Amyloid and Tau as cerebrospinal fluid biomarkers in anti-N-Methyl-D-aspartate receptor encephalitis.

INTRODUCTION: Neuroinfection is associated with the deposition of amyloid-beta (Aß) peptides, and subsequent decrease in cerebrospinal fluid (CSF) amyloid levels. However, whether autoimmune encephalitis involves extracellular deposition of Aß peptides in the brain is unreported. METHODS: We examined CSF amyloid and tau values in adults with anti-N-methyl-D-aspartate receptor encephalitis (NMDAR-E). Forty-two patients with NMDAR-E, 35 patients with viral and bacterial neuroinfections, and 16 controls were included. We measured CSF Aß1-42 (cAß1-42), Aß1-40 (cAß1-40), t-Tau (ct-Tau), and p-Tau181 (cp-Tau181) levels and assessed their efficacies regarding differential diagnosis and predicting prognosis. RESULTS: NMDAR-E patients had lower cAß1-42 levels; however, they were higher than those of patients with bacterial meningitis. ct-Tau levels in NMDAR-E patients were lower than those in patients with neuroinfections. No changes were observed in controls. cAß1-42 and ct-Tau were combined as an excellent marker to distinguish NMDAR-E from neuroinfections. cAß1-42 levels in NMDAR-E patients were positively correlated with Montreal Cognitive Assessment scores. We observed an inverse relationship between cAß1-42 levels and modified Rankin Scale scores. Patients with poor outcomes exhibited low cAß1-42 levels and high levels of several blood parameters. cAß1-42 was the highest quality biomarker for assessing NMDAR-E prognosis. Correlations were found between cAß1-42 and some inflammatory indicators. CONCLUSION: cAß1-42 was decreased in NMDAR-E patients. cAß1-42 levels indicated NMDAR-E severity and acted as a biomarker for its prognosis. Combining cAß1-42 and ct-Tau levels could serve as a novel differential diagnostic marker for NMDAR-E.

Associations between sarcopenia and circulating branched-chain amino acids: a cross-sectional study over 100,000 participants.

BACKGROUND: Emerging evidence suggests that alterations in BCAA metabolism may contribute to the pathogenesis of sarcopenia. However, the relationship between branched-chain amino acids (BCAAs) and sarcopenia is incompletely understood, and existing literature presents conflicting results. In this study, we conducted a community-based study involving > 100,000 United Kingdom adults to comprehensively explore the association between BCAAs and sarcopenia, and assess the potential role of muscle mass in mediating the relationship between BCAAs and muscle strength. METHODS: Multivariable linear regression analysis examined the relationship between circulating BCAAs and muscle mass/strength. Logistic regression analysis assessed the impact of circulating BCAAs and quartiles of BCAAs on sarcopenia risk. Subgroup analyses explored the variations in associations across age, and gender. Mediation analysis investigated the potential mediating effect of muscle mass on the BCAA-muscle strength relationship. RESULTS: Among 108,017 participants (mean age: 56.40 ± 8.09 years; 46.23% men), positive associations were observed between total BCAA, isoleucine, leucine, valine, and muscle mass (beta, 0.56-2.53; p < 0.05) and between total BCAA, leucine, valine, and muscle strength (beta, 0.91-3.44; p < 0.05). Logistic regression analysis revealed that increased circulating valine was associated with a 47% reduced sarcopenia risk (odds ratio = 0.53; 95% confidence interval = 0.3-0.94; p = 0.029). Subgroup analyses demonstrated strong associations between circulating BCAAs and muscle mass/strength in men and individuals aged ≥ 60 years. Mediation analysis suggested that muscle mass completely mediated the relationship between total BCAA, and valine levels and muscle strength, partially mediated the relationship between leucine levels and muscle strength, obscuring the true effect of isoleucine on muscle strength. CONCLUSION: This study suggested the potential benefits of BCAAs in preserving muscle mass/strength and highlighted muscle mass might be mediator of BCAA-muscle strength association. Our findings contribute new evidence for the clinical prevention and treatment of sarcopenia and related conditions involving muscle mass/strength loss.

[Molecular Mechanism and family research of a pedigree with B(A).06 subtype].

