IVIG-mediated effector functions in autoimmune and inflammatory diseases

High-Dose Intravenous Immunoglobulin in Severe Coronavirus Disease 2019: A Multicenter Retrospective Study in China

Background

The effective treatment of coronavirus disease 2019 (COVID-19) remains unclear. We reported successful use of high-dose intravenous immunoglobulin (IVIg) in cases of severe COVID-19, but evidence from larger case series is still lacking.

Methods

A multi-center retrospective study was conducted to evaluate the effectiveness of IVIg administered within two weeks of disease onset at a total dose of 2 g/kg body weight, in addition to standard care. The primary endpoint was 28-day mortality. Efficacy of high-dose IVIg was assessed by using the Cox proportional hazards regression model and the Kaplan-Meier curve adjusted by inverse probability of treatment weighting (IPTW) analysis, and IPTW after multiple imputation (MI) analysis.

Results

Overall, 26 patients who received high-dose IVIg with standard therapy and 89 patients who received standard therapy only were enrolled in this study. The IVIg group was associated with a lower 28-day mortality rate and less time to normalization of inflammatory markers including IL-6, IL-10, and ferritin compared with the control. The adjusted HR of 28-day mortality in high-dose IVIg group was 0.24 (95% CI 0.06–0.99, p<0.001) in IPTW model, and 0.27 (95% CI 0.10–0.57, p=0.031) in IPTW-MI model. In subgroup analysis, patients with no comorbidities or treated in the first week of disease were associated with more benefit from high-dose IVIg.

Conclusions

High-dose IVIg administered in severe COVID-19 patients within 14 days of onset was linked to reduced 28-day mortality, more prominent with those having no comorbidities or treated at earlier stage.

Administration of intravenous immunoglobulin in the treatment of COVID-19: A review of available evidence

Since December 31, 2019, unknown causes of pneumonia have been reported in Wuhan, China. This special pneumonia associated with a novel coronavirus was named 2019-nCoV by the World Health Organization (WHO) in January 2020. From the beginning of this infectious disease, clinicians and researchers have been endeavoring to discover an effective and suitable treatment for affected patients. To date, there is no definitive and specific treatments for coronavirus disease-19 (COVID-19) infection while drugs introduced are still in the clinical trial phase. Intravenous immune globulin (IVIG) is a biological product prepared from the serum and an optional treatment for patients with antibody deficiencies. In many countries, much attention has been paid to the use of IVIG in the treatment of patients with COVID-19. Due to the therapeutic importance of IVIG in virus infections, in the current study, we reviewed the possible effect of IVIG in viral infections and potential evidence of IVIG therapy in patients with COVID-19 virus.

Histobulin as a complementary but essential therapeutic for Intravenous Immune Globulin Therapy of Pfeiffer-Weber-Christian disease with multiple allergic diseases and its effects on allergic disease: A case report

Histobulin is complementary to IVIG therapy but is an essential therapeutic for PWCD. Histoublin is recommended not only in atopic dermatitis and multiple food allergies but also in patients with multiple allergic diseases.

How IvIg Can Mitigate Covid-19 Disease: A Symmetrical Immune Network Model

In this report we provide a hypothesis of how intravenous immunoglobulin (IvIg) (pooled therapeutic normal IgG) mitigates the severe disease after infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. The disease is caused by an overreaction of the innate immune system producing a cytokine storm and inflicting multiple organ damage. Our interpretation of IvIg therapy hinges on a recent analysis of the immune dysregulation in Covid-19 infection. Previous infections with common cold coronavirus induce suppressor memory B cells that inhibit an immune response to Covid-19. The repertoire of natural antibodies (IvIg) contains suppressing antibodies in a symmetrically balanced network structure. When this repertoire interacts with the imbalanced network in the infected patient, it can neutralize the suppression of an antibody response against Covid-19. The described scenario for IvIg in Covid-19 infection may also apply in the therapy of autoimmune diseases.

Efficacy evaluation of intravenous immunoglobulin in non-severe patients with COVID-19: A retrospective cohort study based on propensity score matching

Objectives

At the present time, there is an absence of any proven effective antiviral therapy for patients with coronavirus disease 2019 (COVID-19). The aim of this study was to assess the efficacy of intravenous immunoglobulin (IVIG) in non-severe patients with COVID-19.

Methods

A retrospective study based on propensity score matching (PSM) was designed. Primary outcomes included the severity and mortality rates. Secondary outcomes included the duration of fever, virus clearance time, length of hospital stay, and use of antibiotics.

Results

A total of 639 non-severe patients with COVID-19 were enrolled. Forty-five patients received IVIG therapy and 594 received non-IVIG therapy. After PSM (1:2 ratio), the baseline characteristics were well balanced between the IVIG group (n = 45) and control group (n = 90). No statistically significant difference was found between the IVIG group and control group in the duration of fever (median 3 vs 3 days, p = 0.667), virus clearance time (median 11 vs 10 days, p = 0.288), length of hospital stay (median 14 vs 13 days, p = 0.469), or use of antibiotics (40% vs 38.9%, p = 0.901). Meanwhile, compared to the IVIG group, no more patients in the control group progressed to severe disease (3.3% vs 6.6%, p = 0.376) or died (0 vs 2.2%, p = 0.156).

Conclusions

In non-severe patients with COVID-19, no benefit was observed with IVIG therapy beyond standard therapy.

Intravenous Immunoglobulins at the Crossroad of Autoimmunity and Viral Infections

Intravenous immunoglobulins (IVIG) are blood preparations pooled from the plasma of donors that have been first employed as replacement therapy in immunodeficiency. IVIG interact at multiple levels with the different components of the immune system and exert their activity against infections. Passive immunotherapy includes convalescent plasma from subjects who have recovered from infection, hyperimmune globulin formulations with a high titer of neutralizing antibodies, and monoclonal antibodies (mAbs). IVIG are used for the prevention and treatment of several infections, especially in immunocompromised patients, or in case of a poorly responsive immune system. The evolution of IVIG from a source of passive immunity to a powerful immunomodulatory/anti-inflammatory agent results in extensive applications in autoimmune diseases. IVIG composition depends on the antibodies of the donor population and the alterations of protein structure due to the processing of plasma. The anti-viral and anti-inflammatory activity of IVIG has led us to think that they may represent a useful therapeutic tool even in COVID-19. The human origin of IVIG carries specific criticalities including risks of blood products, supply, and elevated costs. IVIG can be useful in critically ill patients, as well as early empirical treatment. To date, the need for further well-designed studies stating protocols and the efficacy/tolerability profile of IVIG and convalescent plasma in selected situations are awaited.

CIDP Antibodies Target Junction Proteins and Identify Patient Subgroups: An Autoantigenomic Approach

OBJECTIVE

To discover systemic characteristics in the repertoires of targeted autoantigens in chronic inflammatory demyelinating polyneuropathy (CIDP), we detected the entire autoantigen repertoire of patients and controls and analyzed them systematically.

METHODS

We screened 43 human serum samples, of which 22 were from patients with CIDP, 12 from patients with other neuropathies, and 9 from healthy controls via HuProt Human Proteome microarrays testing about 16,000 distinct human bait proteins. Autoantigen repertoires were analyzed via bioinformatical autoantigenomic approaches: principal component analysis, analysis of the repertoire sizes in disease groups and clinical subgroups, and overrepresentation analyses using Gene Ontology and PantherDB.

