Search Results (69)

Objectives: COVID-19, caused by the SARS-CoV-2 virus, has infected over 777 million individuals and led to approximately 7 million deaths worldwide. Despite significant efforts to develop effective therapies, treatment remains largely supportive, especially for severe complications like acute respiratory distress syndrome (ARDS). Numerous compounds from diverse pharmacological classes are currently undergoing preclinical and clinical evaluation, targeting both the virus and the host immune response. Methods: Despite the large number of articles published and after a preliminary attempt was published, we discarded the option of a systematic review. Instead, we have done a description of therapies with these results and a tentative mechanism of action. Results: Preliminary studies and early-phase clinical trials have demonstrated the potential of Mesenchymal Stem Cells (MSCs) in mitigating severe lung damage in COVID-19 patients. Previous research has shown MSCs to be effective in treating various pulmonary conditions, including acute lung injury, idiopathic pulmonary fibrosis, ARDS, asthma, chronic obstructive pulmonary disease, and lung cancer. Their ability to reduce inflammation and promote tissue repair supports their potential role in managing COVID-19-related complications. This review demonstrates the utility of MSCs in the acute phase of COVID-19 and postulates the etiopathogenic role of mitochondria in Long-COVID. Even more, their combination with other therapies is also analyzed. Conclusions: While the therapeutic application of MSCs in COVID-19 is still in early stages, emerging evidence suggests promising outcomes. As research advances, MSCs may become an integral part of treatment strategies for severe COVID-19, particularly in addressing immune-related lung injury and promoting recovery. However, a full pathogenic mechanism may explain or unify the complexity of signs and symptoms of Long COVID and Post-Acute Sequelae (PASC). Full article

Background/Objectives: To investigate the incidence of new-onset diabetic retinopathy (DR) in individuals with pre-existing type 2 diabetes (T2D) up to 3 years post SARS-CoV-2 infection. Methods: This retrospective study consisted of 5151 COVID-19 and 5151 propensity-matched non-COVID-19 patients with T2D in the Montefiore Health System between 1 March 2020 and 17 January 2023. The primary outcome was new-onset DR at least 2 months after the index date up to 17 January 2023. Matching for index date between groups was also used to ensure the same follow-up duration. Hazard ratios (HRs) were computed, adjusted for competing risks. Results: T2D patients with COVID-19 had a higher cumulative incidence of DR than T2D patients. The unadjusted HR for COVID-19 status for developing new DR was 2.44 [1.60, 3.73], p < 0.001. The adjusted HR was 1.70 [1.08, 2.70], p < 0.05, and the adjusted HR for prior insulin use was 3.28 [2.10, 5.12], p < 0.001. Sex, ethnicity, and major comorbidities had no significant association with outcome. Conclusions: T2D patients who contracted COVID-19 exhibited a significantly higher risk of developing DR within three years post infection compared to propensity-matched controls. The increased incidence was primarily driven by greater pre-existing insulin usage and SARS-CoV-2 infection in the COVID-19 positive cohort. Full article

The COVID-19 pandemic has revealed the profound and lasting impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on the nervous system. Beyond acute infection, SARS-CoV-2 acts as a potent immunomodulatory agent, disrupting immune homeostasis and contributing to persistent inflammation, autoimmunity, and neurodegeneration. Long COVID, or post-acute sequelae of SARS-CoV-2 infection (PASC), is characterized by a spectrum of neurological symptoms, including cognitive dysfunction, fatigue, neuropathy, and mood disturbances. These are linked to immune dysregulation involving cytokine imbalance, blood–brain barrier (BBB) disruption, glial activation, and T-cell exhaustion. Key biomarkers such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), glial fibrillary acidic protein (GFAP), and neurofilament light chain (NFL) correlate with disease severity and chronicity. This narrative review examines the immunopathological mechanisms underpinning the neurological sequelae of long COVID, focusing on neuroinflammation, endothelial dysfunction, and molecular mimicry. We also assess the role of viral variants in shaping neuroimmune outcomes and explore emerging diagnostic and therapeutic strategies, including biomarker-guided and immune-targeted interventions. By delineating how SARS-CoV-2 reshapes neuroimmune interactions, this review aims to support the development of precision-based diagnostics and targeted therapies for long COVID-related neurological dysfunction. Emerging approaches include immune-modulatory agents (e.g., anti-IL-6), neuroprotective drugs, and strategies for repurposing antiviral or anti-inflammatory compounds in neuro-COVID. Given the high prevalence of comorbidities, personalized therapies guided by biomarkers and patient-specific immune profiles may be essential. Advancements in vaccine technologies and targeted biologics may also hold promise for prevention and disease modification. Finally, continued interdisciplinary research is needed to clarify the complex virus–immune–brain axis in long COVID and inform effective clinical management. Full article

