Hyperimmune IV immunoglobulin treatment: a multicenter double-blind randomized controlled trial for patients with severe 2009 influenza A(H1N1) infection

Monoclonal Antibodies and Hyperimmune Immunoglobulins in the Next Pandemic

Pandemics are highly unpredictable events that are generally caused by novel viruses. There is a high likelihood that such novel pathogens belong to entirely novel viral families for which no targeted small-molecule antivirals exist. In addition, small-molecule antivirals often have pharmacokinetic properties that make them contraindicated for the frail patients who are often the most susceptible to a novel virus. Passive immunotherapies-available from the first convalescent patients-can then play a key role in controlling pandemics. Convalescent plasma is immediately available, but if manufacturers have fast platforms to generate marketable drugs, other forms of passive antibody treatment can be produced. In this chapter, we will review the technological platforms for generating monoclonal antibodies and hyperimmune immunoglobulins, the current experience on their use for treatment of COVID-19, and the pipeline for pandemic candidates.

Passive immunotherapies for the next influenza pandemic

Influenzavirus is among the most relevant candidates for a next pandemic. We review here the phylogeny of former influenza pandemics, and discuss candidate lineages. After briefly reviewing the other existing antiviral options, we discuss in detail the evidences supporting the efficacy of passive immunotherapies against influenzavirus, with a focus on convalescent plasma.

Passive antibody therapy in emerging infectious diseases

The epidemic of corona virus disease 2019 (COVID-19) caused by severe acute respiratory syndrome Coronavirus 2 and its variants of concern (VOCs) has been ongoing for over 3 years. Antibody therapies encompassing convalescent plasma, hyperimmunoglobulin, and neutralizing monoclonal antibodies (mAbs) applied in passive immunotherapy have yielded positive outcomes and played a crucial role in the early COVID-19 treatment. In this review, the development path, action mechanism, clinical research results, challenges, and safety profile associated with the use of COVID-19 convalescent plasma, hyperimmunoglobulin, and mAbs were summarized. In addition, the prospects of applying antibody therapy against VOCs was assessed, offering insights into the coping strategies for facing new infectious disease outbreaks.

Fc-mediated functions and the treatment of severe respiratory viral infections with passive immunotherapy - a balancing act

Passive immunotherapies have been used to treat severe respiratory infections for over a century, with convalescent blood products from recovered individuals given to patients with influenza-related pneumonia as long ago as the Spanish flu pandemic. However, passive immunotherapy with convalescent plasma or hyperimmune intravenous immunoglobulin (hIVIG) has not provided unequivocal evidence of a clinical benefit for severe respiratory infections including influenza and COVID-19. Efficacy trials, primarily conducted in late-stage disease, have demonstrated inconsistent efficacy and clinical benefit for hIVIG treatment of severe respiratory infections. To date, most serological analyses of convalescent plasma and hIVIG trial samples have focused on the measurement of neutralizing antibody titres. There is, however, increasing evidence that baseline antibody levels and extra-neutralizing antibody functions influence the outcome of passive immunotherapy in humans. In this perspective, findings from convalescent plasma and hIVIG trials for severe influenza, COVID-19 and respiratory syncytial virus (RSV) will be described. Clinical trial results will be discussed in the context of the potential beneficial and deleterious roles of antibodies with Fc-mediated effector functions, with a focus on natural killer cells and antibody-dependent cellular cytotoxicity. Overall, we postulate that treating respiratory viral infections with hIVIG represents a delicate balance between protection and immunopathology.

Multifaceted Tissue-Protective Functions of Polyvalent Immunoglobulin Preparations in Severe Infections-Interactions with Neutrophils, Complement, and Coagulation Pathways

Severe infections induce immune defense mechanisms and initial tissue damage, which produce an inflammatory neutrophil response. Upon dysregulation of these responses, inflammation, further tissue damage, and systemic spread of the pathogen may occur. Subsequent vascular inflammation and activation of coagulation processes may cause microvascular obstruction at sites distal to the primary site of infection. Low immunoglobulin (Ig) M and IgG levels have been detected in patients with severe infections like sCAP and sepsis, associated with increased severity and mortality. Based on Ig's modes of action, supplementation with polyvalent intravenous Ig preparations (standard IVIg or IgM/IgA-enriched Ig preparations) has long been discussed as a treatment option for severe infections. A prerequisite seems to be the timely administration of Ig preparations before excessive tissue damage has occurred and coagulopathy has developed. This review focuses on nonclinical and clinical studies that evaluated tissue-protective activities resulting from interactions of Igs with neutrophils, complement, and the coagulation system. The data indicate that coagulopathy, organ failure, and even death of patients can possibly be prevented by the timely combined interactions of (natural) IgM, IgA, and IgG with neutrophils and complement.

Design of VA CoronavirUs Research and Efficacy Studies-1 (VA CURES-1): A double-blind, randomized placebo-controlled trial of COVID-19 convalescent plasma in hospitalized patients with early respiratory compromise

BACKGROUND

Effective therapeutics for severe acute respiratory syndrome CoronaVirus-2 (SARS-CoV-2) infection are evolving. Under Emergency Use Authorization, COVID-19 convalescent plasma (CCP) was widely used in individuals hospitalized for COVID-19, but few randomized controlled trials supported its efficacy to limit respiratory failure or death.

METHODS

VA CoronavirUs Research and Efficacy Studies-1 (VA CURES-1) was a double-blind, multi-site, placebo-controlled, randomized clinical trial evaluating the efficacy and safety of CCP with conventional therapy in hospitalized Veterans with SARS-CoV-2 infection and early respiratory compromise (requirement for oxygen). Participants (planned sample size 702) were randomized 1:1 to receive CCP with high titer neutralizing activity or 0.9% saline, stratified by site and age (≥65 versus <65 years old). Participants were followed daily during initial hospitalization and at Days 15, 22 and 28.

OUTCOMES

The composite primary outcome was acute hypoxemic respiratory failure or all-cause death by Day 28. Secondary outcomes by day 28 included time-to-recovery, clinical severity, mortality, rehospitalization for COVID-19, and adverse events. Serial respiratory and blood samples were collected for safety, virologic and immunologic analyses and future studies. Key variables in predicting the success of CURES-1 were: (1) enrollment early in the course of severe infection; (2) use of plasma with high neutralizing activity; (3) reliance on unambiguous, clinically meaningful outcomes. CURES-1 was terminated for futility due to perceived inability to enroll in the lull between the Alpha and Delta waves of the SARS CoV-2 epidemic.

CONCLUSIONS

VA CURES-1 was a large multi-site trial designed to provide conclusive information about the efficacy of CCP in well-characterized patients at risk for progression of COVID-19. It utilized a rigorous study design with relevant initial timing, quality of product and outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04539275.

Assessment of antibody levels to SARS-CoV-2 in patients with idiopathic inflammatory myopathies receiving treatment with intravenous immunoglobulin

Antibodies to Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2) have been reported in pooled healthy donor plasma and intravenous immunoglobulin products (IVIG). It is not known whether administration of IVIG increases circulating anti-SARS-CoV-2 antibodies (COVID ab) in IVIG recipients. COVID ab against the receptor binding domain of the spike protein were analyzed using a chemiluminescent microparticle immunoassay in patients with idiopathic inflammatory myopathies (IIM) both receiving and not receiving IVIG (IVIG and non-IVIG group, respectively). No significant differences in COVID ab levels were noted between IVIG and non-IVIG groups (417 [67-1342] AU/mL in IVIG vs 5086 [43-40,442] AU/mL in non-IVIG, p = 0.11). In linear regression models including all post-vaccination patient samples, higher number of vaccine doses was strongly associated with higher COVID ab levels (2.85 [1.21, 4.48] log AU/mL, regression coefficient [Formula: see text] [95% CI], p = 0.001), while use of RTX was associated with lower ab levels (2.73 [- 4.53, - 0.93] log AU/mL, [Formula: see text][95%CI], p = 0.004). In the IVIG group, higher total monthly doses of IVIG were associated with slightly higher COVID ab levels (0.02 [0.002-0.05] log AU/mL, p = 0.04). While patients on IVIG did not have higher COVID ab levels compared to the non-IVIG group, higher monthly doses of IVIG were associated with higher circulating levels of COVID ab in patients receiving IVIG, particularly in patients concomitantly receiving RTX. Our findings suggest that IIM patients, especially those at increased risk of COVID infection and worse COVID outcomes due to RTX therapy may have protective benefits when on concurrent IVIG treatment.

