Gender issues of antibody-mediated diseases in neurology: (NMOSD/autoimmune encephalitis/MG)

Sex hormones and neuromyelitis optica spectrum disorder: a bidirectional Mendelian randomization study

BACKGROUND

Females are considered to have an increased susceptibility to neuromyelitis optica spectrum disorder (NMOSD) than males, especially aquaporin-4 (AQP4) antibody positive NMOSD, indicating that sex hormones may be involved in the NMOSD pathogenesis. However, the causality between sex hormones and NMOSD still remains unclear.

METHODS

Based on the genome-wide association study (GWAS) data of three sex hormones (estradiol (E2), progesterone (PROG) and bioavailable testosterone (BAT)), sex hormone-binding globulin (SHBG), age of menarche, age of menopause, and NMOSD (total, AQP4 + and AQP4 -), we performed a two-sample bidirectional Mendelian randomization (MR) study. Sex-stratified GWAS data of E2, PROG, BAT, and SHBG was obtained for gender-specific MR analysis. Causal inferences were based on the inverse variance weighted method, MR-Egger regression, and weighted median method. The reverse MR analysis was also performed to assess the impact of NMOSD on hormone levels.

RESULTS

PROG in females had aggravative effects on NMOSD (P < 0.001), especially AQP4 - NMOSD (P < 0.001). In the reverse MR analysis, total NMOSD was found to decrease the level of BAT (P < 0.001) and increase the level of SHBG (P = 0.001) in females.

CONCLUSION

Findings of this MR analysis revealed mutual causal associations between sex hormones and NMOSD, which provided novel perspectives about the gender-related pathogenesis of NMOSD.

Clinical characteristics of autoimmune encephalitis with co-existence of multiple anti-neuronal antibodies

BACKGROUND

An increasing number of cases of autoimmune encephalitis (AE) with co-existing multiple anti-neuronal antibodies have been reported in recent years. However, the clinical significance of the concurrent presence of multiple anti-neuronal antibodies in patients with AE remains unclear.

METHODS

We retrospectively enrolled AE patients with multiple anti-neuronal antibodies treated at our center between August 2019 and February 2022. We also reviewed cases reported in multiple literature databases. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was followed on selection process. And then the clinical and laboratory data of these cases were collected for review and summary.

RESULTS

A total of 83 AE cases with multiple antibodies (9 cases from our center and 74 cases from the literatures reviewed) were identified. In our center, nine patients presented with encephalitis symptoms, clinically characterized as disturbed consciousness, seizures, cognitive impairment, and psychiatric disorders. Of the 83 cases, 73 cases had co-existence of 2 types of antibodies, 8 cases had 3 types, and 2 cases had 4 types. Thirty-nine cases (39/83, 46.9%) were confirmed or suspected of also having a tumor, of which the most common was lung cancer (28/83, 33.7%). Partial or complete recovery was achieved in 57 cases (57/83, 68.6%), while 26 cases (26/83, 31.3%) died during treatment or follow-up.

CONCLUSIONS

AE with co-existing multiple anti-neuronal antibodies is a specific subgroup, that is increasingly recognized in clinical practice. The co-existence of multiple anti-neuronal antibodies has a major impact on clinical features, disease progression, and prognosis.

Update on the diagnosis and treatment of neuromyelitis optica spectrum disorders (NMOSD) - revised recommendations of the Neuromyelitis Optica Study Group (NEMOS). Part II: Attack therapy and long-term management