While there are many postulates for the etiology of post-viral chronic fatigue and other symptomatology, little is known. We draw on our past experience of these syndromes to devise means which can expose the primary players of this malady in terms of a panoply participating biomolecules and the state of the stool microbiome. Using databases established from a large dataset of patients at risk of colorectal cancer who were followed longitudinally over 3 decades, and a smaller database dedicated to building a Long PASC cohort (Post-Acute Sequelae of COVID-19), we were able to ascertain factors that predisposed patients to (and resulted in) significant changes in various biomarkers, i.e., the stool microbiome and serum cytokine levels, which we verified by collecting stool and serum samples. There were significant changes in the stool microbiome with an inversion from the usual Bacillota and Bacteroidota species. Serum cytokines showed significant differences in MIP-1β versus TARC (CC chemokine ligand 17) in patients with either PASC or COVID-19 (p < 0.02); IL10 versus IL-12p70a (p < 0.02); IL-1b versus IL-6 (p < 0.01); MCP1 versus TARC (p < 0.03); IL-8 versus TARC (p < 0.002); and Eotaxin3 versus TARC (p < 0.004) in PASC. Some changes were seen solely in COVID-19, including MDC versus MIP-1α (p < 0.01); TNF-α versus IL-1-β (p < 0.06); MCP4 versus TARC (p < 0.0001). We also show correlates with chronic fatigue where an etiology was not identified. These findings in patients with positive criteria for PASC show profound changes in the microbiome and serum cytokine expression. Patients with chronic fatigue without clear viral etiologies also have common associations, including a history of tonsillectomy, which evokes a likely immune etiology. Full article

Background: Long COVID can develop in individuals who have had COVID-19, regardless of the severity of their initial infection or the treatment they received. Several studies have examined the prevalence and manifestation of symptom phenotypes to comprehend the pathophysiological mechanisms associated with these symptoms. Numerous articles outlined specific approaches for multidisciplinary management and treatment of these patients, focusing primarily on those with mild acute illness. The various management models implemented focused on a patient-centered approach, where the specialists were positioned around the patient. On the other hand, the created pathways do not consider the possibility of symptom clusters when determining how to define diagnostic algorithms. Methods: This retrospective longitudinal study took place at the “Fondazione IRCCS Policlinico San Matteo”, Pavia, Italy (SMATTEO) and at the “Ospedale di Cremona”, ASST Cremona, Italy (CREMONA). Information was retrieved from the administrative data warehouse and from two dedicated registries. We included patients discharged with a diagnosis of severe COVID-19, systematically invited for a 3-month follow-up visit. Unsupervised machine learning was used to identify potential patient phenotypes. Results: Three hundred and eighty-two patients were included in these analyses. About one-third of patients were older than 65 years; a quarter were female; more than 80% of patients had multi-morbidities. Diagnoses related to the circulatory system were the most frequent, comprising 46% of cases, followed by endocrinopathies at 20%. PCA (principal component analysis) had no clustering tendency, which was comparable to the PCA plot of a random dataset. The unsupervised machine learning approach confirms these findings. Indeed, while dendrograms for the hierarchical clustering approach may visually indicate some clusters, this is not the case for the PAM method. Notably, most patients were concentrated in one cluster. Conclusions: The extreme heterogeneity of patients affected by post-acute sequelae of SARS-CoV-2 infection (PASC) has not allowed for the identification of specific symptom clusters with the most recent statistical techniques, thus preventing the generation of common diagnostic-therapeutic pathways. Full article

