Anti-peripheral nerve myelin antibodies in Guillain-Barre syndrome bind a neutral glycolipid of peripheral myelin and cross-react with Forssman antigen

Inflammatory neuropathies: pathology, molecular markers and targets for specific therapeutic intervention

Inflammatory neuropathies encompass groups of heterogeneous disorders characterized by pathogenic immune-mediated hematogenous leukocyte infiltration of peripheral nerves, nerve roots or both, with resultant demyelination or axonal degeneration or both. Inflammatory neuropathies may be divided into three major disease categories: Guillain-Barré syndrome (particularly the acute inflammatory demyelinating polyradiculoneuropathy variant), chronic inflammatory demyelinating polyradiculoneuropathy and nonsystemic vasculitic neuropathy (or peripheral nerve vasculitis). Despite major advances in molecular biology, pathology and genetics, the pathogenesis of these disorders remains elusive. There is insufficient knowledge on the mechanisms of hematogenous leukocyte trafficking into the peripheral nervous system to guide the development of specific molecular therapies for immune-mediated inflammatory neuropathies compared to disorders such as psoriasis, inflammatory bowel disease, rheumatoid arthritis or multiple sclerosis. The recent isolation and characterization of human endoneurial endothelial cells that form the blood-nerve barrier provides an opportunity to elucidate leukocyte-endothelial cell interactions critical to the pathogenesis of inflammatory neuropathies at the interface between the systemic circulation and peripheral nerve endoneurium. This review discusses our current knowledge of the classic pathological features of inflammatory neuropathies, attempts at molecular classification and genetic determinants, the utilization of in vitro and in vivo animal models to determine pathogenic mechanisms at the interface between the systemic circulation and the peripheral nervous system relevant to these disorders and prospects for future potential molecular pathology biomarkers and targets for specific therapeutic intervention.

Immunopathology and Th1/Th2 immune response of Campylobacter jejuni-induced paralysis resembling Guillain-Barré syndrome in chicken

Immunopathogenesis of Campylobacter jejuni-associated Guillain-Barré syndrome (GBS) is not yet well established probably due to lack of experimental model. Therefore, we studied the Th1/Th2 immune response and pathological changes in C. jejuni-induced chicken model for GBS. C. jejuni (5 × 10(9) CFU/ml) and placebo were fed to 30 chickens each. Stools of all birds were negative for C. jejuni by culture and PCR before experiment. The birds were regularly assessed for disease symptoms up to 30 days. Sciatic nerves from all chickens were examined at 5 days intervals by histopathology and immunohistochemistry, and also for the expression of Th1/Th2 cytokines. Twenty-two chickens (73.3%) developed diarrhea after C. jejuni infection; 18 (60.0%) experimental chickens developed GBS-like paralytic neuropathy. Pathology in the sciatic nerves of these chickens included perinodal and/or patchy demyelination, perivascular focal lymphocytic infiltration, myelin swelling and presence of macrophages within the nerve fibers on 10th-20th post-infection day (PID). Cytokines (IFN-γ, IL-1β, TNF-α, IL-6 and IL-2) were elevated in early phase (5th-15th PID) and TGF-β2, IL-10 and IL-4 in the recovery phase (25th-30th PID) of the disease. The study provides evidence that C. jejuni infection in the chicken can provide an experimental animal model of GBS.

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

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

Acute paretic syndrome in juvenile White Leghorn chickens resembles late stages of acute inflammatory demyelinating polyneuropathies in humans

Background

Sudden limb paresis is a common problem in White Leghorn flocks, affecting about 1% of the chicken population before achievement of sexual maturity. Previously, a similar clinical syndrome has been reported as being caused by inflammatory demyelination of peripheral nerve fibres. Here, we investigated in detail the immunopathology of this paretic syndrome and its possible resemblance to human neuropathies.

Methods

Neurologically affected chickens and control animals from one single flock underwent clinical and neuropathological examination. Peripheral nervous system (PNS) alterations were characterised using standard morphological techniques, including nerve fibre teasing and transmission electron microscopy. Infiltrating cells were phenotyped immunohistologically and quantified by flow cytometry. The cytokine expression pattern was assessed by quantitative real-time PCR (qRT-PCR). These investigations were accomplished by MHC genotyping and a PCR screen for Marek's disease virus (MDV).

Results

Spontaneous paresis of White Leghorns is caused by cell-mediated, inflammatory demyelination affecting multiple cranial and spinal nerves and nerve roots with a proximodistal tapering. Clinical manifestation coincides with the employment of humoral immune mechanisms, enrolling plasma cell recruitment, deposition of myelin-bound IgG and antibody-dependent macrophageal myelin-stripping. Disease development was significantly linked to a 539 bp microsatellite in MHC locus LEI0258. An aetiological role for MDV was excluded.

Conclusions

The paretic phase of avian inflammatory demyelinating polyradiculoneuritis immunobiologically resembles the late-acute disease stages of human acute inflammatory demyelinating polyneuropathy, and is characterised by a Th1-to-Th2 shift.

Autoimmune neuropathies

Autoimmune neuropathies are common and treatable disorders of the peripheral nerves, which should be properly recognized. This article discusses their diagnosis, differential diagnosis and proper treatment.

