Innate Immunity in Protection and Pathogenesis During Coronavirus Infections and COVID-19.

The COVID-19 pandemic was caused by the recently emerged ß-coronavirus SARS-CoV-2. SARS-CoV-2 has had a catastrophic impact, resulting in nearly 7 million fatalities worldwide to date. The innate immune system is the first line of defense against infections, including the detection and response to SARS-CoV-2. Here, we discuss the innate immune mechanisms that sense coronaviruses, with a focus on SARS-CoV-2 infection and how these protective responses can become detrimental in severe cases of COVID-19, contributing to cytokine storm, inflammation, long-COVID, and other complications. We also highlight the complex cross talk among cytokines and the cellular components of the innate immune system, which can aid in viral clearance but also contribute to inflammatory cell death, cytokine storm, and organ damage in severe COVID-19 pathogenesis. Furthermore, we discuss how SARS-CoV-2 evades key protective innate immune mechanisms to enhance its virulence and pathogenicity, as well as how innate immunity can be therapeutically targeted as part of the vaccination and treatment strategy. Overall, we highlight how a comprehensive understanding of innate immune mechanisms has been crucial in the fight against SARS-CoV-2 infections and the development of novel host-directed immunotherapeutic strategies for various diseases.

Interaction between cardiac resynchronization therapy and cytokines in heart failure patients.

Congestive heart failure (CHF) is a complex multistage syndrome that has a great financial burden on human societies. It was known that the damaged myocardium sends a signal to stimulate the immune system and proliferation of leukocytes. In continuous, cytokine storm can be initiated and causes the probability of CHF. Persistent inflammation by increasing the levels of pro-inflammatory cytokines, plays an important role in the pathogenesis of CHF and causes remodeling, which is a progressive processs. Although treatment by drugs can reduce mortality and partially control the symptoms of heart failure patients, but complications and mortality are still high. Therefore, other treatment options such as Cardiac Resynchronization Therapy (CRT) are necessary. Today, it is known that CRT can be an effective treatment for many patients with heart failure. CRT is novel, non-pharmacological, and device-based therapy that would be beneficial to know more about its performance in the management of heart failure. In this study, we have reviewed the immunological processes involved in heart failure and the effect of CRT in controlling of the cytokine storm.

Tocilizumab, an IL6-receptor antibody, proved effective as adjuvant therapy for cytokine storm induced by severe infection in patients with hematologic malignancy.

Patients with hematological malignancies who experience severe infections are at risk of developing dangerous complications due to excessive inflammatory cytokines. To improve the prognosis, it is crucial to identify better ways to manage the systemic inflammatory storm after infection. In this study, we evaluated four patients with hematological malignancies who developed severe bloodstream infections during the agranulocytosis phase. Despite receiving antibiotics, all four patients presented elevated serum IL-6 levels as well as persistent hypotension or organ injury. Adjuvant therapy with tocilizumab, an IL-6-receptor antibody, was administered, and three of the four patients showed significant improvement. Unfortunately, the fourth patient died due to multiple organ failure caused by antibiotic resistance. Our preliminary experience suggests that tocilizumab, as an adjuvant therapy, may help alleviate systemic inflammation and reduce risk of organ injury in patients with elevated IL-6 levels and severe infection. Further randomized controlled trials are needed to confirm the effectiveness of this IL-6 targeting approach.

COVID-19 vaccination and cancer immunotherapy: should they stick together?

The combination of COVID-19 vaccination with immunotherapy by checkpoint inhibitors in cancer patients could intensify immunological stimulation with potential reciprocal benefits. Here, we examine more closely the possible adverse events that can arise in each treatment modality. Our conclusion is that caution should be exercised when combining both treatments.

Complement cascade in severe forms of COVID-19: Recent advances in therapy.

The complement system is an essential component of the innate immune system. The three complement pathways (classical, lectin, alternative) are directly or indirectly activated by the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). In the most severe forms of COVID-19, overactivation of the complement system may contribute to the cytokine storm, endothelial inflammation (endotheliitis) and thrombosis. No antiviral drug has yet been shown to be effective in COVID-19. Therefore, immunotherapies represent a promising therapeutic in the immunopathological phase (following the viral phase) of the disease. Complement blockade, mostly C5a-C5aR axis blockade, may prevent acute respiratory distress syndrome (ARDS) from worsening or progression to death. Clinical trials are underway.