This manuscript presents practical recommendations for managing acute attacks and implementing preventive immunotherapies for neuromyelitis optica spectrum disorders (NMOSD), a rare autoimmune disease that causes severe inflammation in the central nervous system (CNS), primarily affecting the optic nerves, spinal cord, and brainstem. The pillars of NMOSD therapy are attack treatment and attack prevention to minimize the accrual of neurological disability. Aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) are a diagnostic marker of the disease and play a significant role in its pathogenicity. Recent advances in understanding NMOSD have led to the development of new therapies and the completion of randomized controlled trials. Four preventive immunotherapies have now been approved for AQP4-IgG-positive NMOSD in many regions of the world: eculizumab, ravulizumab - most recently-, inebilizumab, and satralizumab. These new drugs may potentially substitute rituximab and classical immunosuppressive therapies, which were as yet the mainstay of treatment for both, AQP4-IgG-positive and -negative NMOSD. Here, the Neuromyelitis Optica Study Group (NEMOS) provides an overview of the current state of knowledge on NMOSD treatments and offers statements and practical recommendations on the therapy management and use of all available immunotherapies for this disease. Unmet needs and AQP4-IgG-negative NMOSD are also discussed. The recommendations were developed using a Delphi-based consensus method among the core author group and at expert discussions at NEMOS meetings.

Autoimmune encephalitis during pregnancy: A diagnostic and therapeutic challenge-A systematic review with individual patients' analysis and clinical recommendations

Several reports have described the autoimmune encephalitis' (AE) possible onset during pregnancy. In this systematic review, we summarize the available data on the diagnostic and therapeutic approach to AE during pregnancy, highlighting the associated maternal and fetal clinical outcomes. A systematic search of the literature was performed. The following databases were used: PubMed, Google Scholar, EMBASE, and CrossRef. The revision was registered on the PROSPERO platform (CRD42022336357). Forty-nine patients were included. AE onset was mainly observed during the first and the second trimester of pregnancy with psychiatric manifestations and seizures as main onset symptoms. CSF analysis showed AE-specific autoantibody positivity in 33 patients (anti-NMDA receptor as the most frequent). EEG generally showed normal findings. MRI revealed pathological findings in less than half of patients. Tumor screening was positive in 14 cases. First-line immunotherapy (single or combined) was generally employed while second line was administered in a minority of patients. Levetiracetam was the most used antiseizure medication. Cesarean section was performed in 18 women. Most of the women had an excellent early outcome after delivery but 22 showed persistent neurological deficits in long-term follow-up. Fetal outcome was positive in 33 cases, whereas 12 cases of fetal death were reported. A logistic regression showed that no variable significantly influenced the odds of good/bad maternal and fetal clinical outcome. Diagnosis and treatment of AE during pregnancy is challenging. The rate of miscarriage in women with AE seems to be higher than the general population. In addition, mothers may show long-term neurological deficits.

Recent progress in epidemiology, clinical features, and therapy of multiple sclerosis in China

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system characterized by inflammation, demyelination, and neurodegeneration. It mainly affects young adults, imposing a heavy burden on families and society. The epidemiology, clinical features, and management of MS are distinct among different countries. Although MS is a rare disease in China, there are 1.4 billion people in China, so the total number of MS patients is not small. Because of the lack of specific diagnostic biomarkers for MS, there is a high misdiagnosis rate in China, as in other regions. Due to different genetic backgrounds, the clinical manifestations of MS in Chinese are different from those in the West. Herein, this review aims to summarize the disease comprehensively, including clinical profile and the status of disease-modifying therapies in China based on published population-based observation and cohort studies, and also to compare with data from other countries and regions, thus providing help to develop diagnostic guideline and the novel therapeutic drugs. Meanwhile, we also discuss the problems and challenges we face, specifically for the diagnosis and treatment of MS in the middle- and low-income countries.