RESULTS

The autoantigen repertoires enabled the identification of a subgroup of 10/22 patients with CIDP with a younger age at onset and a higher frequency of mixed motor and sensory CIDP. IV immunoglobulin therapy responders targeted 3 times more autoantigens than nonresponders. No CIDP-specific autoantibody is present in all patients; however, anchoring junction components were significantly targeted by 86.4% of patients with CIDP. There are potential novel CIDP-specific autoantigens such as the myelination- or axo-glial structure-related proteins actin-related protein 2/3 complex subunit 1B, band 4.1-like protein 2, cadherin-15, cytohesin-1, epidermal growth factor receptor, ezrin, and radixin.

CONCLUSIONS

The repertoire of targeted autoantigens of patients with CIDP differs in a systematic degree from those of controls. Systematic autoantigenomic approaches can help to understand the disease and to discover novel bioinformatical tools and novel autoantigen panels to improve diagnosis, treatment, prognosis, or patient stratification.

Intravenous Immune Globulin (IVIG) Therapy After Unsuccessful Treatment with Corticosteroid and Cyclosporine A in Pfeifer-Weber-Christian Disease: A Case Report

BACKGROUND Pfeifer-Weber-Christian disease (PWCD), also referred to as idiopathic nodular panniculitis, is a rare idiopathic disease characterized by lobular panniculitis of adipose tissue with systemic symptoms and multiple organ involvement and is usually treated with corticosteroids and cyclosporine A. We report a case of PWCD that was unresponsive to standard treatment but responded to intravenous immune globulin (IVIG) therapy. CASE REPORT A 35-year-old Korean woman presented with fever, malaise, myalgia, and painful nodules in the left breast. Histology of the breast nodules showed lobular panniculitis consistent with PWCD. She did not respond to corticosteroid and cyclosporine A. She was effectively treated with intravenous immune globulin (IVIG). IVIG therapy began with 60 g (1 g/kg) 4 times per week, 2 times every other week. Subsequently, the IVIG dose was reduced for maintenance therapy to 25 g (400 mg/kg) twice every other week and monthly. The patient showed immediate and dramatic improvement. General signs and symptoms, such as fever, malaise, and myalgia, were absent, and the masses had nearly subsided, with several very small hard nodules remaining for 3 months until the time of this report. CONCLUSIONS IVIG was an effective immunomodulatory therapeutic for PWCD in this case. This report shows that PWCD is a rare condition that is difficult to diagnose, but the histopathology of nodular panniculitis supports the diagnosis. In cases that do not respond to standard immunosuppressive therapy, including corticosteroids and cyclosporine A, IVIG therapy may lead to a favorable response with rapid symptomatic relief.

Circulating Immune Cell Profile and Changes in Intravenous Immunoglobulin Responsiveness Over the Disease Course in Children With Kawasaki Disease

Kawasaki disease (KD) is an acute, self-limited febrile illness of young children. The etiology of KD remains to be poorly understood. There has been limited research on longitudinal examination of peripheral blood leukocytes for immune profiling particularly in relation to treatment response with intravenous immunoglobulin (IVIG). This study profiles immune cells at the time of diagnosis and over the disease course. In addition, we identified the characteristics of the immune cells in IVIG-responsive patients with KD. We enrolled patients diagnosed with KD between May 1, 2017, and January 1, 2020. Blood was taken at least three times from all enrolled patients: at diagnosis (before IVIG infusion) and immediately and 2 weeks after IVIG infusion. We evaluated the laboratory findings and results of flow cytometry analysis of immune cells at all stages, focusing on CD4⁺ T lymphocytes, CD8⁺ T lymphocytes, CD19⁺ B lymphocytes, granulocytes, classical monocytes, and natural killer (NK) cells. Non-febrile healthy controls (NFCs) and other febrile controls (OFCs) were also enrolled. A total of 68 patients were enrolled and divided into two groups according to IVIG resistance status: IVIG-responsive (n = 55) and IVIG-resistant (n = 13). The total fever duration was significantly longer in the IVIG-resistant group (9.7 ± 5.3 days) than in the IVIG-responsive group (6.7 ± 3.0 days; P = 0.02). There was a significant difference in intermediate CD14⁺CD16⁺ monocytes between KD patients and both NFC and OFCs; they were significantly higher and lower in KD patients than NFC and OFCs, respectively (P < 0.001). The levels of all three subtypes of NK cells were significantly lower in KD patients than in both NFC and OFCs (P < 0.001). Regarding IVIG responsiveness, CD14⁺CD16⁺ intermediate monocyte levels were significantly lower in the IVIG-resistant group (P < 0.001). In addition, CD56^-CD16⁺ NK cell expression was significantly lower in the IVIG-resistant group than in the IVIG-responsive group (P = 0.002). In conclusion, our results suggest CD56^-CD16⁺N NK cells and CD14⁺CD16⁺ intermediate monocytes might play an essential role in immunopathogenesis of KD. Further studies are warranted to explore the role of these subpopulations particularly for the observed association with coronary artery lesions (CAL) and treatment response.

Immunoglobulin G Glycosylation in Diseases

Changes in immunoglobulin G (IgG) glycosylation pattern have been observed in a vast array of auto- and alloimmune, infectious, cardiometabolic, malignant, and other diseases. This chapter contains an updated catalog of over 140 studies within which IgG glycosylation analysis was performed in a disease setting. Since the composition of IgG glycans is known to modulate its effector functions, it is suggested that a changed IgG glycosylation pattern in patients might be involved in disease development and progression, representing a predisposition and/or a functional effector in disease pathology. In contrast to the glycopattern of bulk serum IgG, which likely relates to the systemic inflammatory background, the glycosylation profile of antigen-specific IgG probably plays a direct role in disease pathology in several infectious and allo- and autoimmune antibody-dependent diseases. Depending on the specifics of any given disease, IgG glycosylation read-out might therefore in the future be developed into a useful clinical biomarker or a supplementary to currently used biomarkers.

Intravenous immunoglobulin G in the treatment of ABO hemolytic disease of the newborn during the early neonatal period at a tertiary academic hospital: a retrospective study

OBJECTIVE

To evaluate the efficacy and safety of intravenous immunoglobulin G (IVIG) in infants with ABO hemolytic disease of the newborn (HDN).

METHODS

Infants with moderate-to-severe ABO HDN during early neonatal period (<7 days) at our hospital in 2017 were included in this retrospective study. Patients treated with IVIG and phototherapy were classified as the IVIG group, and those who only received phototherapy were classified as the phototherapy only group.

RESULTS

Forty-six patients were classified into the IVIG group and 68 other patients were classified into the phototherapy only group. There was no significant difference in duration of phototherapy, hospitalization periods, needs for exchange transfusion, transfusions, and incidence of bilirubin-induced neurological sequelae between these two groups (P = 0.20, 0.27, 0.65, 0.47, 0.78, respectively).

CONCLUSION

It seems unnecessary to expose neonates to IVIG in moderate-to-severe ABO HDN when the available data show no appreciable benefits.