Glial cells as targets for cytotoxic immune mediators

Oligodendrocytes and Schwann cells are the glia principally responsible for the synthesis and maintenance of myelin. Damage may occur to these cells in a number of conditions, but perhaps the most studied are the idiopathic inflammatory demyelinating diseases, multiple sclerosis in the CNS, and Guillain-Barré syndrome and its variants in the peripheral nervous system (PNS). This article explores the effects on these cells of cytotoxic immunological and inflammatory mediators: similarities are revealed, of which perhaps the most important is the sensitivity of both Schwann cells and oligodendrocytes to many such agents. This area of research is, however, characterised and complicated by numerous and often very substantial inter-observer discrepancies. Marked variability in cell culture techniques, and in assays of cell damage and death, provide artifactual explanations for some of this variability; true inter-species differences also contribute. Not the least important conclusion centres on the limited capacity of in vitro studies to reveal disease mechanisms: cell culture findings merely illustrate possibilities which must then be tested ex vivo using human tissue samples affected by the relevant disease.

Can antiglycolipid antibodies present in HIV-infected individuals induce immune demyelination?

Of the eight clinically defined neuropathies associated with HIV infection, there is compelling evidence that acute and chronic inflammatory demyelinating polyneuropathy (IDPN) have an autoimmune pathogenesis. Many non-HIV infected individuals who suffer from sensory-motor nerve dysfunction have autoimmune indicators. The immunopathogenesis of demyelination must involve neuritogenic components in myelin. The various antigens suspected to play a role in HIV-seronegative IDPN include (i) P2 protein; (ii) sulfatide (GalS); (iii) various gangliosides (especially GM1); (iv) galactocerebroside (GalC); and (v) glycoproteins or glycolipids with the carbohydrate epitope glucuronyl-3-sulfate. These glycoproteins or glycolipids may be individually targeted, or an immune attack may be raised against a combination of any of these epitopes. The glycolipids, however, especially GalS, have recently evoked much interest as mediators of immune events underlying both non-HIV and HIV-associated demyelinating neuropathies. The present review outlines the recent research findings of antiglycolipid antibodies present in HIV-infected patients with and without peripheral nerve dysfunction, in an attempt to arrive at some consensus as to whether these antibodies may play a role in the immunopathogenesis of HIV-associated inflammatory demyelinating polyneuropathy.

Terminal complement complexes concomitantly stimulate proliferation and rescue of Schwann cells from apoptosis

The consequences of sublytic terminal complement complex (TCC) assembly on Schwann cell proliferation and apoptosis were examined by using purified complement proteins (C5*-9) or antibody-sensitized Schwann cells in the presence of a serum that was depleted of the seventh component of complement (C7dHS) and reconstituted with purified C7. Stimulation of cultured Schwann cells with antibody plus 10% C7dHS and C7 or C5*-9 induced DNA synthesis over antibody plus 10% C7dHS alone or in Schwann cells in which C5*-9 insertion was inhibited by heat inactivation, respectively. Cell cycle analysis with propidium iodide showed that, at 24 h, viable Schwann cells in defined medium were synchronized in G1/G0 phase. C5*-9 shifted 64% of these cells into S or G2/M phases in a manner similar to beta-neuregulin (beta-NRG), a known Schwann cell mitogen. Furthermore, antibody with 10% C7dHS and C7 or purified C5*-9 induced proliferation of viable Schwann cells. These effects were mediated by signal-transduction pathways involving p44 ERK1 (extracellular-regulated kinase 1), Gi proteins, and protein kinase C. Culturing in defined medium for 24 h resulted in apoptosis of up to 50% of Schwann cells that was prevented by treatment with beta-NRG or TCC. Sublytic C5*-9 significantly inhibited apoptosis 41% by 24 h, as determined by a terminal deoxyuridine triphosphate-biotin nick end labeling assay, and also decreased annexin-V binding at 4 h. Collectively, these data suggest that sublytic TCC, like beta-NRG, is a potent Schwann cell trophic factor that is capable of stimulating mitogenesis and apoptotic rescue. TCC assembly on Schwann cells during inflammatory demyelination of peripheral nerves may promote survival of mature cells to enhance repair and remyelination processes.

Sublytic terminal complement complexes decrease P0 Gene expression in Schwann cells

Complement cascade activation on peripheral nerve myelin can cause myelin destruction. Although terminal complement complexes (TCCs) are transiently detected on Schwann cells (SchCs) during inflammatory neuropathy, SchCs appear resistant to complement-mediated lysis, and little is known about the functional consequences of sublytic TCC deposition on SchCs. We studied the effects of sublytic complement in modulating myelin gene expression at the posttranscriptional and transcriptional levels. Cultured SchCs, stimulated to express protein zero (P0), were treated with sensitizing antibody (Ab) and normal human serum (NHS) complement. P0 mRNA content decreased by 71% during 12 h. In the presence of actinomycin D, P0 mRNA levels declined 50% following incubation with Ab plus 10% NHS over 6 h, compared with control levels, suggesting enhanced P0 mRNA degradation. The decreases, in part, reflected TCC formation because C7 reconstitution of Ab plus C7-depleted human serum (C7dHS) or TCCs assembled from purified components down-regulated P0 mRNA 53 and 55% over that of Ab plus C7dHS or heat-activated components, respectively. Expression of a P0 promoter/luciferase reporter construct transiently transfected into SchCs was reduced 70% by sublytic TCCs at 6 h, demonstrating that P0 gene transcription was also inhibited. c-jun mRNA was up-regulated within 30 min by sublytic TCCs, before the reduction in P0 mRNA expression. Our data suggest that sublytic complement activation on SchCs may contribute to peripheral nerve demyelination by decreasing expression of genes important in myelin formation and compaction.

