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Abnormal CTLA-4 expression is involved in the development of myasthenia gravis (MG), and serum CTLA-4 levels are positively correlated with serum anti-AChR antibody concentration, which might be related with the severity of MG. Polymorphism in CTLA-4 gene is associated with various autoimmune disorders. We investigated the association of polymorphism in CTLA-4 gene with the clinical variables and severity of MG. The frequencies of alleles and genotypes were compared between 480 MG patients and 487 healthy controls, as well as among subgroups of MG patients. The frequency of rs733618*C allele is significantly higher in MG group and several subgroups than in control group. Genotype is not found as independent factor for essential clinical variables of MG. The frequency of rs231775*A allele is significantly lower in ocular onset subgroup than in control group, and the frequencies of rs231775*A allele and rs3087243*A allele are significantly lower in ocular onset subgroup than in generalized onset subgroup. Genotypes of the two SNPs are found as independent factors for ocular onset. The frequency of rs231775*A allele is significantly lower in mild subgroup than that in control group. Genotype is not found as independent factor for mild severity. A haplotype containing rs733618*C, rs231775*G and rs3087243*G is identified to increase the general risk of MG by 1.278-fold and ocular onset MG subgroup by 1.362-fold. There is association of rs733618 with the general susceptibility of MG, and association of rs231775 and rs3087243 with the susceptibility of ocular onset MG, but no association with the severity of MG.

Complement component 3 (C3) had been proved to be involved in the pathogenesis and exacerbation of both myasthenia gravis (MG) patients and experimental autoimmune myasthenia gravis (EAMG) models. We evaluated the underlying association between five SNPs (rs344555, rs7951, rs3745568, rs366510 and rs163913) in C3 gene and Chinese adult MG patients. Our study consisted of 409 adult MG patients and 487 healthy controls. Subgroups were classified by gender, onset age, thymoma, anti-AChR antibody, onset muscle involvement (ocular/generalized) and severity (Oosterhuis score at the maximal severity during the initial two years after the onset of MG). We found significant differences in allele frequencies between MG and the control group, between various MG subgroups and the control group in rs344555 and rs3745568. There were significant differences in genotype frequencies between MG group and the control group, between MG subgroups and the control group under the codominant and additive inheritance models in rs344555 and rs3745568. No association was found between the frequencies of these SNPs and the severity of MG. We also used a comprehensive classification which was close to the clinical scenario to minimize the interaction among clinical features. In rs344555, the T allele frequency in thymoma (-) AChR-Ab (+) subgroup was significantly higher than that in the control group. Our results indicated that rs344555 was associated with the susceptibility of Chinese adult MG patients; rs3745568 was probably associated with the susceptibility of Chinese adult MG patients. No association was found between the frequencies of these SNPs and the severity of MG.

An array of cytokines influences the pathogenesis of early onset myasthenia gravis (MG) and its animal model, experimental autoimmune myasthenia gravis (EAMG). Patients with MG, in particular those with more severe weakness, have elevations of the pro-inflammatory cytokine IL-17 in the blood. We assessed the role of IL-17A in autoimmunity by inducing EAMG in mice with knockout of IL-17 and found a reduction of EAMG severity, but not a complete ablation of disease. The IL-17ko mice had no evidence of weakness, low levels of acetylcholine receptor antibodies, and retention of acetylcholine receptor at the neuromuscular junction. Splenic germinal center size was reduced in EAMG IL-17ko mice along with elevations of Foxp3 and BCL-6 gene expression, suggesting a shift away from pro-inflammatory signals. The results emphasize the importance of IL-17 in EAMG development and that IL-17 independent pathways drive the autoimmune reaction.

