Autoimmune encephalitis with coexistent LGI1 and GABABR1 antibodies: case report

Clinical characteristics and prognostic clinical factors of anti-gamma-aminobutyric acid-B receptor (GABAB-R) encephalitis in Türkiye: a multicenter study

INTRODUCTION

GABAB-R encephalitis is a rare recognized autoimmune disease. This study investigates the clinical and laboratory features, treatment response, prognosis, and malignancy associations in GABAB-R encephalitis.

METHODS

We included consecutive encephalitis patients with GABAB-R autoantibodies and retrospectively analyzed their clinical data, neuroimaging, EEG findings, seizure characteristics, treatment responses, prognosis, and cancer presence. Prognosis was classified using the final Modified Rankin Score (mRS), with mRS > 2 indicating poor prognosis.

RESULTS

There were 17 patients with GABAB-R antibodies (12 males). The mean age at onset was 61.29 (range: 37-86), and the mean follow-up was 20.3 months (range: 6-60). The most common findings at onset were seizures, observed in 10 patients (58.8%), which increased to 13 patients (76.5%) during follow-up, psychiatric symptoms in 35.3%, and hyponatremia in 35.3%. Ten patients required intensive care unit (ICU) admission, and 11 patients had an underlying malignancy, predominantly lung cancer. Additionally, one patient had CASPR2 antibodies, and another had AMPA-R antibodies. Lesion probability map analysis revealed predominant involvement of the bilateral mesiotemporal regions. Patients with a final modified Rankin Scale Score greater than 2 (n = 10) exhibited a higher prevalence of psychiatric symptoms, ICU admission, and hyponatremia. Of the 12 patients on anti-seizure medications, only 8 achieved seizure-free status during follow-up. Those with a paraneoplastic etiology were more likely to present with psychiatric symptoms. Mortality, which occurred in 7 patients, was associated with persistent seizures (4/4 vs 3/10; p = 0.015) and ICU admission (7/7 vs 3/10 p = 0.010) Patients with both serum and CSF antibody positivity showed trends towards exhibiting higher rates of lung cancer and mortality.

DISCUSSION

Male gender and seizures are common in GABAB-R encephalitis, which also displays high malignancy and mortality rates. Remarkable prognostic factors include psychiatric symptoms, seizures, malignancy, and hyponatremia. 4(23%) of 17 patients with GABA-B receptor antibody encephalitis experience persistent seizures during follow-up.

Efgartigimod treatment for therapy-refractory autoimmune encephalitis with coexistent NMDAR and LGI1 antibodies: a case report and literature review

The Fc receptor (FcRn) inhibitors can ameliorate autoimmune conditions such as myasthenia gravis through a rapid and specific clearance of serum IgG levels, and they also have potential for future use in a wider variety of antibody-mediated autoimmune diseases. Some patients with therapy-refractory autoimmune encephalitis (AE) continue to be unresponsive to initial and secondary treatment regimens. A 32-year-old male presented with predominant psychiatric symptoms and seizures, along with imaging evidence indicating multifocal cerebral cortical involvement. Neural antibody testing revealed dual positivity for N-methyl-D-aspartate receptor (NMDAR) and leucine-rich glioma-inactivated 1 (LGI1) antibodies in both serum and cerebrospinal fluid (CSF). Human leukocyte antigen (HLA) genotyping revealed the presence of the DQB1*03:01 and DQB1*06:01 alleles in the patient. Treatment with efgartigimod, the FcRn inhibitor, led to significant clinical improvements accompanied by a significant decrease in both anti-NMDAR and anti-LGI1 antibody levels. Herein, we report a rare case of therapy-refractory anti-NMDAR AE coexisting with positive LGI1 antibodies. Efgartigimod demonstrates promising potential for treating antibody-mediated AE. Clinical trial number Not applicable.

Sleep Disturbances in Autoimmune Neurological Diseases: Mechanisms, Clinical Characteristics, Assessment, and Treatment Strategies

PURPOSE OF REVIEW

Sleep disturbances are a hallmark feature of various autoimmune neurological diseases (AINDs). However, limited awareness of these sleep manifestations exists among clinicians. We provide a comprehensive overview of assessment methods, characteristic sleep disturbances, the impact of specific antibodies on sleep patterns, and treatment strategies for sleep disturbances in AINDs.

RECENT FINDINGS

Research advancements in sleep disturbances in autoimmune neurological disease focus primarily on four areas: mechanisms, clinical characteristics, assessment, and treatment. Regarding mechanisms, animal models for AINDs, particularly those involving specific antibodies like anti-NMDAR, anti-LGI1, and anti-IgLON5, have become more comprehensive. Recent advancements in animal models have led to the establishment of numerous models for AINDs; these models include a wide range of antibodies, including anti-NMDAR, anti-LGI1, and anti-IgLON5. Several studies using these models have revealed common mechanisms underlying sleep disturbances in these diseases. In terms of clinical characteristics, the identification of antibodies associated with recently discovered AINDs has expanded the spectrum of sleep disturbance symptoms observed compared to prior findings. A comprehensive evaluation system for the assessment of sleep disturbances has been established, including questionnaires, polysomnography, functional magnetic resonance imaging, and 18F-FDG PET/CT. Additionally, cardiopulmonary coupling shows promise as a novel assessment tool. Currently, no universally effective treatment exists for sleep disturbances in autoimmune neurological diseases, either through symptomatic treatment or immunosuppressive therapy. Further studies are needed to confirm the efficacy of new therapies and validate the benefits of existing treatments. Sleep disturbances are a hallmark feature of AINDs. Recent advancements have significantly expanded our understanding of their assessment and treatment. However, further studies are needed to address the remaining uncertainties in sleep disturbance management.

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.

Anti-LGI1 Encephalitis With Co-occurring IgLON5 Antibodies: Clinical Features and Human Leukocyte Antigen Haplotypes

OBJECTIVES

Autoimmune encephalitis (AE) with antibodies against LGI1 and IgLON5 are clinically distinctive but share some particularities such as a strong association with specific human leukocyte antigen (HLA) class II alleles.

METHODS

We clinically describe a patient with double positivity for LGI1 and IgLON5 antibodies. In addition, we conducted specific immunodepletion with the patient's serum and HLA typing and investigated the presence of serum IgLON5 antibodies in a cohort of 23 anti-LGI1 patients carrying the HLA predisposing for anti-IgLON5 encephalitis.

RESULTS

A 70-year-old woman with a history of lymphoepithelial thymoma presented with subacute cognitive impairment and seizures. Investigations included MRI and EEG showing medial temporal involvement, increased CSF protein content, and polysomnography with REM and non-REM motor activity, along with obstructive apnea. Neural antibody testing revealed both LGI1 and IgLON5 antibodies in serum and CSF, and serum immunodepletion ruled out cross-reactivity. The patient carried DRB1*07:01 and DQA1*01:01∼DQB1*05:01, but no other IgLON5-positive case was identified in a cohort of anti-LGI1 patients carrying DQA1*01∼DQB1*05. Nearly full therapeutic response was obtained after intensified immunosuppressive treatment.

DISCUSSION

We present a case of anti-LGI1 encephalitis with concomitant IgLON5 antibodies. Co-occurring IgLON5 antibodies in anti-LGI1 encephalitis are exceptional, but may appear in genetically predisposed individuals.