Coexistence of multiple anti-neuronal antibodies in autoimmune encephalitis in China: A multi-center study

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.

A Case Report and Literature Review on Positivity for Multiple Antibodies: Autoimmune Encephalitis in Focus

Autoimmune encephalitis (AE) is a group of neuropsychiatric disorders caused by antibodies that target the neuronal surface, synaptic, or intracellular antigens, impairing brain function. Although AE can affect people of different age groups, the occurrence of AE within specific age brackets depends on the specific type of AE and the antibodies produced. While AE is frequently considered a paraneoplastic syndrome linked to cancer, it is essential to acknowledge that the intensity of this association can vary depending on the specific antibody, leading to diverse relationships with paraneoplastic syndromes. Numerous cases have been recorded where AE manifests without an underlying malignancy. The diagnostic criteria for AE are characterized by a subacute deterioration of cognition, altered mental status, or psychiatric symptoms. Immunotherapy is recommended as a treatment for the condition, and the prognosis varies depending on the subtype. In this case, we present the case of an elderly woman who showed acute mental status changes, psychiatric symptoms, EEG alterations, and positive antibody results in both serum and CSF. Our case breaks new ground as the first documented instance of a female with positive serum anti-LGI 1, anti-AMPAR2, anti-Ri, and anti-CENP-A/B antibodies.

An overview on CV2/CRMP5 antibody-associated paraneoplastic neurological syndromes

Paraneoplastic neurological syndrome refers to certain malignant tumors that have affected the distant nervous system and caused corresponding dysfunction in the absence of tumor metastasis. Patients with this syndrome produce multiple antibodies, each targeting a different antigen and causing different symptoms and signs. The CV2/collapsin response mediator protein 5 (CRMP5) antibody is a major antibody of this type. It damages the nervous system, which often manifests as limbic encephalitis, chorea, ocular manifestation, cerebellar ataxia, myelopathy, and peripheral neuropathy. Detecting CV2/CRMP5 antibody is crucial for the clinical diagnosis of paraneoplastic neurological syndrome, and anti-tumor and immunological therapies can help to alleviate symptoms and improve prognosis. However, because of the low incidence of this disease, few reports and no reviews have been published about it so far. This article intends to review the research on CV2/CRMP5 antibody-associated paraneoplastic neurological syndrome and summarize its clinical features to help clinicians comprehensively understand the disease. Additionally, this review discusses the current challenges that this disease poses, and the application prospects of new detection and diagnostic techniques in the field of paraneoplastic neurological syndrome, including CV2/CRMP5-associated paraneoplastic neurological syndrome, in recent years.

Contactin-associated protein-2 and anti-aquaporin-4 antibody positive autoimmune encephalitis secondary to herpes simplex encephalitis: A case report

RATIONALE

Recurrent herpes simplex encephalitis (HSE) can easily induce autoimmune encephalitis (AE). However, there are few reports of anti-contactin-associated protein-2 (CASPR2)-related encephalitis, especially with positive anti-aquaporin 4 (AQP4) antibodies.

PATIENT CONCERNS

A 14-year-old boy was admitted to the Department of Neurology of the First Affiliated Hospital of Kunming Medical University for "headache, dizziness, and fever for four days" with positive anti-CASPR2 and anti-AQP4 antibodies in the cerebrospinal fluid.

DIAGNOSES

Cranial MRI showed lesions in the right hippocampus, amygdala, and insular lobe, with local sulcus enhancement in the right insular, temporal, and frontal lobes. The fluid-attenuated inversion recovery was significantly enhanced. Human herpes virus type I was detected by cerebrospinal fluid metagenomic testing. The patient was diagnosed with AE secondary to HSE, with positive anti-CASPR2 and anti-AQP4 antibodies.

INTERVENTIONS

After 2 weeks of immunoglobulin and methylprednisolone immunomodulatory therapy, acyclovir antivirus, mannitol dehydration, reducing intracranial pressure, and other symptomatic support therapy.

OUTCOMES

The patient's symptoms significantly improved, with no complaints of discomfort, and he was discharged for observation. The patient was followed up a month after discharge and had no complaints of discomfort.

LESSONS

CASPR2 and anti-aquaporin-4 antibody-positive AE have not been reported to be positive. This case will raise awareness of CASPR2 and anti-aquaporin-4 antibody-positive AE secondary to HSE, strengthen diagnostic capacities, and provide advice to treat it.