Interleukin-4 (IL-4) is a potent growth and differentiation factor for B cells which play a vital role in the pathogenesis of myasthenia gravis (MG). IL-4 exerts its function by binding to three types of IL-4 receptor (IL-4R) complexes. IL-4Rα is the key component of the IL-4R complex. We hypothesize that polymorphism of IL-4Rα gene may be associated with the susceptibility and severity of MG. A Chinese cohort of 480 MG patients and 487 healthy controls were recruited. Polymorphisms of IL-4Rα gene were determined with SNPscanTM methods and compared between MG and control groups, as well as among MG subgroups. Rs2107356 and rs1805010 were found to be associated with adult thymoma associated MG, and rs1801275 was found to be associated with adult non-thymoma AChR-Ab positive MG. We did not found association between IL-4Rα polymorphism and the severity of MG. Genetic variations of IL-4Rα were found associated with the susceptibility of MG in Chinese Han population.

Background: Electrophysiological examination plays an important role in the diagnosis of X-linked Charcot-Marie-Tooth disease (CMTX1) with transient central nervous system deficits. However, the electrophysiological features are seldom reported.Methods: We reviewed and analyzed published reports to determine the electrophysiological features of CMTX1 patients with transient central nervous system deficits.Results: A total of 21 CMTX1 patients with transient central nervous system deficits were found in 17 published case reports/series. The age of onset ranged from 0.5 to 18 years (mean 12.02 ± 0.78 years). All patients were male. Recurrent episodes of central nervous system deficits were reported in all 21 cases and resolved in periods ranging from several minutes to 3 days. All 20 patients who had MRIs at presentation had bilaterally symmetrical abnormal T2/Diffusion signals in the white matter without enhancement of gadolinium. All subsequent MRIs showed improvement or were within normal limits. The median motor nerve conduction velocity (MNCV), motor latencies, and compound muscle action potential (CMAP) amplitude were the most commonly measurable electrophysiological parameters (85.7%). All cases that had MNCV at presentation had slower and significantly decreased MNCV compared with the normal value (34.1 ± 1.10 m/s vs. 46.8±2.05 m/s, P < 0.0001; 95% CI, −17.4 to −7.92). The average variations of MNCV in median nerve, ulnar nerve, peroneal nerve, and tibial nerve were 22.0 ± 5.96%, 27.6 ± 11.9%, 25.9 ± 4.36%, and 27.3 ± 4.30%, respectively. All cases with measured sensory nerve conduction velocity (SNCV) at presentation had slower and significantly decreased SNCV compared with the normal value (35.3 ± 1.33 m/s vs. 47.7 ± 2.40 m/s, P < 0.001; 95% CI −18.2 to −6.46). The average variations of SNCV in median nerve, ulnar nerve, and sural nerve were 19.9 ± 8.24%, 25.2 ± 7.75%, and 23.2 ± 3.95%, respectively.Conclusion: This case series serves as a reminder that electrophysiological examination should be included in the diagnosis of recurrent and episodic neurological deficit with white matter lesions. Median MNCV is a sensitive and valuable parameter to support the diagnosis of CMTX1 with transient central nervous system deficits.

Alleles of IL-17A and IL-17F genes were reported to be associated with many inflammatory and autoimmune disorders in Asian patients. Serum level and mRNA of IL-17A in peripheral blood mononuclear cells were reported to be significantly higher in MG patients than in healthy controls. In experimental autoimmune myasthenia gravis (EAMG) animals, IL-17 may have effects on the severity of MG. This study investigated the association between four SNPs of IL-17A and IL-17F gene (rs8193036, rs2275913 and rs3748067 in IL-17A; rs763780 in IL-17F) and MG in Chinese patients. The allele frequencies were compared between 480 MG patients and 487 healthy controls, between each MG subgroup and the control group, and between each pairs of MG subgroups. Subgroups were specified by clinical features (onset age, gender, thymoma, AChRAb and muscle involvement at onset) and maximal severity during the follow-up. No associations were found between the four SNPs of IL-17A and IL-17F gene and MG in Chinese patients.