Perspectives of association Baricitinib/Remdesivir for adults with Covid-19 infection.

BACKGROUND: The global COVID-19 pandemic is currently underway. A massive worldwide vaccination campaign is still underway, representing the most promising weapon available to stop the pandemic. METHODS AND RESULTS: However, research continues to investigate the most effective drug treatments to reduce and avoid the most serious complications caused by COVID-19 infection. Recently, new evidence of good therapeutic efficacy against COVID-19 has emerged for the antiviral Remdesivir and the immunomodulatory Baricitinib, also in combination. The first one showed SARS-CoV-2 antireplicative activity, the second one useful to reduce the hyperinflammatory state caused by cytokine storm in the most severe phases of the infection. CONCLUSIONS: In this short communication we describe the molecular pharmacological mechanisms and the latest evidence for the use of these therapeutic agents in the treatment of COVID-19 infection.

Thrombocytopathy vs Platelet hyper-reactivity in COVID-19: diverse pathologies, disease outcomes and therapeutic implications.

Coagulopathy is an evident complication of COVID-19 with predominance of a prothrombotic state. Platelet activation plays a key role. The terms "hyper-reactivity" and "hyperactivity" used in recent literature may not be clear or sufficient to explain the pathological events involved in COVID-related thrombosis (CRT). Inflammation may play a bigger role compared to thrombosis in COVID-related mortality because a smaller percentage of patients with COVID-19 die due to direct effects of thrombosis. Not all COVID-19 patients have thrombocytopenia and a few show thrombocytosis. We believe the platelet pathology is more complex than just activation or hyper-activation, particularly due to the platelets' role in inflammation. Understanding the pathology and consequences of platelets' role may help optimize management strategies and diminish CRT-associated morbidity and mortality. In this viewpoint report, we examine the published evidence of platelet hyper-reactivity in COVID-19 with a focused analysis of the key pathologies, diverse alterations, disease outcomes, and therapeutic targets. We believe that COVID-19 is a disease of inflammation and pathologic platelets, and based on the complexity and diverse pathologies, we propose the term "thrombocytopathy" as a more reflective term of the platelets' involvement in COVID-19. In our opinion, thrombocytopathy is the unpredictable pathologic alterations of platelets in function, morphology and number, caused by different factors with a variety of presentations.

Comment on Kopanska et al. Disorders of the Cholinergic System in COVID-19 Era-A Review of the Latest Research. Int. J. Mol. Sci. 2022, 23, 672.

We read the recent review article by Marta Kopanska et al. [...].

Formulation, Device, and Clinical Factors Influencing the Targeted Delivery of COVID-19 Vaccines to the Lungs.

The COVID-19 pandemic has proven to be an unprecedented health crisis in the human history with more than 5 million deaths worldwide caused to the SARS-CoV-2 and its variants ( https://www.who.int/emergencies/diseases/novel-coronavirus-2019 ). The currently authorized lipid nanoparticle (LNP)-encapsulated mRNA vaccines have been shown to have more than 90% vaccine efficacy at preventing COVID-19 illness (Baden et al. New England J Med 384(5):403-416, 2021; Thomas et al., 2021). In addition to vaccines, other small molecules belonging to the class of anti-viral and anti-inflammatory compounds have also been prescribed to reduce the viral proliferation and the associated cytokine storm. These anti-viral and anti-inflammatory compounds have also been shown to be effective in reducing COVID-19 exacerbations especially in reducing the host inflammatory response to SARS-CoV-2. However, all of the currently FDA-authorized vaccines for COVID-19 are meant for intramuscular injection directly into the systemic circulation. Also, most of the small molecules investigated for their anti-COVID-19 efficacy have also been explored using the intravenous route with a few of them explored for the inhalation route (Ramakrishnan et al. Lancet Respir Med 9:763-772, 2021; Horby et al. N Engl J Med 384(8):693-704, 2021). The fact that the SARS-CoV-2 enters the human body mainly via the nasal and airway route resulting in the lungs being the primary organs of infection as characterized by acute respiratory distress syndrome (ARDS)-mediated cytokine storm in the alveolar region has made the inhalation route gain significant attention for the purposes of targeting both vaccines and small molecules to the lungs (Mitchell et al., J Aerosol Med Pulm Drug Deliv 33(4):235-8, 2020). While there have been many studies reporting the safety and efficacy of targeting various therapeutics to the lungs to treat COVID-19, there is still a need to match the choice of inhalation formulation and the delivery device platform itself with the patient-related factors like breathing pattern and respiratory rate as seen in a clinical setting. In that perspective, this review aims to describe the various formulation and patient-related clinical factors that can play an important role in the judicious choice of the inhalation delivery platforms or devices for the development of inhaled COVID-19 vaccines.