Risk of epilepsy in gonadal teratoma: a nationwide population-based study

Epilepsy is a common neurological disease. Systemic tumors are associated with an increased risk of epileptic events. Paraneoplastic encephalitis related to gonadal teratoma is frequently accompanied by seizures and life-threatening status epilepticus (SE). However, the risk of epilepsy in gonadal teratoma has not been studied. This study aims to investigate the relationship between epileptic events and gonadal teratoma. This retrospective cohort study used the Korean National Health Insurance (KNHI) database. The study population was divided into two study arms (ovarian teratoma vs. control and testicular teratoma vs. control) with 1:2 age and gender-matched control groups without a history of gonadal teratoma or other malignancy. Participants with other malignancies, neurologic disorders, and metastatic brain lesions were excluded. We observed the occurrence of epileptic events during the observation period (2013-2018) and investigated the risk of epileptic events in each gonadal teratoma group compared to controls. In addition, the influence of malignancy and tumor removal was investigated. The final analysis included 94,203 women with ovarian teratoma, 2314 men with testicular teratoma, and controls. Ovarian teratoma is associated with a higher risk of epilepsy without SE (HR, 1.244; 95% CI 1.112-1.391) and epilepsy with SE (HR, 2.012; 95% CI 1.220-3.318) compared to the control group. The risk of epilepsy without SE was higher in malignant ovarian teratoma (HR, 1.661; 95% CI 1.358-2.033) than in benign (HR, 1.172; 95% CI 1.037-1.324). Testicular teratoma did not show significant relations with epileptic events. The risk of epileptic events showed a tendency to decrease after removing the ovarian teratoma. This study found that ovarian teratoma is associated with a higher risk of epileptic events, especially in malignant tumors, whereas testicular teratoma did not show significant differences in epileptic events compared to the control group. This study adds to the current understanding of the association between gonadal teratoma and epileptic events.

A systematic literature review to examine the considerations around pregnancy in women of child-bearing age with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) or aquaporin 4 neuromyelitis optica spectrum disorder (AQP4+ NMOSD)

BACKGROUND

Aquaporin-4 antibody positive (AQP4+) neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are rare autoimmune diseases with overlapping phenotypes. Understanding their clinical manifestation prior to, during and after pregnancy may influence the management of women of child-bearing age (WOCBA) with these diseases.

METHODS

This systematic review identified relevant MEDLINE-indexed publications dated between 01 January 2011 and 01 November 2021, and congress materials from key conferences between 01 January 2019 and 01 November 2021. These were manually assessed for relevance to AQP4+ NMOSD and/or MOGAD in WOCBA, with selected data extracted and considered.

RESULTS

In total, 107 articles were retrieved and reviewed for relevancy, including 65 clinical studies. Limited evidence was found regarding a conclusive impact of either disease on female fertility, sexual function or menarche, and impact on maternal outcomes requires further investigation in both conditions to establish risk for pre-eclampsia, gestational diabetes and other complications relative to the general population. Collated data for pregnancy outcomes show clear risks in AQP4+ NMOSD to healthy delivery and a rise in annualised relapse rate postpartum that may require adaptation of treatment regimens. Disease activity appears to be attenuated during pregnancy in MOGAD patients with an increased risk of relapse during the postpartum months, but strong conclusions cannot be made due to a paucity of available data.

CONCLUSIONS

This review brings together the literature on AQP4+ NMOSD and MOGAD in WOCBA. The potential impact of pregnancy and the postpartum period on disease activity suggest a proactive management strategy early on may improve maternal and infant outcomes, but more clinical data are needed, particularly for MOGAD.

Delta brush on EEG: a characteristic EEG finding in autoimmune encephalitis

A woman in her late 20s was admitted via the emergency department in the psychiatric ward with acute-onset behavioural changes and suicidal thoughts in the past 2 weeks. Workup revealed positive N-methyl-D-aspartate (NMDA) receptor antibodies in cerebrospinal fluid and electroencephalogram (EEG) showing a specific pattern of delta brush on bilateral frontal regions. Other investigations were unremarkable. The patient was started on intravenous methylprednisolone 1000 mg for 5 days with oral steroids. She responded on steroids. She has been recommended for workup for teratoma/mediastinal tumours with NMDA receptor encephalitis is an autoimmune disorder predominantly affecting women of childbearing age. Delta brush pattern on EEG is specific for NMDA receptor encephalitis hence can be used as a diagnostic tool. It is advisable to investigate any patient with the presentation of mental deterioration for pathological causes. However, treatment with immunotherapy increases the chance of survival and may prevent cognitive impairment.