Understanding the treatment benefit of hyperimmune anti-influenza intravenous immunoglobulin (Flu-IVIG) for severe human influenza

BACKGROUNDAntibody-based therapies for respiratory viruses are of increasing importance. The INSIGHT 006 trial administered anti-influenza hyperimmune intravenous immunoglobulin (Flu-IVIG) to patients hospitalized with influenza. Flu-IVIG treatment improved outcomes in patients with influenza B but showed no benefit for influenza A.METHODSTo probe potential mechanisms of Flu-IVIG utility, sera collected from patients hospitalized with influenza A or B viruses (IAV or IBV) were analyzed for antibody isotype/subclass and Fcγ receptor (FcγR) binding by ELISA, bead-based multiplex, and NK cell activation assays.RESULTSInfluenza-specific FcγR-binding antibodies were elevated in Flu-IVIG-infused IBV- and IAV-infected patients. In IBV-infected participants (n = 62), increased IgG3 and FcγR binding were associated with more favorable outcomes. Flu-IVIG therapy also improved the odds of a more favorable outcome in patients with low levels of anti-IBV Fc-functional antibody. Higher FcγR-binding antibody was associated with less favorable outcomes in IAV-infected patients (n = 50), and Flu-IVIG worsened the odds of a favorable outcome in participants with low levels of anti-IAV Fc-functional antibody.CONCLUSIONThese detailed serological analyses provide insights into antibody features and mechanisms required for a successful humoral response against influenza, suggesting that IBV-specific, but not IAV-specific, antibodies with Fc-mediated functions may assist in improving influenza outcome. This work will inform development of improved influenza immunotherapies.TRIAL REGISTRATIONClinicalTrials.gov NCT02287467.FUNDINGFunding for this research was provided by subcontract 13XS134 under Leidos Biomedical Research Prime Contract HHSN261200800001E and HHSN261201500003I, NCI/NIAID.

Method for screening influenza neutralizing antibodies in crude human plasma and its derivatives using SPR

We applied Surface Plasmon Resonance (SPR) technology to develop a method for potency screening and quantification of anti-influenza antibodies in minimally processed human plasma samples and intravenous immunoglobulin (IGIV) products. We found that specific antibodies in human plasma or IGIV capable of inhibiting binding of influenza hemagglutinin to receptor-analogous glycans do so in concentration-dependent manner. We ranked the inhibitory activity of plasma samples from multiple donors and found a good correlation (r = 0.87) of SPR assay measurements and conventional hemagglutination inhibition (HAI) assay results. This method was also applied to screen for specific anti-influenza antibodies in IGIV lots manufactured pre- and post-2009 H1N1 pandemic. The SPR method was also applied to study binding inhibition of the intact A/California/04/2009 H1N1 and B/Victoria/504/2000 influenza viruses to α2,6 or α2,3-linked synthetic glycans. In contrast to recombinant H1 hemagglutinin, which was found to interact primarily with α2,6-linked terminal sialic acids, intact H1N1 or influenza B virus recognized both types of receptor analogs with different observed dissociation rates and the inhibitory activity of plasma antibodies was dependent on the type of sialic acid link. The SPR method can provide a high-throughput, time-saving and semi-automated alternative to conventional assays such as HAI or microneutralization in situations where screening of large numbers of plasma donations to identify high titer units is needed to product highly potent immunoglobulins.

Antiviral Approaches against Influenza Virus

Preventing and controlling influenza virus infection remains a global public health challenge, as it causes seasonal epidemics to unexpected pandemics. These infections are responsible for high morbidity, mortality, and substantial economic impact. Vaccines are the prophylaxis mainstay in the fight against influenza. However, vaccination fails to confer complete protection due to inadequate vaccination coverages, vaccine shortages, and mismatches with circulating strains. Antivirals represent an important prophylactic and therapeutic measure to reduce influenza-associated morbidity and mortality, particularly in high-risk populations. Here, we review current FDA-approved influenza antivirals with their mechanisms of action, and different viral- and host-directed influenza antiviral approaches, including immunomodulatory interventions in clinical development. Furthermore, we also illustrate the potential utility of machine learning in developing next-generation antivirals against influenza.

A systematic review of the safety and efficacy of convalescent plasma or immunoglobulin treatment for people with severe respiratory viral infections due to coronaviruses or influenza

OBJECTIVE

Evaluate the safety and effectiveness of convalescent plasma (CP) or hyperimmune immunoglobulin (hIVIG) in severe respiratory disease caused by coronaviruses or influenza, in patients of all ages requiring hospital admission.

METHODS

We searched multiple electronic databases for all publications to 12th October 2020, and RCTs only to 28th June 2021. Two reviewers screened, extracted, and analysed data. We used Cochrane ROB (Risk of Bias)1 for RCTs, ROBINS-I for non-RCTs, and GRADE to assess the certainty of the evidence.

RESULTS

Data from 30 RCTs and 2 non-RCTs showed no overall difference between groups for all-cause mortality and adverse events in four comparisons. Certainty of the evidence was downgraded for high ROB and imprecision. (1) CP versus standard care (SoC) (20 RCTS, 2 non-RCTs, very-low to moderate-high certainty); (2) CP versus biologically active control (6 RCTs, very-low certainty); (3) hIVIG versus SoC (3 RCTs, very-low certainty); (4) early CP versus deferred CP (1 RCT, very-low certainty). Subgrouping by titre improved precision in one outcome (30-day mortality) for the 'COVID high-titre' category in Comparison 1 (no difference, high certainty) and Comparison 2 (favours CP, very-low certainty). Post hoc analysis suggests a possible benefit of CP in patients testing negative for antibodies at baseline, compared with those testing positive.

CONCLUSION

A minimum titre should be established and ensured for a positive biological response to the therapy. Further research on the impact of CP/hIVIG in patients who have not yet produced antibodies to the virus would be useful to target therapies at groups who will potentially benefit the most.

Immune responses in mildly versus critically ill COVID-19 patients

The current coronavirus pandemic (COVID-19), caused by SARS-CoV-2, has had devastating effects on the global health and economic system. The cellular and molecular mediators of both the innate and adaptive immune systems are critical in controlling SARS-CoV-2 infections. However, dysregulated inflammatory responses and imbalanced adaptive immunity may contribute to tissue destruction and pathogenesis of the disease. Important mechanisms in severe forms of COVID-19 include overproduction of inflammatory cytokines, impairment of type I IFN response, overactivation of neutrophils and macrophages, decreased frequencies of DC cells, NK cells and ILCs, complement activation, lymphopenia, Th1 and Treg hypoactivation, Th2 and Th17 hyperactivation, as well as decreased clonal diversity and dysregulated B lymphocyte function. Given the relationship between disease severity and an imbalanced immune system, scientists have been led to manipulate the immune system as a therapeutic approach. For example, anti-cytokine, cell, and IVIG therapies have received attention in the treatment of severe COVID-19. In this review, the role of immunity in the development and progression of COVID-19 is discussed, focusing on molecular and cellular aspects of the immune system in mild vs. severe forms of the disease. Moreover, some immune- based therapeutic approaches to COVID-19 are being investigated. Understanding key processes involved in the disease progression is critical in developing therapeutic agents and optimizing related strategies.

Hyperimmune immunoglobulin for people with COVID-19

BACKGROUND

Hyperimmune immunoglobulin (hIVIG) contains polyclonal antibodies, which can be prepared from large amounts of pooled convalescent plasma or prepared from animal sources through immunisation. They are being investigated as a potential therapy for coronavirus disease 2019 (COVID-19). This review was previously part of a parent review addressing convalescent plasma and hIVIG for people with COVID-19 and was split to address hIVIG and convalescent plasma separately.

OBJECTIVES

To assess the benefits and harms of hIVIG therapy for the treatment of people with COVID-19, and to maintain the currency of the evidence using a living systematic review approach.

