A Three-Part, Randomised Study to Investigate the Safety, Tolerability, Pharmacokinetics and Mode of Action of BC 007, Neutraliser of Pathogenic Autoantibodies Against G-Protein Coupled Receptors in Healthy, Young and Elderly Subjects

Long COVID in pediatrics-epidemiology, diagnosis, and management

This review summarizes current knowledge on post-acute sequelae of COVID-19 (PASC) and post-COVID-19 condition (PCC) in children and adolescents. A literature review was performed to synthesize information from clinical studies, expert opinions, and guidelines. PASC also termed Long COVID - at any age comprise a plethora of unspecific symptoms present later than 4 weeks after confirmed or probable infection with severe respiratory syndrome corona virus type 2 (SARS-CoV-2), without another medical explanation. PCC in children and adolescents was defined by the WHO as PASC occurring within 3 months of acute coronavirus disease 2019 (COVID-19), lasting at least 2 months, and limiting daily activities. Pediatric PASC mostly manifest after mild courses of COVID-19 and in the majority of cases remit after few months. However, symptoms can last for more than 1 year and may result in significant disability. Frequent symptoms include fatigue, exertion intolerance, and anxiety. Some patients present with postural tachycardia syndrome (PoTS), and a small number of cases fulfill the clinical criteria of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). To date, no diagnostic marker has been established, and differential diagnostics remains challenging. Therapeutic approaches include appropriate self-management as well as the palliation of symptoms by non-pharmaceutical and pharmaceutical strategies.    Conclusion: PASC in pediatrics present with heterogenous severity and duration. A stepped, interdisciplinary, and individualized approach is essential for appropriate clinical management. Current health care structures have to be adapted, and research was extended to meet the medical and psychosocial needs of young people with PASC or similar conditions. What is Known: • Post-acute sequelae of coronavirus 2019 (COVID-19) (PASC) - also termed Long COVID - in children and adolescents can lead to activity limitation and reduced quality of life. • PASC belongs to a large group of similar post-acute infection syndromes (PAIS). Specific biomarkers and causal treatment options are not yet available. What is New: • In February 2023, a case definition for post COVID-19 condition (PCC) in children and adolescents was provided by the World Health Organization (WHO), indicating PASC with duration of at least 2 months and limitation of daily activities. PCC can present as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). • Interdisciplinary collaborations are necessary and have been established worldwide to offer harmonized, multimodal approaches to diagnosis and management of PASC/PCC in children and adolescents.

After the Hurricane: Anti-COVID-19 Drugs Development, Molecular Mechanisms of Action and Future Perspectives

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is a new coronavirus in the Coronaviridae family. The COVID-19 pandemic, caused by SARS-CoV-2, has undoubtedly been the largest crisis of the twenty-first century, resulting in over 6.8 million deaths and 686 million confirmed cases, creating a global public health issue. Hundreds of notable articles have been published since the onset of this pandemic to justify the cause of viral spread, viable preventive measures, and future therapeutic approaches. As a result, this review was developed to provide a summary of the current anti-COVID-19 drugs, as well as their timeline, molecular mode of action, and efficacy. It also sheds light on potential future treatment options. Several medications, notably hydroxychloroquine and lopinavir/ritonavir, were initially claimed to be effective in the treatment of SARS-CoV-2 but eventually demonstrated inadequate activity, and the Food and Drug Administration (FDA) withdrew hydroxychloroquine. Clinical trials and investigations, on the other hand, have demonstrated the efficacy of remdesivir, convalescent plasma, and monoclonal antibodies, 6-Thioguanine, hepatitis C protease inhibitors, and molnupiravir. Other therapeutics, including inhaled medicines, flavonoids, and aptamers, could pave the way for the creation of novel anti-COVID-19 therapies. As future pandemics are unavoidable, this article urges immediate action and extensive research efforts to develop potent specialized anti-COVID-19 medications.

