The successful use of therapeutic plasma exchange for severe COVID-19 acute respiratory distress syndrome with multiple organ failure

Evaluation of the Efficacy of Therapeutic and Prophylactic Anticoagulation in COVID-19 Patients With Venous Catheter and Its Correlation With Clinical Outcomes

Introduction

The COVID-19 disease was first detected in December 2019, and since then, various treatments have been used to manage it. One such treatment method is therapeutic plasma exchange. This method involves implanting a venous catheter, which increases the risk of venous thromboembolism (VTE). Other risk factors for VTE include infections like COVID-19, inflammation, or malignancy.

Materials and Methods

In this retrospective study, patients with acute respiratory syndrome caused by COVID-19 who were hospitalized and had venous catheters inserted for therapeutic plasma exchange were enrolled. The prophylactic anticoagulant dose was started for all patients, and after the diagnosis of VTE, it was changed to the therapeutic dose. Patients' information, including demographic data, clinical information, and laboratory findings, was extracted from patients' records and recorded in a checklist designed for each patient.

Results

From a total of 168 patients, 26 were diagnosed with VTE (pulmonary embolism in 5 patients and deep vein thrombosis in 21 patients). The prevalence of VTE in COVID-19 patients with the venous catheter was 15.4%. The right femoral vein was the most used route for catheterization and had the highest occurrence of venous thromboses. The patients diagnosed with thrombosis showed a lower mortality rate, higher D-dimer and lactate dehydrogenase levels, and lower platelet counts.

Conclusions

This study showed a higher risk of VTE and subclinical thrombosis in COVID-19 patients with venous catheters. Continuous screening, higher doses of anticoagulants, and early removal of venous catheters are critical in preventing VTE and mortality.

Basic therapeutic approaches to the management of hematology/oncology patients with new coronavirus infection (COVID-19)

In December 2019, cases of severe respiratory infection were reported in Wuhan, China. The disease was caused by a new, previously undescribed coronavirus, structurally similar to the then known SARS-CoV virus. The World Health Organization has named the new virus SARS-CoV-2 and the disease it causes COVID-19. The problem of COVID-19 is exacerbated by the rapid spread of the SARS-CoV-2 virus and the development of life-threatening complications, the main of which is pneumonia. Due to the severity of the condition, from 5 to 10 % of patients are treated in intensive care units.

SARS-CoV-2 initially attacks the respiratory system and causes symptoms such as fever, vomiting, headache, dizziness, general weakness, and diarrhea. Then these symptoms intensify in different directions, and the disease can often lead to death.

Initially, only a few methods of symptomatic treatment were available and clinical trials of drugs that had previously shown their effectiveness against infection with the MERS-CoV and SARS-CoV viruses began. Temporary recommendations have appeared suggesting the use of some drugs both in monotherapy and in combination.

In patients with hematologic malignancies, the immune response to the SARS-CoV-2 coronavirus is significantly reduced, which explains the high mortality rate (up to 38 %) of these patients hospitalized for SARS-CoV-2 infection. Recently, antiviral drugs and monoclonal antibodies have become available for pre- or post-exposure prophylaxis, as well as for early treatment of COVID-19. These treatments should be offered to patients at high risk of severe COVID-19 and to those who have not responded to vaccination. However, as changes in the genetic structure of the virus accumulate, some treatments may lose their clinical effectiveness against new variants.

The combination of hematological malignancies and new coronavirus infection causes a more severe course of COVID-19 compared to the population and high mortality. Factors for an unfavorable prognosis for new coronavirus infection in patients with hematological malignancies include age over 60 years, a high comorbidity index, diagnoses such as acute leukemia, especially acute myeloid leukemia and myelodysplastic syndrome, disease status (relapse, progression, as well as newly diagnosed acute leukemia), severe COVID-19, agranulocytosis (myelotoxic or tumor).

