Suppression of synaptic plasticity by cerebrospinal fluid from anti-NMDA receptor encephalitis patients
Department of Physiology, Kanazawa Medical University, Ishikawa, Japan. Neurobiology of Disease
(Impact Factor: 5.08).
01/2012; 45(1):610-5. DOI: 10.1016/j.nbd.2011.09.019
The functional effects of cerebrospinal fluid (CSF) from patients with anti-NMDA receptor (NMDAR) encephalitis on the NMDAR-mediated synaptic plasticity were evaluated by using mouse hippocampus slices. Anti-NMDAR antibody detection system was established by immunostaining recombinant NMDAR heteromers expressed in HEK cell culture as well as native NMDARs in cultured hippocampal neurons. Under a complete blind manner for the clinical information, CSF and sera collected from 36 pre-diagnosed patients were tested for anti-NMDAR antibodies. With this test, thirteen patients were diagnosed as anti-NMDAR encephalitis. CSF positive for anti-NMDAR antibodies suppressed induction of long-term potentiation (LTP) at Schaffer collateral-CA1 synapses in mouse hippocampal slices. LTP induction was not suppressed by CSF collected from herpes simplex virus (HSV) encephalitis or non-encephalitis control patients. Antibody absorption with NMDAR-expressing HEK cell culture reversed the suppression of LTP by anti-NMDAR encephalitis patients' CSF, confirming that anti-NMDAR antibodies suppressed LTP. The present experiments firmly support the proposal that the anti-NMDAR encephalitis autoantibody is responsible for cognitive disorders like amnesia accompanying this disease.
Available from: jstage.jst.go.jp
- "(A) Patient's IgG. The patient was a 33-year-old woman who showed psychosis, involuntary movements, convulsions and hypoventilation, and was proven to have a high titer of an anti-NMDAR antibody (×16,000), using a method previously reported (Zhang et al. 2012). (B) Control human IgG. "
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ABSTRACT: Autoimmune synaptic encephalitis is characterized by the presence of autoantibodies against synaptic constituent receptors and manifests as neurological and psychiatric disorders. Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is such an autoimmune disorder that predominantly affects young women. It is associated with antibodies against the extracellular region of the NR1 subunit of postsynaptic NMDAR. Each NMDAR functions as a heterotetrameric complex that is composed of four subunits, including NR1 and NR2A, NR2B, or NR2C. Importantly, ovarian teratoma is a typical complication of anti-NMDAR encephalitis in female patients and may contain antigenic neural tissue; however, antigenic sites remain unknown in female patients without ovarian teratoma. The purpose of this study was to investigate the expression of NMDARs in the ovum. We detected NR1 and NR2B immunoreactivity in protein fractions extracted from the bovine ovary and ova by SDS-polyacrylamide gel electrophoresis and immunoblotting analysis. Immunoprecipitates digested with trypsin were analyzed by reverse phase liquid chromatography coupled to tandem mass spectrometry. We obtained the following five peptides: SPFGRFK and KNLQDR, which are consistent with partial sequences of human NR1, and GVEDALVSLK, QPTVAGAPK, and NEVMSSK, which correspond to those of NR2A, NR2B and NR2C, respectively. Immunocytochemical analysis revealed that the bovine ovum was stained with the immunoglobulin G purified from the serum of a patient with anti-NMDAR encephalitis. Taken together, we propose that the normal ovum expresses NMDARs that have strong affinity for the disease-specific IgG. The presence of NMDARs in ova may help explain why young females without ovarian teratomas are also affected by anti-NMDAR encephalitis.