Clinical Translation of Aptamers for COVID-19

The COVID-19 etiologic agent, SARS-CoV-2, continues to be one of the leading causes of death on a global scale. Although efficient methods for diagnosis and treatment of COVID-19 have been developed, new methods of battling SARS-CoV-2 variants and long COVID are still urgently needed. A number of aptamers have demonstrated tremendous potential to be developed into diagnostic and therapeutic agents for COVID-19. The translation of the aptamers for clinical uses, however, has been extremely slow. Overcoming the difficulties faced by aptamers would advance this technology toward clinical use for COVID-19 and other serious disorders.

The Role of Autoantibodies in Companion Animal Cardiac Disease

Clinical studies exploring the role of autoimmune diseases in cardiac dysfunction have become increasingly common in both human and veterinary literature. Autoantibodies (AABs) specific to cardiac receptors have been found in human and canine dilated cardiomyopathy, and circulating autoantibodies have been suggested as a sensitive biomarker for arrhythmogenic right ventricular cardiomyopathy in people and Boxer dogs. In this article, we will summarize recent literature on AABs and their role in cardiac diseases of small animals. Despite the potential for new discoveries in veterinary cardiology, current data in veterinary medicine are limited and further studies are needed.

Fighting Post-COVID and ME/CFS - development of curative therapies

The sequela of COVID-19 include a broad spectrum of symptoms that fall under the umbrella term post-COVID-19 condition or syndrome (PCS). Immune dysregulation, autoimmunity, endothelial dysfunction, viral persistence, and viral reactivation have been identified as potential mechanisms. However, there is heterogeneity in expression of biomarkers, and it is unknown yet whether these distinguish different clinical subgroups of PCS. There is an overlap of symptoms and pathomechanisms of PCS with postinfectious myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). No curative therapies are available for ME/CFS or PCS. The mechanisms identified so far provide targets for therapeutic interventions. To accelerate the development of therapies, we propose evaluating drugs targeting different mechanisms in clinical trial networks using harmonized diagnostic and outcome criteria and subgrouping patients based on a thorough clinical profiling including a comprehensive diagnostic and biomarker phenotyping.

Harnessing aptamers against COVID-19: a therapeutic strategy

The novel coronavirus crisis caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) was a global pandemic. Although various therapeutic approaches were developed over the past 2 years, novel strategies with more efficient applicability are required to target new variants. Aptamers are single-stranded (ss)RNA or DNA oligonucleotides capable of folding into unique 3D structures with robust binding affinity to a wide variety of targets following structural recognition. Aptamer-based theranostics have proven excellent capability for diagnosing and treating various viral infections. Herein, we review the current status and future perspective of the potential of aptamers as COVID-19 therapies.

Aptamers-Diagnostic and Therapeutic Solution in SARS-CoV-2

The SARS-CoV-2 virus is currently the most serious challenge to global public health. Its emergence has severely disrupted the functioning of health services and the economic and social situation worldwide. Therefore, new diagnostic and therapeutic tools are urgently needed to allow for the early detection of the SARS-CoV-2 virus and appropriate treatment, which is crucial for the effective control of the COVID-19 disease. The ideal solution seems to be the use of aptamers—short fragments of nucleic acids, DNA or RNA—that can bind selected proteins with high specificity and affinity. They can be used in methods that base the reading of the test result on fluorescence phenomena, chemiluminescence, and electrochemical changes. Exploiting the properties of aptamers will enable the introduction of rapid, sensitive, specific, and low-cost tests for the routine diagnosis of SARS-CoV-2. Aptamers are excellent candidates for the development of point-of-care diagnostic devices and are potential therapeutic tools for the treatment of COVID-19. They can effectively block coronavirus activity in multiple fields by binding viral proteins and acting as carriers of therapeutic substances. In this review, we present recent developments in the design of various types of aptasensors to detect and treat the SARS-CoV-2 infection.

Aptamers Against COVID-19: An Untested Opportunity

Given the lack of success in the development of effective drugs to treat COVID-19, which show "game-changing" potential, it is necessary to explore drugs with different modes of action. Single mode-of-action drugs have not been succeeded in curing COVID-19, which is a highly complex disease. This is the case for direct antivirals and anti-inflammatory drugs, both of which treat different phases of the disease. Aptamers are molecules that deliver different modes of action, allowing their effects to be bundled, which, when combined, support their therapeutic efficacy. In this minireview, we summarise the current activities in the development of aptamers for the treatment of COVID-19 and long-COVID. A special emphasis is placed on the capability of their multiple modes of action, which is a promising approach for treating complex diseases such as COVID-19.