The roles of critical pro-inflammatory cytokines in the drive of cytokine storm during SARS-CoV-2 infection

In patients with severe COVID-19, acute respiratory distress syndrome (ARDS), multiple organ dysfunction syndrome (MODS), and even mortality can result from cytokine storm, which is a hyperinflammatory medical condition caused by the excessive and uncontrolled release of pro-inflammatory cytokines. High levels of numerous crucial pro-inflammatory cytokines, such as interleukin-1 (IL-1), IL-2, IL-6, tumor necrosis factor-α, interferon (IFN)-γ, IFN-induced protein 10 kDa, granulocyte-macrophage colony-stimulating factor, monocyte chemoattractant protein-1, and IL-10 and so on, have been found in severe COVID-19. They participate in cascade amplification pathways of pro-inflammatory responses through complex inflammatory networks. Here, we review the involvements of these critical inflammatory cytokines in SARS-CoV-2 infection and discuss their potential roles in triggering or regulating cytokine storm, which can help to understand the pathogenesis of severe COVID-19. So far, there is rarely effective therapeutic strategy for patients with cytokine storm besides using glucocorticoids, which is proved to result in fatal side effects. Clarifying the roles of key involved cytokines in the complex inflammatory network of cytokine storm will help to develop an ideal therapeutic intervention, such as neutralizing antibody of certain cytokine or inhibitor of some inflammatory signal pathways.

Guillain-Barré Syndrome due to COVID-19 Vero Cell Vaccination Associated with Concomitant COVID-19 Infection-induced ARDS and Treated Successfully by Therapeutic Plasma Exchange: A First Case Report from Vietnam

Post-vaccination adverse reactions have been reported with varying symptoms and severity owing to research and production time pressures during the coronavirus disease 2019 (COVID-19) pandemic. In this article, we report a rare case of Guillain-Barré syndrome (GBS) in a patient with COVID-19 with acute respiratory distress syndrome (ARDS) after receiving Sinopharm's Vero Cell vaccine (China). The patient who was initially negative for COVID-19 was diagnosed with GBS based on paralysis that developed from the lower extremities to the upper extremities, as confirmed by cytoalbuminologic dissociation in the cerebrospinal fluid. The patient's condition worsened with ARDS caused by COVID-19 infection during the hospital stay, and SpO₂ decreased to 83% while receiving oxygen through a non-rebreather mask (15 l/min) on day 6. The patient was treated with standard therapy for severe COVID-19, invasive mechanical ventilation, and five cycles of therapeutic plasma exchange (TPE) with 5% albumin replacement on day 11 due to severe progression. The patient was weaned off the ventilator on day 28, discharged on day 42, and was completely healthy after 6 months without any neurological sequelae until now. Our report showed the potential of TPE for GBS treatment in critically ill patients with COVID-19 after COVID-19 vaccination.

Old plasma dilution reduces human biological age: a clinical study

This work extrapolates to humans the previous animal studies on blood heterochronicity and establishes a novel direct measurement of biological age. Our results support the hypothesis that, similar to mice, human aging is driven by age-imposed systemic molecular excess, the attenuation of which reverses biological age, defined in our work as a deregulation (noise) of 10 novel protein biomarkers. The results on biological age are strongly supported by the data, which demonstrates that rounds of therapeutic plasma exchange (TPE) promote a global shift to a younger systemic proteome, including youthfully restored pro-regenerative, anticancer, and apoptotic regulators and a youthful profile of myeloid/lymphoid markers in circulating cells, which have reduced cellular senescence and lower DNA damage. Mechanistically, the circulatory regulators of the JAK-STAT, MAPK, TGF-beta, NF-κB, and Toll-like receptor signaling pathways become more youthfully balanced through normalization of TLR4, which we define as a nodal point of this molecular rejuvenation. The significance of our findings is confirmed through big-data gene expression studies.

Therapeutic plasma exchange: A potential therapeutic modality for critically ill adults with severe acute respiratory syndrome coronavirus 2 infection

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 infection can be severe and fatal due to cytokine storm. Therapeutic plasma exchange (TPE) potentially mitigates the harmful effects of such cytokines. We investigated the use of TPE, as rescue therapy, in patients with severe Coronavirus disease 2019 (COVID-19) infection.

STUDY DESIGN AND METHODS

A retrospective analysis on COVID-19 patients admitted to the intensive care unit and treated with TPE from April 17, 2020 to July 2, 2020. This group was compared with COVID-19 patients who received standard therapy without TPE. The following outcomes were analyzed: changes in laboratory parameters, length of hospital stay (LOS), days on mechanical ventilation, mortality at days 14 and overall mortality.

RESULTS

A total of 95 patients were included, among whom 47% (n = 45) received TPE. Patients who received TPE had reductions in C-reactive protein (P = .002), ferritin (P < .001) and interleukin-6 (P = .013). After employing entropy-balancing matching method, those on TPE were also more likely to discontinue inotropes (72% vs 21%; P < .001). However, they were more likely to be associated with longer LOS (23 vs 14 days; P = .002) and longer days on ventilatory support (14 vs 8 days; P < .001). Despite marginal mortality benefit at 14-days (7.9% vs 24%; P = .071), there was no significant differences in overall mortality (21% vs 31%; P = .315) between the groups.

