Motoi Kuwahara

Characterization of IgG4 anti-neurofascin 155 antibody-positive polyneuropathy.

To investigate anti‐neurofascin 155 (NF155) antibody‐positive chronic inflammatory demyelinating polyneuropathy (CIDP).

Antibodies to LM1 and LM1-containing ganglioside complexes in Guillain–Barré syndrome and chronic inflammatory demyelinating polyneuropathy

LM1 is localized in human peripheral nerve myelin. Antibodies to ganglioside complexes (GSCs) have been reported in Guillain-Barré syndrome (GBS). We investigated IgG antibodies to LM1 and two GSCs (GM1 and LMI, or GD1b and LM1) in the sera of each 40 patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and GBS, using ELISA. We detected anti-LM1 antibody in five with GBS and seven with CIDP; anti-GM1/LM1 antibody in three with GBS and one with CIDP; and anti-GD1b/LM1 antibody in two with CIDP. Antibodies to LM1 and LM1-containing GSCs may be among the targets for autoimmunity in GBS and CIDP.

Clinical features of CIDP with LM1-associated antibodies

Background LM1 is the predominant glycolipid in human peripheral nerve myelin and antibodies to LM1 and LM1-containing ganglioside complexes are detected in some patients with chronic inflammatory demyelinating polyneuropathy (CIDP). The clinical features of patients with such antibodies have not yet been investigated. Methods Serum antibodies to LM1, a mixture of GM1 and LM1 (GM1/LM1), and that of GD1b and LM1 (GD1b/LM1) were examined in 75 consecutive patients with CIDP. The clinical features of the CIDP patients with such antibodies in the present series and those in the previous reports were investigated and compared with those of antibody-negative patients. Results Of the 75 patients with CIDP, two had antibodies to LM1, three had anti-GM1/LM1 complex antibody, one had anti-GD1b/LM1 complex antibody and two had antibodies to both the GM1/LM1 and GD1b/LM1 complexes. Patients with the LM1-associated antibodies did not have cranial nerve deficits (p<0.05) and exhibited ataxia more frequently than the antibody-negative patients (p<0.01). Conclusion In humans, LM1 is contained more in the dorsal root than in the cranial nerves. The clinical features of CIDP patients with antibodies to LM1 and LM1-containing complexes may be associated with the distribution of the LM1 antigen. LM1-associated antibodies are possible markers for a subclass of CIDP.

An antibody to the GM1/GalNAc-GD1a complex correlates with development of pure motor Guillain-Barré syndrome with reversible conduction failure.

Antibodies to a ganglioside complex consisting of GM1 and GalNAc-GD1a (GM1/GalNAc-GD1a) are found in sera from patients with Guillain-Barré syndrome (GBS). To elucidate the clinical significance of anti-GM1/GalNAc-GD1a antibodies in GBS, clinical features of 58 GBS patients with IgG anti-GM1/GalNAc-GD1a antibodies confirmed by enzyme-linked immunosorbent assay and thin layer chromatography immunostaining were analyzed. Compared to GBS patients without anti-GM1/GalNAc-GD1a antibodies, anti-GM1/GalNAc-GD1a-positive patients more frequently had a preceding respiratory infection (n=38, 66%, p<0.01) and were characterized by infrequency of cranial nerve deficits (n=9, 16%, p<0.01) and sensory disturbances (n=26, 45%, p<0.01). Of the 28 anti-GM1/GalNAc-GD1a-positive patients for whom electrophysiological data were available, 14 had conduction blocks (CBs) at intermediate segments of motor nerves, which were not followed by evident remyelination. Eight of 10 bedridden cases were able to walk independently within one month after the nadir. These results show that the presence of anti-GM1/GalNAc-GD1a antibodies correlated with pure motor GBS characterized by antecedent respiratory infection, fewer cranial nerve deficits, and CBs at intermediate sites of motor nerves. The CB may be generated through alteration of the regulatory function of sodium channels in the nodal axolemma.

Refractory acute disseminated encephalomyelitis with anti-galactocerebroside antibody

Acute disseminated encephalomyelitis causes multifocal demyelination in the central nerve system. Although this disease generally responds well to steroid therapy, it is occasionally steroid-resistant, leading to poor outcomes. Serological markers of prognosis are currently unavailable. We measured anti-glycolipid antibodies in 25 consecutive patients with acute disseminated encephalomyelitis, and found that four patients were positive for anti-galactocerebroside antibodies. All four patients had a poor response to steroids. We summarize clinical information on these four patients and three similar patients reported previously. This is the first report to describe concomitant involvement of the central nerve system and peripheral nervous system in anti-galactocerebroside antibody-associated acute disseminated encephalomyelitis, consistent with the location of galactocerebroside, and to document a dramatic response to repeated intravenous immunoglobulin therapy after unsuccessful steroid treatment in one patient.

