Disruption of blood-brain barrier integrity associated with brain lesions in Chinese neuromyelitis optica spectrum disorder patients

NX210c drug candidate peptide strengthens mouse and human blood-brain barriers

BACKGROUND

Alterations of blood-brain barrier (BBB) and blood-spinal cord barrier have been documented in various animal models of neurodegenerative diseases and in patients. Correlations of these alterations with functional deficits suggest that repairing barriers integrity may represent a disease-modifying approach to prevent neuroinflammation and neurodegeneration induced by the extravasation of blood components into the parenchyma. Here, we screened the effect of a subcommissural organ-spondin-derived peptide (NX210c), known to promote functional recovery in several models of neurological disorders, on BBB integrity in vitro and in vivo.

METHODS

In vitro, bEnd.3 endothelial cell (EC) monolayers and two different primary human BBB models containing EC, astrocytes and pericytes, in static and microfluidic conditions, were treated with NX210c (1-100 µM), or its vehicle, for 4 h and up to 5 days. Tight junction (TJ) protein levels, permeability to dextrans and transendothelial electrical resistance (TEER) were evaluated. In vivo, young and old mice (3- and 21-month-old, respectively) were treated daily intraperitoneally with NX210c at 10 mg/kg or its vehicle for 5 days and their brains collected at day 6 to measure TJ protein levels by immunohistochemistry.

RESULTS

NX210c induced an increase in claudin-5 protein expression after 24-h and 72-h treatments in mouse EC. Occludin level was also increased after a 24-h treatment. Accordingly, NX210c decreased by half the permeability of EC to a 40-kDa FITC-dextran and increased TEER. In the human static BBB model, NX210c increased by ∼ 25% the TEER from 3 to 5 days. NX210c also increased TEER in the human 3D dynamic BBB model after 4 h, which was associated with a reduced permeability to a 4-kDa FITC-dextran. In line with in vitro results, after only 5 days of daily treatments in mice, NX210c restored aging-induced reduction of claudin-5 and occludin levels in the hippocampus, and also in the cortex for occludin.

CONCLUSIONS

In summary, we have gathered preclinical data showing the capacity of NX210c to strengthen BBB integrity. Through this property, NX210c holds great promises of being a disease-modifying treatment for several neurological disorders with high unmet medical needs.

Impact of blood-brain barrier disruption on clinical features and treatment response in patients with newly diagnosed autoimmune encephalitis

AIMS

Blood-brain barrier (BBB) breakdown is an essential mechanism in inflammatory diseases of the central nervous system. However, the association between BBB integrity and autoimmune encephalitis (AE) has not been investigated. Our study aimed to analyze this relationship in patients with AE between BBB integrity with clinical manifestations and therapeutic responses.

METHODS

Our study enrolled 147 patients with AE who were newly diagnosed at the First Affiliated Hospital of Zhengzhou University between August 2015 and December 2021. Patients were classified into normal or damaged BBB groups based on cerebrospinal fluid (CSF) albumin/serum albumin (QAlb). To evaluate the severity of the illness, we used the modified Rankin Scale (mRS) and the Clinical Assessment Scale for Autoimmune Encephalitis (CASE).

RESULTS

We found a higher proportion of males, higher CSF protein, immunoglobulin IgG, and 24-h intrathecal IgG synthesis rate in the damaged BBB group. The improvement rate was lower in the damaged BBB group, but we found that double- or triple-combination immunotherapy had better clinical outcomes than single immunotherapy. In addition, there was a positive correlation between the CASE score and mRS score, and a positive correlation between the CASE score or mRS score and QAlb on admission.

CONCLUSIONS

BBB integrity is closely related to the clinical features and treatment responses of newly diagnosed AE. Patients with AE and a damaged BBB may benefit from combination immunotherapy.

Factors influencing the degree of disability in patients with neuromyelitis optica spectrum disorders

OBJECTIVE

To investigate the factors influencing the degree of disability in patients with neuromyelitis optica spectrum disorder (NMOSD) and provide evidence for disease monitoring and clinical intervention.

METHODS

Eighty-four patients with NMOSD at Xuanwu Hospital Capital Medical University were enrolled in this retrospective study. Before treatment, blood was collected from all patients, and their expanded disability status scores were assessed.

RESULTS

Of the 84 patients assessed, 66 (78.57%) had an expanded disability status scale score < 7, and 18 (21.43%) had scores ≥ 7. The univariate analysis showed that the total bilirubin (TBil), cerebrospinal fluid albumin (CSF ALB), cerebrospinal fluid immunoglobulin G (CSF IgG), QALB, and QIgG levels in the group with scores ≥ 7 were significantly different from those with scores < 7 (P < 0.05). In addition, Spearman's correlation analysis showed a significant correlation between ALB and expanded disability status scores in patients with NMOSD (P < 0.05), and the multivariate logistic regression analysis showed that TBil was an independent factor influencing the degree of disability in patients with NMOSD (P < 0.05). The receiver operating characteristic curve was constructed using TBil values; the area under the curve of TBil was 0.729 (P < 0.01), and the best cut-off value was 11.015 g/L. Its sensitivity in predicting the severity of disability in NMOSD patients was 51.5% while its specificity was 88.9%.

