Convalescent plasma in Covid-19: Possible mechanisms of action

Progression and Trends in Virus from Influenza A to COVID-19: An Overview of Recent Studies

Influenza is a highly known contagious viral infection that has been responsible for the death of many people in history with pandemics. These pandemics have been occurring every 10 to 30 years in the last century. The most recent global pandemic prior to COVID-19 was the 2009 influenza A (H1N1) pandemic. A decade ago, the H1N1 virus caused 12,500 deaths in just 19 months globally. Now, again, the world has been challenged with another pandemic. Since December 2019, the first case of a novel coronavirus (COVID-19) infection was detected in Wuhan. This infection has risen rapidly throughout the world; even the World Health Organization (WHO) announced COVID-19 as a worldwide emergency to ensure human health and public safety. This review article aims to discuss important issues relating to COVID-19, including clinical, epidemiological, and pathological features of COVID-19 and recent progress in diagnosis and treatment approaches for the COVID-19 infection. We also highlight key similarities and differences between COVID-19 and influenza A to ensure the theoretical and practical details of COVID-19.

Longitudinal analysis of humoral immunity against SARS-CoV-2 Spike in convalescent individuals up to 8 months post-symptom onset

With the recent approval of highly effective coronavirus disease 2019 (COVID-19) vaccines, functional and lasting immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently under investigation as antibody levels in plasma were shown to decline during convalescence. Since the absence of antibodies does not equate to absence of immune memory, we evaluate the presence of SARS-CoV-2-specific memory B cells in convalescent individuals. Here, we report a longitudinal assessment of humoral immune responses on 32 donors up to 8 months post-symptom onset. Our observations indicate that anti-Spike and anti-receptor binding domain (RBD) immunoglobulin M (IgM) in plasma decay rapidly, whereas the reduction of IgG is less prominent. Neutralizing activity also declines rapidly when compared to Fc-effector functions. Concomitantly, the frequencies of RBD-specific IgM+ B cells wane significantly when compared to RBD-specific IgG+ B cells, which remain stable. Our results add to the current understanding of immune memory following SARS-CoV-2 infection, which is critical for secondary infection prevention and vaccine efficacy.

SARS-CoV-2: An Overview of Virus Genetics, Transmission, and Immunopathogenesis

The human population is currently facing the third and possibly the worst pandemic caused by human coronaviruses (CoVs). The virus was first reported in Wuhan, China, on 31 December 2019 and spread within a short time to almost all countries of the world. Genome analysis of the early virus isolates has revealed high similarity with SARS-CoV and hence the new virus was officially named SARS-CoV-2. Since CoVs have the largest genome among all RNA viruses, they can adapt to many point mutation and recombination events; particularly in the spike gene, which enable these viruses to rapidly change and evolve in nature. CoVs are known to cross the species boundaries by using different cellular receptors. Both animal reservoir and intermediate host for SARS-CoV-2 are still unresolved and necessitate further investigation. In the current review, different aspects of SARS-CoV-2 biology and pathogenicity are discussed, including virus genetics and evolution, spike protein and its role in evolution and adaptation to novel hosts, and virus transmission and persistence in nature. In addition, the immune response developed during SARS-CoV-2 infection is demonstrated with special reference to the interplay between immune cells and their role in disease progression. We believe that the SARS-CoV-2 outbreak will not be the last and spillover of CoVs from bats will continue. Therefore, establishing intervention approaches to reduce the likelihood of future CoVs spillover from natural reservoirs is a priority.

COVID-19 neutralizing antibody-based therapies in humoral immune deficiencies: A narrative review

The outbreak of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), generated an unprecedented global health and social emergency. Despite many efforts from clinicians to develop effective anti-COVID-19 treatment protocols, no specific therapy is currently available. Among anti-viral agents, convalescent plasma (CP) from recovered patients is the object of intense research following the first positive reports in severe COVID-19 patients. Passive immunotherapy the rationale to provide higher benefits in COVID-19 patients with humoral immune deficiencies, such as those with solid and hematologic cancers, patients with primary and acquired immunodeficiencies, and recipients of solid organ and hematopoietic stem cell transplants. The aim of this narrative review will be to critically discuss the literature evidence on CP use in these categories of patients.

An overview of some potential immunotherapeutic options against COVID-19

After the advent of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) in the late 2019, the resulting severe and pernicious syndrome (COVID-19) immediately was deployed all around the world. To date, despite relentless efforts to control the disease by drug repurposing, there is no approved specific therapy for COVID-19. Given the role of innate and acquired immune components in the control and elimination of viral infections and inflammatory mutilations during SARS-CoV2 pathogenesis, immunotherapeutic strategies appear to be beneficent. Passive immunotherapies such as convalescent plasma, which has received much attention especially in severe cases, as well as suppressing inflammatory cytokines, interferon administration, inhibition of kinases and complement cascade, virus neutralization with key engineered products, cell-based therapies, immunomodulators and anti-inflammatory drugs are among the key immunotherapeutic approaches to deal with COVID-19, which is discussed in this review. Also, details of leading COVID-19 vaccine candidates as the most potent immunotherapy have been provided. However, despite salient improvements, there is still a lack of completely assured vaccines for universal application. Therefore, adopting proper immunotherapies according to the cytokine pattern and involved immune responses, alongside engineered biologics specially ACE2-Fc to curb SARS-CoV2 infection until achieving a tailored vaccine is probably the best strategy to better manage this pandemic. Therefore, gaining knowledge about the mechanism of action, potential targets, as well as the effectiveness of immune-based approaches to confront COVID-19 in the form of a well-ordered review study is highly momentous.

Nano-therapeutic strategies to target coronavirus

The coronaviruses have caused severe acute respiratory syndrome (SARS), the Middle East respiratory syndrome (MERS), and the more recent coronavirus pneumonia (COVID-19). The global COVID-19 pandemic requires urgent action to develop anti-virals, new therapeutics, and vaccines. In this review, we discuss potential therapeutics including human recombinant ACE2 soluble, inflammatory cytokine inhibitors, and direct anti-viral agents such as remdesivir and favipiravir, to limit their fatality. We also discuss the structure of the SARS-CoV-2, which is crucial to the timely development of therapeutics, and previous attempts to generate vaccines against SARS-CoV and MERS-CoV. Finally, we provide an overview of the role of nanotechnology in the development of therapeutics as well as in the diagnosis of the infection. This information is key for computational modeling and nanomedicine-based new therapeutics by counteracting the variable proteins in the virus. Further, we also try to effectively share the latest information about many different aspects of COVID-19 vaccine developments and possible management to further scientific endeavors.

Convalescent plasma therapy in patients with moderate-to-severe COVID-19: A study from Indonesia for clinical research in low- and middle-income countries

BACKGROUND

We explored the outcome of convalescent plasma (CP) treatment in patients with moderate and severe coronavirus disease 2019 (COVID-19) and investigated variables for the design of further trials in Indonesia.

METHODS

Hospitalised patients with moderate (n = 5) and severe (n = 5) COVID-19 were recruited and transfused with CP from donors who recovered from mild (n = 5), moderate (n = 5), or severe (n = 1) COVID-19. Neutralising antibodies (NAbs) to the virus were measured at the end of the study using a surrogate virus neutralisation test as an alternative to the plaque reduction assay. Clinical improvement was assessed based on the modified World Health Organization Research and Development Blueprint six-point scale, Brixia Chest-X-Ray scoring, and laboratory parameters. The study was registered at ClinicalTrials.gov (NCT04407208).

FINDINGS

CP transfusion in three doses of 3 mL/kg of recipient body weight at 2-day intervals was well tolerated. Good clinical improvement was achieved in all patients with moderate disease and in two patients with severe disease. Most patients at baseline had detectable NAbs with median inhibition rates comparable to those of the donors (90·91% vs. 86·31%; p = 0·379). This could be due to the unavailability of pre-donation NAb testing and postponed CP administration that required communal consent.

INTERPRETATION

This study highlights the safety of CP therapy. Although improvements were observed, we could not conclude that the outcomes were solely due to CP treatment. Further randomised controlled trials that cover different disease stages with pre-donation NAb measurements using locally applicable strategies are warranted.