Treatment considerations in myasthenia gravis for the pregnant patient

INTRODUCTION

Myasthenia gravis (MG) is an autoimmune disease where muscle antibodies form against the acetylcholine receptor (AChR), MuSK, or LRP4 at the neuromuscular junction leading to weakness. Patients worry about consequences for pregnancy, giving birth, nursing, and child outcome.

AREAS COVERED

This review lists the pharmacological treatments for MG in the reproductive age and gives recommendations. Consequences for pregnancy, giving birth, breastfeeding, and child outcome are discussed.

EXPERT OPINION

Pyridostigmine, corticosteroids in low doses, and azathioprine are regarded as safe during pregnancy and should be continued. Mycophenolate mofetil, methotrexate, and cyclophosphamide should not be used in reproductive age. Rituximab should not be given during pregnancy. Other monoclonal IgG antibodies such as eculizumab and efgartigimod should be given only when regarded strictly necessary to avoid long-term and severe incapacity. Intravenous and subcutaneous immunoglobulin and plasma exchange are safe treatments during pregnancy and are recommended for exacerbations with moderate or severe generalized weakness. Most MG women have spontaneous vaginal deliveries. Indications for Cesarean section are obstetrical and similar to non-MG women. Neonatal myasthenia manifests as a transient weakness caused by the mother's IgG muscle antibodies and affects 10% of the babies. MG women should be supported in their wish to have children.

Pregnancy and antibody-mediated CNS disorders: What do we know and what should we know?

Antibody-mediated central nervous system (CNS) disorders including those associated with aquaporin-4 or myelin oligodendrocyte glycoprotein IgG and autoimmune encephalitis often affect women of childbearing age. Pathogenic antibodies of these diseases can potentially alter reproductive functions and influence fetal development. Hormonal changes occurring during pregnancy may modify the course of autoimmune diseases by influencing relapse risk, attack severity, and affect the delivery and postpartum period. Moreover, balancing treatment related safety issues with the risk of potentially disabling relapses during pregnancy and breastfeeding are major challenges. Intentional prenatal, gestational, and post-partum counseling is paramount to address these issues and mitigate these risks. Fortunately, new insights on risk factors for adverse pregnancy outcomes and possible preventive strategies are emerging. This review aims to summarize the interplay between antibody-mediated CNS disorders and pregnancy during the prenatal, gestational, and postpartum periods, highlight current treatment recommendations, and discuss future areas of research.

Case Report: Possible autoimmune obsessive-compulsive disorder with postpartum onset

Autoimmune obsessive–compulsive disorder (OCD) is rare. The case presented here is that of a female patient in her mid-thirties who developed postpartum OCD. Magnetic resonance imaging showed multiple juxtacortical hyperintensities that may have been post-inflammatory in origin. In tissue-based assays using mouse brain slices, the patient’s cerebrospinal fluid (CSF) showed novel anti-nucleoli autoantibodies in cerebellar Purkinje cells and cortical neurons. The CSF dopamine and glutamate concentrations were dysregulated. The clinical course and diagnostic findings were compatible with possible autoimmune OCD with postpartum onset.

Sex and gender differences in autoimmune demyelinating CNS disorders: Multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD) and myelin-oligodendrocyte-glycoprotein antibody associated disorder (MOGAD)