Assessment of Tocilizumab (Humanized Monoclonal Antibody) for Therapeutic Efficacy and Clinical Safety in Patients with Coronavirus Disease (COVID-19).

Background and objectives: COVID-19 patients exhibit a broad range of manifestations, presenting with a flu-like respiratory tract infection that can advance to a systemic and severe disease characterized by pneumonia, pulmonary edema, severe damage to the airways, and acute respiratory distress syndrome (ARDS, causing fatality in 70% of COVID-19 cases). A 'cytokine storm' profile is found in most severely influenced COVID-19 patients. The treatment protocol of the disease also includes tocilizumab, which is a humanized monoclonal antibody used to treat autoimmune and inflammatory conditions. This study was designed (1) to assess the role of tocilizumab in COVID-19 patients regarding therapeutic efficacy through evaluation of cytokine release syndrome (CRS) resolution and anticoagulant effect, analyzing clinical safety via monitoring of associated adverse effects profile; and (2) to compare the clinical safety and therapeutic efficacy of institutional treatment regimen (alone) versus tocilizumab added to an institutional treatment module in COVID-19 patients. Materials and Methods: In this study, the endpoints parametric assessment of severely diseased patients of COVID-19 was performed (total n = 172, control group (institutional protocol treatment provided), n = 101 and test group (tocilizumab provided), n = 71) at the Khyber Teaching Institution, MTI, Peshawar. The assessments were compared using non-parametric analyses at baseline and after a follow-up of 12−18 days until the patient discharged or expired. Results: Results of the study revealed an insignificant difference among the control vs. test group in resolving inflammatory parameters (C-reactive protein (CRP) 21.30 vs. 50.07; p = 0.470, ferritin 482.9 vs. 211.5; p = 0.612, lactate dehydrogenase (LDH) 29.12 vs.18.8; p = 0.0863, and D-dimer 464 vs.164.4; p = 0.131). However, a statistically significant difference was found between the control group and test group regarding coagulation parameters (international normalized ratio (INR) 0.12 vs. −0.07; p ≤ 0.001; activated partial thromboplastin time (aPTT) 0.42 vs. −1.16; p ≤ 0.001; prothrombin time (PT) 0.31 vs. −0.96; p ≤ 0.001; platelet count −12.34 vs. −1.47; p = 0.012) and clinical survival rate (89.10 vs. 90.14; p < 0.001). Furthermore, there was significantly higher infection rates and raised alanine aminotransferase (ALT) and alkaline phosphatase (ALP) associated with the tocilizumab group as compared to those receiving institutional treatment (bacterial infections: 0.99% vs. 15.49%; p ≤ 0.01, ALT: 3.96% vs. 28.16%; p ≤ 0.01, ALP: 1.98% vs. 22.53%; p ≤ 0.01). Conclusions: From this study, it was concluded that tocilizumab can be a better drug of choice in terms of efficacy, particularly in resolving coagulopathy in severe COVID-19 patients.

Investigation of plasma exchange and hemoperfusion effects and complications for the treatment of patients with severe COVID-19 (SARS-CoV-2) disease: A systematic scoping review.