FUNDING

The study was supported by PT Bio Farma, Indonesia.

Review of pharmacologic and immunologic agents in the management of COVID-19

The novel coronavirus disease 2019 (COVID-19) is the third coronavirus outbreak in the last two decades. Emerging and re-emerging infections like COVID-19 pose serious challenges of the paucity of information and lack of specific cure or vaccines. This leaves utilisation of existing scientific data on related viral infections and repurposing relevant aetiologic and supportive therapies as the best control approach while novel strategies are developed and trialled. Many promising antiviral agents including lopinavir, ritonavir, remdesivir, umifenovir, darunavir, and oseltamivir have been repurposed and are currently trialled for the care for COVID-19 patients. Adjunct therapies for the management of symptoms and to provide support especially in severe and critically ill patients have also been identified. This review provides an appraisal of the current evidence for the rational use of frontline therapeutics in the management of COVID-19. It also includes updates regarding COVID-19 immunotherapy and vaccine development.

A prospective study on COVID-19 convalescent plasma donor (CCP) recruitment strategies in a resource constrained blood centre

Background and Objectives

The COVID-19 pandemic has spread across 87 million people with more than 1·8 million deaths in the world. As there is no definite treatment modality, the use of convalescent plasma has become increasingly popular worldwide. This study aimed to identify an appropriate strategy of donor recruitment and to evaluate the appropriateness of pre-set plasma donation guidelines.

Material and Methods

In this prospective study conducted from May to September 2020, the donors were recruited under the following two circumstances: Group I, patients in the post-COVID-19 follow-up in the clinic, and Group II, patients recovered from COVID-19 recruited through mass and electronic media. A pre-set donor selection criteria and laboratory investigation was designed according to national and international guidelines. Approximately 500 ml of COVID-19 convalescent plasma (CCP) was collected from recovered individuals in each group by two different cell separators. The overall donor's attendance rate, deferral rate, adverse events and donor compliance was analysed and compared between the two groups.

Results

There was a significant difference in attendance in relation to registration between the groups (P < 0·0001). Donor deferral was significantly higher in group II compared with group I. The single most frequent cause of donor deferral was low antibody index (P = 0·0001). The total donor adverse event rate in CCP donation was significantly lower compared with routine plateletpheresis procedures. The donor's compliance to blood centre's protocol was satisfactory in both the groups.

Conclusion

Recruitment of patients in the post-COVID-19 follow-up in the clinic was more effective than the general recruitment through mass and electronic media for convalescence plasma donation in a resource-constrained blood centre.

A Role for Extracellular Vesicles in SARS-CoV-2 Therapeutics and Prevention

Extracellular vesicles (EVs) are the common designation for ectosomes, microparticles and microvesicles serving dominant roles in intercellular communication. Both viable and dying cells release EVs to the extracellular environment for transfer of cell, immune and infectious materials. Defined morphologically as lipid bi-layered structures EVs show molecular, biochemical, distribution, and entry mechanisms similar to viruses within cells and tissues. In recent years their functional capacities have been harnessed to deliver biomolecules and drugs and immunological agents to specific cells and organs of interest or disease. Interest in EVs as putative vaccines or drug delivery vehicles are substantial. The vesicles have properties of receptors nanoassembly on their surface. EVs can interact with specific immunocytes that include antigen presenting cells (dendritic cells and other mononuclear phagocytes) to elicit immune responses or affect tissue and cellular homeostasis or disease. Due to potential advantages like biocompatibility, biodegradation and efficient immune activation, EVs have gained attraction for the development of treatment or a vaccine system against the severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) infection. In this review efforts to use EVs to contain SARS CoV-2 and affect the current viral pandemic are discussed. An emphasis is made on mesenchymal stem cell derived EVs' as a vaccine candidate delivery system.

Potent Molecular Feature-based Neutralizing Monoclonal Antibodies as Promising Therapeutics Against SARS-CoV-2 Infection

The 2019-2020 winter was marked by the emergence of a new coronavirus (SARS-CoV-2) related disease (COVID-19), which started in Wuhan, China. Its high human-to-human transmission ability led to a worldwide spread within few weeks and has caused substantial human loss. Mechanical antiviral control approach, drug repositioning, and use of COVID-19 convalescent plasmas (CPs) were the first line strategies utilized to mitigate the viral spread, yet insufficient. The urgent need to contain this deadly pandemic has led searchers and pharmaceutical companies to develop vaccines. However, not all vaccines manufactured are safe. Besides, an alternative and effective treatment option for such an infectious disease would include pure anti-viral neutralizing monoclonal antibodies (NmAbs), which can block the virus at specific molecular targets from entering cells by inhibiting virus-cell structural complex formation, with more safety and efficiency than the CP. Indeed, there is a lot of molecular evidence about the protector effect and the use of molecular feature-based NmAbs as promising therapeutics to contain COVID-19. Thus, from the scientific publication database screening, we here retrieved antibody-related papers and summarized the repertory of characterized NmAbs against SARS-CoV-2, their molecular neutralization mechanisms, and their immunotherapeutic pros and cons. About 500 anti-SARS-CoV-2 NmAbs, characterized through competitive binding assays and neutralization efficacy, were reported at the writing time (January 2021). All NmAbs bind respectively to SARS-CoV-2 S and exhibit high molecular neutralizing effects against wild-type and/or pseudotyped virus. Overall, we defined six NmAb groups blocking SARS-CoV-2 through different molecular neutralization mechanisms, from which five potential neutralization sites on SARS-CoV-2 S protein are described. Therefore, more efforts are needed to develop NmAbs-based cocktails to mitigate COVID-19.

Chemotherapy vs. Immunotherapy in combating nCOVID19: An update

The nCOVID-19 pandemic initiated its course of contagion from the city of Wuhan and now it has spread all over the globe. SARS-CoV-2 is the causative virus and the infection as well as its symptoms are distributed across the multi-organ perimeters. Interactions between the host and virus governs the induction of ‘cytokine storm’ resulting various immunopathological consequences leading to death. Till now it has caused tens of millions of casualties and yet no credible cure has emerged to vision. This article presents a comprehensive overview on the two most promising remedial approaches that are being attempted for the management, treatment, and plausible cure of nCOVID-19. In this context, chemotherapeutic approach primarily aims to interrupt the interactions between the host and the virus causing inhibition of its entry into the host cell and/or its proliferation and suppressing the inflammatory milieu in the infected patients. On the other side, immunotherapeutic approaches aim to modulate the host immunity by fine tuning the inflammatory signaling cascades to achieve phylaxis from the virus and restoring immune-homeostasis. Considering most of the path-breaking findings, combinatorial therapy involving of chemotherapeutics as well as vaccine could usher to be a hope for all of us to eradicate the crisis

Stem cell therapies and benefaction of somatic cell nuclear transfer cloning in COVID-19 era

BACKGROUND

The global health emergency of COVID-19 has necessitated the development of multiple therapeutic modalities including vaccinations, antivirals, anti-inflammatory, and cytoimmunotherapies, etc. COVID-19 patients suffer from damage to various organs and vascular structures, so they present multiple health crises. Mesenchymal stem cells (MSCs) are of interest to treat acute respiratory distress syndrome (ARDS) caused by SARS-CoV-2 infection.

MAIN BODY

Stem cell-based therapies have been verified for prospective benefits in copious preclinical and clinical studies. MSCs confer potential benefits to develop various cell types and organoids for studying virus-human interaction, drug testing, regenerative medicine, and immunomodulatory effects in COVID-19 patients. Apart from paving the ways to augment stem cell research and therapies, somatic cell nuclear transfer (SCNT) holds unique ability for a wide range of health applications such as patient-specific or isogenic cells for regenerative medicine and breeding transgenic animals for biomedical applications. Being a potent cell genome-reprogramming tool, the SCNT has increased prominence of recombinant therapeutics and cellular medicine in the current era of COVID-19. As SCNT is used to generate patient-specific stem cells, it avoids dependence on embryos to obtain stem cells.

CONCLUSIONS

The nuclear transfer cloning, being an ideal tool to generate cloned embryos, and the embryonic stem cells will boost drug testing and cellular medicine in COVID-19.