The interplay between inflammatory pathways and COVID-19: A critical review on pathogenesis and therapeutic options

COVID-19, caused by SARS-CoV-2, emerged as the deadliest outbreak that has now become a serious health issue to mankind. Activation of inflammatory signaling pathways and cytokine storm are crucial factors that lead to acute respiratory distress syndrome (ARDS) in COVID-19 patients. Excessive secretion of pro-inflammatory cytokines and chemokines leads to the dysregulation of the innate immune system. The cytokine storm attracts many inflammatory cells that infiltrate into the lung tissues and ultimately cause immune damage. In addition to the dysregulation of the immune system, dysfunction of the renin-angiotensin system (RAS) due to the downregulation of ACE2 is also associated with the mortality of COVID-19 patients. Both the mechanisms are directly or indirectly associated with cytokine storm that promotes vascular hyperpermeability, vascular edema leading to hypercoagulation and hence multiorgan damage. As of now, there is no specific treatment available for COVID-19, but scientists have purposed several treatment options including cytokine inhibitors, JAK inhibitors, immunomodulators, plasma therapy, etc. In this article, we have provided the detailed mechanism of occurrence of SARS-CoV-2 induced inflammatory storm and its connection with the pre-existing inflammatory conditions. Possible treatment options to cope up with the severe clinical manifestations of COVID-19 are also discussed.

Is there a Role of Intravenous Immunoglobulin in Immunologic Recurrent Pregnancy Loss?

Recurrent pregnancy loss (RPL) commonly refers to three or more miscarriages that occur before 20 weeks of pregnancy. The immunological cause of RPL could be either an auto- or alloimmune-related event or both. Because of the discovery of immunological abnormalities in RPL patients in clinical practice, several immunomodulatory therapies were introduced to maintain the immune balance at the maternal-fetal interface. Intravenous immunoglobulin (IVIg) is one of the immunomodulators. In recent years, several studies have analyzed the therapeutic effect of IVIg on RPL patients with antiphospholipid syndrome (APS) or unexplained RPL. However, their results are controversial. IVIg can be used in RPL patients with APS who have previously failed in other treatments. It is recommended that IVIg infusion could be considered used before conception in RPL patients who have cellular immune abnormalities such as increased natural killer (NK) cell counts, NK cell cytotoxicity, or increased T helper (Th)1/Th2 ratio, depending on the cut-off values of each hospital. The aim of this review was to summarize the mechanisms, efficacy, pharmacokinetics, and side effects associated with passive immunization using IVIg in immunologic RPL, according to the literature published in recent years. We hope that more obstetricians will be able to understand the timing and indication of IVIg properly in immunologic RPL patients and effectively enhance pregnancy outcomes for mothers and neonates.

Presumed cancer-associated retinopathy (CAR) mimicking Sudden Acquired Retinal Degeneration Syndrome (SARDS) in canines

OBJECTIVE

To describe functional and structural features of presumed cancer-associated retinopathy (CAR) mimicking sudden acquired retinal degeneration syndrome (SARDS) in dogs and describe treatment outcomes.

ANIMALS

Subjects were 17 dogs from 8 eight US states and Canada diagnosed with SARDS or immune-mediated retinitis (IMR) by 12 ophthalmologists. Nine eyes from seven deceased patients were used for microarray (MA), histology, or immunohistochemical (IHC) analysis.

PROCEDURES

Dogs underwent complete ophthalmic examination, including retinal photography, optical coherence tomography (OCT), chromatic pupil light reflex testing (cPLR), and electroretinography (ERG), in addition to complete systemic examination. Histology, microarray, and IHC analysis were performed in CAR retinas to evaluate histological and molecular changes in retinal tissue.

RESULTS

None of the patients evaluated satisfied previously established criteria for diagnosis of SARDS (flat ERG+ no red - good blue PLR), and all were diagnosed with IMR. All patients were diagnosed with a cancer: meningioma (24%), sarcoma (18%), pituitary tumor (12%), and squamous cell carcinoma (12%), other (34%). Median survival time was 6 months from diagnosis (range 1-36 months). Most frequent systemic abnormalities were as follows: proteinuria (78%); elevated liver enzymes (47%); and metabolic changes (PU/PD, polyphagia - 24%). Immunosuppressive therapy resulted in the reversal of blindness in 44% of treated patients, with 61% of all treated patients recovering and/or maintaining vision. Median time for preservation of vision was 5 months (range 1-35 months).

CONCLUSIONS

Observed changes are highly suggestive of immune-mediated damage in IMR-CAR eyes. A relatively high percentage of patients with CAR responded positively to immunosuppressive therapy.

Characteristics of Immunoglobulin M Type Antibodies of Different Origins from the Immunologic and Clinical Viewpoints and Their Application in Controlling Antibody-Mediated Allograft Rejection

Antibody-mediated allograft rejection (AMR) hinders patient prognosis after organ transplantation. Current studies concerning AMR have mainly focused on the diagnostic value of immunoglobulin G (IgG)-type donor-specific antihuman leukocyte antigen antibodies (DSAs), primarily because of their antigen specificity, whereas the clinical significance of immunoglobulin M (IgM)-type DSAs has not been thoroughly investigated in the context of organ transplantation because of their nonspecificity against antigens. Although consensus regarding the clinical significance and role of IgM antibodies is not clear, as discussed in this review, recent findings strongly suggest that they also have a huge potential in novel diagnostic as well as therapeutic application for the prevention of AMR. Most serum IgM antibodies are known to comprise natural antibodies with low affinity toward antigens, and this is derived from B-1 cells (innate B cells). However, some of the serum IgM-type antibodies reportedly also produced by B-2 cells (conventional B cells). The latter are known to have a high affinity for donor-specific antigens. In this review, we initially discuss how IgM-type antibodies of different origins participate in the pathology of various diseases, directly or through cell surface receptors, complement activation, or cytokine production. Then, we discuss the clinical applicability of B-1 and B-2 cell-derived IgM-type antibodies for controlling AMR with reference to the involvement of IgM antibodies in various pathological conditions.

Interleukin-27 levels in patients with myasthenia gravis

Interleukin-27 (IL-27), which belongs to IL-12 family, influences the function of T cells (Tregs) through regulating the expression, and function of forkhead box P3 (FoxP3). In this study, we detected the IL-27 serum levels in 59 myasthenia gravis (MG) patients and 35 healthy controls (HCs). Among them, 32 MG patients received immunoglobulin intravenous (IVIG) injections (0.4 g/kg per day for 5 consecutive days). IL-27 levels were collected before and after the treatments and subjected to a comparative study. Finally, we assessed the correlations of IL-27 levels with the clinical characteristics of MG. As a result, serum IL-27 levels were significantly higher in MG patients than those in the HCs. Meanwhile, significant reduction was detected after the IVIG treatment. IL-27 levels positively correlated with both MG activities of daily living and quantitative MG score. IL-27 may participate in the pathogenesis of MG and can be used as an early marker for the diagnosis and prognosis of MG. In addition, IL-27 can be used as a target for MG treatment through the regulation of specific immune signaling and maintaining immune homeostasis.