OBJECTIVE: To explore the serological and genotypic characteristics of a pedigree with B(A).06 subtype. METHODS: Serological methods was used to identify the ABO phenotypes. Exons 6 and 7 of the ABO gene and flanking regions were subjected to direct sequencing and TA clonal sequencing in order to determine the genotype of individuals with inconsistent results for forward and reverse serological typing. RESULTS: Among 12 individuals from 4 generations, 5 were identified with a AwB phenotype, along with a c.803C>G mutation in exon 7 of the B allele, which was named as B(A).06. The B(A).06/O.01.01 phenotype may be easily missed due to its weak anti-A antibody in the serum upon initial serological test. CONCLUSION: A B(A).06 subtype family was identified. The serological phenotype of individuals carrying the B(A).06 allele may be affected by the opposite DNA strand.

[An investigation on correlation of severity of brain injury with the expression of activin A and C-reactive protein].

OBJECTIVE: To determine the dynamic change in serum levels of activin A (ACTA) and C-reaction protein (CRP) in patients with brain injury, and to investigate its significance. METHODS: A prospective study was conducted. A total of 57 adult patients with brain injury occurring within 24 hours admitted to intensive care unit (ICU) of the First Affiliated Hospital of Zhengzhou University from August 2012 to June 2013 were enrolled. The patients were allocated into three groups according to their Glasgow coma scale (GCS) as follows: minor brain injury (GCS 13-15, n=17), moderate brain injury (GCS 9-12, n=18), heavy brain injury (GCS 3-8, n=22). The clinical and related laboratory data (reflecting the function of liver, kidney, lung, blood coagulability etc.) were recorded after ICU admission. At the same time, venous samples were collected on the day 1, 2, 3, 5, 7 after ICU admission for determination of ACTA with enzyme linked immunosorbent assay (ELISA) and CRP with fluorescence immunoassay technology. The correlation between ACTA and CRP was analyzed by linear correlation. The receiver operating characteristic (ROC) curve was plotted to analyze the accuracy of ACTA and CRP as a prognostic indicator in brain injury. Fifteen healthy persons were enrolled as the control group. RESULTS: The serum levels of ACTA and CRP in patients with minor, moderate and heavy brain injury were significantly higher than those in healthy control group [ACTA (µg/L): 23.96±3.55, 42.06±5.67, 52.32±4.46 vs. 13.66±2.45, all P<0.01; CRP (mg/L): 14.12±2.45, 23.05±2.85, 30.93±2.35 vs. 3.42±2.25, all P<0.01]. As the patients' condition worsening, levels of ACTA and CRP tended to elevate (all P<0.01). Levels of ACTA and CRP in minor, moderate and heavy brain injury groups were increased after ICU admission. On day 3, levels of serum ACTA and CRP reached the peak values [ACTA (µg/L):30.62±2.54, 51.35±2.55, 60.52±2.55; CRP (mg/L): 18.62±2.64, 30.35±2.25, 37.52±2.55], and then they lowered gradually. In minor and moderate brain injury groups, the levels of ACTA and CRP were slowly descending, and on day 7, they maintained at a lower level [ACTA (µg/L): 13.68±2.54, 37.74±2.55; CRP (mg/L): 6.68±2.44, 19.74±2.55]. On the contrary, the levels of ACTA and CRP in heavy brain injury group persistently maintained at a high level on day 7 [ACTA: (42.32±2.54) µg/L, CRP: (33.32±2.56) mg/L]. There were significant differences in ACTA and CRP among different degrees of brain injury groups (all P<0.01). There was a positive correlation between ACTA and CRP (r=0.958, P=0.007). ROC curve analysis showed that the sensitivity for brain injury prediction was 93.3% for ACTA with specificity 95.0%, area under ROC curve(AUC) 0.843, and the sensitivity for CRP was 89.1% with specificity 68.2%, AUC 0.723. CONCLUSIONS: Serum levels of ACTA and CRP in patients with brain injury are strongly correlated with the severity of the injury. Furthermore, ACTA is more sensitive than CRP in detecting early brain injury. Therefore, ACTA is a specific factor for detecting brain injury.