CONCLUSION

TBil is an independent factor that influences the severity of disability in patients with NMOSD. In addition, ALB is closely related to NMOSD severity, and some factors associated with the BBB are significantly increased in severely disabled NMOSD patients.

Secreted aminoacyl-tRNA synthetase-interacting multifunctional protein-1 (AIMP1) is a promising predictor for the severity of acute AQP4-IgG positive neuromyelitis optica spectrum disorder

BACKGROUND AND OBJECTIVES

Aminoacyl-tRNA synthetase complex interacting with multifunctional protein-1 (AIMP1) has been reported to carry pro-inflammatory properties and anti-angiogenesis effects. However, the exact role of AIMP1 in patients with NMOSD is not yet clear. Our objective was to investigate the relationship between plasma AIMP1 levels and disease severity in patients with AQP4-IgG⁺ NMOSD from North China based on the Expanded Disability Status Scale (EDSS) score.

METHODS

Plasma AIMP1 levels were measured using ELISA kits in 94 patients with AQP4-IgG⁺NMOSD (48 in the acute phase before high-dose intravenous methylprednisolone (IVMP) therapy, 21 in the acute phase after IVMP therapy, 25 in the clinical remission-phase)as well as 33 healthy controls (HCs). The disability function of NMOSD patients was evaluated using the EDSS score. Furthermore, the clinical characteristics of the patients were also evaluated, and laboratory tests were performed on blood samples.

RESULTS

The plasma AIMP1 levels in AQP4-IgG⁺NMOSD patients with acute phase before IVMP therapy were significantly higher as compared to those in patients after the IVMP therapy (p < 0.001) as well as those in the clinical remission phase (p = 0.021) or HCs (p < 0.001). Plasma AIMP1 levels were positively correlated with EDSS scores (r = 0.485, p < 0.001) and negatively correlated with serum complement 3 concentrations (r =-0.452, p = 0.001). AIMP1 exhibited the potential to distinguish NMOSD from HCs (AUROC 0.820, p < 0.0001) and could differentiate mild and moderate-severe NMOSD (AUROC 0.790, p = 0.0006). Furthermore, plasma AIMP1 levels of ≥49.55pg/mL were found to be an independent predictor of the risk for moderate-severe NMOSD (with OR 0.03, 95%CI 0.001-0.654, p = 0.026).

CONCLUSION

AIMP1 may be involved in the pathogenesis of AQP4-IgG⁺NMOSD disease and predict the disease activity, severity, or effect of treatment in patients with NMOSD. Further studies should be performed to reveal the precise mechanisms of AQP4-IgG⁺NMOSD.

Evaluation of CSF albumin quotient in neuronal surface antibody-associated autoimmune encephalitis

Background and Objectives

Disruption of brain barriers is considered to be involved in the pathogenesis of neuronal surface antibody-associated autoimmune encephalitis (NSAE), but few studies have focused on their relationship. We aimed to explore the association between the integrity of brain barriers and clinical and paraclinical characteristics in patients with NSAE.

Methods

This retrospective study consecutively recruited patients with NSAE. The cerebrospinal fluid (CSF) / serum albumin quotient (Qalb) was used to evaluate the function of brain barriers. The data on demographic information, clinical manifestations, magnetic resonance imaging (MRI), CSF findings and prognosis were collected and analyzed.

Results

Of the 93 patients included, 33 (35.5%) patients were assigned to the elevated Qalb group and 60 (64.5%) patients to the normal Qalb group. Males and prodromal symptoms were more common in elevated Qalb group (both P < 0.05). The CSF white blood cell, protein, immunoglobulin G and albumin were significantly higher in elevated Qalb group (all P < 0.05). Patients with elevated Qalb were more likely to have brain lesions on MRI (60.6% versus 33.3%, P = 0.011). The modified Rankin Scale (mRS) scores at discharge and at last follow-up were significantly higher in patients with elevated Qalb than those with normal Qalb (both P < 0.05). After univariate and multivariate analyses, Qalb elevation (adjusted odds ratio = 3.96, 95% confidence interval = 1.15–13.59, P = 0.029) was demonstrated as the only independent risk factor for a poor prognosis.

Discussion

Males, prodromal symptoms, brain lesions on MRI, CSF pleocytosis, and elevated CSF protein were more common in NSAE patients with increased Qalb. Qalb elevation was an independent prognostic indicator for a poor prognosis in NSAE.

Serum glial fibrillary acidic protein indicates memory impairment in patients with chronic heart failure

Aims

Cognitive dysfunction occurs frequently in patients with heart failure (HF), but early detection remains challenging. Serum glial fibrillary acidic protein (GFAP) is an emerging biomarker of cognitive decline in disorders of primary neurodegeneration such as Alzheimer's disease. We evaluated the utility of serum GFAP as a biomarker for cognitive dysfunction and structural brain damage in patients with stable chronic HF.