SEARCH METHODS

To identify completed and ongoing studies, we searched the World Health Organization (WHO) COVID-19 Research Database, the Cochrane COVID-19 Study Register, the Epistemonikos COVID-19 L*OVE Platform and Medline and Embase from 1 January 2019 onwards. We carried out searches on 31 March 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that evaluated hIVIG for COVID-19, irrespective of disease severity, age, gender or ethnicity. We excluded studies that included populations with other coronavirus diseases (severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS)), as well as studies that evaluated standard immunoglobulin.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology. To assess bias in included studies, we used RoB 2. We rated the certainty of evidence, using the GRADE approach, for the following outcomes: all-cause mortality, improvement and worsening of clinical status (for individuals with moderate to severe disease), quality of life, adverse events, and serious adverse events.

MAIN RESULTS

We included five RCTs with 947 participants, of whom 688 received hIVIG prepared from humans, 18 received heterologous swine glyco-humanised polyclonal antibody, and 241 received equine-derived processed and purified F(ab')2 fragments. All participants were hospitalised with moderate-to-severe disease, most participants were not vaccinated (only 12 participants were vaccinated). The studies were conducted before or during the emergence of several SARS-CoV-2 variants of concern. There are no data for people with COVID-19 with no symptoms (asymptomatic) or people with mild COVID-19. We identified a further 10 ongoing studies evaluating hIVIG. Benefits of hIVIG prepared from humans We included data on one RCT (579 participants) that assessed the benefits and harms of hIVIG 0.4 g/kg compared to saline placebo. hIVIG may have little to no impact on all-cause mortality at 28 days (risk ratio (RR) 0.79, 95% confidence interval (CI) 0.43 to 1.44; absolute effect 77 per 1000 with placebo versus 61 per 1000 (33 to 111) with hIVIG; low-certainty evidence). The evidence is very uncertain about the effect on worsening of clinical status at day 7 (RR 0.85, 95% CI 0.58 to 1.23; very low-certainty evidence). It probably has little to no impact on improvement of clinical status on day 28 (RR 1.02, 95% CI 0.97 to 1.08; moderate-certainty evidence). We did not identify any studies that reported quality-of-life outcomes, so we do not know if hIVIG has any impact on quality of life. Harms of hIVIG prepared from humans hIVIG may have little to no impact on adverse events at any grade on day 1 (RR 0.98, 95% CI 0.81 to 1.18; 431 per 1000; 1 study 579 participants; low-certainty evidence). Patients receiving hIVIG probably experience more adverse events at grade 3-4 severity than patients who receive placebo (RR 4.09, 95% CI 1.39 to 12.01; moderate-certainty evidence). hIVIG may have little to no impact on the composite outcome of serious adverse events or death up to day 28 (RR 0.72, 95% CI 0.45 to 1.14; moderate-certainty evidence). We also identified additional results on the benefits and harms of other dose ranges of hIVIG, not included in the summary of findings table, but summarised in additional tables. Benefits of animal-derived polyclonal antibodies We included data on one RCT (241 participants) to assess the benefits and harms of receptor-binding domain-specific polyclonal F(ab´)2 fragments of equine antibodies (EpAbs) compared to saline placebo. EpAbs may reduce all-cause mortality at 28 days (RR 0.60, 95% CI 0.26 to 1.37; absolute effect 114 per 1000 with placebo versus 68 per 1000 (30 to 156) ; low-certainty evidence). EpAbs may reduce worsening of clinical status up to day 28 (RR 0.67, 95% CI 0.38 to 1.18; absolute effect 203 per 1000 with placebo versus 136 per 1000 (77 to 240); low-certainty evidence). It may have some effect on improvement of clinical status on day 28 (RR 1.06, 95% CI 0.96 to 1.17; low-certainty evidence). We did not identify any studies that reported quality-of-life outcomes, so we do not know if EpAbs have any impact on quality of life. Harms of animal-derived polyclonal antibodies EpAbs may have little to no impact on the number of adverse events at any grade up to 28 days (RR 0.99, 95% CI 0.74 to 1.31; low-certainty evidence). Adverse events at grade 3-4 severity were not reported. Individuals receiving EpAbs may experience fewer serious adverse events than patients receiving placebo (RR 0.67, 95% CI 0.38 to 1.19; low-certainty evidence). We also identified additional results on the benefits and harms of other animal-derived polyclonal antibody doses, not included in the summary of findings table, but summarised in additional tables.

AUTHORS' CONCLUSIONS

We included data from five RCTs that evaluated hIVIG compared to standard therapy, with participants with moderate-to-severe disease. As the studies evaluated different preparations (from humans or from various animals) and doses, we could not pool them. hIVIG prepared from humans may have little to no impact on mortality, and clinical improvement and worsening. hIVIG may increase grade 3-4 adverse events. Studies did not evaluate quality of life. RBD-specific polyclonal F(ab´)2 fragments of equine antibodies may reduce mortality and serious adverse events, and may reduce clinical worsening. However, the studies were conducted before or during the emergence of several SARS-CoV-2 variants of concern and prior to widespread vaccine rollout. As no studies evaluated hIVIG for participants with asymptomatic infection or mild disease, benefits for these individuals remains uncertain. This is a living systematic review. We search monthly for new evidence and update the review when we identify relevant new evidence.

Use of convalescent plasma therapy in hospitalised adult patients with non-critical COVID-19: a focus on the elderly from Hungary

Convalescent plasma therapy might be a feasible option for treatment of novel infections. During the early phases of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic, several promising results were published with convalescent plasma therapy, followed by more disappointing findings of randomised controlled trials. In our single-centre, open-label, prospective, cohort study, we assessed the findings of 180 patients treated with convalescent plasma during the first four waves of the pandemic in Hungary. The primary outcome was all-cause mortality; secondary outcomes were clinical improvement and need for intensive care unit admission by day 28. Subgroup analysis comparing elderly and non-elderly (less than 65 years of age) was performed. Twenty (11.4%) patients died by day 28, at significantly higher rates in the elderly subgroup (3 vs. 17, p < 0.01). One hundred twenty-eight (72.7%) patients showed clinical improvement, and 15 (8.5%) were transferred to the intensive care unit until day 28. Non-elderly patients showed clinical improvement by day 28 in significantly higher rates (improvement 74 vs. 54, no improvement 15 vs. 11, worsening or death 4 vs. 18 patients, p < 0.01). In conclusion, we found similar clinical outcome results as randomised controlled trials, and the impact of risk factors for unfavourable clinical outcomes among patients in the elderly population.

Recent advances in passive immunotherapies for COVID-19: The Evidence-Based approaches and clinical trials

In late 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged, causing a global pandemic called COVID-19. Currently, there is no definitive treatment for this emerging disease. Global efforts resulted in developing multiple platforms of COVID-19 vaccines, but their efficacy in humans should be wholly investigated in the long-term clinical and epidemiological follow-ups. Despite the international efforts, COVID-19 vaccination accompanies challenges, including financial and political obstacles, serious adverse effects (AEs), the impossibility of using vaccines in certain groups of people in the community, and viral evasion due to emerging novel variants of SARS-CoV-2 in many countries. For these reasons, passive immunotherapy has been considered a complementary remedy and a promising way to manage COVID-19. These approaches arebased on reduced inflammation due to inhibiting cytokine storm phenomena, immunomodulation,preventing acute respiratory distress syndrome (ARDS), viral neutralization, anddecreased viral load. This article highlights passive immunotherapy and immunomodulation approaches in managing and treating COVID-19 patients and discusses relevant clinical trials (CTs).

Human immune globulin treatment controls Zika viremia in pregnant rhesus macaques

There are currently no approved drugs to treat Zika virus (ZIKV) infection during pregnancy. Hyperimmune globulin products such as VARIZIG and WinRho are FDA-approved to treat conditions during pregnancy such as Varicella Zoster virus infection and Rh-incompatibility. We administered ZIKV-specific human immune globulin as a treatment in pregnant rhesus macaques one day after subcutaneous ZIKV infection. All animals controlled ZIKV viremia following the treatment and generated robust levels of anti-Zika virus antibodies in their blood. No adverse fetal or infant outcomes were identified in the treated animals, yet the placebo control treated animals also did not have signs related to congenital Zika syndrome (CZS). Human immune globulin may be a viable prophylaxis and treatment option for ZIKV infection during pregnancy, however, more studies are required to fully assess the impact of this treatment to prevent CZS.