Comprehensive approaches for diagnosis, monitoring and treatment of chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is the most common chronic inflammatory neuropathy. CIDP is diagnosed according to the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) criteria, which combine clinical features with the electrophysiological evidence of demyelination. However, firstly, diagnosis is challenging, as some patients e.g. with severe early axonal damage do not fulfil the criteria. Secondly, objective and reliable tools to monitor the disease course are lacking. Thirdly, about 25% of CIDP patients do not respond to evidence-based first-line therapy. Recognition of these patients is difficult and treatment beyond first-line therapy is based on observational studies and case series only. Individualized immunomodulatory treatment does not exist due to the lack of understanding of essential aspects of the underlying pathophysiology.

Novel diagnostic imaging techniques and molecular approaches can help to solve these problems but do not find enough implementation. This review gives a comprehensive overview of novel diagnostic techniques and monitoring approaches for CIDP and how these can lead to individualized treatment and better understanding of pathophysiology.

Update on treatment and preventive interventions against COVID-19: an overview of potential pharmacological agents and vaccines

The outbreak of coronavirus disease 2019 (COVID-19) triggered by the new member of the coronaviridae family, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has created an unprecedented challenge for global health. In addition to mild to moderate clinical manifestations such as fever, cough, and fatigue, severe cases often developed lethal complications including acute respiratory distress syndrome (ARDS) and acute lung injury. Given the alarming rate of infection and increasing trend of mortality, the development of underlying therapeutic and preventive treatment, as well as the verification of its effectiveness, are the top priorities. Current research mainly referred to and evaluated the application of the empirical treatment based on two precedents, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), including antiviral drugs targeting different stages of virus replication, immunotherapy modulating the overactivated inflammation response, and other therapies such as herbal medicine and mesenchymal stem cells. Besides, the ongoing development of inventing prophylactic interventions such as various vaccines by companies and institutions worldwide is crucial to decline morbidity and mortality. This review mainly focused on promising candidates for the treatment of COVID-19 and collected recently updated evidence relevant to its feasibility in clinical practice in the near future.

Host-pathogen interaction in COVID-19: Pathogenesis, potential therapeutics and vaccination strategies

The current coronavirus pandemic, COVID-19, is the third outbreak of disease caused by the coronavirus family, after Severe Acute Respiratory Syndrome and Middle East Respiratory Syndrome. It is an acute infectious disease caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). This severe disease is characterised by acute respiratory distress syndrome, septic shock, metabolic acidosis, coagulation dysfunction, and multiple organ dysfunction syndromes. Currently, no drugs or vaccines exist against the disease and the only course of treatment is symptom management involving mechanical ventilation, immune suppressants, and repurposed drugs. The severe form of the disease has a relatively high mortality rate. The last six months have seen an explosion of information related to the host receptors, virus transmission, virus structure-function relationships, pathophysiology, co-morbidities, immune response, treatment and the most promising vaccines. This review takes a critically comprehensive look at various aspects of the host-pathogen interaction in COVID-19. We examine the genomic aspects of SARS-CoV-2, modulation of innate and adaptive immunity, complement-triggered microangiopathy, and host transmission modalities. We also examine its pathophysiological impact during pregnancy, in addition to emphasizing various gaps in our knowledge. The lessons learnt from various clinical trials involving repurposed drugs have been summarised. We also highlight the rationale and likely success of the most promising vaccine candidates.

Intravenous Immunoglobulin Plus Methylprednisolone Mitigate Respiratory Morbidity in Coronavirus Disease 2019

Dysregulated neutrophil and platelet interactions mediate immunothrombosis and cause lung injury in coronavirus disease 2019. IV immunoglobulin modulates neutrophil activation through FcγRIII binding. We hypothesized that early therapy with IV immunoglobulin would abrogate immunothrombosis and improve oxygenation and reduce progression to mechanical ventilation in coronavirus disease 2019 pneumonia.

DESIGN

Prospective randomized open label.

SETTING

Inpatient hospital.

PATIENTS AND INTERVENTION

Hypoxic subjects with coronavirus disease 2019 pneumonia were randomized 1:1 to receive standard of care plus IV immunoglobulin 0.5 g/kg/d with methylprednisolone 40 mg 30 minutes before infusion for 3 days versus standard of care alone.

MAIN RESULTS

Sixteen subjects received IV immunoglobulin and 17 standard of care. Median ages were 51 and 58 years for standard of care and IV immunoglobulin, respectively. Acute Physiology and Chronic Health Evaluation II and Charlson comorbidity scores were similar for IV immunoglobulin and standard of care. Seven standard of care versus two IV immunoglobulin subjects required mechanical ventilation (p = 0.12, Fisher exact test). Among subjects with A-a gradient of greater than 200 mm Hg at enrollment, the IV immunoglobulin group showed: 1) a lower rate of progression to requiring mechanical ventilation (2/14 vs 7/12, p = 0.038 Fisher exact test), 2) shorter median hospital length of stay (11 vs 19 d, p = 0.01 Mann Whitney U test), 3) shorter median ICU stay (2.5 vs 12.5 d, p = 0.006 Mann Whitey U test), and 4) greater improvement in Pao2/Fio2 at 7 days (median [range] change from time of enrollment +131 [+35 to +330] vs +44·5 [-115 to +157], p = 0.01, Mann Whitney U test) than standard of care. Pao2/Fio2 improvement at day 7 was significantly less for the standard of care patients who received glucocorticoid therapy than those in the IV immunoglobulin arm (p = 0.0057, Mann Whiney U test).

CONCLUSIONS

This pilot study showed that IV immunoglobulin significantly improved hypoxia and reduced hospital length of stay and progression to mechanical ventilation in coronavirus disease 2019 patients with A-a gradient greater than 200 mm Hg. A phase 3 multicenter randomized double-blinded clinical trial is under way to validate these findings.

Natural Antibodies: from First-Line Defense Against Pathogens to Perpetual Immune Homeostasis

Natural antibodies (nAbs) are most commonly defined as immunoglobulins present in the absence of pathological conditions or deliberate immunizations. Occurrence of nAbs in germ- and antigen-free mice suggest that their production is driven, at least in part, by self-antigens. Accordingly, nAbs are constituted of natural autoantibodies (nAAbs), and can belong to the IgM, IgG, or IgA subclasses. These nAbs provide immediate protection against infection while the adaptive arm of the immune system mounts a specific and long-term response. Beyond immediate protection from infection, nAbs have been shown to play various functional roles in the immune system, which include clearance of apoptotic debris, suppression of autoimmune and inflammatory responses, regulation of B cell responses, selection of the B cell repertoires, and regulation of B cell development. These various functions of nAbs are afforded by their reactivity, which is broad, cross-reactive, and shown to recognize evolutionarily fixed epitopes shared between foreign and self-antigens. Furthermore, nAbs have unique characteristics that also contribute to their functional roles and set them apart from antigen-specific antibodies. In further support for the role of nAbs in the protection against infections and in the maintenance of immune homeostasis, the therapeutic preparation of polyclonal immunoglobulins, intravenous immunoglobulin (IVIG), rich in nAbs is commonly used in the replacement therapy of primary and secondary immunodeficiencies and in the immunotherapy of a large number of autoimmune and inflammatory diseases. Here, we review several topics on nAbs features and functions, and therapeutic applications in human diseases.