Methods and results

Using bead‐based single molecule immunoassays, we quantified serum levels of GFAP in patients with HF participating in the prospective Cognition.Matters‐HF study. Participants were extensively phenotyped, including cognitive testing of five separate domains and magnetic resonance imaging (MRI) of the brain. Univariable and multivariable models, also accounting for multiple testing, were run. One hundred and forty‐six chronic HF patients with a mean age of 63.8 ± 10.8 years were included (15.1% women). Serum GFAP levels (median 246 pg/mL, quartiles 165, 384 pg/mL; range 66 to 1512 pg/mL) did not differ between sexes. In the multivariable adjusted model, independent predictors of GFAP levels were age (T = 5.5; P < 0.001), smoking (T = 3.2; P = 0.002), estimated glomerular filtration rate (T = −4.7; P < 0.001), alanine aminotransferase (T = −2.1; P = 0.036), and the left atrial end‐systolic volume index (T = 3.4; P = 0.004). NT‐proBNP but not serum GFAP explained global cerebral atrophy beyond ageing. However, serum GFAP levels were associated with the cognitive domain visual/verbal memory (T = −3.0; P = 0.003) along with focal hippocampal atrophy (T = 2.3; P = 0.025).

Conclusions

Serum GFAP levels are affected by age, smoking, and surrogates of the severity of HF. The association of GFAP with memory dysfunction suggests that astroglial pathologies, which evade detection by conventional MRI, may contribute to memory loss beyond ageing in patients with chronic HF.

Expression and Clinical Correlation Analysis Between Repulsive Guidance Molecule a and Neuromyelitis Optica Spectrum Disorders

Objectives

This study sought to explore the expression patterns of repulsive guidance molecules a (RGMa) in neuromyelitis optica spectrum disorders (NMOSD) and to explore the correlation between RGMa and the clinical features of NMOSD.

Methods

A total of 83 NMOSD patients and 22 age-matched healthy controls (HCs) were enrolled in the study from October 2017 to November 2021. Clinical parameters, including Expanded Disability Status Scale (EDSS) score, degree of MRI enhancement, and AQP4 titer were collected. The expression of serum RGMa was measured by enzyme-linked immunosorbent assay (ELISA) and compared across the four patient groups. The correlation between serum RGMa levels and different clinical parameters was also assessed.

Results

The average serum expression of RGMa in the NMOSD group was significantly higher than that in the HC group (p < 0.001). Among the patient groups, the acute phase group exhibited significantly higher serum RGMa levels than did the remission group (p < 0.001). A multivariate analysis revealed a significant positive correlation between RGMa expression and EDSS score at admission, degree of MRI enhancement, and segmental length of spinal cord lesions. There was a significant negative correlation between the expression of RGMa in NMOSD and the time from attack to sampling or delta EDSS.

Conclusions

The current study suggests that RGMa may be considered a potential biomarker predicting the severity, disability, and clinical features of NMOSD.

The Clinical Features and Prognosis of Anti-NMDAR Encephalitis Depends on Blood Brain Barrier Integrity

BACKGROUND

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune nervous system disease that has become increasingly recognized. This retrospective study is aimed to analyze the relations between clinical manifestations and blood brain barrier (BBB) integrity in anti-NMDAR encephalitis patients.

METHODS

Anti-NMDAR encephalitis patients were admitted to the First Affiliated Hospital of Guangxi Medical University from April 2014 to April 2020. Patients were grouped by the normal BBB and damaged BBB groups according to the cerebrospinal fluid (CSF) albumin/serum albumin (QAlb). Neutrophil-to-lymphocyte ratio (NLR) in peripheral blood was used for estimating the inflammatory status. The modified Rankin Scale (mRS) was used to assess prognosis.

RESULTS

Seventy-three anti-NMDAR encephalitis patients were diagnosed based on the autoimmune encephalitis diagnosis criteria of 2016. Fifty-three (72.6%) patients were in the normal BBB group and twenty (27.4%) were in the BBB damaged group. There were no significant differences in gender, age, psychiatric disturbances, epilepsy, speech disorder, motor dysfunction, memory dysfunction, and autonomic dysfunction between the two groups (p>0.05). Nevertheless, the proportions of decreased consciousness, ICU admission, NLR, CSF protein and intrathecal IgG synthesis (IgGIF, IgGLoc) in the damaged BBB group were higher than that in the normal BBB group (p<0.05). Patients (79.2%) with normal BBB had good prognosis compared to patients with damaged BBB (50%) after 2 months follow-up. The median mRS before and after immunotherapy in the damaged BBB group were significantly higher than that in the normal BBB group (p<0.01, p<0.05, respectively). Additionally, QAlb increased was positively correlated with the quantitative intrathecal IgG synthesis (IgGLoc: r=0.66; IgGIF: r=0.433, all p<0.001).

CONCLUSION

The dysfunction of BBB can be helpful in evaluating its prognosis since QAlb showed associations with ICU admission, NLR, a higher CSF protein, intrathecal IgG synthesis (IgGLoc, IgGIF) and mRS score after 2 months follow-up.