Immunomodulatory therapy for the management of critically ill patients with COVID-19: A narrative review

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the ongoing coronavirus disease 2019 (COVID-19) pandemic. Understanding the physiological and immunological processes underlying the clinical manifestations of COVID-19 is vital for the identification and rational design of effective therapies.

AIM

To describe the interaction of SARS-CoV-2 with the immune system and the subsequent contribution of hyperinflammation and abnormal immune responses to disease progression together with a complete narrative review of the different immunoadjuvant treatments used so far in COVID-19 and their indication in severe and life-threatening subsets.

METHODS

A comprehensive literature search was developed. Authors reviewed the selected manuscripts following the PRISMA recommendations for systematic review and meta-analysis documents and selected the most appropriate. Finally, a recommendation of the use of each treatment was established based on the level of evidence of the articles and documents reviewed. This recommendation was made based on the consensus of all the authors.

RESULTS

A brief rationale on the SARS-CoV-2 pathogenesis, immune response, and inflammation was developed. The usefulness of 10 different families of treatments related to inflammation and immunopathogenesis of COVID-19 was reviewed and discussed. Finally, based on the level of scientific evidence, a recommendation was established for each of them.

CONCLUSION

Although several promising therapies exist, only the use of corticosteroids and tocilizumab (or sarilumab in absence of this) have demonstrated evidence enough to recommend its use in critically ill patients with COVID-19. Endotypes including both, clinical and biological characteristics can constitute specific targets for better select certain therapies based on an individualized approach to treatment.

The effect of intravenous immunoglobulins on the outcomes of patients with COVID-19: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

Severe or critical COVID-19 has been associated with exaggerated immune responses and anti-inflammatory agents including corticosteroid and interleukin-6 antagonist have been repurposed as the treatment modality against severe SARS-CoV-2 infections. However, the clinical efficacy and safety of intravenous immunoglobulin (IVIG) in the treatment of patients with COVID-19 was controversial.

METHODS

This meta-analysis of randomized controlled trials (RCTs) investigated the effectiveness of IVIG in patients with COVID-19. Electronic databases were searched for RCTs that compared the clinical efficacy of IVIG with standard of care or placebo in the hospitalized patients with COVID-19 were included.

RESULTS

Six RCTs involving 472 patients were included. Patients who received IVIG had a similar mortality rate to the controls (25.3% vs 27.0%, odds ratio [OR], 0.60; 95% confidence interval [CI], 0.27-1.31). Compared with the control group, the study group demonstrated a similar incidence of receiving mechanical ventilation (OR, 0.70; 95% CI, 0.45-1.11), intensive care unit (ICU) admission (OR, 0.58; 95% CI, 0.22-1.53), length of hospital stay (mean difference [MD], -1.81 days; 95% CI, -8.42 to 4.81) and ICU stay (MD, -0.61 days; 95% CI, -2.80 to 1.58).

CONCLUSIONS

The administration of IVIG in hospitalized patients with COVID-19 does not improve clinical outcomes.

Treatment of severe COVID-19 patients with either low- or high-volume of convalescent plasma versus standard of care: A multicenter Bayesian randomized open-label clinical trial (COOP-COVID-19-MCTI)

Background

Administration of convalescent plasma may serve as an adjunct to supportive treatment to prevent COVID-19 progression and death. We aimed to evaluate the efficacy and safety of 2 volumes of intravenous convalescent plasma (CP) with high antibody titers for the treatment of severe cases of COVID-19.

Methods

We conducted a Bayesian, randomized, open-label, multicenter, controlled clinical trial in 7 Brazilian hospitals. Adults admitted to hospital with positive RT-PCR for SARS-CoV2, within 10 days of the symptom onset, were eligible. Patients were randomly assigned (1:1:1) to receive standard of care (SoC) alone, or in combination with 200 mL (150–300 mL) of CP (Low-volume), or 400 mL (300–600 mL) of CP (High-volume); infusion had to be performed within 24 h of randomization. Randomization was centralized, stratified by center. The primary outcome was the time until clinical improvement up to day 28, measured by the WHO ten-point scale, assessed in the intention-to-treat population. Interim and terminal analyses were performed in a Bayesian framework. Trial registered at ClinicalTrials.gov: NCT04415086.

Findings

Between June 2, 2020, and November 18, 2020, 129 patients were enrolled and randomly assigned to SoC (n = 42), Low-volume (n = 43) or High-volume (n = 44) CP. Donors presented a median titer of neutralizing antibodies of 1:320 (interquartile range, 1:160 to 1:1088). No evidence of any benefit of convalescent plasma was observed, with Bayesian estimate of 28-day clinical improvement of 72.7% (95%CI, 58.8 to 84.7) in the SoC versus 64.1% (95%ci, 53.8 to 73.7) in the pooled experimental groups (mean difference of -8.7%, 95%CI, -24.6 to 8.2). There was one case of cutaneous mild allergic reaction related to plasma transfusion and one case of suspected transfusion-related acute lung injury but deemed not to be related to convalescent plasma infusion.

Interpretation

In this prospective, randomized trial of adult hospitalized patients with severe COVID-19, convalescent plasma was not associated with clinical benefits.

Funding

Brazilian Ministry of Science, Technology and Innovation, Fundação de Amparo à Pesquisa do Estado de São Paulo.

Drugs repurposing for SARS-CoV-2: new insight of COVID-19 druggability

INTRODUCTION

The ongoing epidemic of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) creates a massive panic worldwide due to the absence of effective medicines. Developing a new drug or vaccine is time-consuming to pass safety and efficacy testing. Therefore, repurposing drugs have been introduced to treat COVID-19 until effective drugs are developed.

AREA COVERED

A detailed search of repurposing drugs against SARS-CoV-2 was carried out using the PubMed database, focusing on articles published 2020 years onward. A different class of drugs has been described in this article to target hosts and viruses. Based on the previous pandemic experience of SARS-CoV and MERS, several antiviral and antimalarial drugs are discussed here. This review covers the failure of some repurposed drugs that showed promising activity in the earlier CoV-pandemic but were found ineffective against SARS-CoV-2. All these discussions demand a successful drug development strategy for screening and identifying an effective drug for better management of COVID-19. The drug development strategies described here will serve a new scope of research for academicians and researchers.

EXPERT OPINION

Repurposed drugs have been used since COVID-19 to eradicate disease propagation. Drugs found effective for MERS and SARS may not be effective against SARS-CoV-2. Drug libraries and artificial intelligence are helpful tools to screen and identify different molecules targeting viruses or hosts.

Polyclonal hyper immunoglobulin: A proven treatment and prophylaxis platform for passive immunization to address existing and emerging diseases

Passive immunization with polyclonal hyper immunoglobulin (HIG) therapy represents a proven strategy by transferring immunoglobulins to patients to confer immediate protection against a range of pathogens including infectious agents and toxins. Distinct from active immunization, the protection is passive and the immunoglobulins will clear from the system; therefore, administration of an effective dose must be maintained for prophylaxis or treatment until a natural adaptive immune response is mounted or the pathogen/agent is cleared. The current review provides an overview of this technology, key considerations to address different pathogens, and suggested improvements. The review will reflect on key learnings from development of HIGs in the response to public health threats due to Zika, influenza, and severe acute respiratory syndrome coronavirus 2.

Medicinal IgG products (2020) show high infectivity neutralizing activity against seasonal influenza virus strains selected for future vaccines (2020-22)

Immunoglobulin (Ig)G medicinal products manufactured in 2020 were tested for infectivity neutralization and hemagglutination inhibition against World Health Organization-selected influenza strains included in worldwide vaccines 2020–2022. The IgG batches (from US plasma) showed potent activity. Intravenous immunoglobulin could potentially add to therapies for serious influenza cases in immunocompromised patients. Further study is warranted.

Intravenous Immunoglobulin Therapy for Critically Ill COVID-19 Patients With Different Inflammatory Phenotypes: A Multicenter, Retrospective Study

Background

The benefits of intravenous immunoglobulin administration are controversial for critically ill COVID-19 patients.

Methods

We analyzed retrospectively the effects of immunoglobulin administration for critically ill COVID-19 patients. The primary outcome was 28-day mortality. Inverse probability of treatment weighting (IPTW) with propensity score was used to account for baseline confounders. Cluster analysis was used to perform phenotype analysis.

