Clinical scales in autoimmune encephalitis-A retrospective monocentric cohort study

Evaluation of the clinical assessment scale for autoimmune encephalitis (CASE) in a retrospective cohort and a systematic review

BACKGROUND

Autoimmune encephalitis (AE) poses significant challenges in clinical management, requiring effective monitoring tools for therapeutic success and relapse detection. This study aims to assess the Clinical Assessment Scale in Autoimmune Encephalitis (CASE) as compared to the modified Rankin scale (mRS) in evaluating AE patients and to determine the real-world adoption of the CASE score.

METHODS

A retrospective cohort study was conducted on 20 AE patients, assessing clinical data including symptomatology, diagnostic findings, and therapeutic regimens. Furthermore, we performed a systematic review on the test performance criteria and the real-world use of the CASE score.

RESULTS

The CASE score showed a higher sensitivity in detecting clinical changes compared to the mRS, with a significant correlation between the two scales throughout the disease course (r = 0.85, p < 0.01). A systematic review of 150 articles revealed widespread adoption of the CASE score, especially in Asian populations, demonstrating high reliability and internal consistency.

DISCUSSION

Despite limitations such as retrospective design and small sample size, our findings underscore the CASE score's utility in both clinical practice and research settings. The CASE score emerges as a valuable tool for monitoring AE patients, offering improved sensitivity over existing scales like the mRS. Further validation studies in diverse populations are warranted to establish its broader applicability and inform future therapeutic interventions.

Therapeutic potential of natural killer cells in neuroimmunological diseases

Natural killer (NK) cells, a major component of the innate immune system, have prominent immunoregulatory, antitumor proliferation, and antiviral activities. NK cells act as a double-edged sword with therapeutic potential in neurological autoimmunity. Emerging evidence has identified NK cells are involved in the development and progression of neuroimmunological diseases such as multiple sclerosis, neuromyelitis optica spectrum disorders, autoimmune encephalitis, Guillain-Barré Syndrome, chronic inflammatory demyelinating polyneuropathy, myasthenia gravis, and idiopathic inflammatory myopathy. However, the regulatory mechanisms and functional roles of NK cells are highly variable in different clinical states of neuroimmunological diseases and need to be further determined. In this review, we summarize the evidence for the heterogenic involvement of NK cells in the above conditions. Further, we describe cutting-edge NK-cell-based immunotherapy for neuroimmunological diseases in preclinical and clinical development and highlight challenges that must be overcome to fully realize the therapeutic potential of NK cells.

CSF Findings in Chinese Patients with NMDAR, LGI1 and GABABR Antibody-Associated Encephalitis

Purpose

CSF inflammation in subtypes of antibody-defined autoimmune encephalitis (AE) ranges in intensity from moderate to severe. In a retrospective, cross-sectional study, we characterized CSF findings in Chinese patients with anti-N-methyl-D-aspartate receptor encephalitis (NMDAR-E), anti-leucine-rich glioma-inactivated 1 encephalitis (LGI1-E), and anti-gamma aminobutyric acid-B receptor encephalitis (GABABR-E).

Patients and Methods

The AE cases, including 102 NMDAR-E, 68 LGI1-E and 15 GABABR-E, were included. CSF inflammatory parameters consisted primarily of CSF leukocytes, oligoclonal bands (OCBs), and CSF/serum albumin ratios (QAlb). Ten serum cytokines were evaluated in order to classify AE subtypes.

Results

88% of NMDAR-E, 80% of GABABR-E, and 51% of LGI1-E patients had aberrant CSF features. In NMDAR-E, the CSF leukocyte count, CSF protein concentration, and age-adjusted QAlb were significantly higher than in LGI1-E, but did not differ from GABABR-E. Blood-CSF barrier dysfunction was less common in NMDAR-E patients with >40 years old. On admission, inflammatory CSF response was more prevalent in NMDAR-E patients with a higher CASE score. With age <60 years, CSF inflammatory changes were less frequent in LGI1-E patients, but more common in GABABR-E patients. MCP-1, IL-10, IL-1β, and IL-4 were potential classifiers for NMDAR-E, LGI1-E, and GABABR-E, and correlated substantially with CSF leukocyte count and QAlb.

Conclusion

Subtype-specific patterns are formed by the various inflammatory CSF parameters in NMDAR-E, LGI1-E, and GABABR-E, and their correlation with disease severity, age, and disease duration. CSF inflammatory characteristics associated with MCP-1, IL-10, IL-1β, and IL-4 may be potential immunopathogeneses targeting markers for these AE subtypes.

Outcome and Sequelae of Autoimmune Encephalitis

Autoimmune etiologies are a common cause for encephalitis. The clinical syndromes consistent with autoimmune encephalitis are both distinct and increasingly recognized, but less is known about persisting sequelae or outcomes. We searched PubMed for reports on outcomes after autoimmune encephalitis. Studies assessing validated, quantitative outcomes were included. We performed a narrative review of the published literature of outcomes after autoimmune encephalitis. We found 146 studies that produced outcomes data. The mortality rates were 6%-19% and the relapse risks were 10%-62%. Most patients achieved a good outcome based on a score on the modified Rankin Scale (mRS) of ≤2. Forty-nine studies evaluated outcomes beyond mRS; these studies investigated cognitive outcome, psychiatric sequelae, neurological deficits, global function, and quality-of-life/patient-reported outcomes using various tools at varying time points after the index hospital discharge. These more-detailed assessments revealed that most patients had persistent impairments, with frequent deficits in cognitive function, especially memory and attention. Depression and anxiety were also common. Many of these sequelae continued to improve over months or even years after the acute illness. While we found that lasting impairments were common among survivors of autoimmune encephalitis, additional research is needed to better understand the nature and impact of these sequelae. Standardized evaluation protocols are needed to improve the ability to compare outcomes across studies, guide rehabilitation strategies, and inform outcomes of interest in treatment trials as the field advances.