Atezolizumab-associated encephalitis in metastatic lung adenocarcinoma: a case report

Clinical characteristics, diagnosis, treatment, and prognosis of Atezolizumab-induced encephalitis, aseptic meningitis or meningoencephalitis

Objective

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment and expanded the range of tumor indications. However, as the usage of this medication has increased, related adverse events are increasingly being identified. Among these, Atezolizumab-induced encephalitis, aseptic meningitis, and meningoencephalitis remain poorly understood regarding clinical features. This study provides a comprehensive reference for classifying, identifying, and managing Atezolizumab-associated neurological adverse events, specifically encephalitis, aseptic meningitis, and meningoencephalitis.

Methods

This study systematically collected published case reports from public databases such as PubMed, Web of Science, Wanfang Database, and CNKI Database. Two independent reviewers screened titles and abstracts and then extracted data in the included article according to the designed table and analyzed the clinical characteristics of Atezolizumab-induced encephalitis, aseptic meningitis, or meningoencephalitis.

Results

A total of 17 articles were included, with 19 patients diagnosed with encephalitis, aseptic meningitis, or meningoencephalitis after Atezolizumab treatment. The most common presenting symptoms included fever, altered consciousness, fatigue, somnolence, and seizures. Diagnosis was primarily based on cerebrospinal fluid analysis, blood tests, and imaging studies, such as computed tomography (CT) scans. Treatment strategies typically involved systemic steroids, antiviral agents, antibiotics, and anti-epileptic medications, as appropriate.

Conclusion

Neurological immune-related adverse events may rapidly progress and impact prognosis. Therefore, clinical practitioners should have a deep understanding of these neurological immune-related adverse events, promptly diagnose them, and provide accurate and timely treatment.

A rare case of daratumumab-associated encephalopathy in multiple myeloma

Aim: Daratumumab, a CD38 monoclonal antibody, has been widely used in patients with multiple myeloma. Although a variety of adverse events have been reported, consciousness impairment has not been reported yet. We report a case of encephalopathy associated with daratumumab. Case presentation: A 57-year-old male, diagnosed with relapsed multiple myeloma, was treated with daratumumab. He developed a loss of consciousness after the first administration. Cerebral spinal fluid and magnetic resonance imaging of the brain suggested encephalopathy. Conclusion: It is recommended to be aware of rare but life threatening side effects of daratumumab. We present a case of rare encephalopathy characterized by consciousness disorder associated with daratumumab, which was successfully resolved on prompt institution of steroids, although the mechanism was unknown.

Atezolizumab-induced cerebellar ataxia in a patient with metastatic small cell lung cancer: A case report and literature review

INTRODUCTION

The use of immune checkpoint inhibitors, which have an important role in the treatment of malignant tumors, is increasing. Although rarely observed, neurological immune-related adverse events associated with immune checkpoint inhibitors result in high morbidity and mortality. Small cell lung cancer is a common cause of neurological paraneoplastic syndromes. The differentiation between paraneoplastic syndromes and neurological immune-related adverse events is important in patients using immune checkpoint inhibitors. Cerebellar ataxia caused by atezolizumab is a rare immune-related adverse event.

CASE REPORT

In this context, we present a 66-year-old man with small cell lung cancer who developed immune-mediated cerebellar ataxia after three cycles of atezolizumab, a programmed cell death ligand-1 inhibitor. The admission of brain and spinal gadolinium-based contrast-enhanced magnetic resonance imaging supported the preliminary diagnosis and indicated leptomeningeal involvement. However, the blood tests and a lumbar puncture did not reveal any structural, biochemical, paraneoplastic, or infectious cause.

MANAGEMENT AND OUTCOME

High-dose steroid treatment resulted in an improvement in the radiological involvement, as evidenced both clinically and on follow-up whole spine magnetic resonance imaging. Therefore, the immunotherapy was discontinued. The patient was discharged on day 20 without neurological sequelae.

DISCUSSION

In light of this, we present this case to emphasize the differential diagnosis of neurological immune-related adverse events originating from immune checkpoint inhibitors, which require rapid diagnosis and treatment, and clinically similar paraneoplastic syndromes and radiologically similar leptomeningeal involvement, in a case of small cell lung cancer.