Results

Between January 1 and February 29, 2020, 754 patients with complete data from 19 hospitals were enrolled. Death at 28 days occurred for 408 (54.1%) patients. There were 392 (52.0%) patients who received intravenous immunoglobulin, at 11 (interquartile range (IQR) 8, 16) days after illness onset; 30% of these patients received intravenous immunoglobulin prior to intensive care unit (ICU) admission. By unadjusted analysis, no difference was observed for 28-day mortality between the immunoglobulin and non-immunoglobulin groups. Similar results were found by propensity score matching (n = 506) and by IPTW analysis (n = 731). Also, IPTW analysis did not reveal any significant difference between hyperinflammation and hypoinflammation phenotypes.

Conclusion

No significant association was observed for use of intravenous immunoglobulin and decreased mortality of severe COVID-19 patients. Phenotype analysis did not show any survival benefit for patients who received immunoglobulin therapy.

Prevention, treatment and potential mechanism of herbal medicine for Corona viruses: A review

The pandemic of coronavirus disease 2019 (COVID-19) caused by the SARS-coronavirus 2(SARS-CoV-2) virus has become the greatest global public health crisis in recent years,and the COVID-19 epidemic is still continuing. However, due to the lack of effectivetherapeutic drugs, the treatment of corona viruses is facing huge challenges. In thiscontext, countries with a tradition of using herbal medicine such as China have beenwidely using herbal medicine for prevention and nonspecific treatment of corona virusesand achieved good responses. In this review, we will introduce the application of herbalmedicine in the treatment of corona virus patients in China and other countries, andreview the progress of related molecular mechanisms and antiviral activity ingredients ofherbal medicine, in order to provide a reference for herbal medicine in the treatment ofcorona viruses. We found that herbal medicines are used in the prevention and fightagainst COVID-19 in countries on all continents. In China, herbal medicine has beenreported to relieve some of the clinical symptoms of mild patients and shorten the length of hospital stay. However, as most herbal medicines for the clinical treatment of COVID-19still lack rigorous clinical trials, the clinical and economic value of herbal medicines in theprevention and treatment of COVID-19 has not been fully evaluated. Future work basedon large-scale randomized, double-blind clinical trials to evaluate herbal medicines andtheir active ingredients in the treatment of new COVID-19 will be very meaningful.

The Saudi Critical Care Society practice guidelines on the management of COVID-19 in the ICU: Therapy section

BACKGROUND

The rapid increase in coronavirus disease 2019 (COVID-19) cases during the subsequent waves in Saudi Arabia and other countries prompted the Saudi Critical Care Society (SCCS) to put together a panel of experts to issue evidence-based recommendations for the management of COVID-19 in the intensive care unit (ICU).

METHODS

The SCCS COVID-19 panel included 51 experts with expertise in critical care, respirology, infectious disease, epidemiology, emergency medicine, clinical pharmacy, nursing, respiratory therapy, methodology, and health policy. All members completed an electronic conflict of interest disclosure form. The panel addressed 9 questions that are related to the therapy of COVID-19 in the ICU. We identified relevant systematic reviews and clinical trials, then used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach as well as the evidence-to-decision framework (EtD) to assess the quality of evidence and generate recommendations.

RESULTS

The SCCS COVID-19 panel issued 12 recommendations on pharmacotherapeutic interventions (immunomodulators, antiviral agents, and anticoagulants) for severe and critical COVID-19, of which 3 were strong recommendations and 9 were weak recommendations.

CONCLUSION

The SCCS COVID-19 panel used the GRADE approach to formulate recommendations on therapy for COVID-19 in the ICU. The EtD framework allows adaptation of these recommendations in different contexts. The SCCS guideline committee will update recommendations as new evidence becomes available.

Myasthenia gravis exacerbation and myasthenic crisis associated with COVID-19: case series and literature review

BACKGROUND

Myasthenia gravis (MG) is an autoimmune disorder of the neuromuscular junction that can be exacerbated by many viral infections, including COVID-19. The management of MG exacerbations is challenging in this scenario. We report 8 cases of MG exacerbation or myasthenic crisis associated with COVID-19 and discuss prognosis and treatment based on a literature review.

RESULTS

Most patients were female (7/8), with an average age of 47.1 years. Treatment was immunoglobulin (IVIG) in 3 patients, plasma exchange (PLEX) in 2 patients, and adjustment of baseline drugs in 3. In-hospital mortality was 25% and 37.5% in 2-month follow-up.

DISCUSSION

This is the largest case series of MG exacerbation or myasthenic crisis due to COVID-19 to this date. Mortality was considerably higher than in myasthenic crisis of other etiologies. Previous treatment for MG or acute exacerbation treatment did not seem to interfere with prognosis, although sample size was too small to draw definitive conclusions. Further studies are needed to understand the safety and effectiveness of interventions in this setting, particularly of PLEX, IVIG, rituximab, and tocilizumab.

A pregnant woman with COVID-19 gives birth to premature triplets: A case report and literature review

To the best of our knowledge, no case report has been published to date concerning the novel coronavirus disease 2019 (COVID-19) treatment plan for pregnant women with triplets, as well as on the possibility of a vertical transmission to triplets delivered prematurely by a pregnant woman with COVID-19. The present study thus describes such as case. A 29-year-old local resident, a woman with COVID-19, who was pregnant with triplets, had not moved from her residence for the past 6 months. The main symptoms mentioned by the patient on the day of admission were the following: The patient was in the 28th week of pregnancy, 2019 novel coronavirus (2019-nCoV) nucleic acid positive test 13 h prior to admission. Additionally, the patient had a high fever and dyspnea after admission. The patient was treated with convalescent plasma from patients with COVID-19 and methylprednisolone, at the same time her anemia, anxiety and insomnia were treated. Subsequently, the patient's condition improved, and normal body temperature was restored. Cesarean section was performed due to severe intrahepatic cholestasis of pregnancy (ICP), and due to the fetuses being located in three chorionic and amniotic cavities, and due to the fact that each of the three infants was in a different position (cephalic, breech and transverse position). Following delivery, total bile acid values and liver function improved gradually, and the 2019-nCoV nucleic acid test was negative consecutively for two tests, and the woman was then discharged from the hospital. Each premature infant born by caesarean section was individually transported to a neonatal intensive care unit for isolation treatment, with the neonatal escorts and transport teams wearing secondary protective clothing. All three premature infants were transitioned gradually from parenteral intravenous nutrition to full oral feeding. 2019-nCoV nucleic acid test results were negative for all infants. 2019-nCoV IgM test results were negative and IgG were positive for all infants. The pregnant woman and the three premature infants were successfully treated and discharged after they felt no discomfort and were negative consecutively for two 2019-nCoV nucleic acid tests. The three premature infants were monitored for growth and development until December, 2021, and eye, lung, heart, brain, liver, kidney, intestine and other organ functions were normal. The present study reports on the treatment and delivery outcomes of a woman with COVID-19, who was pregnant with triplets. The present case report demonstrated that although the pregnant woman with triplets was suffering from COVID-19, all three premature infants delivered by cesarean section did not present with intrauterine vertical infection, and abnormal growth and development were not observed. The convalescent plasma of patients with COVID-19 and methylprednisolone were effective for the treatment of a continuously high fever, and the timely treatment of complications is helpful for the treatment of patients with COVID-19.

Immunological effects of convalescent plasma therapy for coronavirus: a scoping review

BACKGROUND

Preliminary studies revealed the safety and effectiveness of convalescent plasma (CP) therapy for patients with coronavirus. In this study, we aimed to evaluate and summarize the available evidence on CP therapy, identify the research gap regarding the immunological response to CP therapy and pave the road for future studies.

METHODS

This study was conducted according to the Hilary Arksey and Lisa O'Malley framework. To find out the relevant studies, we searched PubMed, Scopus and Embase databases up to 30th May 2021. Data have been extracted according to three categories: (1) patients' characteristics, (2) clinical and immunological responses to CP therapy and (3) pre-infusion screening of the CP samples.