CONCLUSIONS

TPE was effective in reducing inflammatory markers in patients with severe COVID-19 infection, however, further research is warranted.

SARS-CoV-2 and Guillain-Barré Syndrome: Lessons from Viral Infections

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for the COVID-19 pandemic. COVID-19 has a broad clinical spectrum from asymptomatic patients to multiorgan dysfunction and septic shock. Most of the common symptoms of COVID-19 are classified as respiratory disorders, but some reports show neurological involvements. During the COVID-19 pandemic, a case series of neurological complications, such as Guillain-Barré syndrome (GBS), were reported. GBS is a neuroimmune disorder with acute inflammatory radicular polyneuropathy in different parts of the peripheral nerve. Some studies have reported GBS as an inflammatory neuropathy related to various viral infections, such as cytomegalovirus (CMV), Epstein-Barr Virus (EBV), herpes simplex virus (HSV), human immunodeficiency virus (HIV), influenza, and Zika virus. There are some immunomodulation approaches for the management of GBS. Studies have evaluated the effects of the various therapeutic approaches, including intravenous immunoglobulin (IVIG), plasma exchange (PE), complement inhibitors, and corticosteroids to regulate overactivation of immune responses during GBS in experimental and clinical studies. In this regard, the possible association between GBS and SARS-CoV-2 infection during the outbreak of the current pandemic and also the mentioned therapeutic approaches were reviewed.

Role of therapeutic plasma exchange in the management of COVID-19-induced cytokine storm syndrome

The risk of mortality in patients with coronavirus disease 2019 (COVID-19) is largely related to an excessive immune response, resulting in a hyperinflammatory and hypercoagulable condition collectively referred to as cytokine storm syndrome (CSS). Management of critically ill patients with COVID-19 has included attempts to abate this process, prevent disease progression, and reduce mortality. In this context, therapeutic plasma exchange (TPE) offers an approach to eliminate inflammatory factors and cytokines, offset the pathologic coagulopathy, and reduce the CSS effects. The aim of this review is to analyze available data on the use of TPE for the treatment of CSS in patients with COVID-19. Systematic searches of PubMed, Scopus and COVID-19 Research were conducted to identify articles published between March 1, 2020 and May 26, 2021 reporting the use of TPE for the treatment of COVID-19-induced CSS. A total of 34 peer-reviewed articles (1 randomized controlled trial, 4 matched case-control series, 15 single-group case series, and 14 case reports), including 267 patients, were selected. Despite the low evidence level of the available data, TPE appeared to be a safe intervention for critically ill patients with COVID-19-induced CSS. Although inconsistencies exist between studies, they showed a general trend for decreased interleukin-6, C-reactive protein, ferritin, D-dimer, and fibrinogen levels and increased lymphocyte counts following TPE, supporting the immunomodulatory effect of this treatment. Moreover, TPE was associated with improvements in clinical outcomes in critically ill patients with COVID-19. While TPE may offer a valuable option to treat patients with COVID-19-induced CSS, high-quality randomized controlled clinical trials are needed to confirm its potential clinical benefits, feasibility, and safety. Moreover, clear criteria should be established to identify patients with CSS who might benefit from TPE.

"MATH+" Multi-Modal Hospital Treatment Protocol for COVID-19 Infection: Clinical and Scientific Rationale

In December 2019, coronavirus disease 2019 (COVID-19), a severe respiratory illness caused by the new coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China. The greatest impact that COVID-19 had was on intensive care units (ICUs), given that approximately 20% of hospitalized cases developed acute respiratory failure (ARF) requiring ICU admission. Based on the assumption that COVID-19 represented a viral pneumonia and no anti-coronaviral therapy existed, nearly all national and international health care societies recommended "supportive care only" avoiding other therapies outside of randomized controlled trials, with a specific prohibition against the use of corticosteroids in treatment. However, early studies of COVID-19-associated ARF reported inexplicably high mortality rates, with frequent prolonged durations of mechanical ventilation (MV), even from centers expert in such supportive care strategies. These reports led the authors to form a clinical expert panel called the Front-Line COVID-19 Critical Care Alliance (www.flccc.net). The panel collaboratively reviewed the emerging clinical, radiographic, and pathological reports of COVID-19 while initiating multiple discussions among a wide clinical network of front-line clinical ICU experts from initial outbreak areas in China, Italy, and New York. Based on the shared early impressions of "what was working and what wasn't working", the increasing medical journal publications and the rapidly accumulating personal clinical experiences with COVID-19 patients, a treatment protocol was created for the hospitalized patients based on the core therapies of methylprednisolone, ascorbic acid, thiamine, heparin and non-antiviral co-interventions (MATH+). This manuscript reviews the scientific and clinical rationale behind MATH+ based on published in-vitro, pre-clinical, and clinical data in support of each medicine, with a special emphasis of studies supporting their use in the treatment of patients with viral syndromes and COVID-19 specifically.