The use of intravenous immunoglobulin gamma for the treatment of severe coronavirus disease 2019: a randomized placebo-controlled double-blind clinical trial

BACKGROUND

Coronavirus disease 2019 (COVID-19) has infected people in many countries worldwide. Discovering an effective treatment for this disease, particularly in severe cases, has become the subject of intense scientific investigation. Therefore, the objective of this study was to evaluate the efficacy of intravenous immunoglobulin (IVIg) in patients with severe COVID-19 infection.

METHODS

This study was conducted as a randomized placebo-controlled double-blind clinical trial. Fifty-nine patients with severe COVID-19 infection who did not respond to initial treatments were randomly assigned into two groups. One group received IVIg (human)-four vials daily for 3 days (in addition to initial treatment), while the other group received a placebo. Patients' demographic, clinical, and select laboratory test results, as well as the occurrence of in-hospital mortality, were recorded.

RESULTS

Among total study subjects, 30 patients received IVIg and 29 patients received a placebo. Demographics, clinical characteristics, and laboratory tests were not statistically different (P > 0.05) between the two groups. The in-hospital mortality rate was significantly lower in the IVIg group compared to the control group (6 [20.0%] vs. 14 [48.3%], respectively; P = 0.022). Multivariate regression analysis demonstrated that administration of IVIg did indeed have a significant impact on mortality rate (aOR = 0.003 [95% CI: 0.001-0.815]; P = 0.042).

CONCLUSIONS

Our study demonstrated that the administration of IVIg in patients with severe COVID-19 infection who did not respond to initial treatment could improve their clinical outcome and significantly reduce mortality rate. Further multicenter studies with larger sample sizes are nonetheless required to confirm the appropriateness of this medication as a standard treatment.

TRIAL REGISTRATION

A study protocol was registered at the Iranian Registry of Clinical Trials ( www.IRCT.ir ), number IRCT20200501047259N1 . It was registered retrospectively on May 17th, 2020.

Clinical efficacy of intravenous immunoglobulin therapy in critical ill patients with COVID-19: a multicenter retrospective cohort study

Objective

Coronavirus disease 2019 (COVID‐19) outbreak is a major challenge all over the world, without acknowledged treatment. Intravenous immunoglobulin (IVIG) has been recommended to treat critical coronavirus disease 2019 (COVID‐19) patients in a few reviews, but the clinical study evidence on its efficacy in COVID‐19 patients was lacking.

Methods

325 patients with laboratory‐confirmed critical COVID‐19 were enrolled from 4 government‐designated COVID‐19 treatment centres in southern China from December 2019 to March 2020. The primary outcomes were 28‐ and 60‐day mortality, and the secondary outcomes were the total length of in‐hospital and the total duration of the disease. Subgroup analysis was carried out according to clinical classification of COVID‐19, IVIG dosage and timing.

Results

In the enrolled 325 patients, 174 cases used IVIG and 151 cases did not. The 28‐day mortality was improved with IVIG after adjusting confounding in overall cohort (P = 0.0014), and the in‐hospital and the total duration of disease were longer in the IVIG group (P < 0.001). Subgroup analysis showed that only in patients with critical type, IVIG could significantly reduce the 28‐day mortality, decrease the inflammatory response and improve some organ functions (all P < 0.05); the application of IVIG in the early stage (admission ≤ 7 days) with a high dose (> 15 g per day) exhibited significant reduction in 60‐day mortality in the critical‐type patients.

Conclusion

Early administration of IVIG with high dose improves the prognosis of critical‐type patients with COVID‐19. This study provides important information on clinical application of IVIG in the treatment of SARS‐CoV‐2 infection, including patient selection and administration dosage and timing.

COVID-19: benefits and risks of passive immunotherapeutics

Passive immunotherapeutics (PITs), including convalescent plasma, serum, or hyperimmune immunoglobulin, have been of clinical importance during sudden outbreaks since the early twentieth century for the treatment of viral diseases such as severe acute respiratory syndrome (SARS), middle east respiratory syndrome (MERS) and swine flu (H1N1). With the recent SARS-CoV-2 pandemic, wherein effective antivirals and vaccines are still lacking, an interest in convalescent plasma therapy as a lifesaving option has resurfaced due to its capacity for antigenic neutralization and reducing viremia. This review summarizes convalescent blood products (CBPs) in terms of current technologies and the shortcomings related to the collection, manufacture, pathogen inactivation, and banking of CBPs, with a specific focus on their plausible applications, benefits, and risks in the COVID-19 pandemic.

Pharmaco-Immunomodulatory Therapy in COVID-19

The severe acute respiratory syndrome coronavirus 2 associated coronavirus disease 2019 (COVID-19) illness is a syndrome of viral replication in concert with a host inflammatory response. The cytokine storm and viral evasion of cellular immune responses may play an equally important role in the pathogenesis, clinical manifestation, and outcomes of COVID-19. Systemic proinflammatory cytokines and biomarkers are elevated as the disease progresses towards its advanced stages, and correlate with worse chances of survival. Immune modulators have the potential to inhibit cytokines and treat the cytokine storm. A literature search using PubMed, Google Scholar, and ClinicalTrials.gov was conducted through 8 July 2020 using the search terms ‘coronavirus’, ‘immunology’, ‘cytokine storm’, ‘immunomodulators’, ‘pharmacology’, ‘severe acute respiratory syndrome 2’, ‘SARS-CoV-2’, and ‘COVID-19’. Specific immune modulators include anti-cytokines such as interleukin (IL)-1 and IL-6 receptor antagonists (e.g. anakinra, tocilizumab, sarilumab, siltuximab), Janus kinase (JAK) inhibitors (e.g. baricitinib, ruxolitinib), anti-tumor necrosis factor-α (e.g. adalimumab, infliximab), granulocyte–macrophage colony-stimulating factors (e.g. gimsilumab, lenzilumab, namilumab), and convalescent plasma, with promising to negative trials and other data. Non-specific immune modulators include human immunoglobulin, corticosteroids such as dexamethasone, interferons, statins, angiotensin pathway modulators, macrolides (e.g. azithromycin, clarithromycin), hydroxychloroquine and chloroquine, colchicine, and prostaglandin D2 modulators such as ramatroban. Dexamethasone 6 mg once daily (either by mouth or by intravenous injection) for 10 days may result in a reduction in mortality in COVID-19 patients by one-third for patients on ventilators, and by one-fifth for those receiving oxygen. Research efforts should focus not only on the most relevant immunomodulatory strategies but also on the optimal timing of such interventions to maximize therapeutic outcomes. In this review, we discuss the potential role and safety of these agents in the management of severe COVID-19, and their impact on survival and clinical symptoms.

Efficacy and safety of human intravenous immunoglobulin 5% (Ig VENA) in pediatric patients affected by primary immunodeficiency

Patients affected by primary immunodeficiencies are characterized for high susceptibility for severe infections. Our data demonstrate Kedrion 5% intravenous immunoglobulin G (IVIg) treatment effective and safe as replacement therapy for children and adolescents affected by primary immunodeficiency. The particularities of our study are the selection of a long period of follow-up (71 patient-years of follow-up), and to the best of our knowledge, our study is one of few that assesses the safety and efficacy of intravenous immunoglobulin treatment of primary immunodeficiency specifically in a pediatric population.