SARS-CoV-2-specific humoral and cellular immunity in two renal transplants and two hemodialysis patients treated with convalescent plasma

When patients with chronic kidney disease are infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) they can face two specific problems: virus-specific immune responses may be impaired and remdesivir, an antiviral drug described to shorten recovery, is contraindicated. Antiviral treatment with convalescent plasma (CP) could be an alternative treatment option. In this case report, we present two kidney transplant recipients and two hemodialysis patients who were infected with SARS-CoV-2 and received CP. Antibodies against the receptor-binding domain in the S1 subunit of the SARS-CoV-2 spike protein were determined sequentially by immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) and neutralization assay and specific cellular responses by interferon-gamma ELISpot. Before treatment, in both kidney transplant recipients and one hemodialysis patient antibodies were undetectable by ELISA (ratio < 1.1), corresponding to low neutralizing antibody titers (≤1:40). ELISpot responses in the four patients were either weak or absent. After CP treatment, we observed an increase of SARS-CoV-2-specific antibodies (IgG ratio and neutralization titer) and of specific cellular responses. After intermittent clinical improvement, one kidney transplant recipient again developed typical symptoms on Day 12 after treatment and received a second cycle of CP treatment. Altogether, three patients clinically improved and could be discharged from the hospital. However, one 83-year-old multimorbid patient deceased. Our data suggest that the success of CP therapy may only be temporary in patients with chronic kidney disease; which requires close monitoring of viral load and antiviral immunity and possibly an adaptation of the treatment regimen.

Role of Inflammatory Cytokines in COVID-19 Patients: A Review on Molecular Mechanisms, Immune Functions, Immunopathology and Immunomodulatory Drugs to Counter Cytokine Storm

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a severe pandemic of the current century. The vicious tentacles of the disease have been disseminated worldwide with unknown complications and repercussions. Advanced COVID-19 syndrome is characterized by the uncontrolled and elevated release of pro-inflammatory cytokines and suppressed immunity, leading to the cytokine storm. The uncontrolled and dysregulated secretion of inflammatory and pro-inflammatory cytokines is positively associated with the severity of the viral infection and mortality rate. The secretion of various pro-inflammatory cytokines such as TNF-α, IL-1, and IL-6 leads to a hyperinflammatory response by recruiting macrophages, T and B cells in the lung alveolar cells. Moreover, it has been hypothesized that immune cells such as macrophages recruit inflammatory monocytes in the alveolar cells and allow the production of large amounts of cytokines in the alveoli, leading to a hyperinflammatory response in severely ill patients with COVID-19. This cascade of events may lead to multiple organ failure, acute respiratory distress, or pneumonia. Although the disease has a higher survival rate than other chronic diseases, the incidence of complications in the geriatric population are considerably high, with more systemic complications. This review sheds light on the pivotal roles played by various inflammatory markers in COVID-19-related complications. Different molecular pathways, such as the activation of JAK and JAK/STAT signaling are crucial in the progression of cytokine storm; hence, various mechanisms, immunological pathways, and functions of cytokines and other inflammatory markers have been discussed. A thorough understanding of cytokines' molecular pathways and their activation procedures will add more insight into understanding immunopathology and designing appropriate drugs, therapies, and control measures to counter COVID-19. Recently, anti-inflammatory drugs and several antiviral drugs have been reported as effective therapeutic drug candidates to control hypercytokinemia or cytokine storm. Hence, the present review also discussed prospective anti-inflammatory and relevant immunomodulatory drugs currently in various trial phases and their possible implications.

Mini-Factor H Modulates Complement-Dependent IL-6 and IL-10 Release in an Immune Cell Culture (PBMC) Model: Potential Benefits Against Cytokine Storm

Cytokine storm (CS), an excessive release of proinflammatory cytokines upon overactivation of the innate immune system, came recently to the focus of interest because of its role in the life-threatening consequences of certain immune therapies and viral diseases, including CAR-T cell therapy and Covid-19. Because complement activation with subsequent anaphylatoxin release is in the core of innate immune stimulation, studying the relationship between complement activation and cytokine release in an in vitro CS model holds promise to better understand CS and identify new therapies against it. We used peripheral blood mononuclear cells (PBMCs) cultured in the presence of autologous serum to test the impact of complement activation and inhibition on cytokine release, testing the effects of liposomal amphotericin B (AmBisome), zymosan and bacterial lipopolysaccharide (LPS) as immune activators and heat inactivation of serum, EDTA and mini-factor H (mfH) as complement inhibitors. These activators induced significant rises of complement activation markers C3a, C4a, C5a, Ba, Bb, and sC5b-9 at 45 min of incubation, with or without ~5- to ~2,000-fold rises of IL-1α, IL-1β, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13 and TNFα at 6 and 18 h later. Inhibition of complement activation by the mentioned three methods had differential inhibition, or even stimulation of certain cytokines, among which effects a limited suppressive effect of mfH on IL-6 secretion and significant stimulation of IL-10 implies anti-CS and anti-inflammatory impacts. These findings suggest the utility of the model for in vitro studies on CS, and the potential clinical use of mfH against CS.

SARS-CoV-2: Pathogenesis, Molecular Targets and Experimental Models

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a recent pandemic outbreak threatening human beings worldwide. This novel coronavirus disease-19 (COVID-19) infection causes severe morbidity and mortality and rapidly spreading across the countries. Therefore, there is an urgent need for basic fundamental research to understand the pathogenesis and druggable molecular targets of SARS-CoV-2. Recent sequencing data of the viral genome and X-ray crystallographic data of the viral proteins illustrate potential molecular targets that need to be investigated for structure-based drug design. Further, the SARS-CoV-2 viral pathogen isolated from clinical samples needs to be cultivated and titrated. All of these scenarios demand suitable laboratory experimental models. The experimental models should mimic the viral life cycle as it happens in the human lung epithelial cells. Recently, researchers employing primary human lung epithelial cells, intestinal epithelial cells, experimental cell lines like Vero cells, CaCo-2 cells, HEK-293, H1299, Calu-3 for understanding viral titer values. The human iPSC-derived lung organoids, small intestinal organoids, and blood vessel organoids increase interest among researchers to understand SARS-CoV-2 biology and treatment outcome. The SARS-CoV-2 enters the human lung epithelial cells using viral Spike (S1) protein and human angiotensin-converting enzyme 2 (ACE-2) receptor. The laboratory mouse show poor ACE-2 expression and thereby inefficient SARS-CoV-2 infection. Therefore, there was an urgent need to develop transgenic hACE-2 mouse models to understand antiviral agents' therapeutic outcomes. This review highlighted the viral pathogenesis, potential druggable molecular targets, and suitable experimental models for basic fundamental research.

Case Report: Stepwise Anti-Inflammatory and Anti-SARS-CoV-2 Effects Following Convalescent Plasma Therapy With Full Clinical Recovery

In these times of COVID-19 pandemic, concern has been raised about the potential effects of SARS-CoV-2 infection on immunocompromised patients, particularly on those receiving B-cell depleting agents and having therefore a severely depressed humoral response. Convalescent plasma can be a therapeutic option for these patients. Understanding the underlying mechanisms of convalescent plasma is crucial to optimize such therapeutic approach. Here, we describe a COVID-19 patient who was deeply immunosuppressed following rituximab (anti-CD20 monoclonal antibody) and concomitant chemotherapy for chronic lymphoid leukemia. His long-term severe T and B cell lymphopenia allowed to evaluate the treatment effects of convalescent plasma. Therapeutic outcome was monitored at the clinical, biological and radiological level. Moreover, anti-SARS-CoV-2 antibody titers (IgM, IgG and IgA) and neutralizing activity were assessed over time before and after plasma transfusions, alongside to SARS-CoV-2 RNA quantification and virus isolation from the upper respiratory tract. Already after the first cycle of plasma transfusion, the patient experienced rapid improvement of pneumonia, inflammation and blood cell counts, which may be related to the immunomodulatory properties of plasma. Subsequently, the cumulative increase in anti-SARS-CoV-2 neutralizing antibodies due to the three additional plasma transfusions was associated with progressive and finally complete viral clearance, resulting in full clinical recovery. In this case-report, administration of convalescent plasma revealed a stepwise effect with an initial and rapid anti-inflammatory activity followed by the progressive SARS-CoV-2 clearance. These data have potential implications for a more extended use of convalescent plasma and future monoclonal antibodies in the treatment of immunosuppressed COVID-19 patients.