Cytokine Storm in COVID-19: Immunopathogenesis and Therapy

A cytokine storm is a hyperinflammatory state secondary to the excessive production of cytokines by a deregulated immune system. It manifests clinically as an influenza-like syndrome, which can be complicated by multi-organ failure and coagulopathy, leading, in the most severe cases, even to death. The term cytokine storm was first used in 1993 to describe the graft-versus-host disease following allogeneic hematopoietic stem cell transplantation. It was then reused to define the adverse syndromes secondary to the administration of immunostimulating agents, such as anti-CD28 antibodies or bioengineered immune cells, i.e., CAR T-cell therapy. Currently, the concept of cytokine storm has been better elucidated and extended to the pathogenesis of many other conditions, such as sepsis, autoinflammatory disease, primary and secondary hemophagocytic lymphohistiocytosis, and multicentric Castleman disease. Moreover, cytokine storm has recently emerged as a key aspect in the novel Coronavirus disease 2019, as affected patients show high levels of several key pro-inflammatory cytokines, such as IL-1, IL-2, IL-6, TNF-α, IFN-γ, IP-10, GM-CSF, MCP-1, and IL-10, some of which also correlate with disease severity. Therefore, since the onset of the pandemic, numerous agents have been tested in the effort to mitigate the cytokine storm in COVID-19 patients, some of which are effective in reducing mortality, especially in critically ill patients, and are now becoming standards of care, such as glucocorticoids or some cytokine inhibitors. However, the challenge is still far from being met, and other therapeutic strategies are being tested in the hope that we can eventually overcome the disease.

Blood purification could tackle COVID-19?

Coronavirus disease 2019 (COVID-19) threatened human lives worldwide since first reported. The current challenge for global intensivists is to establish an effective treatment for severe COVID-19. Blood purification has been applied to the treatment of various critical illnesses. Theoretically, its technique also has an enormous possibility of treating severe COVID-19 in managing inflammatory cytokines and coagulopathy. Recent clinical studies have revealed the positive clinical effect of therapeutic plasma exchange. Other studies have also indicated the considerable potential of other blood purification techniques, such as Cytosorb, AN69 surface-treated membrane, and polymyxin b hemoperfusion. Further research is needed to elucidate the actual effects of these applications.

Targeting Macrophage Dysregulation for Viral Infections: Novel Targets for Immunomodulators

A major barrier to human immunodeficiency virus (HIV-1) cure is the latent viral reservoir, which persists despite antiretroviral therapy (ART), including across the non-dividing myeloid reservoir which is found systemically in sanctuary sites across tissues and the central nervous system (CNS). Unlike activated CD4+ T cells that undergo rapid cell death during initial infection (due to rapid viral replication kinetics), viral replication kinetics are delayed in non-dividing myeloid cells, resulting in long-lived survival of infected macrophages and macrophage-like cells. Simultaneously, persistent inflammation in macrophages confers immune dysregulation that is a key driver of co-morbidities including cardiovascular disease (CVD) and neurological deficits in people living with HIV-1 (PLWH). Macrophage activation and dysregulation is also a key driver of disease progression across other viral infections including SARS-CoV-2, influenza, and chikungunya viruses, underscoring the interplay between macrophages and disease progression, pathogenesis, and comorbidity in the viral infection setting. This review discusses the role of macrophages in persistence and pathogenesis of HIV-1 and related comorbidities, SARS-CoV-2 and other viruses. A special focus is given to novel immunomodulatory targets for key events driving myeloid cell dysregulation and reservoir maintenance across a diverse array of viral infections.