Pathogenesis of Guillain-Barré syndrome

Recent neurophysiological and pathological studies have led to a reclassification of the diseases that underlie Guillain-Barré syndrome (GBS) into acute inflammatory demyelinating polyradiculoneuropathy (AIDP), acute motor and sensory axonal neuropathy (AMSAN) and acute motor axonal neuropathy (AMAN). The Fisher syndrome of ophthalmoplegia, ataxia and areflexia is the most striking of several related conditions. Significant antecedent events include Campylobacter jejuni (4-66%), cytomegalovirus (5-15%), Epstein-Barr virus (2-10%), and Mycoplasma pneumoniae (1-5%) infections. These infections are not uniquely associated with any clinical subtype but severe axonal degeneration is more common following C. jejuni and severe sensory impairment following cytomegalovirus. Strong evidence supports an important role for antibodies to gangliosides in pathogenesis. In particular antibodies to ganglioside GM1 are present in 14-50% of patients with GBS, and are more common in cases with severe axonal degeneration associated with any subtype. Antibodies to ganglioside GQ1b are very closely associated with Fisher syndrome, its formes frustes and related syndromes. Ganglioside-like epitopes exist in the bacterial wall of C. jejuni. Infection by this and other organisms triggers an antibody response in patients with GBS but not in those with uncomplicated enteritis. The development of GBS is likely to be a consequence of special properties of the infecting organism, since some strains such as Penner 0:19 and 0:41 are particularly associated with GBS but not with enteritis. It is also likely to be a consequence of the immunogenetic background of the patient since few patients develop GBS after infection even with one of these strains. Attempts to match the subtypes of GBS to the fine specificity of anti-ganglioside antibodies and to functional effects in experimental models continue but have not yet fully explained the pathogenesis. T cells are also involved in the pathogenesis of most or perhaps all forms of GBS. T cell responses to any of three myelin proteins, P2, PO and PMP22, are sufficient to induce experimental autoimmune neuritis. Activated T cells are present in the circulation in the acute stage, up-regulate matrix metalloproteinases, cross the blood-nerve barrier and encounter their cognate antigens. Identification of the specificity of these T cell responses is still at a preliminary stage. The invasion of intact myelin sheaths by activated macrophages is difficult to explain according to a purely T cell mediated mechanism. The different patterns of GBS are probably due to the diverse interplay between antibodies and T cells of differing specificities.

Campylobacter species and Guillain-Barré syndrome

Since the eradication of polio in most parts of the world, Guillain-Barré syndrome (GBS) has become the most common cause of acute flaccid paralysis. GBS is an autoimmune disorder of the peripheral nervous system characterized by weakness, usually symmetrical, evolving over a period of several days or more. Since laboratories began to isolate Campylobacter species from stool specimens some 20 years ago, there have been many reports of GBS following Campylobacter infection. Only during the past few years has strong evidence supporting this association developed. Campylobacter infection is now known as the single most identifiable antecedent infection associated with the development of GBS. Campylobacter is thought to cause this autoimmune disease through a mechanism called molecular mimicry, whereby Campylobacter contains ganglioside-like epitopes in the lipopolysaccharide moiety that elicit autoantibodies reacting with peripheral nerve targets. Campylobacter is associated with several pathologic forms of GBS, including the demyelinating (acute inflammatory demyelinating polyneuropathy) and axonal (acute motor axonal neuropathy) forms. Different strains of Campylobacter as well as host factors likely play an important role in determining who develops GBS as well as the nerve targets for the host immune attack of peripheral nerves. The purpose of this review is to summarize our current knowledge about the clinical, epidemiological, pathogenetic, and laboratory aspects of campylobacter-associated GBS.

Human autoimmune neuropathies

Peripheral nerve diseases are among the most prevalent disorders of the nervous system. Because of the accessibility of the peripheral nervous system (PNS) to direct physiological and pathological study, neuropathies have traditionally played a unique role in developing our understanding of basic mechanism of nervous system injury and repair. At present they are providing new insight into the mechanisms of immune injury to the nervous system. A rapidly growing catalogue of PNS disorders are now suspected to be immune-mediated, and in the best understood of these disorders, the molecular and cellular targets of immune attack are known, and the pathophysiology follows directly from the specific immune injury. This review summarizes the immunologically relevant features of the PNS, then considers selected immune-mediated neuropathies, focusing on pathogenetic mechanisms. Finally, the PNS is providing a testing ground for new immunotherapies and approaches to protection and regeneration, including the use of trophic factors. The current status of treatment and implications for future approaches is reviewed.