Cardiovascular complications are a hallmark of Post-Acute Sequelae of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection (PASC), yet the mechanisms driving persistent cardiac dysfunction remain poorly understood. Emerging evidence implicates mitochondrial dysfunction in immune cells as a key contributor. This study investigated whether CD14⁺⁺ monocytes from long COVID patients exhibit bioenergetic impairment, mitochondrial DNA (mtDNA) damage, and defective oxidative stress adaptation, which may underlie cardiovascular symptoms in PASC. CD14⁺⁺ monocytes were isolated from 14 long COVID patients with cardiovascular symptoms (e.g., dyspnea, angina) and 10 age-matched controls with similar cardiovascular risk profiles. Mitochondrial function was assessed using a Seahorse Agilent Analyzer under basal conditions and after oxidative stress induction with buthionine sulfoximine (BSO). Mitochondrial membrane potential was measured via Tetramethylrhodamine Ethyl Ester (TMRE) assay, mtDNA integrity via qPCR, and reactive oxygen species (ROS) dynamics via Fluorescence-Activated Cell Sorting (FACS). Parallel experiments exposed healthy monocytes to SARS-CoV-2 spike protein to evaluate direct viral effects. CD14⁺⁺ monocytes from long COVID patients with cardiovascular symptoms (n = 14) exhibited profound mitochondrial dysfunction compared to age-matched controls (n = 10). Under oxidative stress induced by buthionine sulfoximine (BSO), long COVID monocytes failed to upregulate basal respiration (9.5 vs. 30.4 pmol/min in controls, p = 0.0043), showed a 65% reduction in maximal respiration (p = 0.4035, ns) and demonstrated a 70% loss of spare respiratory capacity (p = 0.4143, ns) with significantly impaired adaptation to BSO challenge (long COVID + BSO: 9.9 vs. control + BSO: 54 pmol/min, p = 0.0091). Proton leak, a protective mechanism against ROS overproduction, was blunted in long COVID monocytes (3-fold vs. 13-fold elevation in controls, p = 0.0294). Paradoxically, long COVID monocytes showed reduced ROS accumulation after BSO treatment (6% decrease vs. 1.2-fold increase in controls, p = 0.0015) and elevated mitochondrial membrane potential (157 vs. 113.7 TMRE fluorescence, p = 0.0179), which remained stable under oxidative stress. mtDNA analysis revealed severe depletion (80% reduction, p < 0.001) and region-specific damage, with 75% and 70% reductions in amplification efficiency for regions C and D (p < 0.05), respectively. In contrast, exposure of healthy monocytes to SARS-CoV-2 spike protein did not recapitulate these defects, with preserved basal respiration, ATP production, and spare respiratory capacity, though coupling efficiency under oxidative stress was reduced (p < 0.05). These findings suggest that mitochondrial dysfunction in long COVID syndrome arises from maladaptive host responses rather than direct viral toxicity, characterized by bioenergetic failure, impaired stress adaptation, and mitochondrial genomic instability. This study identifies persistent mitochondrial dysfunction in long COVID monocytes as a critical driver of cardiovascular complications in PASC. Key defects—bioenergetic failure, impaired stress adaptation and mtDNA damage—correlate with clinical symptoms like heart failure and exercise intolerance. The stable elevation of mitochondrial membrane potential and resistance to ROS induction suggest maladaptive remodeling of mitochondrial physiology. These findings position mitochondrial resilience as a therapeutic target, with potential strategies including antioxidants, mtDNA repair agents or metabolic modulators. The dissociation between spike protein exposure and mitochondrial dysfunction highlights the need to explore host-directed mechanisms in PASC pathophysiology. This work advances our understanding of long COVID cardiovascular sequelae and provides a foundation for biomarker development and targeted interventions to mitigate long-term morbidity. Full article