Atezolizumab-induced encephalitis with subdural hemorrhage and subarachnoid hemorrhage in a patient with hepatocellular carcinoma

We report the case of a 76-year-old man who was diagnosed with advanced stage hepatocellular carcinoma and was treated with atezolizumab plus bevacizumab therapy. Two weeks after 1st dose, he presented with acute changes in consciousness followed by hypothermia. A cerebrospinal fluid test showed an elevated cell count, total protein, and albumin. Infectious, anatomical, endocrinal, and neoplastic etiologies were ruled out. Based on the findings, atezolizumab-induced encephalitis was suspected, and high dose steroid therapy was administered. The patient's conscious level and hypothermia recovered completely about 9 days after starting the steroids, and he recovered without any neurological sequelae. This case report reminds physicians that prompt administration of steroid treatment after early diagnosis of immune checkpoint inhibitor-related encephalitis is the key for patients to recover without apparent neurological sequelae.

Hope, Cure, and Adverse Effects in Immunotherapy: Atezolizumab-Associated Encephalitis in Metastatic Small Cell Lung Cancer - A Case Report and Literature Review

Cancer immunotherapies have been revolutionary treatments in oncological disease. Such therapies include immune checkpoint inhibitors that target programmed cell death protein, ligands, and cytotoxic T-lymphocyte-associated antigen (CTLA-4). Increased use has led to recognition of immune-related adverse events. Such events are often distinct from the typical adverse events of traditional cancer therapies. Immune-related adverse events are more commonly found to affect the skin, gastrointestinal tract, and endocrine system. The incidence of these adverse events remains low for central nervous system effects. This article describes a case of atezolizumab-associated encephalitis in a patient with metastatic small cell lung cancer.

Atezolizumab-induced Encephalitis in a Patient with Hepatocellular Carcinoma: A Case Report and Literature Review

We herein report a case of encephalitis in a 42-year-old woman with hepatocellular carcinoma following atezolizumab plus bevacizumab therapy. After two weeks of treatment, she was admitted for a high fever, impaired consciousness, and convulsive seizure refractory to diazepam. Magnetic resonance imaging revealed a hyperintense splenial lesion. A cerebrospinal fluid test excluded malignancy and infection. These findings were highly suggestive of a diagnosis of encephalitis due to atezolizumab, an immune-related adverse event. Steroid pulse therapy improved the fever and seizure. However, her incomplete right-sided paralysis and aphasia persisted. This is the first case report of encephalitis caused by atezolizumab plus bevacizumab therapy for hepatocellular carcinoma.

Atezolizumab‑associated encephalitis in metastatic breast cancer: A case report

Immune checkpoint inhibitors have been critical in the treatment of advanced malignancies in recent years. Encephalitis caused by atezolizumab is an uncommon immune-related adverse event. The case of a 65-year-old female diagnosed with encephalitis closely associated with atezolizumab medication for metastatic advanced breast cancer is presented in the current study. Following a fourth atezolizumab dose 10 days previously, the patient fell into a deep coma. Initial brain magnetic resonance imaging revealed multiple patchy T2 hyperintensities in the bilateral cerebellar hemisphere, vermis of the cerebellum, bilateral frontal lobe, temporal lobe, parietal lobe and occipital cortex. Meanwhile, there were aberrant signs on diffusion-weighted imaging. The diagnosis of atezolizumab-induced encephalitis seemed probable after ruling out other possible causes of encephalitis. Subsequently, the condition of the patient worsened and there were indications of cardiac and respiratory arrest. Chest compressions were provided immediately, as well as a balloon mask for assisted ventilation, a medication boost, stimulated breathing and other symptomatic therapy. The patient's vital signs temporarily stabilised after this series of rescue measures. The patient refused further therapy and insisted on being discharged, and died a few days after being discharged from the hospital. In this case, the patient's encephalitis symptoms associated with atezolizumab were not as typical as previously documented. The patient's condition swiftly deteriorated to heartbeat apnea, and steroid pulse therapy was not received in a timely manner, resulting in an unfavourable outcome.

Immune Checkpoint Inhibitor Associated Autoimmune Encephalitis, Rare and Novel Topic of Neuroimmunology: A Case Report and Review of the Literature

Immune checkpoint inhibitors (ICIs) are being used in patients with various advanced malignancies, and patient outcomes have improved considerably. Although ICIs can effectively treat tumors, 30-60% of patients experience immune-related adverse events (irAEs). Autoimmune encephalitis (AE) is a rare irAE that has become a novel topic in neuroimmunology and has received increasing attention in recent years. Herein, we report a rare case of GAD65-antibody-associated AE after metastatic small cell lung cancer treatment with pembrolizumab. The patient received IVIg therapy for AE and continuous pembrolizumab therapy without suspension of tumor treatment. At 1 year follow-up, both the patient's AE symptoms and tumors were stable. We consider that the treatment of ICI-associated AE should be more individualized with prudent decision-making and should balance the tumor progression and AE treatment. In addition, we have also comprehensively reviewed the literature of ICI-associated AE, and summarized the clinical features, treatment, and prognosis of AE caused by ICI, thus broadening our understanding of the neurological complications caused by ICI.