Characterization of the neurological diseases associated with Mycoplasma pneumoniae infection and anti-glycolipid antibodies

Mycoplasma pneumoniae infection often causes various neurological complications of both the central nervous system (CNS) and the peripheral nervous system. We retrospectively investigated the IgM and IgG antibodies to nine glycolipids [GM1, GM2, GM3, GD1a, GD1b, GD3, GT1b, GQ1b, and Gal-C (galactocerebroside)] and clinical features in neurological diseases associated with M. pneumoniae infection diagnosed in multiple hospitals throughout Japan between September 2010 and March 2012. Of the 46 patients with neurological diseases associated with M. pneumoniae infection, 27 were diagnosed with Guillain–Barré syndrome (GBS), 2 with Fisher syndrome (FS), 16 with CNS diseases, and 1 with both GBS and CNS disease. Anti-Gal-C IgM and IgG antibodies were most frequently detected (23/46, 50%). Patients with CNS diseases were younger than patients with GBS or FS, and IgM antibodies to Gal-C were more frequently detected in the patients with CNS diseases (41%) than in those with GBS or FS (13%). Of the nine patients who were positive for anti-Gal-C IgM antibody but lacked IgG antibody, we found the class-switch of anti-Gal-C antibody from IgM to IgG in two patients. The IgG antibodies appeared during their recovery phase, and the IgG belonged to the IgG1 subclass. Anti-Gal-C antibodies are closely associated with neurological diseases after M. pneumoniae infection. Particularly, anti-Gal-C IgM antibody is more frequently detected in younger patients affected with CNS involvement. The class-switch from IgM to IgG sometimes occurs in anti-Gal-C antibodies.

Details of Treatment-Related Difficulties in Men with Anti-N-Methyl-d-Aspartate Receptor Encephalitis

Anti-N-methyl-d-aspartate receptor (anti-NMDAR) antibody-associated encephalitis is an immunologic disease characterized by a female preponderance. Males are infrequently affected. The clinical symptoms of affected boys as well as girls have been summarized, and they have some clinical features distinct from those of adults. However, the characteristics of men have been described in only a few reports. We describe in detail four men with anti-NMDAR encephalitis who presented with several clinical features that complicated disease management and recovery, including venous thrombosis, bilateral hippocampal involvement, hypersexuality, and joint contracture. We also report the first detailed clinical information about a male patient who died of this disease. In addition, we summarize the clinical characteristics of five patients previously reported by others.

Serological study using glycoarray for detecting antibodies to glycolipids and glycolipid complexes in immune-mediated neuropathies

We performed a serological investigation using glycoarray in Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and multifocal motor neuropathy (MMN). Antibodies to 10 glycolipids and 45 glycolipid complexes were tested. Anti-GM1/sulfatide and anti-GA1/sulfatide IgG antibodies were common in GBS (20.0% and 19.0%, respectively). Anti-GQ1b/sulfatide IgG antibody was detected in 14.0% of GBS patients. IgG antibodies to antigens containing GQ1b were significantly correlated with ophthalmoplegia in GBS (p<0.01). IgM antibodies to antigens containing GM1 or GalNAc-GD1a were in 50% and 37.5% of MMN patients, respectively. Glycoarray is efficient for detecting antibodies against numerous glycolipid complexes in immune-mediated neuropathies.

Binding specificity of anti-HNK-1 IgM M-protein in anti-MAG neuropathy: Possible clinical relevance

Anti-myelin-associated-glycoprotein (MAG) neuropathy is an intractable autoimmune polyneuropathy. The antigenic region of MAG is the human natural killer-1 (HNK-1) carbohydrate. We and others previously suggested that the extension of antibody reactivities to HNK-1-bearing proteins other than MAG was associated with treatment resistance, without statistical analyses. In this study, we established an ELISA method with recombinant proteins to test binding specificities of currently available monoclonal antibodies to MAG and another HNK-1-bearing protein, phosphacan. Using this system, we found the distinct binding specificities of anti-MAG antibody in 19 patients with anti-MAG neuropathy. Their clinical relevance was then determined retrospectively with the adjusted 10-points INCAT disability score (0 = normal and 10 = highly disable). The results showed that strong reactivities of anti-MAG antibodies to phosphacan were significantly associated with treatment resistance or progressive clinical courses, indicating a possible clinical relevance of the binding specificities.

Electrophysiological assessment of Guillain-Barré syndrome with both Gal-C and ganglioside antibodies; tendency for demyelinating type

Whether patients who have GBS with antibodies to galactocerebroside (Gal-C) and gangliosides (Gal-C-GS-GBS) more often have demyelinating or axonal neuropathy remains controversial. We assessed the electrophysiological data from 16 patients with Gal-C-GS-GBS based on the two established criteria to clarify this issue. In this largest cohort of Gal-C-GS-GBS, eight patients had demyelinating neuropathy and none exhibited axonal neuropathy on either criterion. These data indicated that antibodies to Gal-C, a myelin antigen, might predominantly be associated with demyelinating neuropathy, even in the presence of concomitant antibodies to gangliosides.