COVID-19 and thrombotic microangiopathies

Severe COVID-19 can manifest as multiorgan dysfunction with pulmonary involvement being the most common and prominent. As more reports emerge in the literature, it appears that an exaggerated immune response in the form of unfettered complement activation and a cytokine storm may be a key driver of the widespread organ injury seen in this disease. In addition, these patients are also known to be hypercoagulable with a high rate of thrombosis and a higher-than-expected failure rate of anticoagulation. While macrovascular thrombosis is common in these individuals, the frequent finding of extensive microvascular thromboses in several series and case reports, raises the possibility of thrombotic microangiopathy (TMA) as being a contributing factor in the thrombotic and multi-organ complications of the disease. If this is correct, rapidly identifying a TMA and treating the underlying pathophysiology may allow for better outcomes in these critically ill patients. To further explore this, we reviewed the published literature on COVID-19, looking for reports describing TMA-like presentations. We summarize our findings here along with a discussion about presentation, pathophysiology, and a suggested treatment algorithm.

Use of convalescent plasma for COVID-19 in India: A review & practical guidelines

Convalescent plasma (CP) therapy is one of the promising therapies being tried for COVID-19 patients. This passive immunity mode involves separating preformed antibodies against SARS-CoV-2 from a recently recovered COVID-19 patient and infusing it into a patient with active disease or an exposed individual for prophylaxis. Its advantages include ease of production, rapid deployment, specificity against the target infectious agent, and scalability. In the current pandemic, it has been used on a large scale across the globe and also in India. However, unequivocal proof of efficacy and effectiveness in COVID-19 is still not available. Various CP therapy parameters such as donor selection, antibody quantification, timing of use, and dosing need to be considered before its use. The current review attempts to summarize the available evidence and provide recommendations for setting up CP protocols in clinical and research settings.

Antibody Responses in COVID-19: A Review

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread worldwide as a severe pandemic. Although its seroprevalence is highly variable among territories, it has been reported at around 10%, but higher in health workers. Evidence regarding cross-neutralizing response between SARS-CoV and SARS-CoV-2 is still controversial. However, other previous coronaviruses may interfere with SARS-CoV-2 infection, since they are phylogenetically related and share the same target receptor. Further, the seroconversion of IgM and IgG occurs at around 12 days post onset of symptoms and most patients have neutralizing titers on days 14-20, with great titer variability. Neutralizing antibodies correlate positively with age, male sex, and severity of the disease. Moreover, the use of convalescent plasma has shown controversial results in terms of safety and efficacy, and due to the variable immune response among individuals, measuring antibody titers before transfusion is mostly required. Similarly, cellular immunity seems to be crucial in the resolution of the infection, as SARS-CoV-2-specific CD4+ and CD8+ T cells circulate to some extent in recovered patients. Of note, the duration of the antibody response has not been well established yet.

PEGylated nanoparticle albumin-bound steroidal ginsenoside derivatives ameliorate SARS-CoV-2-mediated hyper-inflammatory responses

The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on a global scale urges prompt and effective countermeasures. Recently, a study has reported that coronavirus disease-19 (COVID-19), the disease caused by SARS-CoV-2 infection, is associated with a decrease in albumin level, an increase in NETosis, blood coagulation, and cytokine level. Here, we present drug-loaded albumin nanoparticles as a therapeutic agent to resolve the clinical outcomes observed in severe SARS-CoV-2 patients. PEGylated nanoparticle albumin-bound (PNAB) was used to promote prolonged bioactivity of steroidal ginsenoside saponins, PNAB-Rg6 and PNAB-Rgx365. Our data indicate that the application of PNAB-steroidal ginsenoside can effectively reduce histone H4 and NETosis-related factors in the plasma, and alleviate SREBP2-mediated systemic inflammation in the PBMCs of SARS-CoV-2 ICU patients. The engineered blood vessel model confirmed that these drugs are effective in suppressing blood clot formation and vascular inflammation. Moreover, the animal model experiment showed that these drugs are effective in promoting the survival rate by alleviating tissue damage and cytokine storm. Altogether, our findings suggest that these PNAB-steroidal ginsenoside drugs have potential applications in the treatment of symptoms associated with severe SARS-CoV-2 patients, such as coagulation and cytokine storm.

A Phase II Study on the Use of Convalescent Plasma for the Treatment of Severe COVID-19- A Propensity Score-Matched Control Analysis

COVID-19 is a global pandemic associated with increased morbidity and mortality. Convalescent plasma (CP) infusion is a strategy of potential therapeutic benefit. We conducted a multicenter phase II study to evaluate the efficacy and safety of CP in patients with COVID-19, grade 4 or higher. To evaluate the efficacy of CP, a matched propensity score analysis was used comparing the intervention (n = 59) to a control group (n = 59). Sixty patients received CP within a median time of 7 days from symptom onset. During a median follow-up of 28.5 days, 56/60 patients fully recovered and 1 patient remained in the ICU. The death rate in the CP group was 3.4% vs. 13.6% in the control group. By multivariate analysis, CP recipients demonstrated a significantly reduced risk of death [HR: 0.04 (95% CI: 0.004–0.36), p: 0.005], significantly better overall survival by Kaplan–Meir analysis (p < 0.001), and increased probability of extubation [OR: 30.3 (95% CI: 2.64–348.9), p: 0.006]. Higher levels of antibodies in the CP were independently associated with significantly reduced risk of death. CP infusion was safe with only one grade 3 adverse event (AE), which easily resolved. CP used early may be a safe and effective treatment for patients with severe COVID-19 (trial number NCT04408209).

Mortality Benefit of Convalescent Plasma in COVID-19: A Systematic Review and Meta-Analysis

Importance/Background: With a scarcity of high-grade evidence for COVID-19 treatment, researchers and health care providers across the world have resorted to classical and historical interventions. Immunotherapy with convalescent plasma (CPT) is one such therapeutic option. Methods: A systematized search was conducted for articles published between December 2019 and 18th January 2021 focusing on convalescent plasma efficacy and safety in COVID-19. The primary outcomes were defined as mortality benefit in patients treated with convalescent plasma compared to standard therapy/placebo. The secondary outcome was pooled mortality rate and the adverse event rate in convalescent plasma-treated patients. Results: A total of 27,706 patients were included in the qualitative analysis, and a total of 3,262 (2,127 in convalescent plasma-treated patients and 1,135 in the non-convalescent plasma/control group) patients died. The quantitative synthesis in 23 studies showed that the odds of mortality in patients who received plasma therapy were significantly lower than those in patients who did not receive plasma therapy [odds ratio (OR) 0.65, 95% confidence interval (CI) 0.53-0.80, p < 0.0001, I 2 = 15%). The mortality benefit remains the same even for 14 trials/prospective studies (OR 0.59, 95% CI 0.43-0.81, p = 0.001, I 2 = 22%) as well as for nine case series/retrospective observational studies (OR 0.78, 95% CI 0.65-0.94, p = 0.01, I 2 = 0%). However, in a subgroup analysis for 10 randomized controlled trials (RCTs), there was no statistically significant reduction in mortality between the CPT group compared to the non-CPT group (OR 0.76, 95% CI 0.53-1.08, p = 0.13, I 2 = 7%). Furthermore, the sensitivity analysis of 10 RCTs, excluding the study with the highest statistical weight, displayed a lower mortality rate compared to that of non-CPT COVID-19 patients (OR 0.64, 95% CI 0.42-0.97, p = 0.04, I 2 = 0%). The observed pooled mortality rate was 12.9% (95% CI 9.7-16.9%), and the pooled adverse event rate was 6.1% (95% CI 3.2-11.6), with significant heterogeneity. Conclusions and Relevance: Our systemic review and meta-analysis suggests that CPT could be an effective therapeutic option with promising evidence on the safety and reduced mortality in concomitant treatment for COVID-19 along with antiviral/antimicrobial drugs, steroids, and other supportive care. Future exploratory studies could benefit from more standardized reporting, especially in terms of the timing of interventions and clinically relevant outcomes, like days until discharge from the hospital and improvement of clinical symptoms.