Multiple sclerosis (MS), Neuromyelitis optica spectrum disorder (NMOSD) and Myelin-Oligodendrocyte-Glycoprotein antibody associated disorder (MOGAD) are demyelinating disorders of the central nervous system (CNS) of autoimmune origin. Here, we summarize general considerations on sex-specific differences in the immunopathogenesis and hormonal influences as well as key clinical and epidemiological elements. Gender-specific issues are widely neglected starting with the lacking separation of sex as a biological variable and gender comprising the sociocultural components. As for other autoimmune diseases, female preponderance is common in MS and NMOSD. However, sex distribution in MOGAD seems equal. As in MS, immunotherapy in NMOSD and MOGAD is crucial to prevent further disease activity. Therefore, we assessed data on sex differences of the currently licensed disease-modifying treatments for efficacy and safety. This topic seems widely neglected with only fragmented information resulting from post-hoc analyses of clinical trials or real-world post-marketing studies afflicted with lacking power and/or inherent sources of bias. In summary, biological hypotheses of sex differences including genetic factors, the constitution of the immune system and hormonal influences are based upon human and preclinical data, especially for the paradigmatic disease of MS whereas specific data for NMOSD and MOGAD are widely lacking. Epidemiological and clinical differences between men and women are well described for MS and to some extent for NMOSD, yet, with remaining contradictory findings. MOGAD needs further detailed investigation. Sex-specific analyses of safety and efficacy of long-term immunotherapies need to be addressed in future studies designed and powered to answer the pressing questions and to optimize and individualize treatment.

Anti-NMDA receptor encephalitis with initial negative markers: diagnostic and therapeutic challenges of a refractory case with 9-month-long follow-up

Anti-N-methyl-d-aspartate (NMDA) receptor encephalitis is a progressively debilitating, frequently fatal disease caused by autoantibodies against the NMDA receptor. Risk of delayed treatment is high due to variable presentations, lack of awareness and potential false negative diagnostic studies. In this case report, a woman in her 20s presented with psychiatric manifestations and rapidly declined. Dyskinetic movements and dysautonomia were observed. Initial cerebrospinal fluid and serum anti-NMDA receptor antibodies were negative. MRI was inconclusive. Electroencephalography demonstrated extreme delta brush. Pelvic CT revealed an adnexal teratoma. She remained refractory to treatment until day 126 when, after two cycles of cyclophosphamide, she started to improve. She participated in rehabilitation with eventual discharge home on day 269. Recognising the variable presentations of anti-NMDA receptor encephalitis is important in avoiding misdiagnosis and delayed treatment. If clinical suspicion remains high despite negative results, repeat testing should be pursued. Clinical response should guide treatment decisions in refractory cases.

Autoimmune Voltage-Gated Potassium Channel Limbic Encephalitis With Auditory and Visual Hallucinations

The limbic system (LS) coordinates an important role in memory generation, creating an emotional response to stress, and helping regulate autonomic and endocrine functions. Dysfunction of the limbic system can present secondary to many pathologies including autoimmune, infectious, paraneoplastic, etc. Lesions to the limbic system can also lead to varying symptoms which can be challenging for physicians to correctly identify and treat. Here we report a 59-year-old male with aggressive mood changes and acute onset of auditory and visual hallucinations. The cerebrospinal fluid (CSF) and serum immunological antibody panel confirmed the presence of voltage-gated potassium channel (VGKC) antibodies. Significant radiographic findings included an MRI revealing T2 hyperintensities in the bilateral hippocampus. Paraneoplastic screening with testicular ultrasound and chest CT was completed and was negative. A primary diagnosis of voltage-gated potassium channel limbic encephalitis (VGKC-LE) was made. Management included five days of intravenous immunoglobulin (IVIG) with subsequent resolution of symptoms. The limbic system is an intricate network of neurons that generates and relays key information to other parts of the brain. Its function and, in this case, its dysfunction remain an area of continued research. This case aimed to highlight the importance of recognizing the clinical presentation and objective findings of a rare type of autoimmune encephalitis and identifies the significance of paraneoplastic screening.

Pregnancy and Autoimmune Disease: Diseases of the Nervous System, Connective Tissue, and the Bowel

BACKGROUND

Pregnancies in women with chronic disease are on the rise. This pertains to autoimmune diseases in particular since these tend to affect women of childbearing age. The interaction between pregnancy and autoimmune disease may increase the risk of maternal, fetal, and obstetric complications; additional care may be required.

METHODS

This review is based on a selective literature search in PubMed (2015-2020).

