Yukihiro Hamada

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.

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.

Ganglionic acetylcholine receptor autoantibodies in patients with Guillain-Barré syndrome.

OBJECTIVES Although standardized autonomic tests are useful for diagnosing autonomic failure in patients with Guillain-Barré syndrome (GBS), they cannot be used as predictive markers. Thus, serological markers may correctly identify patients with GBS who are at risk for autonomic dysfunction. METHODS We validated a luciferase immunoprecipitation system that detects IgG antibodies in patient serum that specifically bind to the α3 or β4 subunits of ganglionic neuronal nicotinic acetylcholine receptors (gAChR). We then used luciferase-conjugated ligands specific to antibodies against two gAChR subunits to test 79 sera samples from patients with GBS, 34 from subjects with other neurological diseases (OND), and 73 from healthy controls (HC). 1) In the first analysis, patients were classified into two groups according to the presence or absence of autonomic symptoms (AS). We compared the frequency of the anti-gAChR antibodies between these two groups (AS+ and AS-). 2) In the second analysis, furthermore, patients were classified depending on the presence or absence of anti-glycolipid antibodies (AGA). We compared the frequency of the anti-gAChR antibodies between the four categories of GBS (AS+/AGA+, AS+/AGA-, AS-/AGA+, and AS-/AGA-), OND, and HC. RESULTS Eight subjects with GBS were positive for α3 subunits, while one was positive for β4 subunits. Anti-α3 and -β4 gAChR antibodies were also detected in 13.6% of AS+ GBS group in the first analysis. Two of 35 patients in AS-GBS group were seropositive for the anti-gAChR antibodies and AGA in the second analysis. Patients with GBS that were positive for serum antibodies to the α3 and/or β4 subunits of gAChRs showed a range of clinical features including AS and AGA. CONCLUSIONS Patients with GBS may have circulating antibodies against gAChR, which may contribute to the autonomic dysfunction associated with this disease.

Motor-dominant polyneuropathy due to IgM monoclonal antibody against disialosyl gangliosides in a patient with mantle cell lymphoma

A rapidly progressive motor-dominant neuropathy associated with IgM monoclonal antibody against gangliosides with disialosyl residues, GD3, GD1b, GT1b, and GQ1b, in a 60-year-old Japanese man with mantle cell lymphoma is reported. Plasma exchange and chemotherapy for mantle cell lymphoma were performed for the neuropathy and mantle cell lymphoma. After therapy, the motor neuropathy dramatically improved concurrently with substantial reduction of the antibody activities especially in reaction to GD1b. This is the first case report of neuropathy with anti-disialosyl IgM antibodies associated with mantle cell lymphoma, and plasma exchange and chemotherapy were effective.

Diagnosis of Parkinson’s disease and the level of oxidized DJ-1 protein

Parkinsons disease (PD) is difficult to distinguish from progressive supranuclear palsy (PSP) and multiple system atrophy (MSA); in addition, biomarker studies in PD mostly focused on those found in the cerebrospinal fluid, and there are few reports of simple biomarkers identified by blood analysis. Previously, the DJ-1 gene was identified as a causative gene of familial PD. Oxidized DJ-1 protein (oxDJ-1) levels were reported to increase in the blood of patients with unmedicated PD. Therefore, we determined the levels of oxDJ-1 in the erythrocytes of patients with PD, PSP, and MSA using ELISA. The oxDJ-1 levels were 165±117, 96±78, and 69±40ng/mg protein in the PD, PSP, and MSA groups, respectively. The mean level in disease control group was 66±31, revealing significant differences between the PD and PSP groups, the PD and MSA groups, and the PD and disease control groups. Our results indicated that oxDJ-1 levels in erythrocytes can be used as a marker for the differential diagnosis of PD.

Circadian expression and specific localization of a sialyltransferase gene in the suprachiasmatic nucleus.

Polysialic acids are implicated in various biological processes such as neural cell migration, axonal growth, synaptogenesis and resetting of the circadian rhythm. Recently, polysialation has been reported to be involved in the formation and resetting of the circadian clock. However, the genes that control the circadian rhythm of polysialation have not been elucidated. In the present study, we investigated the expression profile of ST8 alpha-N-acetyl-neuraminide alpha-2,8-sialyltransferase 6 (ST8Sia VI) in the suprachiasmatic nucleus (SCN), which is one of the modification transferases that add sialic acids to type O carbohydrate chains. ST8Sia VI mRNA showed strong expression in the SCN with dynamic circadian rhythm. Further, the amount of ST8Sia VI mRNA in the SCN was increased by brief light exposure. Interestingly, the localization of ST8Sia VI mRNA in the SCN differs from those of arginine vasopressin and vasoactive intestinal peptide mRNAs, which are typical SCN subregion markers showing shell and core, dorsomedial and ventrolateral, or light-responsive and unresponsive regions, respectively. The present findings suggest that ST8siVI is involved in rhythmic polysialation in the SCN and that ST8siVI expression provides a novel compartmentation of the mammalian circadian center.