SARS-CoV-2 infection has had a significant impact on global health through both acute illness, referred to as coronavirus disease 2019 (COVID-19), and chronic conditions (long COVID or post-acute sequelae of COVID-19, PASC). Despite substantial advancements in preventing severe COVID-19 cases through vaccination, the rise in the prevalence of long COVID syndrome and a notable degree of genomic mutation, primarily in the S protein, underscores the necessity for a deeper understanding of the underlying pathophysiological mechanisms related to the S protein of SARS-CoV-2. In this review, the latest part of this series, we investigate the potential pathophysiological molecular mechanisms triggered by the interaction between the spike protein and cellular receptors. Therefore, this review aims to provide a differential and focused view on the mechanisms potentially activated by the binding of the spike protein to canonical and non-canonical receptors for SARS-CoV-2, together with their possible interactions and effects on the pathogenesis of long COVID. Full article

SARS-CoV-2 infection has resulted in more than 700 million cases and nearly 7 million deaths worldwide. Although vaccination efforts have effectively reduced mortality and transmission rates, a significant proportion of recovered patients—up to 40%—develop long COVID syndrome (LC) or post-acute sequelae of COVID-19 infection (PASC). LC is characterized by the persistence or emergence of new symptoms following initial SARS-CoV-2 infection, affecting the cardiovascular, neurological, respiratory, gastrointestinal, reproductive, and immune systems. Despite the broad range of clinical symptoms that have been described, the risk factors and pathogenic mechanisms behind LC remain unclear. This review, the first of a two-part series, is distinguished by the discussion of the role of the SARS-CoV-2 spike protein in the primary mechanisms underlying the pathophysiology of LC. Full article

Background/Objectives: The factors associated with post-acute sequelae of COVID-19 (PASC) are not yet fully understood in developing countries. Our objective was to investigate the relationship between food consumption and the occurrence of PASC in Brazilian elderly people. Methods: This cross-sectional study included 1322 elderly people aged 60 or over, infected with SARS-CoV-2 in 2020, living in the state of Roraima in Brazil. Using the Brazilian National Food and Nutrition Surveillance System (SISVAN, in Portuguese) tool, food consumption markers were evaluated. The persistence of post-acute sequelae of COVID-19 was assessed three months after SARS-CoV-2 infection. Poisson regression with robust variance was performed to estimate the prevalence ratio (PR) with a 95% confidence interval (95% CI). Results: Fruit consumption [PR 0.92; 95% CI: 0.85–0.99] was associated with a lower occurrence of PASC, with a significant interaction in individuals aged 60 to 69 years old, not hospitalized, and those without chronic kidney disease. In addition, the consumption of sugar-sweetened beverages [PR 1.23; 95% CI: 1.12–1.35], sandwich cookies, sweets, and treats [PR 1.12; 95% CI 1.03–1.22] was positively associated with the occurrence of PASC in the elderly people, with a significant interaction in individuals living in the capital and without hypercholesterolemia. Conclusions: Unhealthy food consumption was associated with PASC in Brazilian elderly people. An improvement in the diet quality of elderly people is necessary to minimize health complications in PASC. Full article

On 11 March 2020, the World Health Organization (WHO) declared a pandemic caused by SARS-CoV-2, raising global health concerns. Reports of persistent and new symptoms following the acute phase of infection highlighted the complexities of recovery and prompted the investigation of what is now termed long COVID. Officially recognized by the WHO in October 2021, long COVID presents various health implications, though the terminology—such as post-COVID syndrome and post-acute sequelae of COVID-19 (PASC)—remains inconsistent, complicating diagnostic standardization. Long COVID affects an estimated 10% to 30% of SARS-CoV-2-infected individuals, with common symptoms including fatigue, dyspnea, cognitive dysfunction, and joint pain, all of which significantly impair quality of life. Public perception is influenced by factors like education and health history, while misinformation and stigma hinder accurate diagnosis and treatment. The absence of biomarkers and overlap with other post-viral syndromes further complicate clinical recognition. Experts emphasize the need for refined diagnostic criteria and integrated strategies combining biomedical research, public policy, and educational initiatives to improve clinical management, address healthcare inequalities, and mitigate the impacts of long COVID. This review unveils the state of the art and knowledge gaps to encourage discussion, with the aim of achieving better clinical decision-making and public awareness related to long COVID. Full article