Convalescent Plasma for the Prevention and Treatment of COVID-19: A Systematic Review and Quantitative Analysis

BACKGROUND

The COVID-19 pandemic, caused by a novel coronavirus termed SARS-CoV-2, has spread quickly worldwide. Convalescent plasma (CP) obtained from patients following recovery from COVID-19 infection and development of antibodies against the virus is an attractive option for either prophylactic or therapeutic treatment, since antibodies may have direct or indirect antiviral activities and immunotherapy has proven effective in principle and in many clinical reports.

OBJECTIVE

We seek to characterize the latest advances and evidence in the use of CP for COVID-19 through a systematic review and quantitative analysis, identify knowledge gaps in this setting, and offer recommendations and directives for future research.

METHODS

PubMed, Web of Science, and Embase were continuously searched for studies assessing the use of CP for COVID-19, including clinical studies, commentaries, reviews, guidelines or protocols, and in vitro testing of CP antibodies. The screening process and data extraction were performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Quality appraisal of all clinical studies was conducted using a universal tool independent of study designs. A meta-analysis of case-control and randomized controlled trials (RCTs) was conducted using a random-effects model.

RESULTS

Substantial literature has been published covering various aspects of CP therapy for COVID-19. Of the references included in this review, a total of 243 eligible studies including 64 clinical studies, 79 commentary articles, 46 reviews, 19 guidance and protocols, and 35 in vitro testing of CP antibodies matched the criteria. Positive results have been mostly observed so far when using CP for the treatment of COVID-19. There were remarkable heterogeneities in the CP therapy with respect to patient demographics, donor antibody titers, and time and dose of CP administration. The studies assessing the safety of CP treatment reported low incidence of adverse events. Most clinical studies, in particular case reports and case series, had poor quality. Only 1 RCT was of high quality. Randomized and nonrandomized data were found in 2 and 11 studies, respectively, and were included for meta-analysis, suggesting that CP could reduce mortality and increase viral clearance. Despite promising pilot studies, the benefits of CP treatment can only be clearly established through carefully designed RCTs.

CONCLUSIONS

There is developing support for CP therapy, particularly for patients who are critically ill or mechanically ventilated and resistant to antivirals and supportive care. These studies provide important lessons that should inform the planning of well-designed RCTs to generate more robust knowledge for the efficacy of CP in patients with COVID-19. Future research is necessary to fill the knowledge gap regarding prevention and treatment for patients with COVID-19 with CP while other therapeutics are being developed.

Assessment of the Safety and Therapeutic Benefits of Convalescent Plasma in COVID-19 Treatment: A Systematic Review and Meta-Analysis

Background: The coronavirus disease (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), prompted a global health crisis, with no available specific treatments. Convalescent plasma (CP) with neutralizing antibodies could be a promising therapeutic approach to reduce mortality. Objectives: To evaluate the therapeutic potential of CP for COVID-19 and to assess its safety and efficacy in reducing the patients' mortality. Methods: We retrieved clinical trial references from multiple Databases (e.g., PubMed, B-On, SCOPUS), for complete studies until November 26th 2020. We included Randomized controlled trials (RCT) and controlled non-randomized trials (CNRT), that assessed the efficacy of CP to treat hospitalized COVID-19 patients. Trials were included regardless of concomitant medications in the intervention's arms. Eleven trials met our eligibility criteria. This study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. We defined a methodological protocol to extract and evaluate all pertinent baseline demographics and interventions' characteristics from trials. The primary outcomes were the safety profile of CP, measured by the type, frequency and severity of adverse events, and CP effectiveness in reducing mortality, measured by the number of deaths registered for this therapy. Results: We assessed 11 trials (5 RCT and 6 CNRT) with 3,098 participants, of whom 923 patients were treated with CP. Only 32 (3.5%) of the treated patients suffered adverse events (from which 9.4% serious transfusion-related adverse events). The overall mortality rates were significantly decreased by CP administration {risk ratio (RR) 0.71, p = 0.005, 95% confidence interval (Cl) [0.57-0.90]}, with low heterogeneity. In the sub-analysis by period of transfusion, CP transfusion within a week of hospitalization contributed to diminished mortality rate (RR = 0.71, p = 0.03, 95%Cl [0.53-0.96]). CP therapy also led to significantly reduced viral loads at 72 h after transfusion (RR = 0.61, p = 0.04, 95%Cl [0.38-0.98]), despite high heterogeneity due to disease severity. Conclusion: This meta-analysis established CP as a safe and potentially effective therapy for COVID-19, decreasing the mortality rates and promoting a swift viral clearance. Further studies are necessary to provide stronger evidence.

Convalescent plasma treatment is associated with lower mortality and better outcomes in high-risk COVID-19 patients - propensity-score matched case-control study

OBJECTIVE

This study aimed to investigate the efficacy and safety of convalescent plasma (CP) transfusion in a group of high-risk COVID-19 patients.

METHODS

This prospective study included 204 patients from a single tertiary-care hospital, hospitalized with COVID-19, of whom 102 were treated with CP administration and standard care (PG) and 102 others who received standard care only (CG). The CG was selected from 336 hospitalized patients using the propensity-score matching (PSM) technique using age, MEWS score, and comorbidities. The primary outcome was mortality rate; secondary outcomes were the requirement of a ventilator, length of ventilator need, length of intensive care unit (ICU) stay, and length of overall hospital confinement. Additionally, parameters predicting death in COVID-19 patients were identified.

RESULTS

Findings confirmed a significantly lower mortality rate in the PG versus the CG (13.7% vs. 34.3 %, p = 0.001) and a significant difference in the cumulative incidence of death between the two groups (p <  0.001). CP treatment was associated with lower risk of death (OR = 0.25 CI95 [0.06; 0.91], p =  0.041). There were no significant differences in ICU stay, ventilator time, and hospitalization time between the two groups.

CONCLUSIONS

A significantly lower mortality rate was observed in the group of patients treated with CP. Age, presence of cardiac insufficiency, active cancer, a ventilator requirement, and length of hospitalization significantly increased the risk of death in both groups. Our study shows that CP affords better outcomes when administrated in the earlier stage of high-risk COVID-19 disease.

Clinical predictors of donor antibody titre and correlation with recipient antibody response in a COVID-19 convalescent plasma clinical trial

BACKGROUND

Convalescent plasma therapy for COVID-19 relies on transfer of anti-viral antibody from donors to recipients via plasma transfusion. The relationship between clinical characteristics and antibody response to COVID-19 is not well defined. We investigated predictors of convalescent antibody production and quantified recipient antibody response in a convalescent plasma therapy clinical trial.

METHODS

Multivariable analysis of clinical and serological parameters in 103 confirmed COVID-19 convalescent plasma donors 28 days or more following symptom resolution was performed. Mixed-effects regression models with piecewise linear trends were used to characterize serial antibody responses in 10 convalescent plasma recipients with severe COVID-19.

RESULTS

Donor antibody titres ranged from 0 to 1 : 3892 (anti-receptor binding domain (RBD)) and 0 to 1 : 3289 (anti-spike). Higher anti-RBD and anti-spike titres were associated with increased age, hospitalization for COVID-19, fever and absence of myalgia (all P < 0.05). Fatigue was significantly associated with anti-RBD (P = 0.03). In pairwise comparison amongst ABO blood types, AB donors had higher anti-RBD and anti-spike than O donors (P < 0.05). No toxicity was associated with plasma transfusion. Non-ECMO recipient anti-RBD antibody titre increased on average 31% per day during the first three days post-transfusion (P = 0.01) and anti-spike antibody titre by 40.3% (P = 0.02).

CONCLUSION

Advanced age, fever, absence of myalgia, fatigue, blood type and hospitalization were associated with higher convalescent antibody titre to COVID-19. Despite variability in donor titre, 80% of convalescent plasma recipients showed significant increase in antibody levels post-transfusion. A more complete understanding of the dose-response effect of plasma transfusion amongst COVID-19-infected patients is needed.

