ganglioside--gd1b and Autoimmune-Diseases-of-the-Nervous-System

Antiglycolipid antibody titers are frequently elevated in the serum of patients with autoimmune neuropathies. Some antibodies may be involved in the pathogenesis because glycolipids are surface antigens in the nervous system. Sensory ataxic neuropathy was induced in rabbits sensitized with GD1b ganglioside, which is localized in the rabbit primary sensory neurons of the larger cytoplasms. Systemic infusion of high-titer anti-GD1b antiserum to rabbits pre-inoculated with adjuvant caused vacuolar degeneration with macrophage infiltration in a few axons in the dorsal column of the spinal cord. Anti-GD1b antibody therefore may cause degeneration in rabbit sensory neurons with central axons extending to the dorsal column. Investigations on the clinical features of GBS patients with monospecific anti-GD1b IgG antibodies showed that the antibodies are associated with sensory disturbance, especially disturbance in the deep sensation, and with primary demyelinating form. GD1b is localized in primary sensory neurons and paranodal myelin in the human peripheral nervous system. Monospecific anti-GD1b IgG antibodies may bind to those regions and be involved in the pathogenesis of sensory disturbance and demyelination. Thus, some antiglycolipid antibodies may determine the clinical features of GBS by binding to the regions where the antigens are localized.

Topics: Animals; Antigens, Surface; Autoantibodies; Autoimmune Diseases of the Nervous System; Gangliosides; Glycolipids; Humans; Immunoglobulin G; Peripheral Nervous System Diseases

Antibodies to the ganglioside GD1b have been reported in various forms of immune-mediated neuropathy, but their clinical relevance for diagnosis and prognosis is unknown. We investigated the prevalence of anti-GD1b antibodies in acute and chronic immune-mediated neuropathies, and the clinical presentation and outcome in Guillain-Barré syndrome (GBS) and Miller Fisher-GBS overlap syndrome (MF-GBS). Anti-GD1b, anti-GM1 and anti-GQ1b antibodies were tested in serum of patients with GBS (N = 165), Miller Fisher syndrome (N = 10), MF-GBS (N = 28), monoclonal gammopathy of unknown significance neuropathy (MGUS; N = 101), chronic inflammatory demyelinating polyneuropathy (N = 29), paraneoplastic syndrome with anti-Hu-associated neuropathy (PNS; N = 11), other auto-immune diseases (AID; N = 60), and healthy controls (HC; N = 60). All samples were tested by enzyme-linked immunosorbent assay according to the Inflammatory Neuropathy Cause and Treatment protocol. IgM anti-GD1b antibodies were found in GBS (N = 4; 2.4%), MGUS (N = 3; 3.0%), and PNS patients (N = 1; 9.1%). IgG anti-GD1b antibodies were found in GBS (N = 20; 12.1%) and MF-GBS (N = 4; 14.3%) patients, but not in the AID and HC group. In the combined group of MF-GBS and GBS patients ((MF-)GBS), 14/36 (38.9%) patients with IgG anti-GD1b antibodies also had IgG anti-GM1 antibodies, and IgG anti-GD1b and IgG anti-GQ1b antibodies were found in 3/29 (10.3%) patients. Patients with (MF-)GBS and anti-GD1b without anti-GM1 antibodies did not differ regarding sensory disturbances or disease severity but recovered faster regarding the ability to walk independently compared with patients without anti-GD1b antibodies (P = 0.031) and with patients with both anti-GD1b and anti-GM1 antibodies (P = 0.034). In conclusion, testing for anti-GD1b antibodies may identify a specific group of immune-mediated neuropathies and (MF-)GBS patients with only anti-GD1b antibodies tend to recover faster.