Gangliosides and glycosphingolipids of peripheral nervous system myelins--a minireview

A summary is provided of the available data on the composition of gangliosides and glycosphingolipids in the peripheral nervous system (PNS) including myelins and their antigenic properties. The composition of gangliosides and glycosphingolipids in the PNS is very different from that in the central nervous system (CNS), both quantitatively and qualitatively. One major difference is the abundance of neolacto-series gangliosides in the PNS, with the backbone structure Gal beta 1-4GlcNAc beta1-3Gal beta 1-4Glc1-1'Cer. Their abundance contrasts with the abundance of ganglio-series gangliosides in the CNS. The neolacto-series gangliosides are localized mainly in the myelins of the PNS. In addition to gangliosides, other acidic and neutral glycosphingolipids in the neolactoseries are also characteristic of the myelins of the PNS. The ceramide (fatty acid and sphingosine base) compositions of gangliosides in the PNS are different from those in the CNS gangliosides, having greater percentages of long-chain fatty acids and dehydrosphingosines than found in the CNS gangliosides.

[Therapeutic plasma exchange 1996]

Therapeutic plasma exchange (TPE) is an extracorporeal blood purification technique to remove large molecular weight substances. Since the late seventies TPE was used in a variety of diseases in which humoral factors may play a part in the pathogenesis. Today, accepted indications only exist for a few entities in defined situations: Anti-glomerular basement membrane antibody mediated disease, TTP/HUS, Guillain-Barré-syndrome, hyperviscosity syndrome, chronic polyneuropathy associated with IgG and IgA gammopathy, chronic inflammatory demyelinating polyneuropathy and myasthenia gravis.

Tumour necrosis factor alpha is elevated in serum and cerebrospinal fluid in multiple sclerosis and inflammatory neuropathies

Tumour necrosis factor alpha (TNFalpha) is a peptide that is derived from T lymphocytes and macrophages and is used as a marker of activated cellular immune responses. TNFalpha was measured in paired sera and cerebrospinal fluid (CSF) from 30 patients with multiple sclerosis (MS) with worsening disability, 54 patients with other neurological diseases, and 20 normal subjects. A sensitive enzyme-linked immunosorbent assay was used to determine the TNFalpha levels. We found significantly elevated serum and CSF levels in 12 (40%) and 6 (20%) MS patients, respectively, compared with healthy controls (P < 0.007 and P < 0.05). Among the 18 patients with neuropathy, we also found high serum and CSF TNFalpha values in 3 (17%) and 5 (28%) patients, respectively (P < 0.04 and P < 0.002). Our study shows that TNFalpha is probably involved in the pathogenetic mechanisms of MS and other inflammatory neurological diseases.

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

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

Immunopathogenesis and treatment of the Guillain-Barré syndrome--Part I

The etiology of the Guillain-Barré syndrome (GBS) still remains elusive. Recent years have witnessed important advances in the delineation of the mechanisms that may operate to produce nerve damage. Evidence gathered from cell biology, immunology, and immunopathology studies in patients with GBS and animals with experimental autoimmune neuritis (EAN) indicate that GBS results from aberrant immune responses against components of peripheral nerve. Autoreactive T lymphocytes specific for the myelin antigens P0 and P2 and circulating antibodies to these antigens and various glycoproteins and glycolipids have been identified but their pathogenic role remains unclear. The multiplicity of these factors and the involvement of several antigen nonspecific proinflammatory mechanisms suggest that a complex interaction of immune pathways results in nerve damage. Data on disturbed humoral immunity with particular emphasis on glycolipid antibodies and on activation of autoreactive T lymphocytes and macrophages will be reviewed. Possible mechanisms underlying initiation of peripheral nerve-directed immune responses will be discussed with particular emphasis on the recently highlighted association with Campylobacter jejuni infection.

Myelin- and microbe-specific antibodies in Guillain-Barré syndrome

We surveyed the frequency of reported infections and target autoantigens in 56 Guillain Barré syndrome (GBS) patients by detecting antibodies to myelin and microbes. Sulfatide (43%), cardiolipin (48%), GD1a (15%), SGPG (11%), and GM3 (11%) antibodies were the most frequently detected heterogenous autoantibodies. A wide spectrum of antimicrobial IgG and IgM antibodies were also detected; mumps-specific IgG (66%), adenovirus-specific IgG (52%), varicella-zoster virus-specific IgG (46%), and S. pneumoniae serotype 7-specific IgG (45%) were the most prevalent. Our results indicate that polyclonal expansion of physiologic and pathologic antibodies and/or molecular mimicry likely occurs following infection and is related to other autoimmune factors in the etiology of GBS. Although no single definitive myelin-specific autoantibody was identified, our results suggest a unique pattern of reactivity against autoantigens.

Guillain-Barré syndrome in pregnancy: reflections on immunopathogenesis

Here we describe the case of a 29-year-old woman, 36 weeks pregnant, with severe Guillain-Barré syndrome who delivered by Caesarean section because of respiratory insufficiency. The detection of high antibody titers to glycolipids of human peripheral nerve myelin in both the mother and the newborn, as well as differences regarding lymphocyte typing and levels of complement components, give rise to some reflections on the immunopathogenesis of this disorder supporting the hypothesis that cell-mediated immunity is the major mechanism in the development of Guillain-Barré syndrome.

