IVIG-mediated effector functions in autoimmune and inflammatory diseases

Recent advances in treatment Crimean-Congo hemorrhagic fever virus: A concise overview

The Crimean Congo Hemorrhagic Fever Virus (CCHFV) is widespread in Africa, Asia, and Europe, among other places. The disease was initially discovered in the Crimean cities of the Soviet Union and the Congo, and it was given the name Crimean Congo because it induces hemorrhagic fever. According to studies, when the virus enters the body, it settles in immune cells such as macrophages and dendritic cells, causing them to malfunction and secrete inflammatory cytokines such as TNF-alpha, IL1, and IL6, resulting in cytokine storms that induces shock via endothelial activation and vascular leakage, while on the other hand, clots and disseminated intravascular coagulation (DIC) formation causes massive defects in various organs such as the liver and kidneys, as well as fatal bleeding. Disease prevention and treatment are crucial since no other effective vaccination against the disease has yet been developed. Immunotherapy is utilized as a consequence. One of the most effective treatments, when combined with compensatory therapies such as blood and platelet replacement, water, electrolytes, Fresh Frozen Plasma (FFP) replacement, and other compensatory therapies, is one of the most effective treatments. Studies; show that immunotherapy using IVIG and neutralizing and non-neutralizing monoclonal antibodies; cytokine therapy, and anti-inflammatory therapy using corticosteroids are effective ways to treat the disease.

Intramuscular administration of autologous total immunoglobulin G induces immunomodulatory effects on T cells in healthy human subjects: An open-labeled prospective single-arm trial

BACKGROUND

We hypothesized that intramuscular administration of autologous total immunoglobulin G (IgG) could induce an immunomodulatory effect in human subjects. In our previous studies, we showed that intramuscular administration of autologous total IgG could induce significant clinical improvements and increases of the serum levels of interleukin-10 (IL-10) and interferon-gamma (IFN-γ) in patients with atopic dermatitis.

OBJECTIVE

To investigate the mechanism of immunomodulation induced by intramuscular administration of autologous total IgG, we evaluated changes in T cells before and after intramuscular administrations of autologous total IgG in this study.

METHODS

Thirteen healthy adults received 8 intramuscular injections of 50 mg autologous total IgG for 4 weeks (from week 0 to week 4). The percentages of IL-10- or IFN-γ-producing peripheral blood T cells, as well as serum levels of IL-10, IFN-γ, and immunoglobulins, were measured at baseline (week 0) and at weeks 4, 8, and 12.

RESULTS

The percentage of IL-10-producing CD4+ T cells was significantly increased at weeks 8 and 12 compared to baseline (P < .05), while the percentage of IFN-γ-producing CD3+ T cells was significantly increased at week 12 compared to baseline (P < .05). There were no significant differences in the serum levels of IL-10, IFN-γ, and immunoglobulins before and after intramuscular administration of autologous total IgG (P > .05). No serious adverse events were observed.

CONCLUSION

Intramuscular administration of autologous total IgG induced immunomodulatory effects on T cells in healthy human subjects. This simple intervention could be a safe, effective, and economical T cell immunomodulation method for human subjects (NCT03695757).

Efficacy and safety of intravenous immunoglobulin for treating refractory livedoid vasculopathy: a systematic review

Introduction:

Intravenous immunoglobulin (IVIG) was reported to be the third most used monotherapy in livedoid vasculopathy (LV). There is currently a lack of randomized controlled clinical trials and no standardized therapeutic regimen for IVIG therapy in LV.

Methods:

We performed a systematic review of the efficacy and safety of IVIG in treating patients with LV using PubMed, Cochrane, and Embase databases.

Results:

Eighty LV patients from 17 articles were included, receiving IVIG therapy at a dose of 1–2.1 g/kg body weight every 4 weeks. The effective rate of IVIG therapy in LV patients was 95% (76/80) in published studies, showing a good clinical response for resolution of pain, skin ulcerations, and neurological symptoms, and reducing the dependence on glucocorticoids and immunosuppressive agents. IVIG therapy was well tolerated, and no severe adverse events were observed.