In this study, we intended to genotype 2 single nucleotide polymorphisms (SNPs) of tumor necrosis factor α-induced protein 3 (TNFAIP3) genes and explore an association of TNFAIP3 genetic polymorphism with the patients of myasthenia gravis (MG) at clinical level. In brief, 215 of adult MG patients were divided into subgroups according to their clinical features, age of onset, thymic pathology, and autoantibodies. Two hundred thirty-five of healthy controls were also divided into subgroups with gender- and age-matched. The allele and genotype frequencies of subgrouped patients were found to be higher than those of healthy controls. The distribution of TNFAIP3 gene rs7749323∗A allele of late onset MG (LOMG, with positive acetylcholine receptor antibody and without thymoma) subgrouped patients was also significantly higher than that of gender- and age-matched healthy controls (7.4% vs 2.4%, odds ratio [OR] = 3.27, 95% confidence interval [CI] 1.01–10.6, P = .04). Furthermore, analysis to the genotype frequencies indicates that the carriers of rs7749323∗A allele of LOMG group became more frequent than that of age-matched healthy controls (14.9% vs 4.8%, OR = 3.47, 95% CI 1.04–11.6, dominant model: P = .03). It is interesting to notice that there is no significant association between the rs7749323 and susceptibility of other MG subgroups. Therefore, it is suggested that the SNPs in the 3′ flanking region (rs7749323) of TNFAIP3 gene and the genetic variations of TNFAIP3 gene may take an important role in the susceptibility of LOMG.

In the international consensus for managing myasthenia gravis (MG), minimal manifestation status (MMS) or better was recommended as the treatment goal.1 MMS refers to no symptoms of functional limitations from MG, but some weakness on examination of some muscles.2 However, there are no criteria to detect the minimal weakness that is clinically important and biologically plausible. Only one study tried to link MMS and MG-specific quality of life scores.3 Moreover, the dose of pyridostigmine is an important factor that should be considered in attributing symptoms or functional limitations to MG. What is the optimal cutoff on measurements of weakness and pyridostigmine dose in the definition of MMS?

The cause of myasthenia gravis (MG) is unknown, but it is widely believed to be an autoimmune disease occurring in genetically susceptible individuals. The human leukocyte antigen (HLA) region is considered to be the most important genetic region for MG susceptibility genes. To investigate the association between HLA-DRB1 and myasthenia gravis (MG) in a northern Han Chinese population, a polymerase chain reaction with sequence-specific oligonucleotide probe hybridization method was used to determine the HLA-DRB1 genotypes of 91 patients with MG and 171 healthy individuals. We found that the HLA-DRB1(*)09 allele was significantly more prevalent among patients with MG than among healthy controls, especially those who experienced early onset of the disease (≤40 years), those who were seronegative for acetylcholine receptor antibody, and those with ocular MG. The prevalence of the HLA-DRB1(*)08 allele was significantly lower among patients with MG than among controls. These results indicate that HLA-DRB1(*)09 might be positively associated and DRB1(*)08 negatively associated with MG in the northern Han Chinese population.

Background and purpose Glucocorticoids (GCs) are the mainstay treatment of myasthenia gravis (MG). However, wide inter-individual variability exists in the response to GCs. Methods A Chinese cohort of 257 MG patients treated with GCs was evaluated for the association between 19 single nucleotide polymorphisms in the GR gene and clinical response to the initial 3 month GC therapy. A quantitative MG score decreasing by ≥3 units or becoming zero was defined as sensitivity to GCs. Results The rs17209237* G allele was less frequent in the GC insensitive group compared with the GC sensitive group [P = 0.013, odds ratio (OR) 0.119]. The rs9324921* A allele was more frequent in the GC insensitive group than in the GC sensitive group (P = 0.046, OR 1.94). Carriers of the rs17209237 G allele were less frequent in the GC insensitive group than in the GC sensitive group (dominant model, P = 0.009). Carriers of the rs9324921 A allele were more frequent in the GC insensitive group than in the GC sensitive group (dominant model, P = 0.037). Multivariate logistic regression revealed that the rs17209237 G allele carrier (P = 0.037, OR 0.12) and disease duration before GC treatment (P = 0.011, OR 3.45) were independent factors that contributed to GC efficacy. Conclusion rs17209237 in the GR gene was identified as an independent factor that contributes to GC efficacy in MG patients. The genetic variations of the GR gene may play a role in predicting response to GC treatment.