Plasmapheresis: a feasible choice for bullous pemphigoid patients infected with SARS-CoV-2

Bullous pemphigoid (BP) patients were vulnerable to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection because they have similar risk factors, so we should pay attention to patients with BP during the epidemic of coronavirus disease-19 (COVID-19). As far as treatment is concerned, many strategies for BP were changed during the epidemic. Plasmapheresis not only has been included in the guidelines for BP but also has been used successfully to rescue COVID-19 patients, especially in severe cases. Therefore, it is a feasible choice for BP patients, especially for refractory BP patients, infected with SARS-CoV-2. Apart from these, we have reviewed some points for attention during the plasmapheresis session.

Understanding the role of therapeutic plasma exchange in COVID-19: preliminary guidance and practices

BACKGROUND AND OBJECTIVES

Cytokine release syndrome in COVID-19 is due to a pathological inflammatory response of raised cytokines. Removal of these cytokines by therapeutic plasma exchange (TPE) prior to end-organ damage may improve clinical outcomes. This manuscript is intended to serve as a preliminary guidance document for application of TPE in patients with severe COVID-19.

MATERIAL AND METHODS

The available literature pertaining to the role of TPE for treatment of COVID-19 patients was reviewed to guide optimal management. It included indication, contraindication, optimal timing of initiation and termination of TPE, vascular access and anticoagulants, numbers and mode of procedures, outcome measures and adverse events.

RESULTS

Out of a total of 78 articles, only 65 were directly related to the topic. From these 65, only 32 were acceptable as primary source, while 33 were used as supporting references. TPE in critically ill COVID-19 patients may be classified under ASFA category III grade 2B. The early initiation of TPE for 1-1·5 patient's plasma volume with fresh frozen plasma, or 4-5% albumin or COVID-19 convalescent plasma as replacement fluids before multiorgan failure, has better chances of recovery. The number of procedures can vary from three to nine depending on patient response.

CONCLUSION

TPE in COVID-19 patients may help by removing toxic cytokines, viral particles and/or by correcting coagulopathy or restoring endothelial membrane. Severity score (SOFA & APACHE II) and cytokine levels (IL-6, C-reactive protein) can be used to execute TPE therapy and to monitor response in COVID-19 patients.

COVID-19 Sepsis: Pathogenesis and Endothelial Molecular Mechanisms Based on "Two-Path Unifying Theory" of Hemostasis and Endotheliopathy-Associated Vascular Microthrombotic Disease, and Proposed Therapeutic Approach with Antimicrothrombotic Therapy

COVID-19 sepsis is characterized by acute respiratory distress syndrome (ARDS) as a consequence of pulmonary tropism of the virus and endothelial heterogeneity of the host. ARDS is a phenotype among patients with multiorgan dysfunction syndrome (MODS) due to disseminated vascular microthrombotic disease (VMTD). In response to the viral septicemia, the host activates the complement system which produces terminal complement complex C5b-9 to neutralize pathogen. C5b-9 causes pore formation on the membrane of host endothelial cells (ECs) if CD59 is underexpressed. Also, viral S protein attraction to endothelial ACE2 receptor damages ECs. Both affect ECs and provoke endotheliopathy. Disseminated endotheliopathy activates two molecular pathways: inflammatory and microthrombotic. The former releases inflammatory cytokines from ECs, which lead to inflammation. The latter initiates endothelial exocytosis of unusually large von Willebrand factor (ULVWF) multimers and FVIII from Weibel-Palade bodies. If ADAMTS13 is insufficient, ULVWF multimers activate intravascular hemostasis of ULVWF path. In activated ULVWF path, ULVWF multimers anchored to damaged endothelial cells recruit circulating platelets and trigger microthrombogenesis. This process produces "microthrombi strings" composed of platelet-ULVWF complexes, leading to endotheliopathy-associated VMTD (EA-VMTD). In COVID-19, microthrombosis initially affects the lungs per tropism causing ARDS, but EA-VMTD may orchestrate more complex clinical phenotypes, including thrombotic thrombocytopenic purpura (TTP)-like syndrome, hepatic coagulopathy, MODS and combined micro-macrothrombotic syndrome. In this pandemic, ARDS and pulmonary thromboembolism (PTE) have often coexisted. The analysis based on two hemostatic theories supports ARDS caused by activated ULVWF path is EA-VMTD and PTE caused by activated ULVWF and TF paths is macrothrombosis. The thrombotic disorder of COVID-19 sepsis is consistent with the notion that ARDS is virus-induced disseminated EA-VMTD and PTE is in-hospital vascular injury-related macrothrombosis which is not directly  related to viral pathogenesis. The pathogenesis-based therapeutic approach is discussed for the treatment of EA-VMTD with antimicrothrombotic regimen and the potential need of anticoagulation therapy for coinciding macrothrombosis in comprehensive COVID-19 care.

