboratory features. One year after rituximab therapy, anti-MAG immunoglobulin M (IgM) titers were significantly reduced. At that time, eight patients (62%) had improved in both the inflammatory neuropathy cause and treatment (INCAT) sensory sumscore and the Medical Research Council sumscore for muscle strength and seven of them also in the INCAT disability score. The improvement in the mean INCAT sensory sumscore was significant at 12 months and correlated with lower anti-MAG antibody at entry and at follow-up. This study suggests that rituximab may be efficacious in patients with anti-MAG associated neuropathy and particularly on sensory impairment and in those with moderately elevated antibody titers. These findings suggest that antibody reduction below a critical level may be necessary to achieve clinical improvement.

Cytogenetic aberrations in neuropathy associated with IgM monoclonal gammopathy

The occurrence and nature of cytogenetic aberrations in polyneuropathy associated with IgM monoclonal gammopathy was determined. Therefore, interphase fluorescence in situ hybridization (FISH) was applied in 22 patients with polyneuropathy associated with IgM monoclonal gammopathy, multiplex ligation-dependent probe amplification (MLPA) assay in 18 of these patients and genome-wide-array-based comparative genomic hybridization (CGH) in eight of these 18 patients. Four patients had 10-20% and one patient had 30% B cells with IgH rearrangements; one patient had additional loss of 14qter; one patient had amplification of 6p and loss of 6q. Cytogenetic aberrations may be found in one third of the patients with neuropathy associated with IgM monoclonal gammopathy and are mainly associated with indolent Waldenstrom's Macroglobulinemia.

Efficacy of Intravenous Immunoglobulin in Multifocal Motor Neuropathy

Multifocal motor neuropathy is a distinct entity, whose treatment differs from that of other chronic immune-mediated neuropathies, mainly chronic inflammatory demyelinating polyradiculoneuropathy, and its variant, multifocal acquired demyelinating sensory and motor neuropathy, although they share some electrophysiological characteristics. From the first descriptions, intravenous immunoglobulins (IVIg) have been considered to be the gold standard of treatment for multifocal motor neuropathy. However, if the effectiveness of IVIg has been confirmed by several randomized, double-blind, placebo-controlled trials, only a few patients experience persistent improvement after a single or few courses of therapy, and the long-term efficacy of IVIg in this disease is currently debated. Consequently, there is a need for new therapeutic strategies that focus on the effects and the costs of this therapy over long-term follow-up.

Anti-MAG/SGPG associated neuropathy does not commonly cause distal nerve temporal dispersion

Patients with anti-myelin associated glycoprotein (anti-MAG) neuropathy have uniform slowing without temporal dispersion, but do usually have disproportionately distal slowing. We evaluated distal compound muscle action potential (CMAP) dispersion in 29 patients with anti-MAG/sulphated glucuronyl paragloboside (SGPG) neuropathy (titres > or = 12,800). Among 138 motor responses, 15% (tibial), 7.3% (peroneal), 10.7% (median) and 13.8% (ulnar) had distal CMAP duration > 9 ms. Disproportionate distal slowing with normal distal CMAP duration in the arms may be useful to differentiate chronic inflammatory demyelinating polyneuropathy from anti-MAG/SGPG associated neuropathy.

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.

Persistent multifocal conduction block in vasculitic neuropathy with IgM anti-gangliosides

A 30-year-old man with essential cryoglobulinemia presented with an axonal neuropathy and was found to have vasculitis at nerve biopsy. After 44 months, in accord with clinical deterioration, motor conduction studies showed excessive temporal dispersion multifocally, with partial conduction block persisting for 3 years. Antibody testing showed the presence of IgM anti-GM1, anti-GD1a, and anti-GM2 antibodies. Transitory conduction block has been reported occasionally in patients with vasculitis. The persistent multifocal conduction abnormalities found in this patient were more likely due to a superimposed immunomediated demyelination rather than to chronic nerve ischemia secondary to vasculitis.