RESULTS

A total of 12,553 articles were identified. One hundred fifty-four studies met the inclusion criteria for full-text review. More than half of the included studies (112 studies, (75.6%)) concluded satisfactory outcomes and or safety of CP infusion in patients. Results of studies showed the efficacy of CP therapy in clinical improvement (101 studies), decreasing in the level of inflammatory factors (62 studies), elimination or decreasing in viral load (60 studies), and induction or increase in antibody response (37 studies). Despite these promising results, the results of the 49 studies revealed that CP therapy was ineffective in the survival of patients, clinical improvement, viral infection elimination or decrease in the inflammatory factor levels. Furthermore, the adaptive immune response was evaluated in 3 studies. Information related to the pre-infusion screening for human leukocyte antigen/human neutrophil antigen (HLA/HNA) antibodies was not reported in most of the studies. Our gap analysis revealed that the influence of the CP infusion on the adaptive immune and inflammatory responses in patients with coronavirus needs further investigation.

CONCLUSIONS

Based on the results of most included studies, CP infusion was safe and resulted in clinical improvement of patients and decreasing the viral load. The effect of the CP infusion on adaptive immune response and inflammatory cytokines in patients with coronavirus needs further investigation.

Therapeutic Uses of Traditional Chinese Medicines Against COVID-19

COVID-19 is a pandemic and a serious respiratory disorder that is caused by coronavirus. It has produced an outbreak of acute infectious pneumonia in China and afterward all around the world. There is not a single anti-viral drug, vaccine or any kind of treatment available for this fatal disease. There are only a few options available for symptomatic relief. Thus, in China, 85% of SARS-CoV-2 infected individuals have been treated with traditional Chinese medicines (TCM). Thus, this article focused on the previous kinds of literature regarding COVID-19 and its treatment with TCM along with its applications. SARS-CoV-2 and SARS-CoV showed similarity in genes, pathological processes, and epidemiology, so these can be treated with TCM. The proof regarding treatment of SARS-CoV with TCM explicitly shows the advantages of using TCM therapy for COVID-19. Present literature explains the mode of action and efficacy of TCM and elaborates on the natural compounds introduced to treat COVID-19.

Functional convalescent plasma antibodies and pre-infusion titers shape the early severe COVID-19 immune response

Transfer of convalescent plasma (CP) had been proposed early during the SARS-CoV-2 pandemic as an accessible therapy, yet trial results worldwide have been mixed, potentially due to the heterogeneous nature of CP. Here we perform deep profiling of SARS-CoV-2-specific antibody titer, Fc-receptor binding, and Fc-mediated functional assays in CP units, as well as in plasma from hospitalized COVID-19 patients before and after CP administration. The profiling results show that, although all recipients exhibit expanded SARS-CoV-2-specific humoral immune responses, CP units contain more functional antibodies than recipient plasma. Meanwhile, CP functional profiles influence the evolution of recipient humoral immunity in conjuncture with the recipient's pre-existing SARS-CoV2-specific antibody titers: CP-derived SARS-CoV-2 nucleocapsid-specific antibody functions are associated with muted humoral immune evolution in patients with high titer anti-spike IgG. Our data thus provide insights into the unexpected impact of CP-derived functional anti-spike and anti-nucleocapsid antibodies on the evolution of SARS-CoV-2-specific response following severe infection.

Treatment of SARS-CoV-2 (COVID-19): A safety perspective

The goal of this review is to report a balanced perspective of current evidence for efficacy of treatments for coronavirus disease 2019 (COVID-19) against the historical safety of these treatments as of May 2021. We preselected therapies of interest for COVID-19 based on national guidelines and modified over time. We searched PubMed and Medline for these specific COVID-19 treatments and data related to their efficacy. We also searched for prior randomized controlled trials of each therapy to assess adverse effects, and we obtained the Food and Drug Administration Approval label for this information. Several drugs have been approved for the treatment of COVID-19, and many more are under study. This includes dexamethasone, remdesivir, hydroxychloroquine/chloroquine, lopinvir/ritonavir, interferon or interleukin inhibitors, convalescent plasma and several vitamins and minerals. The strongest evidence for benefit is mortality benefit with dexamethasone in patients with COVID-19 and hypoxemia, although there is a signal of harm if this is started too early. There are several other promising therapies, like interleukin inhibitors and ivermectin. Hydroxychloroquine/chloroquine, lopinvir/ritonavir, and convalescent plasma do not have enough evidence of benefit to outweigh the known risks of these drugs.

A randomized clinical trial evaluating the immunomodulatory effect of convalescent plasma on COVID-19-related cytokine storm

Evaluating the effect of convalescent plasma (CP) on some cytokine storm indices in severe COVID-19 patients. Totally, 62 patients were randomly assigned into two groups for this clinical trial. Patients in the intervention group received one unit (500 mL) plasma on the admission day plus standard drugs while the controls merely received standard treatments. Eventually, primary and secondary outcomes were evaluated. In the CP group, compared with controls, the mean levels of lymphocytes and IL-10 significantly increased while the levels of IL-6, TNF-α, and IFN-γ decreased (p < 0.05). The length of in-hospital stay, and mortality rate did not significantly reduce in the CP group compared with controls (p > 0.05) while WHO severity scores remarkably improved (p = 0.01), despite the higher frequency of underlying diseases among the CP group (66.7%) vs. controls (33.3%). Although CP has a remarkable immunomodulatory and antiviral potential to improve the cytokine storm and disease severity in COVID-19 patients, it did not considerably affect the mortality rate.

Specific Cytokine Profiles Predict the Severity of Influenza A Pneumonia: A Prospectively Multicenter Pilot Study

Purpose

Studying the cytokine profiles in influenza A pneumonia could be helpful to better understand the pathogenesis of the disease and predict its prognosis. Patients and Methods. Patients with influenza A pneumonia (including 2009H1N1, H1N1, H3N1, and H7N1) hospitalized in six hospitals from January 2017 to October 2018 were enrolled (ClinicalTrials.gov ID, NCT03093220). Sputum samples were collected within 24 hours after admission and subsequently analyzed for cytokine profiles using a Luminex assay.

Results

A total of 35 patients with influenza A pneumonia were included in the study. The levels of IL-6, IFN-γ, and IL-2 were increased in patients with severe influenza A pneumonia (n =10) (P = 0.002, 0.009, and 0.008, respectively), while those of IL-5, IL-25, IL-17A, and IL-22 were decreased compared to patients with nonsevere pneumonia (P = 0.0001, 0.009, 0.0001, and 0.006, respectively). The levels of IL-2 and IL-6 in the nonsurvivors (n = 5) were significantly higher than those in the survivors (P = 0.043 and 0.0001, respectively), while the levels of IL-5, IL-17A, and IL-22 were significantly lower (P = 0.001, 0.012, and 0.043, respectively). The IL-4/IL-17A ratio has the potential to be a good predictor (AUC = 0.94, P < 0.05, sensitivity = 88.89%, specificity = 92.31%) and an independent risk factor (OR, 95% CI: 3.772, 1.188-11.975; P < 0.05) for intermittent positive pressure ventilation (n = 9).

Conclusion

Significant dysregulation of cytokine profiles can be observed in patients with severe influenza A pneumonia.

Potential therapeutic approach of intravenous immunoglobulin against COVID-19

Since the outbreak of the novel coronavirus disease (COVID-19), the therapeutic and management options to reduce the burden of the COVID-19 disease are under investigation. IVIG therapy is used as an effective treatment for immunodeficient patients and patients with inflammatory or autoimmune conditions. The therapeutic effect of IVIG in COVID-19 patients has been investigated. But, the results are controversial and some studies reported no benefit of IVIG therapy. More clinical trials on the effect of IVIG therapy in COVID-19 patients should be performed to establish a certain conclusion about IVIG effectiveness.

A comprehensive review of COVID-19 biology, diagnostics, therapeutics, and disease impacting the central nervous system

The ongoing COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a highly transmissible disease. SARS-CoV-2 is estimated to have infected over 153 million people and to have caused over 3.2 million global deaths since its emergence in December 2019. SARS-CoV-2 is the seventh coronavirus known to infect humans, and like other coronaviruses, SARS-CoV-2 infection is characterized by a variety of symptoms including general flu-like symptoms such as a fever, sore throat, fatigue, and shortness of breath. Severe cases often display signs of pneumonia, lymphopenia, acute kidney injury, cardiac injury, cytokine storms, lung damage, acute respiratory distress syndrome (ARDS), multiple organ failure, sepsis, and death. There is evidence that around 30% of COVID-19 cases have central nervous system (CNS) or peripheral nervous system (PNS) symptoms along with or in the absence of the previously mentioned symptoms. In cases of CNS/PNS impairments, patients display dizziness, ataxia, seizure, nerve pain, and loss of taste and/or smell. This review highlights the neurological implications of SARS-CoV-2 and provides a comprehensive summary of the research done on SARS-CoV-2 pathology, diagnosis, therapeutics, and vaccines up to May 5.