To better define the role of IL-17A in myasthenia gravis (MG), we assessed plasma concentrations in 69 adult patients with MG prior to initiation of immunosuppression and monitored their clinical course for the subsequent 2years with quantitative MG scores (QMGS) and Osserman classification. IL-17A was higher among patients than healthy control subjects. Early-onset women without thymoma had greater elevations of IL-17A. Logistic regression analysis indicated that the absence of thymoma rather than women gender or early-onset was the significant determinant associated with IL-17A elevation. Elevated IL-17A levels were associated with more severe MG. In summary, IL-17A has role in the pathogenesis of a subgroup of patients with early-onset women with MG with greater disease severity who are most likely to have thymic hyperplasia. This subgroup may be a target for IL-17 treatments, which are under development.

Background Transient white matter lesions have been rarely reported in X-linked Charcot-Marie-Tooth disease type 1. Case presentation We describe a 15-year-old boy who presented transient and recurrent weakness of the limbs for 5 days. His mother, his mother’s mother and his mother’s sister presented pes cavus. MRI and electrophysiology were performed in the proband. Gap junction protein beta l gene was analyzed by PCR-sequencing in the proband and his parents. The electrophysiological studies showed a mixed demyelinating and axonal sensorimotor neuropathy. MRI showed white matter lesions in the internal capsule, corpus callosum and periventricular areas, which showed almost complete resolution after two months. T278G mutation in Gap junction protein beta l gene was detected in the proband and his mother. Conclusion This case report highlights that the novel T278G mutation of Gap junction protein beta l maybe could result in X-linked Charcot-Marie-Tooth disease type 1 with predominant leucoencephalopathy. The white matter changes in MRI of X-linked Charcot-Marie-Tooth disease type 1 patient are reversible.

Background Cytotoxic T lymphocyte-associated antigen-4 (CTLA4), a critical negative regulator of the T-cell response, has been considered a candidate for many autoimmune diseases. Evidence from Caucasians supported a genetic predisposition of CTLA4 to myasthenia gravis (MG), but the contribution in East Asians has not been established. Objectives To investigate the role of CTLA4 variants in the susceptibility to MG and the contribution to subtypes of MG. Methods Six autoimmune disease-related risk alleles of CTLA4 (rs1863800, rs733618, rs4553808, rs5742909, rs231775, and rs3087243) were investigated for MG in northern Chinese. 168 patients with MG (mean age 37.1±20.5 years, 64 men and 104 women) and 233 healthy controls (mean age 53.3±8.7 years, 96 men and 137 women) were screened, and the contribution of CTLA4 to the general risk of MG and each subgroup was explored. Results rs1863800*C, rs733618*C, and rs231775*G were significantly associated with the whole cohort of patients with MG after permutation correction for multiple-testing adjustment (P = 0.027, 0.001, and 0.032, respectively). A risk haplotype (CCACG) [odds ratio (OR) = 1.535, range = 1.150–2.059, P = 0.004)] was also identified. The stratified subtype analysis indicated that the positive contribution was possibly derived from early onset MG (EOMG), seropositive MG (SPMG), female patients, and MG without thymoma. No association was observed in juvenile MG/LOMG, and MG coupled with thymoma. Conclusion A predisposing effect of rs1863800*C, rs733618*C, and rs231775*G of CTLA4 gene to general risk of MG in Chinese was demonstrated for the first time, which was likely derived from EOMG, SPMG, MG without thymoma and the female patients.