Zoonotic coronavirus epidemics: Severe acute respiratory syndrome, Middle East respiratory syndrome, and coronavirus disease 2019

OBJECTIVE

To review the virology, immunology, epidemiology, clinical manifestations, and treatment of the following 3 major zoonotic coronavirus epidemics: severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and coronavirus disease 2019 (COVID-19).

DATA SOURCES

Published literature obtained through PubMed database searches and reports from national and international public health agencies.

STUDY SELECTIONS

Studies relevant to the basic science, epidemiology, clinical characteristics, and treatment of SARS, MERS, and COVID-19, with a focus on patients with asthma, allergy, and primary immunodeficiency.

RESULTS

Although SARS and MERS each caused less than a thousand deaths, COVID-19 has caused a worldwide pandemic with nearly 1 million deaths. Diagnosing COVID-19 relies on nucleic acid amplification tests, and infection has broad clinical manifestations that can affect almost every organ system. Asthma and atopy do not seem to predispose patients to COVID-19 infection, but their effects on COVID-19 clinical outcomes remain mixed and inconclusive. It is recommended that effective therapies, including inhaled corticosteroids and biologic therapy, be continued to maintain disease control. There are no reports of COVID-19 among patients with primary innate and T-cell deficiencies. The presentation of COVID-19 among patients with primary antibody deficiencies is variable, with some experiencing mild clinical courses, whereas others experiencing a fatal disease. The landscape of treatment for COVID-19 is rapidly evolving, with both antivirals and immunomodulators demonstrating efficacy.

CONCLUSION

Further data are needed to better understand the role of asthma, allergy, and primary immunodeficiency on COVID-19 infection and outcomes.

Landscape of humoral immune responses against SARS-CoV-2 in patients with COVID-19 disease and the value of antibody testing

A new pandemic is ongoing in several parts of the world. The agent responsible is the newly emerged severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The symptoms associated with this virus are known as the coronavirus disease-2019 (COVID-19). In this review, we summarize the published data on virus specific antibodies in hospitalized patients with COVID-19 disease, patients recovered from the disease and the individuals who are asymptomatic with SARS-CoV-2 infections. The review highlights the following: i) an adjunct role of antibody tests in the diagnosis of COVID-19 in combination with RT-PCR; ii) status of antibodies from COVID-19 convalescent patients to select donors for plasma therapy; iii) the potential confounding effects of other coronaviruses, measles, mumps and rubella in antibody testing due to homology of certain viral genes; and iv) the role of antibody testing for conducting surveillance in populations, incidence estimation, contact tracing and epidemiologic studies.

Immunobiology and immunotherapy of COVID-19: A clinically updated overview

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a new member of the coronavirus family that can cause coronavirus disease 2019 (COVID-19). COVID-9 has become a global pandemic with severe health issues around the world. Identifying the accurate immunopathogenesis of the COVID-19 and the immune response against SARS-CoV-2 is necessary for the development of therapeutic approaches and rational drug design. This paper aims to overview the updated clinical data on the immunopathogenesis of the COVID-19 and review the innate and adaptive immune response to SARS-CoV-2. Also, challenges of the immune response to SARS-CoV-2 leading to dysfunctional immune response and their contribution to the progression of the disease have been discussed. To achieve a more efficient immune response, multiple methods could be applied, including regulation of the immune response, augmentation of the immune system against the virus, inhibition of the dysfunctional immune checkpoints, and inhibition of the viral replication/infection. Based on the immune response against SARS-CoV-2 and its dysfunction, we introduce potential immunotherapies as well as reviewing recruiting/completed clinical trials of COVID-19.

Wuhan to World: The COVID-19 Pandemic

COVID-19 is a Severe Acute Respiratory Syndrome (SARS), caused by SARS-CoV-2, a novel virus which belongs to the family Coronaviridae. It was first reported in December 2019 in the Wuhan city of China and soon after, the virus and hence the disease got spread to the entire world. As of February 26, 2021, SARS-CoV-2 has infected ~112.20 million people and caused ~2.49 million deaths across the globe. Although the case fatality rate among SARS-CoV-2 patient is lower (~2.15%) than its earlier relatives, SARS-CoV (~9.5%) and MERS-CoV (~34.4%), the SARS-CoV-2 has been observed to be more infectious and caused higher morbidity and mortality worldwide. As of now, only the knowledge regarding potential transmission routes and the rapidly developed diagnostics has been guiding the world for managing the disease indicating an immediate need for a detailed understanding of the pathogen and the disease-biology. Over a very short period of time, researchers have generated a lot of information in unprecedented ways in the key areas, including viral entry into the host, dominant mutation, potential transmission routes, diagnostic targets and their detection assays, potential therapeutic targets and drug molecules for inhibiting viral entry and/or its replication in the host including cross-neutralizing antibodies and vaccine candidates that could help us to combat the ongoing COVID-19 pandemic. In the current review, we have summarized the available knowledge about the pathogen and the disease, COVID-19. We believe that this readily available knowledge base would serve as a valuable resource to the scientific and clinical community and may help in faster development of the solution to combat the disease.

Anti-Inflammation, Immunomodulation and Therapeutic Repair in Current Clinical Trials for the Management of COVID-19

The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), continues to spread around the world. While prophylactic vaccines against SARS-CoV-2 are making great progress, there is still a need to explore safe and effective therapies with biological products for COVID-19. Currently clinical trial efforts are planned and ongoing using different biological agents for anti-inflammatory therapies, immunomodulation, and therapeutic repair in COVID-19. Targeting inflammatory cytokines with antibodies or inhibitors may be an urgent therapeutic strategy for COVID-19. Importantly, it is critical for an in-depth understanding of these new clinical therapeutic agents in their conditions that are probably involved in both physiological and pathological host responses. In this article, we analyze the potential implications for the current clinical trials of therapeutic biologics and address issues for the development of the COVID-19-related biological therapies.

ASSURED-SQVM diagnostics for COVID-19: addressing the why, when, where, who, what and how of testing

Introduction: SARS-CoV-2, the new coronavirus that originated in 2019, continues to impact every aspect of society in a profound manner. Testing will remain an important tool to mitigate the effects of this pandemic as early and accurate diagnosis can lead to appropriate countermeasures to reduce mortality and morbidity. However, testing isn’t a simple yes/no answer as the target and host are complex, the virus is a moving target, there is a plethora of tests that identify different parts of the virus and have their own limits and range of detection, and when prevalence is low, false positives and negatives can be very high.

Areas covered: This article covers all the major questions related to COVID-19 diagnostics, the why, when, where, who, what and how of testing, the different types of tests, interpretation of results and the ideal ASSURED-SQVM diagnostic. A comprehensive literature review using all the publicly available databases and government websites and reports was performed.

Expert opinion: Diagnostics that meet the ‘ASSURED-SQVM’ (Affordable, Selective and Sensitive, User-friendly, Rapid and Robust, Equipment-free, Deliverable to end-users and additionally, allows for Self-testing, Quantifiable, detects if pathogens are Viable and can detect Multiple pathogens) would make a major impact in our fight against the current pandemic. While a significant majority of researchers focus on developing novel diagnostics that are highly selective and sensitive, it is the opinion of these authors that other aspects of the ASSURED-SQVM principles also be considered early in the development process for widespread use.

Inflammatory pathways and potential therapies for COVID-19: A mini review

The public health crisis of the novel coronavirus disease (COVID-19) is alarming since January 2020. COVID-19 genome (SARS-CoV-2) is related to other highly pathogenic coronaviruses SARS-CoV (severe acute respiratory syndrome coronavirus) and MERS-CoV (Middle East respiratory syndrome coronavirus). Amino acid substitutions in some of SARS-CoV-2 proteins resulted in mutations proposing more virulent and contagious properties for this novel virus. Coronavirus penetrates the host cell via endocytosis and once infected, immune responses are triggered to fight against the pathogen. Innate immune response activates major transcription factors to secrete proinflammatory cytokines and type 1 interferon response (T1INF) to induce antiviral immunity. While adaptive immunity initiates cascade of B-cells antibody mediated and T-cells cellular mediate immunities, several mechanisms are raised by SARS-CoV-2 to evade host immune response. Consequently, a surge of proinflammatory cytokines, known as cytokine storm (CS) are released. Failure to manage CS results in several pathological complications as acute respiratory distress syndrome (ARDS). Although researches have not discovered an effective treatment against SARS-CoV-2, recent therapeutic approaches recommending the use of anti-inflammatories in combination with antivirals and some repurposed drugs for COVID-19 patients. Future medications should be designed to target essential hallmarks in the CS to improve clinical outcomes.