Conclusion:

Overall, to a certain degree, IVIG is probably a safe and effective treatment alternative for refractory LV patients, which still need to be confirmed by large-scale randomized controlled clinical trials.

Vaccination and immunotherapies in neuroimmunological diseases

Neuroimmunological diseases and their treatment compromise the immune system, thereby increasing the risk of infections and serious illness. Consequently, vaccinations to protect against infections are an important part of the clinical management of these diseases. However, the wide variety of immunotherapies that are currently used to treat neuroimmunological disease — particularly multiple sclerosis and neuromyelitis optica spectrum disorders — can also impair immunological responses to vaccinations. In this Review, we discuss what is known about the effects of various immunotherapies on immunological responses to vaccines and what these effects mean for the safe and effective use of vaccines in patients with a neuroimmunological disease. The success of vaccination in patients receiving immunotherapy largely depends on the specific mode of action of the immunotherapy. To minimize the risk of infection when using immunotherapy, assessment of immune status and exclusion of underlying chronic infections before initiation of therapy are essential. Selection of the required vaccinations and leaving appropriate time intervals between vaccination and administration of immunotherapy can help to safeguard patients. We also discuss the rapidly evolving knowledge of how immunotherapies affect responses to SARS-CoV-2 vaccines and how these effects should influence the management of patients on these therapies during the COVID-19 pandemic.

In this Review, the authors discuss how various immunotherapies for neuroimmunological diseases interact with vaccination responses, including responses to SARS-CoV-2 vaccinations, and the implications for the safe and effective use of vaccines in patients with these diseases.

Vaccination against infection is an essential part of the management of neuroimmunological diseases.

All indicated vaccinations should be administered before initiation of immunotherapy whenever possible; appropriate intervals between vaccination and treatment vary with treatment and vaccination.

Inactivated vaccines are considered safe in neuroimmunological diseases but live vaccines are generally contraindicated during immunotherapy.

Vaccination responses during immunotherapy can be diminished or abrogated, depending on the treatment and vaccination; antibody titre testing to monitor responses can be considered where appropriate.

Vaccinations must be avoided during relapses or exacerbations of neuroimmunological diseases.

Vaccination against SARS-CoV-2 is recommended for patients with neuroimmunological disease but some immunotherapies limit the immune response; therefore, timing should be considered carefully.

[The efficacy of eculizumab against post-thymectomy exacerbations in thymoma associated myasthenia gravis (MG)]

We report a 62-year-old woman with thymoma associated myasthenia gravis (MG). She had significant dysphagia and was treated with corticosteroids, intravenous immunoglobulin (IVIG), immunoadsorption plasmapheresis (IAPP), and immunosuppressive drugs, and the extended thymectomy. Her symptoms gradually improved, but 3 weeks after thymectomy, her bulbar symptoms recurred. Although she was treated with repeated IVIG and IAPP, her symptom remained. Finally, after starting eculizumab did her symptoms go into complete remission. This case suggests the efficacy of anti-complement therapy for postoperative exacerbation of MG.

The safety and efficacy of intravenous immunoglobulin in autoimmune encephalitis

OBJECTIVE

Although intravenous immunoglobulin (IVIG) is the first-line immunotherapy in autoimmune encephalitis, all supporting evidence comes from retrospective case series. Here, we performed a prospective clinical trial of IVIG for functional recovery in autoimmune encephalitis.

METHODS

This single-arm, open-label study assessed the efficacy and safety of 10% intravenous IVIG treatment in newly diagnosed patients with possible autoimmune encephalitis. Patients received IVIG (0.4 g/kg/day) for 5 days. Rescue immunotherapy was permitted when the patient deteriorated before day 8 or showed no improvement at day 8. The primary outcome was the change in the modified Rankin Scale (mRS) score at day 8 and 29. The secondary outcomes were the mRS score improvement and the score changes and improvements on four other clinical scales.