Some previous studies suggested that the plasma exchange (PE) and hemoperfusion (HP) played a cardinal role in the treatment of severe coronavirus disease 2019 (COVID-19) cases by diminishing the cytokine storm. This study aimed to assess the effects of PE and HP on cytokine storms in patients with severe COVID-19 through a systematic scoping review. Four Electronic databases (Medline [accessed from PubMed], Scopus, Science Direct, and Cochrane library) were searched systematically on February 2, 2021, using MESH terms and related keywords in the English language. Considering the titles and abstracts, unrelated studies were excluded. The full texts of the remained studies were evaluated by authors, independently. Then, their findings were assessed and reported. A total of 755 articles were obtained within the first step of searching, and 518 remained after removing the duplications. Through the title and abstract screening, 438 were removed. Of the rest, 59 papers were excluded. Finally, after reading the full text of the remained articles, 21 were included in data extraction. Most of the previously reported evidence were case reports and case series. Findings were summarized in two categories. The first category encompassed nine studies regarding HP and continuous renal replacement therapy, and the second category included twelve studies about PE. The results revealed that HP and PE within the cytokine storm phase would be beneficial with a high probability in the treatment of severely ill COVID-19 patients. Highlights Some studies showed that plasma exchange (PE) and hemoperfusion (HP) played an important role in the treatment of patients with severe COVID-19 disease. The results of this systematic scoping review revealed that HP and PE within the cytokine storm phase would be beneficial with a high probability in the treatment of severely ill COVID-19 patients.

Successful Treatment of Covid-19 Associated Cytokine Release Syndrome with Colchicine. A Case Report and Review of Literature.

We describe the case of a 42 year old, healthy patient with Covid-19 who despite improvement in his respiratory symptoms developed a mild to moderate cytokine release syndrome (CRS) and an associated monoarticular gout flare. Since the patient refused admission to the hospital and had stable vital signs, we chose to treat him with a safe anti-inflammatory and non-immunosuppressive therapy. To hit two birds with one stone, we considered colchicine, as it has systemic anti-inflammatory effects and is also effective in gout flare. Unexpectedly, 48 hours after treatment, not only did his ongoing fever and toe pain disappear, he also had significant improvements in his general state of health and all his inflammatory markers including fibrinogen, ferritin, D-dimer, and IL-6 levels normalized. To our knowledge, the use of colchicine in Covid-19 and CRS has not been reported. This observation merits the consideration of colchicine as a safe, inexpensive and oral medication for the treatment of mild to moderate CRS in Covid-19 patients. More importantly, in Covid-19 patients with early lung involvement colchicine may be an appropriate candidate to prevent CRS in adjunction with routine antiviral agents. Indeed, multicenter, randomized controlled studies are required to evaluate the benefits of this therapy.

Macrophage biomimetic nanocarriers for anti-inflammation and targeted antiviral treatment in COVID-19.

BACKGROUND: The worldwide pandemic of COVID-19 remains a serious public health menace as the lack of efficacious treatments. Cytokine storm syndrome (CSS) characterized with elevated inflammation and multi-organs failure is closely correlated with the bad outcome of COVID-19. Hence, inhibit the process of CSS by controlling excessive inflammation is considered one of the most promising ways for COVID-19 treatment. RESULTS: Here, we developed a biomimetic nanocarrier based drug delivery system against COVID-19 via anti-inflammation and antiviral treatment simultaneously. Firstly, lopinavir (LPV) as model antiviral drug was loaded in the polymeric nanoparticles (PLGA-LPV NPs). Afterwards, macrophage membranes were coated on the PLGA-LPV NPs to constitute drugs loaded macrophage biomimetic nanocarriers (PLGA-LPV@M). In the study, PLGA-LPV@M could neutralize multiple proinflammatory cytokines and effectively suppress the activation of macrophages and neutrophils. Furthermore, the formation of NETs induced by COVID-19 patients serum could be reduced by PLGA-LPV@M as well. In a mouse model of coronavirus infection, PLGA-LPV@M exhibited significant targeted ability to inflammation sites, and superior therapeutic efficacy in inflammation alleviation and tissues viral loads reduction. CONCLUSION: Collectively, such macrophage biomimetic nanocarriers based drug delivery system showed favorable anti-inflammation and targeted antiviral effects, which may possess a comprehensive therapeutic value in COVID-19 treatment.

Early Cytokine Removal in Critical COVID-19 Patients with Extracorporeal Therapies (HA-380 plus High Volume Hemofiltration) May Prevent Progression of Acute Respiratory Distress Syndrome: Case Report.