COVID-19: Transmission, prevention, and potential therapeutic opportunities

The novel coronavirus disease (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains a global challenge. Despite intense research efforts worldwide, an effective vaccine and viable treatment options have eluded investigators. Therefore, infection prevention, early viral detection and identification of successful treatment protocols provide the best approach in controlling disease spread. In this review, current therapeutic options, preventive methods and transmission routes of COVID-19 are discussed.

Intravenous Immunoglobulin G Suppresses Heat Shock Protein (HSP)-70 Expression and Enhances the Activity of HSP90 and Proteasome Inhibitors

Intravenous immunoglobulin G (IVIgG) is approved for primary immunodeficiency syndromes but may induce anti-cancer effects, and while this has been attributed to its anti-inflammatory properties, IgG against specific tumor targets may play a role. We evaluated IVIgG alone, and with a Heat shock protein (HSP)-90 or proteasome inhibitor, using multiple myeloma and mantle cell lymphoma (MCL) cells in vitro, and with the proteasome inhibitor bortezomib in vivo. IVIgG inhibited the growth of all cell lines tested, induced G₁ cell cycle arrest, and suppressed pro-tumor cytokines including Interleukin (IL)-6, IL-8, and IL-10. Genomic and proteomic studies showed that IVIgG reduced tumor cell HSP70-1 levels by suppressing the ability of extracellular HSP70-1 to stimulate endogenous HSP70-1 promoter activity, and reduced extracellular vesicle uptake. Preparations of IVIgG were found to contain high titers of anti-HSP70-1 IgG, and recombinant HSP70-1 reduced the efficacy of IVIgG to suppress HSP70-1 levels. Combining IVIgG with the HSP90 inhibitor AUY922 produced superior cell growth inhibition and correlated with HSP70-1 suppression. Also, IVIgG with bortezomib or carfilzomib was superior to each single agent, and enhanced bortezomib's activity in bortezomib-resistant myeloma cells. Moreover, IVIgG reduced transfer of extracellular vesicles (EVs) to cells, and blocked transfer of bortezomib resistance through EVs. Finally, IVIgG with bortezomib were superior to the single agents in an in vivo myeloma model. These studies support the possibility that anti-HSP70-1 IgG contained in IVIgG can inhibit myeloma and MCL growth by interfering with a novel mechanism involving uptake of exogenous HSP70-1 which then induces its own promoter.

COVID-19 treatment: close to a cure? A rapid review of pharmacotherapies for the novel coronavirus (SARS-CoV-2)

Currently, there is no approved therapy for coronavirus disease 2019 (COVID-19). The World Health Organization (WHO) therefore endorses supportive care only. However, frontline clinicians and researchers have been experimenting with several virus-based and host-based therapeutics since the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in China. China's National Health Commission has issued the first COVID-19 treatment guidelines with therapy suggestions, which has inspired clinical studies worldwide. This review evaluates the major therapeutics. Key evidence from in vitro research, animal models and clinical research in emerging coronaviruses is examined. The antiviral therapies remdesivir, lopinavir/ritonavir and umifenovir, if considered, should be initiated before the peak of viral replication for an optimal outcome. Ribavirin may be beneficial as an add-on therapy but is ineffective as monotherapy. Corticosteroid use should be limited to specific co-morbidities. Intravenous immunoglobulin (IVIg) is not recommended owing to lack of data in COVID-19. The traditional Chinese medicine Xuebijing may benefit patients with complications of bacterial pneumonia or sepsis. The efficacy of interferon is unclear owing to conflicting outcomes in coronavirus studies. Chloroquine and hydroxychloroquine have shown in vitro inhibition of SARS-CoV-2, but studies on their clinical efficacy and whether the benefits outweigh the risk of dysrhythmias remain inconclusive. For patients who develop cytokine release syndrome, interleukin-6 inhibitors may be beneficial.

Treatment Options for COVID-19: A Review

Background: The recent COVID-19 pandemic sweeping the globe has caused great concern worldwide. Due to the limited evidence available on the dynamics of the virus and effective treatment options available, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had a huge impact in terms of morbidity and mortality. The economic impact is still to be assessed. Aims: The purpose of this article is to review the evidence for the multiple treatment options available, to consider the future of this global pandemic, and to identify some potential options that could revolutionize the treatment of COVID-19. Moreover, this article underscores the sheer importance of repurposing some of the available antiviral and antimicrobial agents that have long been in use so as to have an effective and expeditious response to this widespread pandemic and the need to conduct a multicenter global randomized controlled trial to find an effective single antiviral agent or a cocktail of available antimicrobial agents. Method: We thoroughly searched and reviewed various case reports, retrospective analyses, and in vitro studies published in PubMed, EMBASE, and Google Scholar regarding the treatment options used for SARS-CoV, MERS-CoV, and SARS-CoV-2 since its outbreak in an attempt to highlight treatments with the most promising results. Conclusion: We are currently facing one of the worst pandemics in history. Although SARS-CoV-2 is associated with a lower mortality rate than are SARS-CoV and MERS-CoV, its higher infectivity is making it a far more serious threat. Unfortunately, no vaccine against SARS-CoV-2 or effective drug regimen for COVID-19 currently exists. Drug repurposing of available antiviral agents may provide a respite; moreover, a cocktail of antiviral agents may be helpful in treating this disease. Here, we have highlighted a few available antimicrobial agents that could be very effective in treating COVID-19; indeed, a number of trials are underway to detect and confirm the efficacy of these agents.

Immunoglobulins with Non-Canonical Functions in Inflammatory and Autoimmune Disease States

Immunoglobulins are known to combine various effector mechanisms of the adaptive and the innate immune system. Classical immunoglobulin functions are associated with antigen recognition and the initiation of innate immune responses. However, in addition to classical functions, antibodies exhibit a variety of non-canonical functions related to the destruction of various pathogens due to catalytic activity and cofactor effects, the action of antibodies as agonists/antagonists of various receptors, the control of bacterial diversity of the intestine, etc. Canonical and non-canonical functions reflect the extreme human antibody repertoire and the variety of antibody types generated in the organism: antigen-specific, natural, polyreactive, broadly neutralizing, homophilic, bispecific and catalytic. The therapeutic effects of intravenous immunoglobulins (IVIg) are associated with both the canonical and non-canonical functions of antibodies. In this review, catalytic antibodies will be considered in more detail, since their formation is associated with inflammatory and autoimmune diseases. We will systematically summarize the diversity of catalytic antibodies in normal and pathological conditions. Translational perspectives of knowledge about natural antibodies for IVIg therapy will be also discussed.

Dissecting the mechanism of action of intravenous immunoglobulin in human autoimmune disease: Lessons from therapeutic modalities targeting Fcγ receptors

Since the first description of the administration of high doses of pooled serum IgG, also referred to as intravenous IgG (IVIg) therapy, as being able to ameliorate various autoimmune diseases, researchers have been investigating which molecular and cellular pathways underlie IVIg activity. Apart from trying to understand the obvious conundrum that IgG can trigger both autoimmune pathology and resolution of inflammation, the rapidly expanding use of IVIg has led to a lack of availability of this primary blood product, providing a strong rationale for developing recombinant alternatives. During the last decade, a tremendous number of novel insights into IVIg activity brought the goal of replacing IVIg within reach, at least in select indications, and has led to the initiation of several clinical trials. At the forefront of this effort is the modulation of autoantibody half-life and blocking access of autoantibodies to fragment cystallizable γ receptors (Fcγ receptors). In this rostrum article, we will briefly discuss current models of IVIg activity, followed by a more specific focus on novel therapeutic avenues that are entering the clinic and may replace IVIg in the future.