Lack of efficacy of mono-mode of action therapeutics in COVID-19 therapy - How the lack of predictive power of preclinical cell and animal studies leads developments astray

The diverse experiences regarding the failure of tested drugs in the fight against COVID‐19 made it clear that one should at least question the requirement to apply classical preclinical development strategies that demand cell and animal efficacy models to be tested before going into clinical trials. Most animals are not susceptible to infection with SARS‐CoV‐2, and so this led to one‐sided virus replication experiments in cells and the use of animal models that have little in common with the complex pathogenesis of COVID‐19 in humans. Therefore, non‐clinical development strategies were designed to meet regulatory requirements, but they did not truly reflect the situation in the clinic. This has led the search for effective agents astray in many cases. As proof of this statement, we now bring together the results of such required preclinical experiments and compare with the results in clinical trials. Two clear conclusions that can be drawn from the experience to date: The required preclinical models are unsuitable for the development of innovative treatments medical devices in the case of COVID‐19 and mono‐action strategies (e.g. direct antivirals) are of very little or no benefit to patients under randomized,blinded conditions. Our hypothesis is that the complex situation of COVID‐19 may benefit from multi‐mode drugs. Here, the molecular class of aptamers could be a solution.

Aptamer BC 007's Affinity to Specific and Less-Specific Anti-SARS-CoV-2 Neutralizing Antibodies

COVID-19 is a pandemic respiratory disease that is caused by the highly infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Anti-SARS-CoV-2 antibodies are essential weapons that a patient with COVID-19 has to combat the disease. When now repurposing a drug, namely an aptamer that interacts with SARS-CoV-2 proteins for COVID-19 treatment (BC 007), which is, however, a neutralizer of pathogenic autoantibodies in its original indication, the possibility of also binding and neutralizing anti-SARS-CoV-2 antibodies must be considered. Here, the highly specific virus-neutralizing antibodies have to be distinguished from the ones that also show cross-reactivity to tissues. The last-mentioned could be the origin of the widely reported SARS-CoV-2-induced autoimmunity, which should also become a target of therapy. We, therefore, used enzyme-linked immunosorbent assay (ELISA) technology to assess the binding of well-characterized publicly accessible anti-SARS-CoV-2 antibodies (CV07-209 and CV07-270) with BC 007. Nuclear magnetic resonance spectroscopy, isothermal calorimetric titration, and circular dichroism spectroscopy were additionally used to test the binding of BC 007 to DNA-binding sequence segments of these antibodies. BC 007 did not bind to the highly specific neutralizing anti-SARS-CoV-2 antibody but did bind to the less specific one. This, however, was a lot less compared to an autoantibody of its original indication (14.2%, range 11.0–21.5%). It was also interesting to see that the less-specific anti-SARS-CoV-2 antibody also showed a high background signal in the ELISA (binding on NeutrAvidin-coated or activated but noncoated plastic plate). These initial experiments suggest that the risk of binding and neutralizing highly specific anti-SARS CoV-2 antibodies by BC 007 should be low.

The AT1 receptor autoantibody causes hypoglycemia in fetal rats via promoting the STT3A-GLUT1-glucose uptake axis in liver