Post-acute sequelae of SARS-CoV-2 infection (PASC), commonly known as “Long COVID”, represents a significant clinical challenge characterized by persistent symptoms following acute COVID-19 infection. We conducted a comprehensive retrospective cohort study to identify serum autoantibody biomarkers associated with PASC. Initial screening using a protein bead array comprising approximately 20,000 human proteins identified several candidate PASC-associated autoantibodies. Subsequent validation by enzyme-linked immunosorbent assay (ELISA) in an expanded cohort—consisting of PASC patients, non-PASC COVID-19 convalescents, and pre-pandemic healthy controls—revealed two promising biomarkers: autoantibodies targeting PITX2 and FBXO2. PITX2 autoantibodies demonstrated high accuracy in distinguishing PASC patients from both non-PASC convalescents (area under the curve [AUC] = 0.891) and healthy controls (AUC = 0.866), while FBXO2 autoantibodies showed moderate accuracy (AUC = 0.762 and 0.786, respectively). Notably, the levels of these autoantibodies were associated with several PASC symptoms, including fever, dyspnea, palpitations, loss of appetite, and brain fog. The identification of PITX2 and FBXO2 autoantibodies as biomarkers not only enhances our understanding of PASC pathophysiology but also provides promising candidates for further investigation. Full article

Background/ Objectives: Long COVID or post-acute sequelae of SARS-CoV-2 infection (PASC) are symptoms that manifest despite passing the acute infection phase. These manifestations encompass a wide range of symptoms, the most common being fatigue, shortness of breath, and cognitive dysfunction. Genetic predisposition is clearly involved in the susceptibility of individuals to developing these persistent symptoms and the variation in the severity and forms. This review summarizes the role of genetic factors and gene polymorphisms in the development of major pulmonary vascular disorders associated with long COVID. Methods: A comprehensive review of current literature was conducted to examine the genetic contributions to pulmonary complications following SARS-CoV-2 infection. Studies investigating genetic polymorphisms linked to pulmonary hypertension, pulmonary thromboembolism, and pulmonary vascular endothelialitis were reviewed and summarized. Results: Findings show that specific genetic variants contribute to increased susceptibility to pulmonary vascular complications in long COVID patients. Variants associated with endothelial dysfunction, coagulation pathways, and inflammatory responses have been implicated in the development of pulmonary hypertension and thromboembolic events. Genetic predispositions influencing vascular integrity and immune responses appear to influence disease severity and progression. Conclusions: Understanding these mechanisms and genetic predispositions could pave the way for targeted therapeutic interventions to alleviate the burden on patients experiencing long COVID. Full article

