Lipid profiles and their potential inflammatory effects in anti-N-methyl-D-aspartate receptor encephalitis

Distinct plasma metabolomic signatures differentiate autoimmune encephalitis from drug-resistant epilepsy

OBJECTIVE

Differentiating forms of autoimmune encephalitis (AE) from other causes of seizures helps expedite immunotherapies in AE patients and informs studies regarding their contrasting pathophysiology. We aimed to investigate whether and how Nuclear Magnetic Resonance (NMR)-based metabolomics could differentiate AE from drug-resistant epilepsy (DRE), and stratify AE subtypes.

METHODS

This study recruited 238 patients: 162 with DRE and 76 AE, including 27 with contactin-associated protein-like 2 (CASPR2), 29 with leucine-rich glioma inactivated 1 (LGI1) and 20 with N-methyl-d-aspartate receptor (NMDAR) antibodies. Plasma samples across the groups were analyzed using NMR spectroscopy and compared with multivariate statistical techniques, such as orthogonal partial least squares discriminant analysis (OPLS-DA).

RESULTS

The OPLS-DA model successfully distinguished AE from DRE patients with a high predictive accuracy of 87.0 ± 3.1% (87.9 ± 3.4% sensitivity and 86.3 ± 3.6% specificity). Further, pairwise OPLS-DA models were able to stratify the three AE subtypes. Plasma metabolomic signatures of AE included decreased high-density lipoprotein (HDL, -(CH2)n-, -CH3), phosphatidylcholine and albumin (lysyl moiety). AE subtype-specific metabolomic signatures were also observed, with increased lactate in CASPR2, increased lactate, glucose, and decreased unsaturated fatty acids (UFA, -CH2CH=) in LGI1, and increased glycoprotein A (GlycA) in NMDAR-antibody patients.

INTERPRETATION

This study presents the first non-antibody-based biomarker for differentiating DRE, AE and AE subtypes. These metabolomics signatures underscore the potential relevance of lipid metabolism and glucose regulation in these neurological disorders, offering a promising adjunct to facilitate the diagnosis and therapeutics.

Influential Factors, Treatment and Prognosis of Autoimmune Encephalitis Patients With Poor Response to Short-Term First-Line Treatment

Objective

This study was performed to assess the potential factors for poor short-term first-line treatment response, the appropriate further treatment options, and the prognosis in patients with autoimmune encephalitis (AE).

Methods

This retrospective study consisted of 135 patients with AE. According to their short-term first-line treatment response, patients were divided into the response group and the non-response group. The demographics, clinical characteristics, main accessory examinations, immunotherapy, and outcomes of patients were compared between the two groups. Univariate and multivariate logistic regression models were used to analyze whether non-responders have poor long-term outcomes. Further treatment and prognosis of non-responders were also analyzed.

Results

Of the 128 patients who were treated with first-line immunotherapy, 59 (46.1%) were non-responders. Patients in the non-response group had more symptoms and exhibited a higher proportion of mental behavior disorder, central hypoventilation, and autonomic nervous dysfunction. The modified Rankin scale (mRS) scores and neutrophil-to-lymphocyte ratio (NLR) levels were significantly higher and albumin, high-density lipoprotein cholesterol (HDL-C), apolipoprotein A (apoA) levels were significantly lower in the non-response group (p < 0.05, all). Multivariate logistic regression analysis showed that the number of clinical symptoms, mental behavior disorder, central hypoventilation, maximum mRS score, and albumin level was independently associated with non-response to short-term first-line treatment. Non-responders had poor long-term outcomes compared with the responders at all times of followed-up (p < 0.05, all). In multivariable analysis, initial first-line treatment response was independently associated with the long-term prognosis, both at 12-month [odds ratio (OR), 4.74, 95% CI, 1.44–15.59, and p=0.010] and 24-month follow-ups (OR, 8.81, 95% CI, 1.65–47.16; and p = 0.011). Among the non-responders, a higher improvement of mRS scores was observed in those who received second-line treatment than those who had no further treatment or repetition of first-line immunotherapy in the follow-up. However, the rate of a good outcome and median mRS scores were not significantly different among the three groups.

Conclusion

Disease severity, clinical features, anti-N-methyl-D-aspartate receptor subtypes, antibody titers, NLR, albumin, HDL-C, and apoA levels were all associated with non-response to short-term first-line treatment. The short-term first-line treatment response is a valuable predictor of long-term outcomes in patients with AE. Second-line immunotherapy may be a more aggressive treatment option for patients who failed short-term first-line immunotherapy.

Simple and effective serum biomarkers potential for predicting status epilepticus in anti-N-methyl-D-aspartate receptor encephalitis

Background

Patients with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis who also present with status epilepticus (SE) often have a poor prognosis. The aim of this study is to explore simple and effective predictors for anti-NMDAR encephalitis accompanied with SE.

Methods

We retrospectively analyzed 65 anti-NMDAR encephalitis patients from January 2015 to December 2018 who admitted to the Third Affiliated Hospital of Sun Yat-sen University. Patients were divided into SE group and non-SE groups. Their pre-treatment data and 3-month follow-up data were retrospectively analyzed.

Results

The results showed that compared with the non-SE group, the levels of serum uric acid (UA) and high-density lipoprotein cholesterol (HDL-C) in anti-NMDAR encephalitis patients with SE decreased significantly before treatment. Additionally, the levels of serum UA and HDL-C increased while the level of C-reactive protein (CRP) decreased 3 months after treatment in the SE group. Compared with the non-SE group, the SE patients had higher modified Rankin scale (mRS) scores before (mRS1) and after treatment (mRS2). Serum UA concentrations before treatment showed significantly negative correlations with mRS1 (r = − 0.407, p < 0.01) and mRS2 (r = − 0.458, p < 0.001), while the level of serum CRP before treatment had strong positive correlations with mRS1 (r = 0.304, p < 0.05) and mRS2 (r = 0.301, p < 0.05) in anti-NMDAR encephalitis patients. The receiver operating characteristic curve demonstrated that the combined detection of UA, HDL-C and CRP before treatment had a significantly higher value (the area under the curve = 0.848; 95% confidence interval [CI], 0.74–0.957; p < 0.001) to predict anti-NMDAR encephalitis accompanied with SE than that of single detection.

Conclusions

Hence, the combined detection of serum UA, HDL-C and CRP before treatment may be simple and effective indicators for predicting SE in anti-NMDAR encephalitis, which may be helpful in early stages to remind clinicians to be alert to the emergence of SE.