Blood glucose is of great importance to development and metabolic homeostasis in fetuses. Stimulation of harmful factors during gestation induces pathoglycemia. Angiotensin II type 1 receptor autoantibody (AT1-AA), a newly discovered gestational harmful factor, has been shown to induce intrauterine growth restriction in fetuses and glucose disorders in adults. However, whether and how AT1-AA influences the blood glucose level of fetuses during gestation is not yet clear. The purpose of the current study was to observe the fetal blood glucose level of AT1-AA-positive pregnant rats during late pregnancy and to determine the roles that hepatic glucose transporters play in this process. We established AT1-AA-positive pregnant rats by injecting AT1-AA into the caudal veins of rats in the 2nd trimester of gestation. Although the fetal blood glucose level in the 3rd trimester of gestation decreased, hepatic glucose uptake increased detected. Through separating membrane and cytosolic proteins, we demonstrated that both the expression and membrane transport ratio of glucose transporter 1 (GLUT1), which is responsible for glucose transport in fetal hepatocytes, were upregulated, accompanied by increased expression of N-glycosyltransferase STT3A, which contributes to the N-glycosylation of GLUT1. In vitro, we identified that AT1-AA increased glucose uptake, the expression and membrane transport ratio of GLUT1 and the expression of STT3A in HepG2 cell lines via separating membrane and cytosolic proteins and immunofluorescence, resulting in the decreased glucose content in the medium. The GLUT1 inhibitor WZB117 reversed the decreases in glucose content in the medium, the increases in glucose uptake, the increases in the expression and membrane transport ratio of GLUT1 caused by AT1-AA. The N-glycosyltransferase inhibitor NGI as well as si-STT3A reversed the AT1-AA-induced upregulation of the STT3A-GLUT1-glucose uptake effect. This study demonstrates that AT1-AA lowers the blood glucose level of fetuses via the STT3A-GLUT1-glucose uptake axis in liver.

Aptamer BC 007 - Efficient binder of spreading-crucial SARS-CoV-2 proteins

Corona virus disease 2019 (COVID-19) is a respiratory disease caused by a new coronavirus (SARS-CoV-2) which causes significant morbidity and mortality. The emergence of this novel and highly pathogenic SARS-CoV-2 and its rapid international spread poses a serious global public health emergency. To date 32,174,627 cases, of which 962,613 (2.99%) have died, have been reported (https://www.who.int/westernpacific/health-topics/coronavirus, accessed 23 Sep 2020). The outbreak was declared a Public Health Emergency of International Concern on 30 January 2020.

There are still not many SARS-CoV-2-specific and effective treatments or vaccines available. A second round of infection is obviously unavoidable.

Aptamers had already been at the centre of interest in the fight against viruses before now. The selection and development of a new aptamer is, however, a time-consuming process. We therefore checked whether a clinically developed aptamer, BC 007, which is currently in phase 2 of clinical testing for a different indication, would also be able to efficiently bind DNA-susceptible peptide structures from SARS-CoV-2-spreading crucial proteins, such as the receptor binding domain (RBD) of the spike protein and the RNA dependent RNA polymerase of SARS-CoV-2 (re-purposing). Indeed, several such sequence-sections have been identified. In particular for two of these sequences, BC 007 showed specific binding in a therapy-relevant concentration range, as shown in Nuclear magnetic resonance (NMR)- and Circular dicroism (CD)-spectroscopy and isothermal titration calorimetry (ITC). The excellent clinical toxicity and tolerability profile of this substance opens up an opportunity for rapid clinical testing of its COVID-19 effectiveness.

Aptamers against Immunoglobulins: Design, Selection and Bioanalytical Applications

Nucleic acid aptamers show clear promise as diagnostic reagents, as highly specific strands were reported against a large variety of biomarkers. They have appealing benefits in terms of reproducible generation by chemical synthesis, controlled modification with labels and functionalities providing versatile means for detection and oriented immobilization, as along with high biochemical and temperature resistance. Aptamers against immunoglobulin targets-IgA, IgM, IgG and IgE-have a clear niche for diagnostic applications, therefore numerous aptamers have been selected and used in combination with a variety of detection techniques. The aim of this review is to overview and evaluate aptamers selected for the recognition of antibodies, in terms of their design, analytical properties and diagnostic applications. Aptamer candidates showed convincing performance among others to identify stress and upper respiratory tract infection through SIgA detection, for cancer cell recognition using membrane bound IgM, to detect and treat hemolytic transfusion reactions, autoimmune diseases with IgG and detection of IgE for allergy diseases. However, in general, their use still lags significantly behind what their claimed benefits and the plethora of application opportunities would forecast.