ABSTRACT
INTRODUCTION: Plasma phosphorylated tau (p-tau)217 is a promising biomarker for Alzheimer's disease (AD) diagnosis, but its clinical implementation remains challenging. We propose a strategy based on Bayes' theorem and test it in real-life memory clinics. METHODS: Memory clinic patients were evaluated by neurocognitive specialists for prespecified diagnosis and subsequently underwent blood collection for p-tau217, cerebrospinal fluid, or amyloid positron emission tomography. Using cross-validation, the Bayesian approach (pretest probability × individualized likelihood ratio) was compared to other models for AD diagnosis. RESULTS: The Bayesian strategy demonstrated an area under the receiver operating characteristic curve (AUC) of 0.98 (95% confidence interval [CI]: 0.96-1.0), significantly outperforming multivariable logistic regression (p-tau217, age, apolipoprotein E; AUC 0.95, p = 0.024) and p-tau217 alone (AUC = 0.94, p = 0.007). When applying the two-threshold approach, the Bayesian strategy yielded an accuracy of 0.94 (95% CI: 0.88-1.0) without requiring confirmatory tests in 62.9% of the iterations. DISCUSSION: The Bayesian strategy offers an effective and flexible approach to address the limitations of plasma p-tau217 in clinical practice. HIGHLIGHTS: Incorporating pretest probability into the interpretation of plasma phosphorylated tau (p-tau)217 improves the diagnostic performance significantly. The strategy could obviate the need for confirmatory testing in most of the patients. Plasma p-tau217 proves useful as a biomarker for Alzheimer's disease in low- and middle-income country such as Thailand.
ABSTRACT
Introduction: Numerous reports regarding cognitive deficits after the coronavirus disease 2019 (COVID-19), described as "brain fog," have been published. However, the clinical presentations and risk factors of post-COVID-19 cognitive impairment are controversial. This study aimed to assess (a) the prevalence of cognitive impairment after COVID-19 hospitalization, (b) characteristics of the cognitive deficits, (c) risk factors of post-COVID-19 cognitive impairment, and (d) comparison of cognitive function between post-COVID-19 patients and healthy people. Methods: The study comprised 34 SARS-CoV-2-infected patients, admitted to the Neurological Institute of Thailand during the peak of COVID-19 pandemic in 2021-2022. These patients came for neuropsychological and clinical evaluations at 2-week follow-up visit. The cognitive impairment and characteristics were measured by TMSE and MoCA. Clinical risk factors and post-COVID-19 cognitive impairment were assessed. The comparison of cognitive function in post-acute COVID-19 patients and 22 healthy controls was also performed. Results: The prevalence of post-COVID-19 cognitive impairment defined by a total MoCA score below 25 points was 61.76%. Years of education were the only predictive factors related to cognitive impairment. Our multivariate analysis revealed no statistical difference in cognitive outcomes between post-acute COVID-19 patients and healthy controls. Conclusion: This study showed a moderate prevalence of cognitive dysfunction after COVID-19 hospitalization similar to previous reports. However, there was no significant difference in cognitive measurements between these patients and healthy people. Whether SARS-CoV-2 infection causes cognitive dysfunction is a myth or fact that still has a long way to prove via further longitudinal study.
ABSTRACT
Introduction: Neuromyelitis optica spectrum disorder (NMOSD) is a devastating inflammatory CNS demyelinating disease. Two groups of monoclonal antibodies (mAbs) are used to prevent disease relapse, i.e., Food and Drug Administration (FDA)-approved mAbs (e.g., eculizumab satralizumab, inebilizumab), and off-label mAb drugs (e.g., rituximab and tocilizumab). The FDA-approved mAbs have high efficacy but more expensive compared to the off-labels, and thus are less accessible. This systematic review and network meta-analysis (NMA) was to assess the efficacy and safety of both classes of mAbs compared to the current standard treatments. Methods: Systematically searches were conducted in MEDLINE and SCOPUS from inception until July 2021. Randomized-controlled trials (RCTs) were eligible if they compared any pair of treatments (mAbs, immunosuppressive drugs, or placebo) in adult patients with NMOSD. Studies with AQP4-IgG positive or negative were used in the analysis. Probability of relapse and time to event were extracted from the Kaplan-Meier curves using Digitizer. These data were then converted into individual patient time-to-event data. A one-stage mixed-effect survival model was applied to estimate the median time to relapse and relative treatment effects using hazard ratios (HR). Two-stage NMA was used to determine post-treatment annualized relapse rate (ARR), expanded disability status score (EDSS) change, and serious adverse events (SAE). Risk of bias was assessed using the revised cochrane risk of bias tool. Results: A total of 7 RCTs with 776 patients were eligible in the NMA. Five of the seven studies were rated low risk of bias. Both FDA-approved and off-label mAbs showed significantly lower risk of relapse than standard treatments, with HR (95% CI) of 0.13 (0.07, 0.24) and 0.16 (0.07, 0.37) respectively. In addition, the FDA-approved mAbs had 20% lower risk of relapse than the off-label mAbs, but this did not reach statistical significance. The ARRs were also lower in FDA-approved and off-label mAbs than the standard treatments with the mean-difference of-0.27 (-0.37,-0.16) and-0.31(-0.46,-0.16), respectively. Conclusion: The off-label mAbs may be used as the first-line treatment for improving clinical outcomes including disease relapse, ARR, and SAEs for NMOSD in countries where resources and accessibility of the FDA-approved mAbs are limited. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=283424, identifier: CRD42021283424.