Noteworthy Neurological Manifestations Associated With COVID-19 Infection

March 11, 2020, marked the start of the coronavirus disease 2019 (COVID-19) pandemic. COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was being reported as severe respiratory illness. However, since the recognition of this novel virus, there has been a constant realization that it may present or manifest in a multitude of ways. At first, the typical signs and symptoms were what one would expect from a respiratory virus: cough, shortness of breath, and fever. However, as the disease became more prevalent, neurologic symptoms were reported such as headaches, hypogeusia, and hyposmia. This case report aims to add to the growing body of neurologic manifestations by presenting two cases, Bell's palsy and Guillain-Barre Syndrome. Each case involves flaccid paralysis as the primary presentation.

Fc Gamma Receptors and Their Role in Antigen Uptake, Presentation, and T Cell Activation

The cellular uptake, intracellular processing, and presentation of foreign antigen are crucial processes for eliciting an effective adaptive host response to the majority of pathogens. The effective recognition of antigen by T cells requires that it is first processed and then presented on MHC molecules that are expressed on other cells. A critical step leading to the presentation of antigen is delivering the foreign cargo to an intracellular compartment where the antigen can be processed and loaded onto MHC molecules. Fc-gamma receptors (FcγRs) recognize IgG-coated targets, such as opsonized pathogens or immune complexes (ICs). Cross-linking leads to internalization of the cargo with associated activation of down-stream signaling cascades. FcγRs vary in their affinity for IgG and intracellular trafficking, and therefore have an opportunity to regulate antigen presentation by controlling the shuttling and processing of their cargos. In this way, they critically influence physiological and pathophysiological adaptive immune cell functions. In this review, we will cover the contribution of FcγRs to antigen-presentation with a focus on the intracellular trafficking of IgG-ICs and the pathways that support this function. We will also discuss genetic evidence linking FcγR biology to immune cell activation and autoimmune processes as exemplified by systemic lupus erythematosus (SLE).

Immunomodulatory therapy for the management of severe COVID-19. Beyond the anti-viral therapy: A comprehensive review

Severe Acute Respiratory Syndrome related to Coronavirus-2 (SARS-CoV-2), coronavirus disease-2019 (COVID-19) may cause severe illness in 20% of patients. This may be in part due to an uncontrolled immune-response to SARS-CoV-2 infection triggering a systemic hyperinflammatory response, the so-called "cytokine storm". The reduction of this inflammatory immune-response could be considered as a potential therapeutic target against severe COVID-19. The relationship between inflammation and clot activation must also be considered. Furthermore, we must keep in mind that currently, no specific antiviral treatment is available for SARS-CoV-2. While moderate-severe forms need in-hospital surveillance plus antivirals and/or hydroxychloroquine; in severe and life-threating subsets a high intensity anti-inflammatory and immunomodulatory therapy could be a therapeutic option. However, right data on the effectiveness of different immunomodulating drugs are scarce. Herein, we discuss the pathogenesis and the possible role played by drugs such as: antimalarials, anti-IL6, anti-IL-1, calcineurin and JAK inhibitors, corticosteroids, immunoglobulins, heparins, angiotensin-converting enzyme agonists and statins in severe COVID-19.

The anti-viral facet of anti-rheumatic drugs: Lessons from COVID-19

The outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has posed the world at a pandemic risk. Coronavirus-19 disease (COVID-19) is an infectious disease caused by SARS-CoV-2, which causes pneumonia, requires intensive care unit hospitalization in about 10% of cases and can lead to a fatal outcome. Several efforts are currently made to find a treatment for COVID-19 patients. So far, several anti-viral and immunosuppressive or immunomodulating drugs have demonstrated some efficacy on COVID-19 both in vitro and in animal models as well as in cases series. In COVID-19 patients a pro-inflammatory status with high levels of interleukin (IL)-1B, IL-1 receptor (R)A and tumor necrosis factor (TNF)-α has been demonstrated. Moreover, high levels of IL-6 and TNF-α have been observed in patients requiring intensive-care-unit hospitalization. This provided rationale for the use of anti-rheumatic drugs as potential treatments for this severe viral infection. Other agents, such as hydroxychloroquine and chloroquine might have a direct anti-viral effect. The anti-viral aspect of immunosuppressants towards a variety of viruses has been known since long time and it is herein discussed in the view of searching for a potential treatment for SARS-CoV-2 infection.

Acute Inflammation and Elevated Cardiac Markers in a Two-Month-Old Infant with Severe Acute Respiratory Syndrome Coronavirus 2 Infection Presenting with Cardiac Symptoms

Severe acute respiratory syndrome coronavirus 2 infection in children mainly shows a milder course. In complicated cases, it is unknown whether inflammation is predictive of disease severity, as in adults. Moreover, cardiac involvement is anecdotally described. We report the case of a 2-month-old infant with severe acute respiratory syndrome coronavirus 2 infection presenting with fever, tachycardia and elevated interleukin-6, who was diagnosed with myocarditis and treated with immunoglobulins.

Antibodies and Immunity During Kawasaki Disease

The cause of Kawasaki disease (KD), the leading cause of acquired heart disease in children, is currently unknown. Epidemiology studies support that an infectious disease is involved in at least starting the inflammatory cascade set off during KD. Clues from epidemiology support that humoral immunity can have a protective effect. However, the role of the immune system, particularly of B cells and antibodies, in pathogenesis of KD is still unclear. Intravenous immunoglobulin (IVIG) and other therapies targeted at modulating inflammation can prevent development of coronary aneurysms. A number of autoantibody responses have been reported in children with KD and antibodies have been generated from aneurysmal plasma cell infiltrates. Recent reports show that children with KD have similar plasmablast responses as other children with infectious diseases, further supporting an infectious starting point. As ongoing studies are attempting to identify the etiology of KD through study of antibody responses, we sought to review the role of humoral immunity in KD pathogenesis, treatment, and recovery.

Adjunct Immunotherapies for the Management of Severely Ill COVID-19 Patients

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It has infected millions, with more than 275,000 fatal cases as of May 8, 2020. Currently, there are no specific COVID-19 therapies. Most patients depend on mechanical ventilation. Current COVID-19 data clearly highlight that cytokine storm and activated immune cell migration to the lungs characterize the early immune response to COVID-19 that causes severe lung damage and development of acute respiratory distress syndrome. In view of uncertainty associated with immunosuppressive treatments, such as corticosteroids and their possible secondary effects, including risks of secondary infections, we suggest immunotherapies as an adjunct therapy in severe COVID-19 cases. Such immunotherapies based on inflammatory cytokine neutralization, immunomodulation, and passive viral neutralization not only reduce inflammation, inflammation-associated lung damage, or viral load but could also prevent intensive care unit hospitalization and dependency on mechanical ventilation, both of which are limited resources.

