Clinical Characteristics and Predictors of Outcome for Onconeural Antibody-Associated Disorders: A Retrospective Analysis

Second-line immunotherapy and functional outcomes in autoimmune encephalitis: A systematic review and individual patient data meta-analysis

Autoimmune encephalitis (AE) is a neurological disorder caused by autoimmune attack on cerebral proteins. Experts currently recommend staged immunotherapeutic management, with first-line immunotherapy followed by second-line immunotherapy if response to first-line therapy is inadequate. Meta-analysis of the evidence base may provide higher quality evidence to support this recommendation. We undertook a systematic review of observational cohort studies reporting AE patients treated with either second-line immunotherapy or first-line immunotherapy alone, and outcomes reported using the modified Rankin Scale (mRS; search date: April 22, 2020). We performed several one-stage multilevel individual patient data (IPD) meta-analyses to examine the association between second-line immunotherapy and final mRS scores (PROSPERO ID CRD42020181805). IPD were obtained for 356 patients from 25 studies. Most studies were rated as moderate to high risk of bias. Seventy-one patients (71/356, 19%) were treated with second-line immunotherapy. We did not find a statistically significant association between treatment with second-line immunotherapy and final mRS score for the cohort overall (odds ratio [OR] = 1.74, 95% confidence interval [CI] = .98-3.08, p = .057), or subgroups with anti-N-methyl-D-aspartate receptor encephalitis (OR = 1.03, 95% CI = .45-2.38, p = .944) or severe AE (maximum mRS score > 2; OR = 1.673, 95% CI = .93-3.00, p = .085). Treatment with second-line immunotherapy was associated with higher final mRS scores in subgroups with anti-leucine-rich glioma-inactivated 1 AE (OR = 6.70, 95% CI = 1.28-35.1, p = .024) and long-term (at least 12 months) follow-up (OR = 3.94, 95% CI = 1.67-9.27, p = .002). We did not observe an association between treatment with second-line immunotherapy and lower final mRS scores in patients with AE. This result should be interpreted with caution, given the risk of bias, limited adjustment for disease severity, and insensitivity of the mRS in estimating psychiatric and cognitive disability.

Evaluation of the Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes in China

Background

Recently, the paraneoplastic neurologic syndrome (PNS) diagnostic criteria have received a major update with a new score system over the past 16 years. We aimed to evaluate the diagnostic performance and clinical utility in China.

Methods

An eligible cohort of 113 Chinese patients diagnosed with PNSs from the Second Affiliated Hospital School of Medicine Zhejiang University and published data were enrolled retrospectively. Data including clinical phenotype, antibody type, the presence of cancer, and duration of follow-up were reviewed and re-evaluated to classify the diagnostic levels for the 2004 and 2021 PNS criteria. The performances of these 2 criteria were compared. The critical parameters of antibody and cancer for the updated criteria were further explored.

Results

The cohort consisted of 69 males and 44 females with a median age of 60 years. Limbic encephalitis (23, 20.4%), anti-Hu antibody (32, 28.3%), and small-cell lung cancer (32, 28.3%) were the most common clinical phenotype, detected antibody, and concomitant cancer, respectively. A total of 97 (85.8%) patients were diagnosed with definite PNS according to the 2004 criteria: only 42.3% (41/97) fulfilled the 2021 criteria, while the remaining 40, 14, and 2 re-diagnosed with probable PNS, possible PNS, and non-PNS. The requirement of cancers consistent with antibody and phenotype increased the specificity and thus greatly enhanced the accuracy of the 2021 criteria.

Conclusion

The updated criteria for PNS emphasized the consistency between cancer phenotype and antibody and showed a better diagnostic value. A better diagnostic yield could benefit disease management.

Diagnosing autoimmune encephalitis in a real-world single-centre setting

BACKGROUND

Early recognition and treatment of autoimmune encephalitis (AE) are crucial for patients, but diagnosis is often difficult and time-consuming. For this purpose, a syndrome-based diagnostic approach was published by Graus et al. (Lancet Neurol 15:391-404, 2016), but very little is known in the literature about its application in clinical practice.

AIM

Our aims are to test the feasibility of such approach in a real-world single-centre setting and to analyse the most relevant factors in criteria fulfilment.

METHODS

We retrospectively applied these criteria to our cohort of patients discharged from our hospital with diagnosis of autoimmune encephalitis (n = 33, 58% antibody-positive).

RESULTS

All the subjects fulfilled criteria for possible AE (pAE), with EEG and MRI playing a central role in diagnosis, while CSF was useful mainly to rule out other conditions. Three patients respected criteria for probable anti-NMDA-R encephalitis (pNMDA). Definite anti-NMDAR encephalitis was diagnosed in 4 patients with detection of the autoantibody but, surprisingly, none of these subjects had fulfilled criteria for pNMDA. 18 patients were diagnosed with definite limbic AE (15 patients were antibody-positive, three antibody-negative). Need for MRI bilateral involvement in antibody-negative limbic AE limited diagnosis. One patient fulfilled criteria for probable antibody-negative AE, while ten patients remained classified as pAE.