Fine specificity of antibodies against phospholipids and beta-2-glycoprotein I in monoclonal gammopathy associated neuropathies

Phospholipids are abundantly represented within the nervous system. Aim of our study was to evaluate the presence and fine specificity of anti phospholipid antibodies (aPLAb) among patients with monoclonal gammopathy associated neuropathy. Thirty nine percent of these patients had high titers of aPLAb, mostly associated with low levels of anti beta2 glycoprotein I, which suggests different antibody specificity compared to patients with anti phospholipid syndrome. Further 6/48 patients with dysimmune neuropathy without monoclonal gammopathy had positive aPLAb titers. APLAb strongly cross-reacted with sulfatide. These findings suggest an adjuntive role of aPLAb on nerve damage and may help to better understand the nerve binding properties of anti-sulfatide antibodies.

Chronic polyneuropathy and Lyme disease

Infection of the peripheral nervous system with Borrelia burgdorferi can present as a cranial neuropathy or radiculopathy with cerebrospinal fluid (CSF) pleocytosis and intrathecal antibody production against B. burgdorferi, or as an asymmetric peripheral neuropathy with acrodermatitis chronica atrophicans (ACA) and normal CSF findings. According to North American studies, it can also present as a symmetric chronic polyneuropathy without ACA or other Lyme manifestations. Our purpose was to investigate the prevalence of B. burgdorferi antibodies in patients presenting with isolated chronic polyneuropathy (PN) in a European region with high incidence of Lyme disease. Sera from 209 PN patients and 247 healthy blood donors from Vest-Agder County, Norway, were examined. Borrelia burgdorferi antibodies were detected in 43 (21%) PN patients and in 45 (18%) healthy blood donors (P = 0.553). The prevalence of B. burgdorferi antibodies was similar (P = 0.311) in cryptogenic PN (24/102, 24%) and PNs of identified etiologies (19/107, 18%). PN patients with B. burgdorferi antibodies had normal spinal fluid white cell count and they did not differ clinically or electrophysiologically from PN patients without antibodies. None of 20 antibody-positive PN patients responded to antimicrobial treatment. The study shows that, in Europe, chronic distal PN without ACA or other Lyme manifestations is very rarely caused by a B. burgdorferi infection.

Severe cranial nerve involvement in a patient with monoclonal anti-MAG/SGPG IgM antibody and localized hard palate amyloidosis

We report a patient with severe cranial polyneuropathy as well as sensory limb neuropathy. Biclonal serum IgM-kappa/IgM-lambda gammopathy was found and serum anti-myelin-associated glycoprotein (MAG)/sulfoglucuronyl paragloboside (SGPG) IgM antibody was also detected. Immunofluorescence analysis of a sural nerve biopsy specimen revealed binding of IgM and lambda-light chain on myelin sheaths. No amyloid deposition was detected in biopsied tissues except for the hard palate, suggesting that the amyloidosis was of the localized type and had no relation to the pathogenesis of cranial neuropathy. Our observations indicate that the anti-MAG/SGPG IgM antibody may be responsible for this patient's cranial polyneuropathy, which is a rare manifestation in anti-MAG/SGPG-associated neuropathy.

High-dose rituximab and anti-MAG-associated polyneuropathy

Rituximab has been administered successfully in patients with polyneuropathy associated with antibodies to myelin-associated glycoprotein (anti-MAG). The authors present a follow-up study with high-dose rituximab. Increase of rituximab from 375 mg/m2 to a dose of 750 mg/m2 was well tolerated and led to clinical improvement in four of eight patients, along with improvement of nerve conduction velocities and a reduction of anti-MAG antibody titers.