Miller Fisher's syndrome (MFS) commonly presents in the fourth and fifth decades and are rare in people over 70 years. An 85-year-old female with no significant medical history presented with upper extremity anesthesia, ptosis, and unsteady gait. The patient had a history of hypertension and diabetes mellitus. Physical examination showed bilateral total external ophthalmoplegia, areflexia, and cerebellar ataxia. Radiological and laboratory studies were unremarkable. Lumbar puncture showed albuminocytological dissociation. The combined history, physical examination, and lumbar puncture results established a presumptive diagnosis of MFS. Intravenous immunoglobulin was given for 5 days. The patient gradually improved 10 days after the onset of symptoms. Ophthalmoplegia had fully recovered after 6 months. To the best of our knowledge, this case represented the oldest patient with MFS.

Myasthenia gravis (MG) is a prototypic autoimmune disease with overt clinical and immunological heterogeneity. The data of MG is far from individually precise now, partially due to the rarity and heterogeneity of this disease. In this review, we provide the basic insights of MG data precision, including onset age, presenting symptoms, generalization, thymus status, pathogenic autoantibodies, muscle involvement, severity and response to treatment based on references and our previous studies. Subgroups and quantitative traits of MG are discussed in the sense of data precision. The role of disease registries and scientific bases of precise analysis are also discussed to ensure better collection and analysis of MG data.

Genetic analyses indicate that HLA complex genes can be involved in susceptibility to autoimmune myasthenia gravis (MG). Various HLA alleles serve as genetic elements that either predispose to or protect against MG. This study investigates the probable relationship between HLA-DQ allele polymorphisms and MG cases in northern China. The HLA-DQA1 and DQB1 alleles were determined by polymerase chain reaction/sequence-specific primers (PCR-SSP) in 84 MG patients, and the results were compared to 293 healthy controls. Our findings indicate that DQ A1*0401(P = 0.008, OR: 2.5, 95%CI: 1.24–3.07) and B1*0301(P = 0.000, OR: 2.29, 95%CI: 1.48–3.54) were the most frequent allele; the frequencies of DQA1*0103(P = 0.000, OR:0.24, 95%CI 0.13–0.49) and DQB1*0601(P = 0.001, OR:0.40, 95%CI 0.22–0.50) were significantly decreased in MG patients compared with healthy controls. Patients with thymomatous MG were positively associated with DQA1 *0401(P = 0.011, OR:4.57, 95% CI 1.40–14.90) and DQB1 *0604 (P = 0.001, OR:4.01, 95% CI 1.65–9.73) as compared to MG patients without thymoma. Different genetic mechanisms may exist between MG patients with thymoma and those without thymoma. The HLA-DQ associations in MG subgroups suggest that disease heterogeneity may be influenced by different genes or alleles.

The oxidative stress caused by nitric oxide (NO) in the brain has been proposed as a pathogenic mechanism in Alzheimer’s disease. Endothelial NO synthase (ecNOS) produces the majority of circulating NO. The biological functional and genetic association studies suggested that the Glu298Asp polymorphism of the ecNOS gene (NOS3) may be a genetic risk factor for late-onset Alzheimer’s disease (LOAD). To investigate an association between the NOS31 Glu298Asp polymorphism and sporadic LOAD in Chinese, we examined 338 LOAD patients and 378 healthy controls. The associations of the Glu/Glu genotype and Glu allele with LOAD (χ 2 = 9.12, df = 1, P = 0.003 by genotype; χ 2 = 8.37, df = 1, P = 0.038 by allele) were found. After stratifying by apolipoprotein E allele 4 (APOE ɛ4) status, increased LOAD risks associated with the Glu/Glu genotype and Glu allele only in the APOE ɛ4 noncarriers (χ 2 = 6.28, df = 1, P = 0.012 by genotype; χ 2 = 5.62, df = 1, P = 0.018 by allele) were seen. These results suggest that the NOS3 gene Glu298Asp polymorphism might be a risk factor for LOAD and dependent on APOE ɛ4 status in Chinese.