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.

Severe COVID-19 Infection Associated with Endothelial Dysfunction Induces Multiple Organ Dysfunction: A Review of Therapeutic Interventions

Since December 2019, the SARS-CoV-2 (COVID-19) pandemic has transfixed the medical world. COVID-19 symptoms vary from mild to severe and underlying chronic conditions such as pulmonary/cardiovascular disease and diabetes induce excessive inflammatory responses to COVID-19 and these underlying chronic diseases are mediated by endothelial dysfunction. Acute respiratory distress syndrome (ARDS) is the most common cause of death in COVID-19 patients, but coagulation induced by excessive inflammation, thrombosis, and disseminated intravascular coagulation (DIC) also induce death by multiple-organ dysfunction syndrome. These associations imply that maintaining endothelial integrity is crucial for favorable prognoses with COVID-19 and therapeutic intervention to support this may be beneficial. Here, we summarize the extent of heart injuries, ischemic stroke and hemorrhage, acute kidney injury, and liver injury caused by immune-mediated endothelial dysfunction that result in the phenomenon of multi-organ dysfunction seen in COVID-19 patients. Moreover, the potential therapeutic effect of angiotensin receptor blockers and angiotensin-converting enzyme inhibitors that improve endothelial dysfunction as well as the bradykinin storm are discussed.

The use of therapeutic plasma exchange as adjunctive therapy in the treatment of coronavirus disease 2019: A critical appraisal of the current evidence

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to a major pandemic. While vaccine development moves forward, optimal treatment continues to be explored. Efforts include an ever-expanding number of clinical trials along with newly proposed experimental and off-label investigational therapies; one of which is therapeutic plasma exchange (TPE). There have been a number of publications on TPE use as adjunctive therapy for coronavirus disease 2019 (COVID-19), but no prospective randomized controlled trials (RCTs) have been completed. This article critically appraises the current available evidence on TPE as a treatment modality for SARS-CoV-2 infection.

Immunopathogenesis and treatment of cytokine storm in COVID-19

Severe coronavirus disease 2019 (COVID-19) is characterized by systemic hyper-inflammation, acute respiratory distress syndrome, and multiple organ failure. Cytokine storm refers to a set of clinical conditions caused by excessive immune reactions and has been recognized as a leading cause of severe COVID-19. While comparisons have been made between COVID-19 cytokine storm and other kinds of cytokine storm such as hemophagocytic lymphohistiocytosis and cytokine release syndrome, the pathogenesis of cytokine storm has not been clearly elucidated yet. Recent studies have shown that impaired response of type-1 IFNs in early stage of COVID-19 infection played a major role in the development of cytokine storm, and various cytokines such as IL-6 and IL-1 were involved in severe COVID-19. Furthermore, many clinical evidences have indicated the importance of anti-inflammatory therapy in severe COVID-19. Several approaches are currently being used to treat the observed cytokine storm associated with COVID-19, and expectations are especially high for new cytokine-targeted therapies, such as tocilizumab, anakinra, and baricitinib. Although a number of studies have been conducted on anti-inflammatory treatments for severe COVID-19, no specific recommendations have been made on which drugs should be used for which patients and when. In this review, we provide an overview of cytokine storm in COVID-19 and treatments currently being used to address it. In addition, we discuss the potential therapeutic role of extracorporeal cytokine removal to treat the cytokine storm associated with COVID-19.

Antibody response and therapy in COVID-19 patients: what can be learned for vaccine development?

The newly emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected millions of people and caused tremendous morbidity and mortality worldwide. Effective treatment for coronavirus disease 2019 (COVID-19) due to SARS-CoV-2 infection is lacking, and different therapeutic strategies are under testing. Host humoral and cellular immunity to SARS-CoV-2 infection is a critical determinant for patients' outcomes. SARS-CoV-2 infection results in seroconversion and production of anti-SARS-CoV-2 antibodies. The antibodies may suppress viral replication through neutralization but might also participate in COVID-19 pathogenesis through a process termed antibody-dependent enhancement. Rapid progress has been made in the research of antibody response and therapy in COVID-19 patients, including characterization of the clinical features of antibody responses in different populations infected by SARS-CoV-2, treatment of COVID-19 patients with convalescent plasma and intravenous immunoglobin products, isolation and characterization of a large panel of monoclonal neutralizing antibodies and early clinical testing, as well as clinical results from several COVID-19 vaccine candidates. In this review, we summarize the recent progress and discuss the implications of these findings in vaccine development.