CD8+ lymphocyte-mediated injury of dorsal root ganglion neurons during lentivirus infection: CD154-dependent cell contact neurotoxicity

Neuronal damage in dorsal root ganglia (DRGs) with accompanying axonal injury is a key feature of human immunodeficiency virus (HIV)-related distal sensory polyneuropathy (DSP). In a model of HIV-related DSP, we observed numerous CD3+ T lymphocytes (p < 0.05) in DRGs from feline immunodeficiency virus (FIV)-infected animals, which also exhibited low CD4+ and high CD8+ lymphocyte levels in blood accompanied by a selective loss of small-diameter sural nerve axons (p < 0.05). FIV-infected lymphocytes cocultured with syngeneic DRGs caused neuronal damage, indicated by neurite retraction, neuronal soma atrophy, and loss (p < 0.05). In contrast, supernatants from FIV-infected or uninfected lymphocytes were minimally neurotoxic, despite high FIV virion levels. Among lymphocyte subsets cocultured with DRG cultures, CD8+ T cells from both FIV-infected and uninfected lymphocytes selectively caused DRG neuronal injury (p < 0.05). FIV-infected CD8+ T cells showed markedly increased CD154 expression (p < 0.05), whereas neurons were the predominant cells expressing CD40 in DRGs. Blocking CD154 on activated CD8+ T cells protected DRG neurons (p < 0.05). These findings indicated that CD8+ T cells were principal effectors of DRG neuronal injury after FIV infection through a CD40-CD154 interaction in a cell contact-dependent manner.

Neuropathie motrice multifocale avec blocs de conduction persistants

Multifocal motor neuropathy with persistent conduction blocks was first specifically identified in 1986. Its major criterion is conduction blocks in motor nerves only. Clinically, this is a multifocal, thus asymmetric, neuropathy that begins and predominant touches upper limbs; it especially affects men after the age of 50 years and has a chronic course with relapses. Approximately 40-50% of patients also have IgM serum antibodies directed against GM1 ganglioside. There are no other laboratory criteria, although moderately high protein levels are found in cerebrospinal fluid. Its course is unpredictable, because the neuropathy may remain limited to one or two motor nerves or extend progressively to all the motor nerves of all four limbs. In general, there is no damage to sensory or cranial nerves or to the autonomic or central nervous systems. Intravenous polyvalent immunoglobulins at high doses are remarkably effective in the short term in 70 to 80% of cases. Corticosteroids and plasma exchange are generally ineffective and may aggravate the neuropathy. The long-term efficacy of intravenous immunoglobulins in delaying motor decline and axon loss in the affected motor nerves is controversial. No information is currently available about the long-term efficacy of other immunomodulatory treatment.

Motor axonal polyneuropathy in the course of ulcerative colitis: a case report

We describe an axonal motor polyneuropathy in a patient with ulcerative colitis. Symptoms of neuropathy occurred during active colitis. Electrophysiological study showed motor axonal degeneration. After treatment with steroid added to mesalazine, the patient had a gastrointestinal recovery and neurological symptoms were improved. Axonal motor polyneuropathy is an unusual extraintestinal manifestation of ulcerative colitis, and is probably associated with an autoimmune process.

Circulating levels of cytokines and their modulation by intravenous immunoglobulin in multifocal motor neuropathy

We found comparable levels of tumor necrosis factor (TNF)-alpha, interferon-gamma, interleukin (IL)-2, IL-4, IL-10, and IL-12 in the sera of 22 patients with multifocal motor neuropathy (MMN), 12 with amyotrophic lateral sclerosis (ALS), 12 multiple sclerosis, seven chronic inflammatory demyelinating polyneuropathy, five myasthenia gravis, and 13 healthy controls (NS). TNF-alpha levels, however, were higher in 15 (68%) MMN patients than in any NS. In all but one MMN patient tested, TNF-alpha levels repeatedly, albeit slightly, increased after each intravenous immunoglobulin infusion in parallel with clinical improvement and decreased 3-4 weeks after therapy, while in both ALS patients tested, they decreased or remained unchanged. The possible pathogenetic relevance of serum TNF-alpha modification in MMN remains to be clarified.