RESULTS

In women with autoimmune diseases, the course of pregnancy is highly variable. Some autoimmune diseases tend to improve during pregnancy and do not to result in any serious obstetric complications. Others may worsen during pregnancy, with deterioration of the maternal condition as well as obstetric and perinatal complications. In systemic lupus erythematosus and myasthenia gravis, placental transfer of specific autoantibodies may cause fetal or neonatal disease.

CONCLUSION

The care of pregnant women with chronic diseases requires collaboration between specialists of the pertinent levels of care. A stable course of disease before conception, close interdisciplinary care, and pregnancy-compatible medication contribute to a reduction in maternal and perinatal complications.

Therapeutic Plasma Exchange: For Cancer Patients

Therapeutic plasma exchange is used as a trial method for the treatment of cancer patients. Therapeutic plasma exchange uses in vitro technology to remove pathogenic factors in the plasma, returning the replacement and remaining components to the patient to facilitate cure. In the effort to explore new methods of cancer treatment, the introduction of therapeutic plasma exchange brings new hope for cancer treatment; however, the current evidence supporting therapeutic plasma exchange is controversial, and most of the evidence comes from observational studies, lacking large prospective randomized trials. Therefore, this review attempts to focus on the main indications of therapeutic plasma exchange for the treatment of tumors and their complications, including hematological tumors (multiple myeloma cast nephropathy and hyperviscosity syndrome), nervous system tumors (myasthenia gravis associated with thymoma, paraneoplastic neurological syndrome, Lambert–Eaton myasthenia syndrome, and anti-N-methyl-D-aspartate receptor encephalitis), overdose of chemotherapy drugs. In addition, the issues of side-effects and safety in the use of therapeutic plasma exchange are also discussed. However, well-designed prospective trials are needed to better define the role of therapeutic plasma exchange in cancer.

The Incidence of Catatonia Diagnosis Among Pediatric Patients Discharged From General Hospitals in the United States: A Kids' Inpatient Database Study

OBJECTIVE

Catatonia is a neuropsychiatric condition occurring across the age spectrum and associated with great morbidity and mortality. While prospective cohorts have investigated catatonia incidence among psychiatric patients, no studies have comprehensively explored the incidence of catatonia in general hospitals. We examine the incidence of catatonia diagnosis, demographics of catatonia patients, comorbidities, and inpatient procedures utilized among pediatric patients hospitalized with catatonia in the United States.

METHODS

The Kids' Inpatient Database, a national all-payors sample of pediatric hospitalizations in general hospitals, was examined for the year 2019. Hospitalizations with a discharge diagnosis of catatonia were included in the analysis. Hospitalizations with catatonia as the primary discharge diagnosis were compared to hospitalizations with catatonia as a secondary discharge diagnosis.

RESULTS

A total of 900 (95% CI: 850-949) pediatric discharges (291 with catatonia as a primary diagnosis, 609 with catatonia as a secondary diagnosis) occurred during the study year. Mean age was 15.6 ± 2.6 years, and 9.9% were under age 13. Comorbidities were common among patients with catatonia, with psychotic disorders (165; 18.3%), major depressive disorder (69; 7.7%), bipolar disorder (39; 4.3%) and substance-related disorders (20; 2.2%) as the most common primary diagnoses. There was significant comorbidity with neurologic illness, developmental disorders, autism spectrum disorder, and inflammatory conditions. In total 390 catatonia discharges (43.3%) included at least one procedure during admission.

CONCLUSIONS

catatonia is rarely diagnosed in pediatric patients in general hospitals but is associated with significant and severe psychiatric and medical comorbidities. Further research is needed into the optimal diagnosis, workup, and treatment of catatonia in pediatric patients.