Impact of pathogen reduction methods on immunological properties of the COVID-19 convalescent plasma

BACKGROUND AND OBJECTIVES

COVID-19 convalescent plasma is an experimental treatment against SARS-CoV-2. The aim of this study is to assess the impact of different pathogen reduction methods on the levels and virus neutralizing activity of the specific antibodies against SARS-CoV2 in convalescent plasma.

MATERIALS AND METHODS

A total of 140 plasma doses collected by plasmapheresis from COVID-19 convalescent donors were subjected to pathogen reduction by three methods: methylene blue (M)/visible light, riboflavin (R)/UVB and amotosalen (A)/UVA. To conduct a paired comparison, individual plasma doses were divided into 2 samples that were subjected to one of these methods. The titres of SARS-CoV2 neutralizing antibodies (NtAbs) and levels of specific immunoglobulins to RBD, S- and N-proteins of SARS-CoV-2 were measured before and after pathogen reduction.

RESULTS

The methods reduced NtAbs titres differently: among units with the initial titre 80 or above, 81% of units remained unchanged and 19% decreased by one step after methylene blue; 60% were unchanged and 40% decreased by one step after amotosalen; after riboflavin 43% were unchanged and 50% (7%, respectively) had a one-step (two-step, respectively) decrease. Paired two-sample comparisons (M vs. A, M vs. R and A vs. R) revealed that the largest statistically significant decrease in quantity and activity of the specific antibodies resulted from the riboflavin treatment.

CONCLUSION

Pathogen reduction with methylene blue or with amotosalen provides the greater likelihood of preserving the immunological properties of the COVID-19 convalescent plasma compared to riboflavin.

Predictive Analysis of the Neutralization Activity in Convalescent Plasmas From COVID-19 Recovered Patients in Zhejiang Province, China, January-March, 2020

Background

Convalescent plasma (CP) transfusion is considered to be the priority therapeutic option for COVID-19 inpatients when no specific drugs are available for emerging infections. An alternative, simple, and sensitive method is urgently needed for clinical use to detect neutralization activity of the CP to avoid the use of inconvenient micro-neutralization assay.

Method

This study aims to explore optimal index in predicting the COVID-19 CP neutralization activity (neutralizing antibody titers, NAb titers) in an indirect ELISA format. Fifty-seven COVID-19-recovered patients plasma samples were subjected to anti-SARS-CoV-2 RBD, S1, and N protein IgG antibody by indirect ELISA.

Results

ELISA-RBD exhibited high specificity (96.2%) and ELISA-N had high sensitivity (100%); while ELISA-S1 had low sensitivity (86.0%) and specificity (73.1%). Furthermore, ELISA-RBD IgG titers and pseudovirus-based NAb titers correlated significantly, with R² of 0.2564 (P < 0.0001).

Conclusion

ELISA-RBD could be a substitute for the neutralization assay in resource-limited situations to screen potential plasma donors for further plasma infusion therapy.

Intravenous Immunoglobulin for Treatment of Patients with COVID-19: A Case-control Study

Background: It seems that the risk of developing complications associated with coronavirus disease 2019 (COVID-19) is higher among individuals with weakened immune systems. Objectives: Therefore, this study was carried out to determine the effectiveness of intravenous immunoglobulin (IVIG) for the treatment of patients not entering the intubation phase compared to those entering the intubation phase. Methods: This descriptive case-control study was performed on 26 patients with COVID-19 referring to Imam Reza hospital in Mashhad, Iran, in March 2020. For subjects with COVID-19 not responding to the standard three-drug protocol (i.e., ribavirin, hydroxychloroquine, and lopinavir/ritonavir), three doses of IVIG (0.4 g/kg/day) were added to the protocol. The patients were divided into two groups of subjects not entering the intubation phase and those entering the intubation phase and compared in terms of different variables. Results: The comparison of laboratory findings showed a significant difference before and after receiving IVIG regarding oxygen saturation (P < 0.005), white blood cell (P = 0.001), hemoglobin level (P = 0.0002), lymphocyte count (P = 0.03), and C-reactive protein (P = 0.001). In general, 53.8% and 46.2% of the patients were discharged and expired, respectively. All the subjects not entering the intubation phase were recovered; nevertheless, only one case entering the intubation phase was recovered, and 92.3% of the patients expired. A significant difference was observed between the patients not entering the intubation phase and those entering the intubation phase in terms of mortality (χ2 = 22.28; P < 0.005). Conclusions: In summary, the obtained results of the current study confirmed the therapeutic effects of IVIG on patients with COVID-19. Moreover, better treatment results, shorter hospital stay, and lower mortality rates were observed among COVID-19 patients who did not enter the intubation phase in comparison with those entering the intubation phase.

Treatment of COVID-19: a review of current and prospective pharmacotherapies

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread and have grave health and socioeconomic consequences worldwide. Researchers have raced to understand the pathophysiological mechanisms underpinning the disease caused by SARS-CoV-2 so that effective therapeutic targets can be discovered. This review summarises the key pharmacotherapies that are being investigated for treatment of COVID-19, including antiviral, immunomodulator and anticoagulation strategies.

Early Administration of Convalescent Plasma Improves Survival in Patients with Hematological Malignancies and COVID-19

The use of convalescent plasma in the treatment of COVID-19 may lead to a milder course of infection and has been associated with improved outcomes. Determining optimal treatments in high risk populations is crucial, as is the case in those with hematological malignancies. We analyzed a cohort of 23 patients with hematological malignancies and COVID-19 who had received plasma 48-72 h after the diagnosis of infection and compared it with a historical group of 22 patients who received other therapy. Overall survival in those who received convalescent plasma was significantly higher than in the historical group (p = 0.03460). The plasma-treated group also showed a significantly milder course of infection (p = 0.03807), characterized by less severe symptoms and faster recovery (p = 0.00001). In conclusion, we have demonstrated that convalescent plasma is an effective treatment and its early administration leads to clinical improvement, increased viral clearance and longer overall survival in patients with hematological malignancies and COVID-19. To our knowledge, this is the first report to analyze the efficacy of convalescent plasma in a cohort of patients with hematological malignancies.

COVID-19 vaccines: The status and perspectives in delivery points of view

Due to the high prevalence and long incubation periods often without symptoms, the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has infected millions of individuals globally, causing the coronavirus disease 2019 (COVID-19) pandemic. Even with the recent approval of the anti-viral drug, remdesivir, and Emergency Use Authorization of monoclonal antibodies against S protein, bamlanivimab and casirimab/imdevimab, efficient and safe COVID-19 vaccines are still desperately demanded not only to prevent its spread but also to restore social and economic activities via generating mass immunization. Recent Emergency Use Authorization of Pfizer and BioNTech's mRNA vaccine may provide a pathway forward, but monitoring of long-term immunity is still required, and diverse candidates are still under development. As the knowledge of SARS-CoV-2 pathogenesis and interactions with the immune system continues to evolve, a variety of drug candidates are under investigation and in clinical trials. Potential vaccines and therapeutics against COVID-19 include repurposed drugs, monoclonal antibodies, antiviral and antigenic proteins, peptides, and genetically engineered viruses. This paper reviews the virology and immunology of SARS-CoV-2, alternative therapies for COVID-19 to vaccination, principles and design considerations in COVID-19 vaccine development, and the promises and roles of vaccine carriers in addressing the unique immunopathological challenges presented by the disease.