Glycosphingolipids of human peripheral nervous system myelins isolated from cauda equina

Compositions of neutral and sulfated glucuronyl glycosphingolipids purified from human motor and sensory nerves and myelins were studied. Higher neutral glycosphingolipids (fraction B), which were separated from GalCer (fraction A), were analyzed by TLC and TLC-immunostaining. Both nerve myelins contained paragloboside (nLc4Cer) and nLc6Cer dominantly as major higher glycosphingolipids and very little globoside (Gb4Cer), whereas both nerves contained Gb4Cer and nLc4Cer. Besides these major glycosphingolipids, a neutral glycolipid containing asialoGM1 (Gg4Cer) epitope and other minor components such as ceramide trihexoside and ceramide dihexoside were detected in both nerves and their myelins. Furthermore, sulfated glucuronyl nLc4Cer and nLc6Cer, which were monoclonal antibody HNK-1 reactive glycolipids, were detected in both nerves and myelins.

Antibody responses to P0 and P2 myelin proteins in Guillain-Barré syndrome and chronic idiopathic demyelinating polyradiculoneuropathy

Immunisation with the peripheral nerve myelin proteins P0 or P2 induces inflammatory neuropathy in animals. We sought antibodies with an ELISA to these proteins in 38 patients with acute Guillain-Barré syndrome (GBS), 32 patients with chronic idiopathic demyelinating polyradiculoneuropathy (CIDP), 31 patients with other neuropathies (ONP) and 26 normal control (NC) subjects. We discovered IgM antibodies to human P0 protein in the sera of 18.5% of the patients with GBS, 15.6% with CIDP, 6.4% with ONP and 3.8% of NC subjects. Of the sera which reacted with P0, sera from 4/7 of GBS, 3/5 of CIDP, 1/2 of ONP patients and 0/1 of NC subjects reacted with a synthetic P0 peptide representing residues 150-169 from the cytoplasmic portion of the molecule. IgG antibodies to P0 were slightly less common than IgM antibodies, being present in only 7.9% of GBS, 0% of CIDP and 3% of ONP patients and 0% of NC subjects. We found antibodies to bovine P2 protein more commonly than antibodies to P0. IgM antibodies were present in 39.5% of GBS, 34.4% of CIDP, 16.1% of ONP patients and 15.4% of NC subjects. IgG antibodies were present in 18.4% of GBS, 12.5% of CIDP, 3.2% of ONP patients and 7.6% of NCs. Of the sera which contained antibodies to P2 protein, only a few reacted with P2 peptides 14-25 or 58-81, but without any consistent pattern of reactivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolated bovine spinal motoneurons have specific ganglioside antigens recognized by sera from patients with motor neuron disease and motor neuropathy

The gangliosides GM1 and GD1b have recently been reported to be potential target antigens in human motor neuron disease (MND) or motor neuropathy. The mechanism for selective motoneuron and motor nerve impairment by the antibodies directed against these gangliosides, however, is not fully understood. We recently investigated the ganglioside composition of isolated bovine spinal motoneurons and found that the ganglioside pattern of the isolated motoneurons was extremely complex. GM1, GD1a, GD1b, and GT1b, which are major ganglioside components of CNS tissues, were only minor species in motoneurons. Among the various ganglioside species in motoneurons, several were immunoreactive to sera from patients with MND and motor neuropathy. One of these gangliosides was purified from bovine spinal cord and characterized as N-glycolylneuraminic acid-containing GM1 [GM1(NeuGc)] by compositional analysis, fast atom bombardment mass spectra, and the use of specific antibodies. Among seven sera with anti-GM1 antibody activities, five sera reacted with GM1(NeuGc) and two did not. Two other gangliosides, which were recognized by another patient's serum, appeared to be specific for motoneurons. We conclude that motoneurons contained, in addition to the known ganglioside antigens GM1 and GD1b, other specific ganglioside antigens that could be recognized by sera from patients with MND and motor neuropathy.

Effects of Guillain-Barré sera containing antibodies against glycolipids in cultures of rat Schwann cells and sensory neurons

Serum samples from 52 patients with the acute Guillain-Barré syndrome (GBS), 19 patients with other neurological disorders, and 18 healthy volunteers were tested for cytotoxicity in cultures of rat Schwann cells and dorsal root ganglion neurons. The samples were also examined by enzyme-linked immunosorbent assay for IgG and IgM antibodies against various acidic and neutral glycolipids. Samples from 16 of the 52 (31%) acute GBS patients and from 1 of the 6 patients with chronic inflammatory demyelinating polyneuropathy produced myelin breakdown in culture. Although 10 of the 16 cytotoxic acute GBS serum samples contained anti-glycolipid immunoglobulins, there was no correlation in individual samples between cytotoxic activity and the presence of antibodies against specific glycolipids. While our results do not exclude a role for anti-glycolipid antibodies in the pathogenesis of the acute GBS, the cytotoxic effects of acute GBS serum in cultures of Schwann cells and sensory neurons are probably not due to these antibodies alone.