Tacrolimus as Single-Agent Immunotherapy and Minimal Manifestation Status in Nonthymoma Myasthenia Gravis

Background

Tacrolimus is a second-line immunosuppressant in myasthenia gravis (MG) therapy, which is mainly used in combination with corticosteroids to reduce steroid dose and maintain the effect of immunotherapy. However, few studies have focused on the effect of tacrolimus as single-agent immunotherapy on achieving minimal manifestation status (MMS). Thus, this study is aimed at exploring the efficacy and influencing factors of tacrolimus as single-agent immunotherapy in MG.

Methods

Clinical data of 75 nonthymoma MG patients treated with tacrolimus single-agent as initial immunotherapy were retrospectively analyzed. The therapeutic effect was evaluated by Myasthenia Gravis Foundation of America postintervention status. Clinical factors affecting the achievement of MMS and treatment reactivity of different MG subtypes were determined by Cox regression analysis.

Results

Tacrolimus was generally safe, with only two patients (2.7%) switching medications due to side effects. 32% of patients had improved symptoms after 1 month of treatment. 69.2% of patients achieved MMS or better after one year. The age < 39 years old, QMG score < 11 points, and AChR − Ab titer < 8.07 nmol/L were indicative of a favorable response, which was independent of gender, course of the disease. As for MG subtypes, ocular and seronegative MG showed better treatment sensitivity.

Conclusions

Tacrolimus as single-agent immunotherapy takes effect quickly and can effectively enable nonthymoma MG patients to achieve MMS. Tacrolimus can be used alone for the initial immunotherapy of MG patients, especially for young, mild, and low antibody titer patients.

Comparisons of clinical phenotype, radiological and laboratory features, and therapy of neuromyelitis optica spectrum disorder by regions: update and challenges

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory demyelinating disease of the central nervous system (CNS) associated with autoantibody (ab) to aquaporin-4 (AQP4). There is obvious variation between regions and countries in the epidemiology, clinical features and management in NMOSD. Based on published population-based observation and cohort studies, the different clinical pattern of NMOSD has been seen in several geographical regions and some of these patients with NMOSD-like features do not fully meet the current diagnostic criteria, which is needed to consider the value of recently revised diagnostic criteria. At present, all treatments applied in NMOSD have made great progress, however, these treatments failed in AQP4 ab negative and refractory patients. Therefore, it is necessary to turn into an innovative idea and to open a new era of NMOSD treatment to develop novel and diverse targets and effective therapeutic drugs in NMOSD and to conduct the trails in large clinical samples and case-control studies to confirm their therapeutic effects on NMOSD in the future, which still remain a challenge.

Age at sampling and sex distribution of AChRAb vs. MuSKAb myasthenia gravis in a large Greek population

OBJECTIVE

Myasthenia gravis (MG) is a typical B-cell-mediated neuromuscular junction disease that can be classified into seropositive and seronegative subtypes. Association of patients' age at sampling and sex with the two major seropositive MG subcategories, i.e., MGs linked to antibodies directed against the acetylcholine receptor (AChRAb) and against the muscle-specific kinase (MuSKAb), has not been compared in a large population.

METHODS

We performed a retrospective analysis of samples from patients with MG in Greece who underwent neurochemical diagnostic evaluation between January 2, 2013, and August 31, 2016.

RESULTS

Overall, 1620 adult (623 male and 997 female patients; male-to-female ratio = 0.62) and 51 pediatric patients were found to be seropositive for MG. The distributions in both male and female patients were bimodal in the total and AChRAb MG cases but not in the total MuSKAb MG cases. Significant differences in the age at sampling distribution between the male and female adult patients were observed only in the AChRAb MG subtype. Significant differences between the AChRAb and MuSKAb MG categories were noted in the mean age values (60.10 and 51.49 years, respectively, for female and 65.69 and 56.19 years, respectively, for male adult patients).

CONCLUSION

Our findings confirm an uneven profile of age at sampling and sex between the AChRAb and MuSKAb MG cases in a large population. Future mechanistic studies can elucidate the cause of these differences. Moreover, clinical studies can explore how such differences can affect MG treatment and prognosis.