Potential of therapeutic plasmapheresis in treatment of COVID-19 patients: Immunopathogenesis and coagulopathy

Therapeutic plasmapheresis (TP) is the process of the separation and removal of plasma from other blood components and is considered as an adjunctive treatment strategy to the discarded abnormal agent in the management of respiratory viral pandemics. This article reviews the mechanisms of immunopathogenesis and coagulopathy induced by SARS-CoV-2 and the potential benefits of TP as adjunctive treatment in critically COVID-19 patients.

Life-threatening COVID-19 presenting as stroke with antiphospholipid antibodies and low ADAMTS-13 activity, and the role of therapeutic plasma exchange: A case series

We present a case series of three patients with COVID-19 who were admitted to our intensive care unit due to acute respiratory distress syndrome, brain infarction, pulmonary embolism, and antiphospholipid antibodies. We applied therapeutic plasma exchange on all cases. On intensive care unit admission, all patients had low (<10) Glasgow Coma Scale, and central nervous imaging showed multiple brain infarctions. COVID-19 was confirmed by reverse transcriptase polymerase chain reaction assays. Patients underwent rescue therapeutic plasma exchange using the Spectra OptiaTM Apheresis System (Terumo BCT Inc., USA), which operates with acid-citrate dextrose anticoagulant as per Kidney Disease Improving Global Outcomes 2019 guidelines. A dose of 1.5 plasma volume was used for the first dose and then 1 plasma volume daily for a total of five doses. Plasma was replaced with Octaplas LG® (Octapharma AG, USA), which is an artificial fresh frozen plasma product that has undergone viral inactivation by prion reduction technology. We administered ARDS-net/prone positioning ventilation, empiric antiviral treatment, therapeutic anticoagulation, and intensive care unit supportive care. Laboratory tests showed lymphocytopenia; elevated levels of D-dimer, fibrinogen, total bilirubin, C-reactive protein, lactate dehydrogenase, and ferritin; as well as low levels of ADAMTS-13 activity and antibody. Serology tests depicted positive IgM and IgG antiphospholipid antibodies (anti-cardiolipin and anti-β2-glycoprotein I antibodies). No side effects of therapeutic plasma exchange were recorded. After the completion of therapeutic plasma exchange, patients improved clinically and gradually recovered neurologically (after 27-32 days). To conclude, in life-threatening COVID-19, especially when immune dysregulation features such as antiphospholipid antibodies exist, therapeutic plasma exchange could be an effective rescue therapy.

Convalescent Plasma Therapy for COVID-19: State of the Art

Convalescent plasma (CP) therapy has been used since the early 1900s to treat emerging infectious diseases; its efficacy was later associated with the evidence that polyclonal neutralizing antibodies can reduce the duration of viremia. Recent large outbreaks of viral diseases for which effective antivirals or vaccines are still lacking has renewed the interest in CP as a life-saving treatment. The ongoing COVID-19 pandemic has led to the scaling up of CP therapy to unprecedented levels. Compared with historical usage, pathogen reduction technologies have now added an extra layer of safety to the use of CP, and new manufacturing approaches are being explored. This review summarizes historical settings of application, with a focus on betacoronaviruses, and surveys current approaches for donor selection and CP collection, pooling technologies, pathogen inactivation systems, and banking of CP. We additionally list the ongoing registered clinical trials for CP throughout the world and discuss the trial results published thus far.

Efficacy of Plasmapheresis and Immunoglobulin Replacement Therapy (IVIG) on Patients with COVID-19

Since the rapidly evolving outbreak of COVID-19, several empirical therapeutic options have been recommended including the use of antivirals, steroids, and vaccines. According to recent observations about different modalities in treatment of patients infected with COVID-19, plasmapheresis and intravenous immunoglobulin (IVIg) have been reported to be an effective empirical therapeutic option to control the infection. In this review, we aimed to provide an overview on the possible application of plasmapheresis and intravenous immunoglobulin in patients with COVID-19.