High-dose intravenous immunoglobulins as a therapeutic option in critical illness polyneuropathy accompanying SARS-CoV-2 infection: A case-based review of the literature (Review)

The still ongoing COVID-19 pandemic has exposed the medical community to a number of major challenges. A significant number of patients require admission to intensive care unit (ICU) services due to severe respiratory, thrombotic and septic complications and require long-term hospitalization. Neuromuscular weakness is a common complication in critically ill patients who are treated in ICUs and are mechanically ventilated. This complication is frequently caused by critical illness myopathy (CIM) or critical illness polyneuropathy (CIP) and leads to difficulty in weaning from the ventilator. It is thought to represent an important neurologic manifestation of the systemic inflammatory response syndrome (SIRS). COVID-19 infection is known to trigger strong immune dysregulation, with an intense cytokine storm, as a result, the frequency of CIP is expected to be higher in this setting. The mainstay in the diagnosis of this entity beside the high level of clinical awareness is the electrophysiological examination that provides evidence of axonal motor and sensory polyneuropathy. The present article presents the case of a 54-year-old woman with severe COVID 19 infection who developed neuromuscular weakness, which turned out to be secondary to CIP and was treated successfully with a high dose of human intravenous immunoglobulins. Related to this case, we reviewed the relevant literature data regarding the epidemiology, pathophysiology and clinical features of this important complication and discussed also the treatment options and prognosis.

Harnessing immunological targets for COVID-19 immunotherapy

COVID-19 is an infectious and highly contagious disease caused by SARS-CoV-2. The immunotherapy strategy has a great potential to develop a permanent cure against COVID-19. Innate immune cells are in constant motion to scan molecular alteration to cells led by microbial infections throughout the body and helps in clearing invading viruses. Harnessing immunological targets for removing viral infection, generally based on the principle of enhancing the T-cell and protective immune responses. Currently-approved COVID-19 vaccines are mRNA encapsulated in liposomes that stimulate the host immune system to produce antibodies. Given the vital role of innate immunity, harnessing these immune responses opens up new hope for the generation of long-lasting and protective immunity against COVID-19.

Rationale for Polyclonal Intravenous Immunoglobulin Adjunctive Therapy in COVID-19 Patients: Report of a Structured Multidisciplinary Consensus

Introduction: Adjunctive therapy with polyclonal intravenous immunoglobins (IVIg) is currently used for preventing or managing infections and sepsis, especially in immunocompromised patients. The pathobiology of COVID-19 and the mechanisms of action of Ig led to the consideration of this adjunctive therapy, including in patients with respiratory failure due to the SARS-CoV-2 infection. This manuscript reports the rationale, the available data and the results of a structured consensus on intravenous Ig therapy in patients with severe COVID-19. Methods: A panel of multidisciplinary experts defined the clinical phenotypes of COVID-19 patients with severe respiratory failure and, after literature review, voted for the agreement on the rationale and the potential role of IVIg therapy for each phenotype. Due to the scarce evidence available, a modified RAND/UCLA appropriateness method was used. Results: Three different phenotypes of COVID-19 patients with severe respiratory failure were identified: patients with an abrupt and dysregulated hyperinflammatory response (early phase), patients with suspected immune paralysis (late phase) and patients with sepsis due to a hospital-acquired superinfection (sepsis by bacterial superinfection). The rationale for intravenous Ig therapy in the early phase was considered uncertain whereas the panelists considered its use in the late phase and patients with sepsis/septic shock by bacterial superinfection appropriate. Conclusion: As with other immunotherapies, IVIg adjunctive therapy may have a potential role in the management of COVID-19 patients. The ongoing trials will clarify the appropriate target population and the true effectiveness.

The role of influenza A virus-induced hypercytokinemia

Influenza viruses are one of the leading causes of respiratory tract infections in humans and their newly emerging and re-emerging virus strains are responsible for seasonal epidemics and occasional pandemics, leading to a serious threat to global public health systems. The poor clinical outcome and pathogenesis during influenza virus infection in humans and animal models are often associated with elevated proinflammatory cytokines and chemokines production, which is also known as hypercytokinemia or "cytokine storm", that precedes acute respiratory distress syndrome (ARDS) and often leads to death. Although we still do not fully understand the complex nature of cytokine storms, the use of immunomodulatory drugs is a promising approach for treating hypercytokinemia induced by an acute viral infection, including highly pathogenic avian influenza virus infection and Coronavirus Disease 2019 (COVID-19). This review aims to discuss the immune responses and cytokine storm pathology induced by influenza virus infection and also summarize alternative experimental strategies for treating hypercytokinemia caused by influenza virus.

Early but not late convalescent plasma is associated with better survival in moderate-to-severe COVID-19

BACKGROUND

Limited therapeutic options exist for coronavirus disease 2019 (COVID-19). COVID-19 convalescent plasma (CCP) is a potential therapeutic, but there is limited data for patients with moderate-to-severe disease.

RESEARCH QUESTION

What are outcomes associated with administration of CCP in patients with moderate-to-severe COVID-19 infection?

STUDY DESIGN AND METHODS

We conducted a propensity score-matched analysis of patients with moderate-to-severe COVID-19. The primary endpoints were in-hospital mortality. Secondary endpoints were number of days alive and ventilator-free at 30 days; length of hospital stay; and change in WHO scores from CCP administration (or index date) to discharge. Of 151 patients who received CCP, 132 had complete follow-up data. Patients were transfused after a median of 6 hospital days; thus, we investigated the effect of convalescent plasma before and after this timepoint with 77 early (within 6 days) and 55 late (after 6 days) recipients. Among 3,217 inpatients who did not receive CCP, 2,551 were available for matching.

RESULTS

Early CCP recipients, of whom 31 (40%) were on mechanical ventilation, had lower 14-day (15% vs 23%) and 30-day (38% vs 49%) mortality compared to a matched unexposed cohort, with nearly 50% lower likelihood of in-hospital mortality (HR 0.52, [95% CI 0.28-0.96]; P = 0.036). Early plasma recipients had more days alive and ventilator-free at 30 days (+3.3 days, [95% CI 0.2 to 6.3 days]; P = 0.04) and improved WHO scores at 7 days (-0.8, [95% CI: -1.2 to -0.4]; P = 0.0003) and hospital discharge (-0.9, [95% CI: -1.5 to -0.3]; P = 0.004) compared to the matched unexposed cohort. No clinical differences were observed in late plasma recipients.

INTERPRETATION

Early administration of CCP improves outcomes in patients with moderate-to-severe COVID-19, while improvement was not observed with late CCP administration. The importance of timing of administration should be addressed in specifically designed trials.

The Rise of SARS-CoV-2 Variants and the Role of Convalescent Plasma Therapy for Management of Infections

Novel therapies for the treatment of COVID-19 are continuing to emerge as the SARS-Cov-2 pandemic progresses. PCR remains the standard benchmark for initial diagnosis of COVID-19 infection, while advances in immunological profiling are guiding clinical treatment. The SARS-Cov-2 virus has undergone multiple mutations since its emergence in 2019, resulting in changes in virulence that have impacted on disease severity globally. The emergence of more virulent variants of SARS-Cov-2 remains challenging for effective disease control during this pandemic. Major variants identified to date include B.1.1.7, B.1.351; P.1; B.1.617.2; B.1.427; P.2; P.3; B.1.525; and C.37. Globally, large unvaccinated populations increase the risk of more and more variants arising. With successive waves of COVID-19 emerging, strategies that mitigate against community transmission need to be implemented, including increased vaccination coverage. For treatment, convalescent plasma therapy, successfully deployed during recent Ebola outbreaks and for H1N1 influenza, can increase survival rates and improve host responses to viral challenge. Convalescent plasma is rich with cytokines (IL-1β, IL-2, IL-6, IL-17, and IL-8), CCL2, and TNFα, neutralizing antibodies, and clotting factors essential for the management of SARS-CoV-2 infection. Clinical trials can inform and guide treatment policy, leading to mainstream adoption of convalescent therapy. This review examines the limited number of clinical trials published, to date that have deployed this therapy and explores clinical trials in progress for the treatment of COVID-19.