The acute paralysis in Guillain-Barré syndrome is related to a Na+ channel blocking factor in the cerebrospinal fluid

The effect of cerebrospinal fluid (CSF) from patients with severe polyradiculoneuritis (Guillain-Barré syndrome, GBS) on voltage-dependent Na+ channels of myoballs was studied. The transient Na+ currents, elicited by repetitive stimulation at 1 Hz, were inhibited by the CSF from most of the GBS patients to 10%-40% the control value. The inhibition was complete in about 5 s and was fully reversible. Such inhibition was never seen with control CSF. The blocking property of the CSF from GBS patients was lost after the number of cells and the protein content had been lowered by means of a clinical filtration technique for cerebrospinal fluid. The results demonstrate that in Guillain-Barré syndrome blocking factors of Na+ channels are present in the CSF, impairing neuron impulse conduction, and thereby causing muscular weakness and sensory disturbances in the affected patient.

Immunointervention with cyclosporin A in autoimmune neurological disorders

Cyclosporin A has proven a remarkably effective compound in suppressing disease activity in a number of animal models of autoimmune neurological disorders. During the last decade a number of controlled clinical trials have been carried out in human neurological disorders which are considered to be immune-mediated. The results of those trials are reviewed.

Antibodies to acidic glycolipids in Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy

Using an enzyme-linked immunosorbent assay and a thin-layer chromatography-immunostaining procedure, we detected serum antibodies against acidic glycolipids in 36 of 53 patients with Guillain-Barré syndrome (GBS) and 8 of 16 patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Although we also found anti-acidic glycolipid antibodies in 4 of 13 patients with other neurological diseases; 2 of 10 patients with multiple sclerosis; 8 of 33 patients with inflammatory, infectious, allergic or autoimmune disorders and 3 of 32 healthy subjects, the levels of antibodies in these controls were much lower than in GBS patients. There were several patterns of reactivity of GBS sera including antibodies to LM1 and HexLM1, GM1 or GD1b or both, various other gangliosides, sulfated glycolipids, and as yet unidentified glycolipids. Sera from 30% of GBS patients had antibodies against two or more antigenically distinct acidic glycolipid antigens. Levels of anti-acidic glycolipid antibodies correlated with clinical symptoms in 9 of 11 GBS patients. While the increased incidence of antibodies to acidic glycolipids in patients with GBS (P less than 0.001) and CIDP (P less than 0.025) compared to controls could be an epiphenomenon, anti-acidic glycolipid antibodies may play a role in nerve injury in some GBS and CIDP patients.

Anti-GM1 antibodies in patients with Guillain-Barré syndrome

Anti-GM1 antibodies were measured in 22 patients with the Guillain-Barré syndrome (GBS) and compared with anti-GM1 antibody activity in patients with other neurological or immunological diseases and in normal subjects. Four out of 22 patients with GBS had raised IgM, IgG, or IgA anti-GM1 antibody activities. All four patients were tetraparetic with only minimal or no sensory deficit. Three of the patients had highly raised antibody activity and showed severe residual deficits, while of the remaining patients with GBS, only one remained severely affected. One patient had anti-GM1 antibodies specific for GM1, whereas the other three patients showed antibody activity with asialo-GM1 or GD1b. The presence of anti-GM1 antibodies may define a subgroup of patients with GBS who have a poor prognosis.

Autoantibodies against Forssman glycolipids in Graves' disease and Hashimoto's thyroiditis

Sera from patients with Graves' disease and Hashimoto's thyroiditis have been shown to react with the Forssman glycolipid antigen (Gb5) using the techniques of high performance thin-layer chromatography (HPTLC) immunostaining and ELISA. Human monoclonal antibodies (MoAbs) have been prepared by fusion of human myeloma with peripheral lymphocytes from patients with Graves' disease. A MoAb, TRMo-4, reacted strongly and specifically with Gb5. These results suggest that anti-Forssman antibody may be involved in the pathogenesis of these autoimmune diseases. The detection of anti-Forssman glycolipid antibody may provide a useful means for clinical diagnosis and therapy.

Antibodies to sulfated glycolipids in Guillain-Barré syndrome

Sera from 53 patients with acute Guillain-Barré syndrome (GBS), 15 patients with chronic inflammatory demyelinating polyneuropathy (CIDP), 13 patients with other neurological diseases (OND) and 31 healthy controls were tested for IgM and IgG antibodies to sulfoglucuronyl paragloboside (SGPG) and sulfatide by both an ELISA and a thin-layer chromatogram-overlay technique. Although the mean levels of anti-SGPG or anti-sulfatide antibodies in GBS patients were not elevated compared to controls, the occurrence of anti-SGPG antibodies was more frequent in GBS patients than in controls (P less than 0.02). Acute GBS patients with antibodies to SGPG or sulfatide were clinically indistinguishable from other GBS patients. Our data suggest that elevated levels of antibodies to SGPG could be important in the pathogenesis of neuropathy in some GBS patients.