Length dependence in polyneuropathy associated with IgM gammopathy

OBJECTIVE

In polyneuropathy associated with monoclonal IgM gammopathy, nerve conduction studies may show disproportionate distal slowing consistent with segmental demyelination. This was suggested to represent a length-dependent demyelinating process, starting in distal and proceeding to proximal segments. Because the evidence for this is incomplete, we assessed whether length dependence occurs in IgM neuropathy.

METHODS

In 22 patients with IgM neuropathy, 20 disease controls with chronic inflammatory demyelinating polyneuropathy (CIDP) and 36 normal controls, we investigated motor conduction, sensory conduction, and needle electromyography for nerves with short, intermediate-length, and long axons as well as conduction in short segments of the ulnar nerve from proximal to distal. To compare variables in nerves of different length, we normalized individual values with respect to the median in normal controls.

RESULTS

In IgM neuropathy, distal slowing and features of axon loss increased with nerve length, and ulnar nerve conduction became gradually slower from proximal to distal when the elbow segment was excluded. In CIDP, no clear length dependence was found except for distal amplitude.

INTERPRETATION

The disproportionate distal slowing in IgM neuropathy may be part of a length-dependent process, assuming that this process is randomly distributed due to a generalized exposure to IgM.

Subacute demyelinating polyneuropathy in B-cell lymphoma with IgM antibodies against glycolipid GD1b

Peripheral neuropathy associated with IgM monoclonal gammopathy of unknown significance is a common disorder, while the association of paraproteinaemic neuropathies with haematological malignancies is far less frequent. We report a 76-year-old patient with a subacute and rapidly progressive sensorimotor demyelinating polyneuropathy causing sensory ataxia, painful paraesthesias and marked motor and sensory deficit in four limbs. Monoclonal gammopathy of IgM type associated with a rectal low-grade B-cell non-Hodgkin lymphoma was detected. Research for anti-MAG and antiganglioside autoantibodies including anti-GM1 and anti-GQ1b evidenced a high titre of IgM antibodies against the disialosyl group of GD1b. This is the first report on a paraproteinaemic polyneuropathy with IgM autoantibodies against glycolipid GD1b associated with B-cell lymphoma. The IgM type of these autoantibodies suggests that they represent all or part of the paraprotein produced by lymphoma cells.

Use of intravenous immunoglobulin for treatment of neurologic conditions: a systematic review

BACKGROUND

Given the increasing use of intravenous immunoglobulin (IVIG) for various neurologic conditions and uncertainty pertaining to its benefits and harms, a systematic review was conducted of randomized controlled trials (RCTs) evaluating IVIG for all neurologic indications for which there was at least one published trial.

STUDY DESIGN AND METHODS

For this systematic review, a systematic search strategy was applied to MEDLINE (1966-June 2003) and the Cochrane Register of Controlled Trials (June 2003) to identify potentially eligible RCTs comparing IVIG to placebo or an active control. All dosage regimens were considered. Abstracts were excluded, and no restriction was placed on language of publication. Two investigators independently performed data extraction with a standardized form. Measures of effect were calculated for each trial independently, and studies were pooled based on clinical and methodologic judgment as to its appropriateness. Where pooling of trials was inappropriate, a qualitative discussion of findings is provided.

RESULTS AND CONCLUSIONS

Thirty-seven trials representing 14 conditions were identified. IVIG is more effective than placebo for treatment of relapsing-remitting multiple sclerosis and idiopathic chronic inflammatory demyelinating polyneuropathy. There is also potential benefit for treatment of multifocal motor neuropathy, myasthenia gravis, dermatomyositis, stiff-person syndrome, and Lambert-Eaton myasthenic syndrome. There was insufficient evidence to determine whether IVIG therapy was more effective than plasma exchange for Guillain-Barré syndrome. There was also insufficient evidence regarding paraprotein-associated polyneuropathy. No evidence of benefit was observed for secondary progressive multiple sclerosis or inclusion body myositis.