COVID-19 convalescent plasma cohort study: Evaluation of the association between both donor and recipient neutralizing antibody titers and patient outcomes

Background

Current evidence regarding COVID‐19 convalescent plasma (CCP) transfusion practices is limited and heterogeneous. We aimed to determine the impact of the use of CCP transfusion in patients with previous circulating neutralizing antibodies (nAbs) in COVID‐19.

Methods

Prospective cohort including 102 patients with COVID‐19 transfused with ABO compatible CCP on days 0–2 after enrollment. Clinical status of patients was assessed using the adapted World Health Organization (WHO) ordinal scale on days 0, 5, and 14. The nAbs titration was performed using the cytopathic effect‐based virus neutralization test with SARS‐CoV‐2 (GenBank MT126808.1). The primary outcome was clinical improvement on day 14, defined as a reduction of at least two points on the adapted WHO ordinal scale. Secondary outcomes were the number of intensive care unit (ICU)‐free days and the number of invasive mechanical ventilation‐free days.

Results

Both nAbs of CCP units transfused (p < 0.001) and nAbs of patients before CCP transfusions (p = 0.028) were associated with clinical improvements by day 14. No significant associations between nAbs of patients or CCP units transfused were observed in the number of ICU or mechanical ventilation‐free days. Administration of CCP units after 10 days of symptom onset resulted in a decrease in ICU‐free days (p < 0.001) and mechanical ventilation‐free days (p < 0.001).

Conclusion

Transfusion of high titer nAbs CCP units may be a determinant in clinical strategies against COVID‐19. We consider these data as useful parameters to guide future CCP transfusion practices.

The signal pathways and treatment of cytokine storm in COVID-19

The Coronavirus Disease 2019 (COVID-19) pandemic has become a global crisis and is more devastating than any other previous infectious disease. It has affected a significant proportion of the global population both physically and mentally, and destroyed businesses and societies. Current evidence suggested that immunopathology may be responsible for COVID-19 pathogenesis, including lymphopenia, neutrophilia, dysregulation of monocytes and macrophages, reduced or delayed type I interferon (IFN-I) response, antibody-dependent enhancement, and especially, cytokine storm (CS). The CS is characterized by hyperproduction of an array of pro-inflammatory cytokines and is closely associated with poor prognosis. These excessively secreted pro-inflammatory cytokines initiate different inflammatory signaling pathways via their receptors on immune and tissue cells, resulting in complicated medical symptoms including fever, capillary leak syndrome, disseminated intravascular coagulation, acute respiratory distress syndrome, and multiorgan failure, ultimately leading to death in the most severe cases. Therefore, it is clinically important to understand the initiation and signaling pathways of CS to develop more effective treatment strategies for COVID-19. Herein, we discuss the latest developments in the immunopathological characteristics of COVID-19 and focus on CS including the current research status of the different cytokines involved. We also discuss the induction, function, downstream signaling, and existing and potential interventions for targeting these cytokines or related signal pathways. We believe that a comprehensive understanding of CS in COVID-19 will help to develop better strategies to effectively control immunopathology in this disease and other infectious and inflammatory diseases.

Case Report: Effects of Anti-SARS-CoV-2 Convalescent Antibodies Obtained With Double Filtration Plasmapheresis

Passive antibody therapy has been used to treat outbreaks of viral disease, including the ongoing pandemic of severe respiratory acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2) or COVID-19. However, the real benefits of the procedure are unclear. We infused a concentrated solution of neutralizing anti-SARS-CoV-2 antibodies obtained from a convalescent donor with a single session of double filtration plasmapheresis (DFPP) into a 56-year-old woman with long history of unremitting, severe COVID-19. She was unable to establish an adequate antiviral immune response because of previous chemotherapy, including the infusion of the anti-CD20 monoclonal antibody rituximab, administered to treat a diffuse large B-cell lymphoma. The disease promptly recovered despite evidence of no endogenous anti-SARS-CoV-2 antibody production. The observation that passive antibody therapy might prove particularly effective in immunodepressed COVID-19 patients requires evaluation in prospective randomized controlled trial.

Therapeutic Agents Rounding Up the Immunopathology of COVID-19

COVID-19 pandemic has caused more than 3 million deaths globally during the past year. The direct attack from SARS-CoV-2 and hyperactivated immune response contribute to the progress and deterioration of COVID-19. After the virus invades, the activation and release of cytokines/chemokines cause "cytokine storm", leading to acute respiratory distress syndrome (ARDS) and multiple organs dysfunction syndrome (MODS). Eliminating virus and blocking cytokines are important checkpoints of COVID-19 therapy, and several agents targeting immunopathology, including interferons, thymosin, glucocorticoids and immunoglobulin, have shown therapeutic effects in severe patients with COVID-19. Herein, we reviewed the practice evidences and concluded that several agents rounding up the immunopathology of COVID-19 may be the alternative approaches under the scenario of the lacking of effective antiviral drugs.

A single center experience of intravenous immunoglobulin treatment in Covid-19

Background

Intravenous immunoglobulins (IVIg) have been used in management of severe Covid-19. Here in this study, we report our single-center experience regarding IVIg treatment in management of severe Covid-19.

Materials and Method

Among hospitalized adult Covid-19 patients between April 1 and December 31, 2020, patients with confirmed diagnosis of Covid-19 who had Brescia-COVID respiratory severity scale score ≥ 3, hyperinflammation and received IVIg treatment in addition to standard of care were retrospectively investigated. We grouped IVIg recipients into three according to reasons for IVIg administration: Group 1 patients requiring anti-inflammatory treatment but complicated with secondary infection and/or sepsis , group 2 patients with Covid-19 related complications including progressive disease refractory to other anti-inflammatory agents, myocarditis, adult multisystem inflammatory syndrome, hemophagocytic lymphohystiocytosis like syndrome and group 3 patients with other complications non-specific to Covid-19. Mortality and clinical data was compared among groups.

Results

A total of 46 IVIg recipients were enrolled. Group 1 comprised 17 (36.9%), group 2 comprised 18 (39.1%) and group 3 comprised 11 (23.9%) patients. No significant differences in means of age, gender and comorbidities were observed among groups. Mortality was significantly lower in group 3 when compared to group 1 (64.7% vs 18.2%, p = 0.016) and close to significance when compared to group 2 (50% vs 18.2% p = 0.087).

Conclusions

IVIg seemed to be used mostly in severe, refractory and complicated cases in our population. As a rescue agent in severe cases refractory to other anti-inflammatory strategies, 33.7% survival rate was observed with IVIg.

The Convalescent Plasma Craze! Where Does India Stand?

India becomes the country with second highest number of coronavirus disease 2019 (COVID-19) cases (59,03,932) as of September 2020. As the world debates various treatment options, the current pandemic has led to the resurgence of an ancient technique, namely convalescent plasma therapy. Although it has been in use from the late 19th century, it is an uncharted territory for most developing nations. In this article, we have discussed the pros and cons of convalescent plasma transfusion in COVID-19 patients. Articles discussed in this review have been obtained from search engines, namely PubMed, Scopus, and Embase. We have also expressed our viewpoint on the feasibility and logistical challenges of convalescent plasma use in India.

Effects of potent neutralizing antibodies from convalescent plasma in patients hospitalized for severe SARS-CoV-2 infection

In a randomized clinical trial of 86 hospitalized COVID-19 patients comparing standard care to treatment with 300mL convalescent plasma containing high titers of neutralizing SARS-CoV-2 antibodies, no overall clinical benefit was observed. Using a comprehensive translational approach, we unravel the virological and immunological responses following treatment to disentangle which COVID-19 patients may benefit and should be the focus of future studies. Convalescent plasma is safe, does not improve survival, has no effect on the disease course, nor does plasma enhance viral clearance in the respiratory tract, influence SARS-CoV-2 antibody development or serum proinflammatory cytokines levels. Here, we show that the vast majority of patients already had potent neutralizing SARS-CoV-2 antibodies at hospital admission and with comparable titers to carefully selected plasma donors. This resulted in the decision to terminate the trial prematurely. Treatment with convalescent plasma should be studied early in the disease course or at least preceding autologous humoral response development.