Induction of demyelination by intraneural injection of antibodies against sulfoglucuronyl paragloboside

Sulfoglucuronyl glycolipids (SGGLs) carry the glucuronyl 3-sulfate (HNK-1) epitope which is recognized by monoclonal IgM paraproteins from patients with demyelinating polyneuropathy. We report that intraneural injections of rat anti-SGGL antibodies induce demyelination in rat sciatic nerve, along with mild to moderate clinical symptoms. Morphologically, vesiculation and loosening of the myelin sheath were observed 3 h postinjection, followed by extensive demyelination and macrophage infiltration after 4 days. Since the anti-SGGL antibodies showed no cross-reactivity with other components in rat sciatic nerve, these results indicate that SGGLs alone can serve as the target antigens in demyelinating neuropathy.

Clinical and serological studies in a series of 45 patients with Guillain-Barré syndrome

We retrospectively reviewed the clinical files of 45 Guillain-Barré syndrome (GBS) patients admitted to our Department between 1979 and 1989. The age distribution was bimodal with a first peak in young adults (20-40 years), and a second one between 60 to 70 years. Seasonal distribution showed a late fall and a hivernal predominance. Three patients experienced a second attack of GBS 2-9 years after the first one. Thirty-one (69%) presented antecedent events, most often a respiratory tract infection (n = 20) or enteritis (n = 6). Serological studies were systematically performed, including antibody titers against herpes simplex virus, Epstein-Barr virus, cytomegalovirus (CMV), respiratory syncytial virus, human immunodeficiency virus, Mycoplasma pneumoniae, Campylobacter jejuni/coli and cardiolipin. These studies showed the presence of antibodies indicative of a CMV primary infection in 22% cases and of a Campylobacter jejuni/coli infection in 13%. Co-infection was observed in 3 cases. Serology remained negative in 12 patients with a preceding respiratory infection. There was no correlation between serology and the severity of the disease. Absence of antecedent events and of positive anti-infectious serology was observed in only 10 patients.

Serum interleukin-2 concentrations in Guillain-Barré syndrome and chronic idiopathic demyelinating polyradiculoneuropathy: comparison with other neurological diseases of presumed immunopathogenesis

Serum concentrations of the cytokine interleukin-2 (IL-2) were quantitated by enzyme-linked immunosorbent assay in 42 patients with Guillain-Barré syndrome, 15 patients with chronic idiopathic demyelinating polyradiculoneuropathy, 37 patients with other neuropathies, 54 patients with other noninflammatory, nondemyelinating neurological disorders, and 26 healthy control subjects. We found markedly increased serum levels of IL-2 in patients with Guillain-Barré syndrome and to a much lesser extent, in patients with chronic idiopathic demyelinating polyradiculoneuropathy. Increased serum concentrations of IL-2 in patients with Guillain-Barré syndrome returned to normal in parallel with recovery from the disease. These findings suggest ongoing T-cell proliferation in patients with Guillain-Barré syndrome and some patients with chronic idiopathic demyelinating polyradiculoneuropathy. IL-2 levels were also raised in patients with active multiple sclerosis, myasthenia gravis, and herpes simplex encephalitis, and some patients with polymyositis, invoking T cells in the pathogenesis of these diseases.

Guillain-Barré syndrome associated with idiopathic thrombocytopenic purpura

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Serum antibodies to GM1 and GM3-gangliosides in systemic lupus erythematosus with chronic inflammatory demyelinating polyradiculoneuropathy

Acute symmetric demyelinating polyneuropathy of the Guillain-Barré type is known in systemic lupus erythematosus (SLE). Chronic idiopathic demyelinating polyneuropathy (CIDP) has been reported rarely with SLE. A case is reported of CIDP accompanying SLE with autoantibodies against GM1- and GM3-gangliosides. There was no historical evidence to suggest SLE, and CIDP was the first manifestation of SLE. The 38-year-old patient had elevated CSF-protein, slow nerve conduction velocities, sural nerve biopsy revealed mixed axon loss with demyelination and CIDP white matter lesions were observed in magnetic resonance imaging, the GM1- and GM3-autoantibodies may play a role in the pathogenesis of CIDP in SLE.

IgG from amyotrophic lateral sclerosis affects tubular calcium channels of skeletal muscle

Amyotrophic lateral sclerosis (ALS) is a devastating human disease of upper and lower motoneurons. We studied the action of the immunoglobulin G (IgG) from ALS and disease control patients on dihydropyridine (DHP)-sensitive Ca2+ channels in single mammalian skeletal muscle fibers with the double Vaseline gap technique. The peak of the Ca2+ current (ICa) and the charge movement were reduced when the fibers were incubated in ALS IgG. These effects were lost when the IgG was boiled or adsorbed with skeletal tubular membranes. ALS IgG reduced skeletal muscle ICa in a similar fashion as nifedipine; the ICa blockade was voltage dependent, and the associated charge movement was reduced. These observations suggest that IgG from ALS patients reacts with the skeletal muscle DHP-sensitive Ca2+ channels or some associated regulatory moiety.