Impact of immune enhancement on Covid-19 polyclonal hyperimmune globulin therapy and vaccine development

The pandemic spread of a novel coronavirus - SARS coronavirus-2 (SARS-CoV-2) as a cause of acute respiratory illness, named Covid-19, is placing the healthcare systems of many countries under unprecedented stress. Global economies are also spiraling towards a recession in fear of this new life-threatening disease. Vaccines that prevent SARS-CoV-2 infection and therapeutics that reduces the risk of severe Covid-19 are thus urgently needed. A rapid method to derive antiviral treatment for Covid-19 is the use of convalescent plasma derived hyperimmune globulin. However, both hyperimmune globulin and vaccine development face a common hurdle - the risk of antibody-mediated disease enhancement. The goal of this review is to examine the body of evidence supporting the hypothesis of immune enhancement that could be pertinent to Covid-19. We also discuss how this risk could be mitigated so that both hyperimmune globulin and vaccines could be rapidly translated to overcome the current global health crisis.

Do different IgG repertoires play a role in B- and T-cell functional modulation during ontogeny? The "hooks without bait" theory

The mechanisms by which immunoglobulin (Ig)G can modulate immunity have been investigated over the past few decades. In the past three years, some studies have demonstrated that IgG can play a pivotal role in mediating complex interactions that result in functional lymphocyte modulation during maturation in self or offspring primary lymphoid organs. This effect appears to be dependent on the IgG repertoire in the absence of the influence of antigens and the functionality of diverse cell populations, including B, αβT (CD4 T and CD8 T), invariant natural killer T and γδT cells, in mice and humans. Based on the literature, especially on findings resulting from the therapeutic use of purified IgG (intravenous Ig) and recent pieces of evidence obtained by my group, the "hooks without bait" theory is described here to guide the future development of therapies for specific immune regulation.

Treatment with intravenous immunoglobulin increases the level of small EVs in plasma of pregnant women with recurrent pregnancy loss

Extracellular vesicles (EVs), which are small cell-derived compartments, take part in numerous different physiological processes. The contents of EVs reveal the cell of origin and indicates pathophysiological states in different diseases. In pregnancy disorders, changes have been reported in the composition, bioactivity and concentration of placental and non-placental EVs. The purpose of this study was to monitor the effects on EVs in patients receiving intravenous immunoglobulin (IVIG) or placebo (albumin) treatment due to recurrent pregnancy loss (RPL). In a placebo-controlled trial study of IVIG treatment, plasma collected from 39 women with RPL were investigated using the Extracellular Vesicle Array (EV Array). Plasma was sampled consecutively (from gestational week (GW) 5) and the protein phenotypes of the smaller EVs (sEVs) were analyzed for the presence of 34 markers. The levels of sEVs or changes in their levels in early pregnancy were correlated with treatment. There was statistically significant increased levels of sEVs in patients who received IVIG versus placebo. In conclusion, the treatment with high-doses of IVIG clearly boosted the production and release of sEVs to the circulation; however, the biological role of this boost remains to be clarified in further studies.

Could Intravenous Immunoglobulin Collected from Recovered Coronavirus Patients Protect against COVID-19 and Strengthen the Immune System of New Patients?

The emergence of the novel coronavirus in Wuhan, China, which causes severe respiratory tract infections in humans (COVID-19), has become a global health concern. Most coronaviruses infect animals but can evolve into strains that cross the species barrier and infect humans. At the present, there is no single specific vaccine or efficient antiviral therapy against COVID-19. Recently, we showed that intravenous immunoglobulin (IVIg) treatment reduces inflammation of intestinal epithelial cells and eliminates overgrowth of the opportunistic human fungal pathogen Candida albicans in the murine gut. Immunotherapy with IVIg could be employed to neutralize COVID-19. However, the efficacy of IVIg would be better if the immune IgG antibodies were collected from patients who have recovered from COVID-19 in the same city, or the surrounding area, in order to increase the chance of neutralizing the virus. These immune IgG antibodies will be specific against COVID-19 by boosting the immune response in newly infected patients. Different procedures may be used to remove or inactivate any possible pathogens from the plasma of recovered coronavirus patient derived immune IgG, including solvent/detergent, 60 °C heat-treatment, and nanofiltration. Overall, immunotherapy with immune IgG antibodies combined with antiviral drugs may be an alternative treatment against COVID-19 until stronger options such as vaccines are available.

Could Intravenous Immunoglobulin Collected from Recovered Coronavirus Patients Protect against COVID-19 and Strengthen the Immune System of New Patients?

The emergence of the novel coronavirus in Wuhan, China, which causes severe respiratory tract infections in humans (COVID-19), has become a global health concern. Most coronaviruses infect animals but can evolve into strains that cross the species barrier and infect humans. At the present, there is no single specific vaccine or efficient antiviral therapy against COVID-19. Recently, we showed that intravenous immunoglobulin (IVIg) treatment reduces inflammation of intestinal epithelial cells and eliminates overgrowth of the opportunistic human fungal pathogen Candida albicans in the murine gut. Immunotherapy with IVIg could be employed to neutralize COVID-19. However, the efficacy of IVIg would be better if the immune IgG antibodies were collected from patients who have recovered from COVID-19 in the same city, or the surrounding area, in order to increase the chance of neutralizing the virus. These immune IgG antibodies will be specific against COVID-19 by boosting the immune response in newly infected patients. Different procedures may be used to remove or inactivate any possible pathogens from the plasma of recovered coronavirus patient derived immune IgG, including solvent/detergent, 60 °C heat-treatment, and nanofiltration. Overall, immunotherapy with immune IgG antibodies combined with antiviral drugs may be an alternative treatment against COVID-19 until stronger options such as vaccines are available.

High-Dose Intravenous Immunoglobulin as a Therapeutic Option for Deteriorating Patients With Coronavirus Disease 2019

The outbreak of coronavirus disease 2019 (COVID-19) has spread rapidly in China. Until now, no definite effective treatment has been identified. We reported on 3 patients with severe COVID-19 who received high-dose intravenous immunoglobulin (IVIg) with satisfactory recovery. Based on these observations, randomized studies of high-dose IVIg should be considered in deteriorating patients infected with COVID-19.

Therapeutic normal IgG intravenous immunoglobulin activates Wnt-β-catenin pathway in dendritic cells

Therapeutic normal IgG intravenous immunoglobulin (IVIG) is a well-established first-line immunotherapy for many autoimmune and inflammatory diseases. Though several mechanisms have been proposed for the anti-inflammatory actions of IVIG, associated signaling pathways are not well studied. As β-catenin, the central component of the canonical Wnt pathway, plays an important role in imparting tolerogenic properties to dendritic cells (DCs) and in reducing inflammation, we explored whether IVIG induces the β-catenin pathway to exert anti-inflammatory effects. We show that IVIG in an IgG-sialylation independent manner activates β-catenin in human DCs along with upregulation of Wnt5a secretion. Mechanistically, β-catenin activation by IVIG requires intact IgG and LRP5/6 co-receptors, but FcγRIIA and Syk are not implicated. Despite induction of β-catenin, this pathway is dispensable for anti-inflammatory actions of IVIG in vitro and for mediating the protection against experimental autoimmune encephalomyelitis in vivo in mice, and reciprocal regulation of effector Th17/Th1 and regulatory T cells.