Long COVID-19, also known as post-acute sequelae of SARS-CoV-2 infection (PASC), involves symptoms or effects that persist for more than 4 weeks after the initial SARS-CoV-2 infection. One contributing factor to this condition is the disruption in the expression of the antioxidant enzyme Nuclear Factor Erythroid-2 (Nrf2) induced by the COVID-19 infection. Apigenin and related flavonoids, known for their diverse pharmacological activities, including potent antioxidant properties, have emerged as promising candidates for Long COVID-19 therapy. These compounds, particularly apigenin, are recognized for their ability to modulate oxidative stress and inflammation, making them potential activators of the Nrf2 pathway. This study aims to predict the activity of apigenin and its related flavonoids as Nrf2 activators using molecular modeling and molecular dynamics (MD) techniques, providing insights into their therapeutic potential in managing Long COVID-19. The findings from the molecular modeling analysis indicate that apigenin has a favorable affinity, with a free energy value (ΔG) of −6.40 kcal/mol. Additionally, MD simulation results demonstrate the strong stability of the Keap1-apigenin complex, with an average Root Mean Square Deviation (RMSD) value below 0.20 nm and the lowest average Root Mean Square Fluctuation (RMSF) value of 0.86 nm. Using the Molecular Mechanics/Generalized Born Surface Area (MM-GBSA) calculation method, the binding affinity of the Keap1-apigenin complex yields a lower free energy value (ΔG) of −67.039 kJ/mol, consistent with the molecular modeling results. Apigenin also exhibits the ability to inhibit the binding of Nrf2 to the hydrophobic surface of Keap1, with a total energy value of 993.266 kcal/mol and binding affinity value of −1.162 kJ/mol through peptide−receptor docking. In conclusion, the comprehensive results suggest that apigenin has the potential to be a lead compound for developing Nrf2 activators specifically designed for Long COVID-19 therapy. Full article

The mechanisms underlying post-acute sequelae of SARS-CoV-2 infection (PASC) are a topic of debate. This study examined the presence of SARS-CoV-2 microRNA (miRNA)-like small RNAs in extracellular fluids and their potential link to PASC by using a quantitative stem-loop RT-PCR MiRNA assay. Initially, it was demonstrated that three previously identified SARS-CoV-2 miRNA-like small RNAs, specifically svRNA 1 and 2 and miR-07a, were significantly expressed in infected cells in vitro and released into the supernatant following infection by different SARS-CoV-2 variants. Then, the expression of three SARS-CoV-2 small RNAs was studied in both nasopharyngeal swabs (NPS) and sera from 24 patients at their initial COVID-19 diagnosis (T0) and in sera collected 91 to 193 days post-diagnosis (T1). Notably, 11 out of 24 patients (46%) reported PASC consequences. All NPS samples showed SARS-CoV-2 small RNA expression with an altered cytokine network during acute infection, but it did not correlate with PASC outcomes. Serum samples had similar small RNA statuses, though PASC patients, notably at T1, but not at T0, displayed reduced overall positivity compared to those without PASC. The host target expression of SARS-CoV-2 small RNAs was not significantly different between groups. This suggests a need for further research into SARS-CoV-2 small RNA and its role in viral behavior and PASC consequences. Full article

Long COVID, also known as post-acute sequelae of SARS-CoV-2 infection (PASC), is increasingly recognized as a condition affecting not only adults but also children and adolescents. While children often experience milder acute COVID-19 symptoms compared to adults, some develop persistent physical, psychological, and neurological symptoms lasting for weeks or months after initial infection. The most commonly reported symptoms include debilitating fatigue, respiratory issues, headaches, muscle pain, gastrointestinal disturbances, and cognitive difficulties, which significantly impact daily activities, schooling, and social interactions. Additionally, many children with long COVID experience psychological symptoms, such as anxiety, depression, mood swings, and irritability, likely exacerbated by prolonged illness and lifestyle disruptions. Risk factors for long COVID in children include pre-existing health conditions such as asthma, obesity, and neurological disorders, with adolescents and females seemingly more affected. Hypothesized mechanisms underlying long COVID include chronic immune dysregulation, persistent viral particles stimulating inflammation, autonomic nervous system dysfunction, and mitochondrial impairment, which may collectively contribute to the variety of observed symptoms. Long-term outcomes remain uncertain; however, long COVID can lead to school absenteeism, social withdrawal, and psychological distress, potentially affecting cognitive development. Severe cases may develop chronic conditions such as postural orthostatic tachycardia syndrome (POTS) and reduced exercise tolerance. This review synthesizes the existing literature on long COVID in children, examining its prevalence, symptomatology, risk factors, and potential mechanisms, with an emphasis on the need for further clinical studies. While existing research largely relies on surveys and self-reported data, clinical assessments are essential to accurately characterize long COVID in pediatric populations and to guide effective management strategies. Full article