The Tohoku Journal of Experimental Medicine 03/2015; 235(3):223-31. DOI:10.1620/tjem.235.223 · 1.35 Impact Factor
Available from: Thomas A Pollak
- "Studies conducted in vitro and in vivo have demonstrated the pathogenicity of these cell-surface antibodies ; notably, they have been shown to cause a reversible reduction in numbers of neuronal surface NMDA receptors in addition to a reduction in the NMDA-mediated component of the excitatory postsynaptic potential (EPSP), without causing neuronal death (Hughes et al. 2010). Application of the antibodies to neuronal slices inhibits long-term potentiation (LTP), possibly through direct antagonism at the receptor (Zhang et al. 2012). Importantly, an increase in extracellular glutamate levels has been found in rats following injection of patients' cerebrospinal fluid (CSF) (Manto et al. 2010). "
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ABSTRACT: Anti-N-methyl-d-aspartate (NMDA) receptor encephalitis is an autoimmune condition caused by immunoglobulin (Ig)G antibodies directed against the NR1 subunit of the NMDA glutamate receptor. Approximately 65% of cases present with psychiatric symptoms, particularly psychosis. It remains to be established whether anti-NMDA receptor antibodies can cause a 'purely' psychotic illness without overt neurological symptoms.
We conducted a systematic literature search to establish what proportion of patients with schizophrenia and related psychoses have antibodies directed against the NMDA receptor. Studies were included if (a) subjects had a diagnosis of schizophrenia, schizophrenia spectrum disorder or first-episode psychosis (FEP) using standard criteria, (b) serum was analysed for the presence of anti-NMDA receptor antibodies; and (c) the purpose of the study was to look for the presence of anti-NMDA receptor antibodies in patients with a primary psychiatric diagnosis without clinical signs of encephalitis.
Seven studies were included, comprising 1441 patients, of whom 115 [7.98%, 95% confidence interval (CI) 6.69-9.50] were anti-NMDA receptor antibody positive. Of these, 21 (1.46%, 95% CI 0.94-2.23) patients were positive for antibodies of the IgG subclass. Prevalence rates were greater in cases than controls only for IgG antibodies; other subclasses are of less certain aetiological relevance. There was significant heterogeneity in terms of patient characteristics and the antibody assay used.
A minority of patients with psychosis are anti-NMDA receptor antibody positive. It remains to be established whether this subset of patients differs from antibody-negative patients in terms of underlying pathology and response to antipsychotic treatment, and whether immunomodulatory treatments are effective in alleviating psychotic symptoms in this group.
Psychological Medicine 12/2013; 44(12):1-13. DOI:10.1017/S003329171300295X · 5.94 Impact Factor
Available from: Yuji Urabe
- "Research Article alcohol consumption, age at infection, co-infection of HIV or HBV   , insulin resistance, steatosis, and metabolic syndrome . Previous gene expression analyses also identified various genes associated with liver fibrosis among patients with CHC   . "
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ABSTRACT: Background & aims:
We performed a genome-wide association study (GWAS) of hepatitis C virus (HCV)-induced liver cirrhosis (LC) to identify predictive biomarkers for the risk of LC in patients with chronic hepatitis C (CHC).
A total of 682 HCV-induced LC cases and 1045 CHC patients of Japanese origin were genotyped by Illumina Human Hap 610-Quad bead Chip.
Eight SNPs which showed possible associations (p<1.0 × 10(-5)) at the GWAS stage were further genotyped using 936 LC cases and 3809 CHC patients. We found that two SNPs within the major histocompatibility complex (MHC) region on chromosome 6p21, rs910049 and rs3135363, were significantly associated with the progression from CHC to LC (pcombined=9.15 × 10(-11) and 1.45 × 10(-10), odds ratio (OR)=1.46 and 1.37, respectively). We also found that HLA-DQA1(*)0601 and HLA-DRB1(*)0405 were associated with the progression from CHC to LC (p=4.53 × 10(-4) and 1.54 × 10(-4) with OR=2.80 and 1.45, respectively). Multiple logistic regression analysis revealed that rs3135363, rs910049, and HLA-DQA1(*)0601 were independently associated with the risk of HCV-induced LC. In addition, individuals with four or more risk alleles for these three loci have a 2.83-fold higher risk for LC than those with no risk allele, indicating the cumulative effects of these variations.
Our findings elucidated the crucial roles of multiple genetic variations within the MHC region as prognostic/predictive biomarkers for CHC patients.
Journal of Hepatology 01/2013; 58(5). DOI:10.1016/j.jhep.2012.12.024 · 11.34 Impact Factor
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