CONCLUSION

From our retrospective analysis, some suggestions for a better definition of the criteria may emerge. Larger studies on prospective cohorts may be more helpful to explore possible important issues.

Neuronal damage and neuroinflammation markers in patients with autoimmune encephalitis and multiple sclerosis

Inflammatory diseases of the central nervous system (CNS) are a diagnostic challenge to clinicians. Autoimmune encephalitis (AE) is an important diagnostic consideration in patients with CNS inflammatory disorders; despite of a wide range of neuropsychiatric symptoms it should be diagnosed as soon as possible and the patient transferred to the neurologist. We studied a group of AE patients (n = 24) as compared to multiple sclerosis (MS, n = 61) and control (n = 19) groups. Detailed clinical pictures of patients are presented. We focused on relevant cerebrospinal fluid (CSF) tests like protein levels, cytosis and oligoclonal bands, neuroinflammation indices (interleukin-6, soluble receptor of IL-6, neopterin, anti-ribosomal proteins antibodies) and markers of neurodegeneration (phosphorylated neurofilament heavy chain, pNfh). Elevated neopterin level was found in AE group as compared to the MS and control groups, while protein and pNfh were increased in both AE and MS groups. In the MS group, the cytosis and soluble receptor of IL-6 were higher as compared to the control group. Anti-ribosomal proteins antibodies were increased in a single patient with AE. High levels of protein were predictive of mortality in AE patients, while IL-6 and pNfh were elevated in severe AE patients. AE patients with paraneoplastic etiology demonstrated oligoclonal bands positivity. Taken together, our results suggest the neopterin as an additional marker of autoimmune brain inflammation. Though higher levels of protein, IL-6 and pNfh were found in patients with severe disease progression and death, prognostic values of these markers should be validated in larger cohorts of patients.

Clinical characteristics and factors associated with short-term prognosis in adult patients with autoimmune encephalitis of non-neoplastic etiology

BACKGROUND

Reports that autoimmune encephalitis (AE) is associated with antibodies have increased; however, little is known about the distribution of clinical symptoms, imaging changes, and prognostic factors in patients with AE of non-neoplastic etiology. Accordingly, we evaluated the clinical characteristics and factors associated with short-term prognosis.

METHODS

From January 2016 to June 2018, 31 adult patients were diagnosed with AE of non-neoplastic etiology at Shengjing Hospital of China Medical University and their demographic and clinical characteristics were abstracted. Factors affecting disease severity and predictors of prognosis were analyzed.

RESULTS

Among 31 patients, 19 had anti-NMDAR, 5 had anti-GABABR, and 7 had anti-LGI1 antibody encephalitis. Status epilepticus, ataxia, and cognitive dysfunction were the most common neurological symptoms. Deep white matter (DWM) abnormalities were the most common changes observed on MRI. Logistic regression analysis indicated that conscious disturbance (odds ratio = 11.67, 95%, confidence interval 2.13-64.04; p = 0.005) is an independent factor associated with poor prognosis in AE.

CONCLUSION

The clinical manifestations of AE are diverse; status epilepticus, ataxia, and cognitive dysfunction are most common. The DWM of the brain, rather than the limbic lobe system, was most prone to MR signal abnormalities. Conscious disturbance may be an important predictor of poor short-term prognosis in patients with AE of non-neoplastic etiology.

Paraneoplastic limbic encephalitis associated with lung cancer

Paraneoplastic limbic encephalitis (PLE) is a rare autoimmune neurological syndrome observed in lung cancer patients. We retrospectively investigated the clinical characteristics, treatment responses, and prognoses in 16 PLE patients who were subsequently diagnosed with lung cancer. Fifteen patients initially presented with disturbance of consciousness, 13 with disorientation, and 12 with seizures. Thirteen patients had autoantibodies, including eight with gamma aminobutyric acid B receptor (GABABR) antibodies and eight with Hu antibodies. PET-CT revealed lung neoplasms in 13 patients, nine of whom exhibited abnormal metabolic activity in the temporal lobe and hippocampus. Fifteen cases were confirmed as limited-stage small cell lung cancer and one as stage IV large cell neuroendocrine carcinoma. Eleven patients received immunomodulatory therapy, and four showed neurological improvement, who all had antibodies against GABABR. Fifteen patients received chemotherapy, of which 14 maintained or improved their PLE status. The overall cancer response rate was 75%, and two-year overall survival was 74.7%. Our results suggest patients with GABAB encephalitis might respond better to immunotherapy than the classical PLE patients with anti-Hu antibodies. Anti-cancer treatment could further improve neurological symptoms. Lung cancer patients with PLE, especially those in limited stage, might have better outcome due to earlier diagnosis and prompt anti-cancer treatment.