Pembrolizumab-Induced Meningoencephalitis: A Brain Autopsy Case

Encephalitis is very rare, but often fatal immune-related adverse event (irAE) of immune checkpoint inhibitors (ICIs). A 65-year-old Japanese woman was admitted to our hospital because of general fatigue, chillness and high-grade fever for 4 days, 8 months after the initiation of the first-line pembrolizumab monotherapy for metastatic pulmonary adenocarcinoma. On the hospital day 3, she suddenly presented delirium and uncontrollable impaired consciousness. Although the magnetic resonance imaging (MRI) did not suggest a diagnosis of encephalitis and meningitis, the spinal fluid showed abnormally elevated levels of protein (317.6 mg/L) and cell count (197 cells/µL) with increased mononuclear cells (93%). An empirical and intravenous administration of acyclovir in doses of 10 mg/kg body weight every 8 h and steroid pulse therapy in dose of 1 g/body/day from the hospital day 5 until her death failed to improve her conditions. She died on the hospital day 8. The postmortem autopsy showed viable cancer cells in the metastatic tumor in the left occipital lobe and in the spinal fluids. However, many inflammatory cells infiltration in the meninges and perivascular cuffing were prominent especially in the brain stem and medial part of the temporal lobe. Infiltrating lymphocytes in the meninges and parenchyma of the brain stem were mainly composed of cluster of differentiation (CD)8-positive lymphocytes. For irAE encephalitis, early recognition of early signs and symptoms and subsequent early therapeutic intervention are necessary. It is important for oncologists to keep in mind of the possible adverse effects of immunotherapies on the nervous system.

Case Report: Durvalumab-Associated Encephalitis in Extensive-Stage Small Cell Lung Carcinoma

In recent years, the clinical importance of immunotherapy has been demonstrated in the treatment of extensive-stage small-cell lung cancer (ES-SCLC). However, immune checkpoint inhibitors (ICIs) have been shown to cause immune-related adverse events (irAEs), including autoimmune encephalitis. Here, we describe th treatment of a patient with ES-SCLC who developed immune-related encephalitis. A 68-year-old Japanese woman with ES-SCLC treated with carboplatin plus etoposide plus durvalumab 20 days earlier was admitted to our hospital with a high fever and anorexia. Her symptoms gradually worsened over time, and she had a headache daily and showed reduced levels of consciousness. An electroencephalogram showed diffuse slow waves, and there was a slight increase in cell counts and an increase in protein levels in the cerebrospinal fluid. The patient was diagnosed with durvalumab-associated encephalitis. Her symptoms improved immediately after steroid pulse therapy. Following steroid pulse therapy, oral prednisolone (1 mg/kg) was administered, and then, the dose was gradually reduced. Subsequently, treatment with carboplatin plus etoposide without durvalumab was restarted. In conclusion, this study shows the efficacy of steroid therapy in the treatment of durvalumab-induced encephalitis in ES-SCLC.

Neurological complications of cancer immunotherapy

Immunotherapy has emerged as a powerful therapeutic approach in many areas of clinical oncology and hematology. The approval of ipilimumab, a monoclonal antibody targeting the immune cell receptor CTLA-4, has marked the beginning of the era of immune checkpoint inhibitors. In the meantime, numerous antibodies targeting the PD-1 pathway have expanded the class of clinically approved immune checkpoint inhibitors. Furthermore, novel antibodies directed against other immune checkpoints are currently in clinical evaluation. More recently, bispecific antibodies, which link T cells directly to tumor cells as well as adoptive T cell transfer with immune cells engineered to express a chimeric antigen receptor, have been approved in certain indications. Neurological complications associated with the use of these novel immunotherapeutic concepts have been recognized more and more frequently. Immune checkpoint inhibitors may cause various neurological deficits mainly by alterations of the peripheral nervous system's integrity. These include radiculopathies, neuropathies, myopathies as well as myasthenic syndromes. Side effects involving the central nervous system are less frequent but may result in severe clinical symptoms and syndromes. The administration of chimeric antigen receptor (CAR) T cell is subject to rigorous patient selection and their use is frequently associated with neurological complications including encephalopathy and seizures, which require immediate action and appropriate therapeutic measures. Close clinical monitoring for neurological symptoms is key for early recognition of immunotherapy-related side effects. Comprehensive diagnostic work-up and adequate therapeutic measures are essential to avoid further clinical deterioration and residual neurological deficits.