Evaluation of serum IgM and IgG antibodies in COVID-19 patients by enzyme linked immunosorbent assay

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is sweeping the world since the end of 2019. The titer change of antibodies against SARS-CoV-2 needs to be further clarified, the clinical and preventive value of antibodies still needs to be further investigated. An enzyme-linked immunosorbent assay (ELISA) was established by coating with SARS-CoV-2 recombinant spike protein and used to detect serum immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies against SARS-CoV-2 in coronavirus disease 2019 patients to evaluate the pattern of changes of antibodies. The specificity of the ELISA for detection SARS-CoV-2 IgM and IgG were 96% (144/150) and 100% (150/150), respectively. The sensitivity of ELISA was 100% (150/150) for IgM, and 99.3% (149/150) for IgG. SARS-CoV-2-SP-IgM and SP-IgG antibodies could be detected on Day 1 of hospitalization in 12.5% patients, and SP-IgM began to decrease after reaching its peak at around 22-28 days, and become negative at Month 3 in 30% patients and negative at Month 7 in 79% of these patients after onset; IgG reached its peak around Day 22-28 and kept at a high level within the longest observation period for 4 months, it dropped very sharply at 7 months. The positive rates of SP-IgM and SP-IgG were higher than those of reverse transcription-polymerase chain reaction on Day 7 and 4. The established indirect ELISA has good specificity and sensitivity. IgM and IgG against SARS-CoV-2 appeared almost simultaneously in the early stage, and the level of IgG antibodies could not maintain a high plateau in the observation period of 7 months. Our data will help develop the diagnosis and vaccine of SARS-CoV-2.

COVID-19 convalescent plasma composition and immunological effects in severe patients

Convalescent plasma (CP) has emerged as a treatment for COVID-19. However, the composition and mechanism of action are not fully known. Therefore, we undertook a two-phase controlled study in which, first the immunological and metabolomic status of recovered and severe patients were evaluated. Secondly, the 28-day effect of CP on the immune response in severe patients was assessed. Nineteen recovered COVID-19 patients, 18 hospitalized patients with severe disease, and 16 pre-pandemic controls were included. Patients with severe disease were treated with CP transfusion and standard therapy (i.e., plasma recipients, n = 9) or standard therapy alone (n = 9). Clinical and biological assessments were done on day 0 and during follow-up on days 4, 7, 14, and 28. Clinical parameters, viral load, total immunoglobulin (Ig) G and IgA anti-S1-SARS-CoV-2 antibodies, neutralizing antibodies (NAbs), autoantibodies, cytokines, T and B cells, and metabolomic and lipidomic profiles were examined. Total IgG and IgA anti-S1-SARS-CoV-2 antibodies were key factors for CP selection and correlated with NAbs. In severe COVID-19 patients, mostly interleukin (IL)-6 (P = <0.0001), IL-10 (P = <0.0001), IP-10 (P = <0.0001), fatty acyls and glycerophospholipids were higher than in recovered patients. Latent autoimmunity and anti-IFN-α antibodies were observed in both recovered and severe patients. COVID-19 CP induced an early but transient cytokine profile modification and increases IgG anti-S1-SARS-CoV-2 antibodies. At day 28 post-transfusion, a decrease in activated, effector and effector memory CD4+ (P < 0.05) and activated and effector CD8+ (P < 0.01) T cells and naïve B cells (P = 0.001), and an increase in non-classical memory B cells (P=<0.0001) and central memory CD4+ T cells (P = 0.0252) were observed. Moreover, IL-6/IFN-γ (P = 0.0089) and IL-6/IL-10 (P = 0.0180) ratios decreased in plasma recipients compared to those who received standard therapy alone. These results may have therapeutic implications and justify further post-COVID-19 studies.

What do we know about the antibody responses to SARS-CoV-2?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide causing a pandemic with millions of infected people and deaths. Currently, the scientific community is working hard to develop a specific vaccine or treatment. However, since antibody production is an important part of the adaptive immune response, to develop vaccines and therapies, we must understand the antibody response to SARS-CoV-2 infection. In this work, we summarize the most important findings of antibody-mediated immunity against SARS-CoV-2 and highlight its role in the efficient use of plasma from convalescent patients and the direct application of antibodies as treatment.

Potential mechanisms of action of convalescent plasma in COVID-19

The COVID-19 pandemic will be remembered as one of the worst catastrophic events in human history. Unfortunately, no universally recognized effective therapeutic agents are currently available for the treatment of severe SARS-CoV-2 infection. In this context, the use of convalescent plasma from recovered COVID-19 patients has gained increasing interest thanks to the initially positive clinical reports. A number of mechanisms of action have been proposed for convalescent plasma, including direct neutralization and suppression of viremia, anti-inflammatory and immunomodulation effects and mitigation of the COVID-19-associated hypercoagulable state. These immune and non-immune mechanisms will be critically discussed in this narrative review.

Perspectives for immune plasma treatment of COVID-19

Background/aim

The SARS-CoV-2 infection was declared as a pandemic by the World Health Organization (WHO) on March 11, 2020, and the death toll from COVID-19, which is the disease caused by SARS-CoV-2, has already surpassed that of many previous epidemics. A wide variety of treatment options are being considered for COVID-19, but there is still no definitive treatment or vaccine. This study aims to explain the background of convalescent plasma (CP) treatment and its relations with COVID-19 immunity, to define ideal treatment procedures, and to reveal present and future perspectives in the light of the rapidly growing data. Immunological basis of COVID-19-associated immune response and convalescent plasma as a treatment option: Since it has been shown that the impaired immune response of the host is one of the most important factors that increase the severity of the infection, treatment strategies to suppress aberrant immune activation are currently being considered. CP, which is derived from recently recovered patients and contains neutralizing antibodies and many other immune- modulatory substances, seems to be the most convenient strategy to restore normal immune function considering the fast spreading nature of the ongoing pandemic.

Conclusion

Even though mechanisms of action of plasma therapy are not fully delineated, it was shown that it could lead to a reduction in mortality since other alternatives such as monoclonal antibodies or SARS-CoV-2 hyperimmunoglobulin require much more time and effort to be developed.

Part of the Covid19 puzzle: Acute parkinsonism

Parkinsonism developed owing to viruses is one of the important causes of secondary parkinsonism. After the Spanish flu pandemic, the increase in the number of parkinsonian cases in the long term has drawn attention on the relationship between viruses and parkinsonism. For this reason, the relationship between influenza and parkinsonism has been studied most. Nowadays in which we are experiencing the COVID-19 pandemic, scientists, based on the experiences gained from the Spanish flu pandemic, have drawn attention to the fact that the third wave of the pandemic might be parkinsonism. However, as we have reviewed in the literature, acute parkinsonism due to COVID-19 was not reported during this pandemic. Here, we present a case in which signs of acute parkinsonism developed on the 3rd day of the illness and neurological symptoms regressed with convalescent plasma treatment.

Current views on the potentials of convalescent plasma therapy (CPT) as Coronavirus disease 2019 (COVID-19) treatment: A systematic review and meta-analysis based on recent studies and previous respiratory pandemics

Convalescent plasma therapy (CPT) has been investigated as a treatment for COVID-19. This review evaluates CPT in COVID-19 and other viral respiratory diseases, including severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and influenza. PubMed and Google scholar databases were used to collect eligible publications until 8 December 2020. Meta-analysis used Mantel-Haenszel risk ratio (RR) with 95% confidence interval (CI) and pooled analysis for individual patient data with inverse variance weighted average. The study is registered at PROSPERO with the number of CRD4200270579. Forty-four studies with 36,716 participants were included in the pooled analysis and 20 studies in the meta-analysis. Meta-analysis showed reduction of mortality (RR 0.57, 95% CI [0.43, 0.76], z = 3.86 [p < 0.001], I²  = 44% [p = 0.03]) and higher number of discharged patients (RR 2.53, 95% CI [1.72, 3.72], z = 4.70 [p < 0.001], I²  = 3% [p = 0.39]) in patients receiving CPT compared to standard care alone. A possible mechanism of action is prompt reduction in viral titre. Serious transfusion-related adverse events were reported to be less than 1% of cases, suggesting the overall safety of CPT; nevertheless, the number of patients participating in the studies was still limited. It is also important to notice that in all the studies, the majority of patients were also given other medications, such as antivirals, antibiotics and corticosteroid; furthermore, randomized controlled studies involving more patients and in combination with other treatment modalities are urgently needed.