We present the case of a patient who suffered from acute respiratory distress syndrome caused by pneumonia associated with COVID-19 and cytokine release syndrome. This patient received a high-volume hemofiltration plus adsorption, solving the hemodynamic deterioration, pulmonary infiltrates, and gas exchange. Our clinical case proposes that the extracorporeal therapies can have a role in the management of severe COVID-19.

Effect of Chloroquine and Hydroxychloroquine on Cytokine Release Syndrome in Patients with COVID-19.

Objective: To assess the effect of chloroquine and hydroxychloroquine on cytokine release syndrome (CRS) in adult patients with coronavirus disease 2019 (COVID-19) having mild to moderate symptoms.Methods: This blinded, placebo-controlled, randomized study was conducted in the Department of Medicine, Pak Emirates Military Hospital Rawalpindi, from June 1-15, 2020. A total of 150 hospitalized patients were enrolled after diagnoses with COVID-19 through reverse transcription polymerase chain reaction (RT-PCR). They were divided into three groups: hydroxychloroquine plus general care (HGC, n=50), chloroquine plus general care (CGC, n=50); and only general care (OGC, n=50). The HGC group received treatment with hydroxychloroquine 400 mg every 12 hours for day one and 200 mg for the next 4 days. The CGC group received treatment with chloroquine 250 mg every 12 hours for 7 days. The OGC group was kept as a control with only general care. After 12 days, the patients were screened for development of CRS through detection of interleukin 6 (IL-6) in serum samples by using Roche cobas e411 electrochemiluminescence immunoassay analyzer.Results: The mean duration from onset of symptoms to randomization was 7.65 days (SD = 3.287 days; range, 2-15 days). The mean age of patients was 37.57 (range 19-63) years. Results showed that out of a total 150 patients, only 10 patients (6%, mean=1.93; CI=1.89-1.97, P=0.651) developed CRS in all study groups. Four patients (8%) developed CRS in the HGC group, 2 patients (4%) in the CGC group, and 4 patients (8%) in the OGC group. There was no significant difference in the mean level of CRS among study groups.Conclusion: Administration of hydroxychloroquine and chloroquine has no effect in reducing the development of CRS in patients with COVID-19 having mild to moderate symptoms.

Cytokine Storm and Failed Resolution in COVID-19: Taking a Cue from Multiple Sclerosis.

INTRODUCTION: Excessive inflammatory responses and failed resolution are major common causes of tissue injury and organ dysfunction in a variety of diseases, including multiple sclerosis (MS), diabetes, and most recently, COVID-19, despite the distinct pathoetiology of the diseases. The promotion of the natural process of inflammatory resolution has been long recognized to improve functional recovery and disease outcomes effectively. To mitigate the excessive inflammation in MS, scientific investigations identified a group of derivatives of omega fatty acids, known as specialized pro-resolving lipid mediators (SPM) that have been significantly effective in treating preclinical disease models of MS. METHODS: This chapter is based on our observations from MS. It is being increasingly deliberated that the ongoing COVID-19 infection induces severe cytokine storm that ultimately triggers rampant inflammation. The impact of infection and associated mortality is much higher in patients with co-morbid diseases. Also, reports suggest a better outcome in diabetic patients with reasonable glycemic control, which certainly hints towards a hidden role of anti-hyperglycemic drugs such as metformin in alleviating disease pathology through its anti-inflammatory feature. Notably, SPM and metformin share common therapeutic features in exerting a broad-spectrum anti-inflammatory activity in human patients with a superior safety profile. RESULTS: When there is an immediate need to encounter the fast-rampant infection of COVID-19 and control the viral-infection associated morbid inflammatory cytokine storm causing severe organ damage, SPM and metformin should be seriously considered as a potential adjunctive treatment. CONCLUSION: Given the fact that current treatment for COVID-19 is only supportive, global research is aimed at developing safe and effective therapeutic options that can result in a better clinical course in patients with comorbid conditions. Accordingly, taking a cue from our experiences in controlling robust inflammatory response in MS and diabetes by simultaneously inhibiting inflammatory process and stimulating its resolution, combinatorial therapy of metformin and SPM in COVID-19 holds significant promise in treating this global health crisis.

Purinergic receptor ligands: the cytokine storm attenuators, potential therapeutic agents for the treatment of COVID-19.