Plasma C3c in immune-mediated neurological diseases: a preliminary report

Plasma C3c levels were examined in 56 patients with immune (27) and non-immune (29) mediated neurological diseases by crossed immunoelectrophoresis. Plasma samples were collected during the active phase of illness in both groups, usually within 7 days of admission. 11 patients (4 Guillain-Barré Syndrome-GBS, 3 chronic inflammatory demyelinating polyneuropathy-CIDP, 4 myasthenia gravis-MG) had their plasma saved sequentially during the active and the recovery phase. Plasma C3c levels were elevated in the group with immune mediated diseases when compared with those of non-immune mediated diseases. The sensitivity and specificity of C3c as a diagnostic test for immune mediated neurological diseases were 61.4 and 100% respectively with a positive and negative predictive value of 100 and 41%. the C3c levels in plasma correlated well with disease severity in MG and GBS patients. Such a correlation was also evident in all CIDP patients except one that had persistent elevation in the presence of clinical improvement. Results suggest that the plasma C3c level may be useful for differentiating immune from non-immune mediated neurological diseases. Plasma C3c may also be used for monitoring disease severity, particularly in myasthenia gravis.

In vitro demyelination by serum antibody from patients with Guillain-Barré syndrome requires terminal complement complexes

Serum from 7 patients who had acute-phase Guillain-Barré syndrome with high anti-peripheral nerve myelin antibody activity (54 to 210 units/ml) was compared with serum from 3 patients in the recovery phase (0 to 17 units/ml) and serum from 7 disease control subjects (0 to 24 units/ml) and 7 normal control subjects (0 to 7 units/ml) for its ability to demyelinate rodent dorsal root ganglion cultures. The demyelinating capacity of each serum was quantitated by counting the percent of damaged internodal segments in each of four cultures. All sera from patients in the acute phase GBS caused 50 to 78% demyelination, in contrast with 6 to 19% by the sera from all 3 patients in the recovery phase and all other control subjects. The degree of demyelination correlated with anti-peripheral nerve myelin antibody activity of the sera and demyelination was complement-dependent. Further, cultures were treated with an immunoglobulin M (IgM) fraction of an acute-phase Guillain-Barré syndrome plasma plus normal human serum depleted of complement component C7. Only those cultures treated with IgM and C7-depleted human serum reconstituted with purified C7 resulted in 50.8% demyelination, which was significantly greater than the 14.2 to 16.2% demyelination observed in the presence of heat-inactivated, C7-depleted human serum plus purified C7 or in the absence of C7 or antibody. In summary, our work suggests that anti-peripheral nerve myelin antibody in Guillain-Barré syndrome mediated complement dependent-demyelination of rodent dorsal root ganglion cultures. Further, this in vitro demyelination required generation of activation complexes of the terminal complement cascade.

Antibodies in sera from patients with inflammatory demyelinating polyradiculoneuropathy react with ganglioside LM1 and sulphatide of peripheral nerve myelin

Sera from 23 patients with acute Guillain Barré syndrome (GBS), 15 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and from 40 age-matched blood donors were analysed for antibodies to acidic glycosphingolipids from human brain and peripheral nerve. Antibodies to ganglioside LM1, the major ganglioside of peripheral nerve myelin. were found in 43% of GBS and in 67% of CIDP patients' sera, and in 20% of the blood donors. However, antisulphatide antibodies were detected in 65% and 87% of the sera from GBS and CIDP patients, respectively, but only in 15% of the control sera. Sulphatide is the major acidic glycosphingolipid in myelin and its concentration in peripheral nerve myelin is 100 times higher than that of LM1. The high frequency of LM1 and, in particular of sulphatide antibodies, might thus be relevant to the pathogenesis of the GBS and CIDP.

Search for antibodies to neutral glycolipids in sera of patients with Guillain-Barré syndrome

Sera from 54 patients with Guillain-Barré syndrome (GBS), 34 patients with other neurological diseases (OND) and 32 healthy controls were tested for antibodies to total lipid fractions and higher neutral glycolipid fractions isolated from human and dog nerves, purified Forssman glycolipid and a panel of purified neutral glycolipids by both an enzyme-linked immunosorbent assay (ELISA) and a thin-layer chromatogram (TLC)-overlay technique. IgM and IgG antibodies to total lipid fractions, as well as to galactocerebroside, ceramide dihexoside, ceramide trihexoside, and globoside were not significantly elevated in the sera of GBS patients as compared to controls. High levels of anti-asialo-GM1 IgG antibodies, however, were detected in 6 of 54 (11%) GBS patients and 1 of 30 (3%) OND patients. Intense reactivity with purified Forssman glycolipid and a number of glycolipid antigens in higher neutral glycolipid enriched fractions of human cauda equina and dog sciatic nerves was noted by TLC-immunostaining in many GBS and control sera. Although the levels of anti-Forssman IgM were significantly decreased in GBS sera compared with normal sera (P less than 0.05) and OND sera (P less than 0.02), the levels of anti-Forssman IgG antibodies were not significantly different. With the possible exception of IgG antibodies to asialo-GM1, our results suggest that serum antibodies against Forssman glycolipid and neutral glycolipids are not significantly elevated in GBS patients and, thus, are unlikely to play an important role in the pathogenesis of this disease.