Background: Alzheimer’s disease (AD) affects a significant portion of the aging population, presenting a serious challenge due to the limited availability of effective therapies during its progression. The disease advances rapidly, underscoring the need for early diagnosis and the application of preventative measures. Current diagnostic methods for AD are often expensive and invasive, restricting access for the general public. One potential solution is the use of biomarkers, which can facilitate early detection and treatment through objective, non-invasive, and cost-effective evaluations of AD. This review critically investigates the function and role of biofluid biomarkers in detecting AD, with a specific focus on cerebrospinal fluid (CSF), blood-based, and saliva biomarkers. Results: CSF biomarkers have demonstrated potential for accurate diagnosis and valuable prognostic insights, while blood biomarkers offer a minimally invasive and cost-effective approach for diagnosing cognitive issues. However, while current biomarkers for AD show significant potential, none have yet achieved the precision needed to replace expensive PET scans and CSF assays. The lack of a single accurate biomarker underscores the need for further research to identify novel or combined biomarkers to enhance the clinical efficacy of existing diagnostic tests. In this context, artificial intelligence (AI) and deep-learning (DL) tools present promising avenues for improving biomarker analysis and interpretation, enabling more precise and timely diagnoses. Conclusions: Further research is essential to confirm the utility of all AD biomarkers in clinical settings. Combining biomarker data with AI tools offers a promising path toward revolutionizing the personalized characterization and early diagnosis of AD symptoms.

The SARS-CoV-2 pandemic has posed global medical challenges due to its ability to affect multiple organ systems. Among the post-COVID-19 complications, multisystem inflammatory syndrome has emerged as a severe condition affecting both children (MIS-C) and adults (MIS-A). This review aims to compile and analyze published data to investigate clinical characteristics, laboratory findings, and outcomes of MIS post-COVID-19. A comprehensive search of various databases was conducted to identify studies reporting MIS-related complications in pediatric and adult populations post-COVID-19 infection. Screening, data extraction, and cross-checking were performed by two independent reviewers. Only 64 studies met our inclusion criteria, and compiled results revealed that cardiac complications were the predominant manifestation followed by gastrointestinal, hematologic, neurological, and mucocutaneous involvement. Laboratory findings consistently demonstrated elevated inflammatory markers including CRP, ferritin, D-dimer, and IL-6. Most patients required hospitalization, and many needed intensive care; treatment typically involved IVIG, corticosteroids, and biologic therapies. While most patients recovered, a subset experienced persistent complications. These findings highlight the importance of early recognition, multidisciplinary management, and structured follow-up for MIS. Future research is warranted to clarify the underlying mechanisms, risk factors, and long-term outcomes associated with MIS in post-COVID-19 patients.