The coronavirus disease-19 (COVID-19), at first, was reported in Wuhan, China, and then rapidly became pandemic throughout the world. Cytokine storm syndrome (CSS) in COVID-19 patients is associated with high levels of cytokines and chemokines that cause multiple organ failure, systemic inflammation, and hemodynamic instabilities. Acute respiratory distress syndrome (ARDS), a common complication of COVID-19, is a consequence of cytokine storm. In this regard, several drugs have been being investigated to suppress this inflammatory condition. Purinergic signaling receptors comprising of P1 adenosine and P2 purinoceptors play a critical role in inflammation. Therefore, activation or inhibition of some subtypes of these kinds of receptors is most likely to be beneficial to attenuate cytokine storm. This article summarizes suggested therapeutic drugs with potential anti-inflammatory effects through purinergic receptors.

Innate Immunity as an Executor of the Programmed Death of Individual Organisms for the Benefit of the Entire Population.

In humans, over-activation of innate immunity in response to viral or bacterial infections often causes severe illness and death. Furthermore, similar mechanisms related to innate immunity can cause pathogenesis and death in sepsis, massive trauma (including surgery and burns), ischemia/reperfusion, some toxic lesions, and viral infections including COVID-19. Based on the reviewed observations, we suggest that such severe outcomes may be manifestations of a controlled suicidal strategy protecting the entire population from the spread of pathogens and from dangerous pathologies rather than an aberrant hyperstimulation of defense responses. We argue that innate immunity may be involved in the implementation of an altruistic programmed death of an organism aimed at increasing the well-being of the whole community. We discuss possible ways to suppress this atavistic program by interfering with innate immunity and suggest that combating this program should be a major goal of future medicine.

Inflammatory Mechanisms in COVID-19 and Atherosclerosis: Current Pharmaceutical Perspectives.

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been associated with excess mortality worldwide. The cardiovascular system is the second most common target of SARS-CoV-2, which leads to severe complications, including acute myocardial injury, myocarditis, arrhythmias, and venous thromboembolism, as well as other major thrombotic events because of direct endothelial injury and an excessive systemic inflammatory response. This review focuses on the similarities and the differences of inflammatory pathways involved in COVID-19 and atherosclerosis. Anti-inflammatory agents and immunomodulators have recently been assessed, which may constitute rational treatments for the reduction of cardiovascular events in both COVID-19 and atherosclerotic heart disease.

[Treatment of a Patient with a Pronounced Cytokine Storm in Severe COVID-19 Pneumonia using a Hemoadsorption in Combination with the Administration of tocilizumab]. / Die Behandlung eines Patienten mit ausgeprägtem Zytokinsturm bei schwerer COVID-19-Pneumonie unter Einsatz von Hämoadsorption in Kombination mit der Gabe von Tocilizumab.

Despite growing experience due to increasing patient numbers, the intensive care treatment of patients with severe COVID-19 pneumonia continues to be a particular challenge in individual cases, which may also therefore legitimize individualized therapeutic attempts. In this context, the so-called hyperinflammation syndrome characterized by a cytokine storm accompanied by a massive increase in inflammatory markers such as interleukin(IL)-6, represents such a situation. This case report describes the therapeutic approach of using the IL-6-specific antibody tocilizumab in combination with hemoadsorption therapy (CytoSorb) in a 58-year-old male patient with severe COVID-19 pneumonia. The patient suffered a massive clinical deterioration with concomitant Horovitz index of 127 mmHg that occurred on the 6th day of ventilation. After combined application of the above-mentioned therapeutic approaches, the patient stabilized rapidly paralleled by a significant increase in the Horovitz index, and the possibility of de-escalating the ventilation regimen, which ultimately enabled successful extubation after only 13 days of ventilation. Moreover, the combined treatment was associated with significant hemodynamic stabilization and a consecutive reduction in vasopressor doses, while hyperinflammation could be kept well under control. The incorporation of the hemoadsorber into the therapeutic regimen proved to be safe and straightforward. In conclusion, the combination of CytoSorb therapy and IL-6 blockade by tocilizumab appeared, at least in this case, to be an effective measure to modulate an overshooting immune response in COVID-19 pneumonia with a concomitant clinical improvement in both respiratory and hemodynamic function, and thus could be used as a potential therapeutic option in this clinical picture.