Topics: Adult; Aged; Autoantibodies; Autoantigens; Autoimmune Diseases of the Nervous System; G(M1) Ganglioside; Gangliosides; Guillain-Barre Syndrome; Humans; Immunoglobulin G; Immunoglobulin M; Lupus Erythematosus, Systemic; Middle Aged; Miller Fisher Syndrome; Monoclonal Gammopathy of Undetermined Significance; Paraneoplastic Polyneuropathy; Polyradiculoneuropathy, Chronic Inflammatory Demyelinating; Sjogren's Syndrome

Antibodies against several neural antigens have been associated with different chronic immune-mediated neuropathies but their practical clinical relevance remains unclear. To determine the possible diagnostic usefulness of these antibodies we reviewed the clinical correlate of IgM antibodies to the myelin-associated glycoprotein (MAG), sulfatide, the gangliosides GM1, GM2, GD1a and GD1b in 539 consecutive patients examined for neuropathy or related diseases in our Neuropathy Clinics and tested for these antibodies in our laboratory since 1985. 302 patients (56%) had an established diagnosis of definite or possible chronic immune-mediated neuropathy while 237 had a neuropathy of non-immune-mediated origin or of unknown aetiology or a closely related disease. Antibodies to one or more antigen were more frequent (chi(2)=63.32; p<0.00001) in patients with chronic immune-mediated neuropathy (37.7%) than with other neuropathy or related diseases (7.2%) and their presence was associated in 87% of the patients with an immune-mediated neuropathy, incrementing by 31% the probability of having this form. Testing for MAG permitted to identify 24.8% of patients with an immune-mediated neuropathy, GM1 an additional 9.9%, while GM2, GD1b, GD1a and sulfatide altogether an additional 3% of the patients. Concerning clinical correlations, all 75 patients with anti-MAG IgM had neuropathy and IgM monoclonal gammopathy (PN+IgM) with a positive predictive value for this neuropathy of 100%. A similarly high predictive value for neuropathy (91.4%) was observed among 269 patients with IgM monoclonal gammopathy including 103 patients without neuropathy. Anti-sulfatide IgM, though rare, were also significantly and constantly associated with PN+IgM and permitted to identify few patients not bearing anti-MAG IgM. Anti-GM1 IgM were significantly associated with multifocal motor neuropathy (MMN) (29.2%) but where also found in a few patients with other immune or non-immune neuropathies or related diseases with a positive predictive value for MMN of 25.5%. Anti-GM2 IgM were also significantly associated with MMN and increased the sensitivity (36.2%) for MMN obtained with anti-GM1 IgM only, without affecting its specificity and positive predictive value. Anti-GD1a, GD1b, though not significantly more frequent in patients with immune-mediated neuropathy, were associated in 80 to 100% of patients with these neuropathies. In conclusion anti-neural IgM antibodies may help in identifying patie

Topics: Antibody Specificity; Autoimmune Diseases of the Nervous System; Enzyme-Linked Immunosorbent Assay; G(M1) Ganglioside; G(M2) Ganglioside; Gangliosides; Humans; Immunoblotting; Immunoglobulin M; Myelin-Associated Glycoprotein; Paraproteinemias; Retrospective Studies; Sulfoglycosphingolipids

Recent years have seen major progress in our understanding of the clinical pathophysiology of autoimmune neuropathies particularly with the identification and analysis of antibodies to gangliosides and related glycolipids in the serum of patients. Anti-glycolipid antibodies react with epitopes on the carbohydrate region of glycolipid molecules and can be routinely measured by standard immunoassays. In multifocal motor neuropathy, IgM anti-GM1 antibodies that cross react with GD1b and asialo-GM1 are detectable in around 50p. 100 of cases. This condition may clinically resemble certain forms of lower motor neurone disease. IgM anti-GD1b antibodies are found in IgM paraproteinaemic neuropathy characterised by profound sensory ataxia. In the anti-myelin associated glycoprotein (anti-MAG) IgM paraproteinaemic neuropathy, antibodies also react with the acidic glycolipids, sulphated glucuronyl paragloboside and its higher lactosaminyl homologue (SGPG and SGPLG). Thus a variety of chronic syndromes can be defined by their anti-glycolipid antibody profile. In Guillain-Barré syndrome, anti GM1, GM1b, GD1a and GalNAc-GD1a antibodies are found in patients with acute motor axonal neuropathy (AMAN) and anti-GQ1b IgG antibodies are a very sensitive and specific marker for the Miller Fisher syndrome. Many other anti-glycolipid antibodies are being increasingly identified in other neuropathy subtypes. The article will summarise existing clinical and serological information in this field.

Topics: Acute Disease; Antibodies; Autoimmune Diseases of the Nervous System; beta-Galactosidase; Chronic Disease; Gangliosides; Globosides; Humans