RESULTS

Overall, 23 patients received IVIG (intension-to-treat, ITT), and 18 patients completed the study according to the protocol (per-protocol, PP). mRS improved significantly at days 8 and 29 compared to baseline in both the ITT and PP populations. Other secondary outcomes also improved significantly at day 8, 15, and 29 versus baseline. In the PP population, 6/18 patients achieved favorable outcomes with IVIG alone (mRS = 0~2 at day 8), and 12/18 patients received rescue immunotherapy. Five adverse events were reported in relation to IVIG, all of which were mild.

INTERPRETATION

IVIG improved neurological functional outcomes, and the improvement was evident by day 8. Adverse effects were tolerable. These data provide the prospective evidence regarding the efficacy of IVIG in improving the functional outcomes of autoimmune encephalitis.

Intravenous immunoglobulins improve live birth rate among women with underlying immune conditions and recurrent pregnancy loss: a systematic review and meta-analysis

Intravenous immunoglobulin (IVIG) is increasingly used as a treatment for recurrent pregnancy loss (RPL) despite lack of clear evidence on efficacy. Recent data suggest IVIG might be more effective in a subgroup of women with an aberrant immunological profile. Therefore, a systematic review and meta-analysis of studies on the effectiveness of IVIG treatment on pregnancy outcome among women with RPL and underlying immunological conditions (e.g., elevated NK cell percentage, elevated Th1/Th2 ratio, diagnosis with autoimmune disorders) was conducted. Eight non-randomized controlled trials, including 478 women (intervention: 284; control: 194), met eligibility criteria. Meta-analysis showed that treatment with IVIG was associated with a two-fold increase in live birth rate (RR 1.98, 95% CI 1.44–2.73, P < 0.0001). The effect of IVIG was particularly marked in the subgroup of studies including patients based on presence of elevated (> 12%) NK-cell percentage (RR 2.32, 95% CI 1.77–3.02, P < 0.0001) and when starting intervention prior to or during cycle of conception (RR 4.47, 95% CI 1.53–13.05, P = 0.006). In conclusion, treatment with IVIG may improve live birth rate in women with RPL and underlying immune conditions. However, these results should be interpreted with caution as studies are limited by low number of participants and the non-randomized design, which represent seriously biases. Future randomized controlled trials in women with RPL and underlying immune conditions are needed before using IVIG in a clinical setting.

LGI1 antibody encephalitis: acute treatment comparisons and outcome

OBJECTIVE

To compare acute treatment responses and long-term outcome in leucine-rich glioma-inactivated 1 (LGI1) antibody encephalitis.

METHODS

Retrospective case series of 118 patients with LGI1 antibody encephalitis evaluated at Mayo Clinic across all US sites from 1 May 2008 to 31 March 2019. Patient clinical data were identified and analysed through the neuroimmunology laboratory and electronic medical record. LGI1 antibody detection was by cell-based indirect immunofluorescence assay of serum, cerebrospinal fluid or both. Clinical outcomes were faciobrachial dystonic seizure (FBDS) resolution, modified Rankin Scale (mRS) score, Kokmen Short Test of Mental Status (STMS) score (0-38 point scale) and neuropsychometric testing results.

RESULTS

Compared with intravenous immunoglobulin (IVIg) (n=21), patients treated with single-agent acute corticosteroids (intravenous, oral or both) (n=49) were more likely to experience resolution of FBDS (61% vs 7%, p=0.002) and improvements in mRS score (ΔmRS score 2 vs 0, p=0.008) and median Kokmen STMS scores (ΔKokmen STMS score 5 points vs 0 points, p=0.01). In 54 patients with long-term follow-up (≥2 years), the median mRS score was 1 (range 0-6) and the median Kokmen STMS score was 36 (range 24-38) after all combinations of immunotherapy. Neuropsychometric testing in 32 patients with long-term follow-up (≥2 years) demonstrated short-term memory impairments in 37%.

CONCLUSIONS

Corticosteroids appeared more effective acutely than IVIg in improving LGI1 antibody encephalitis in this retrospective comparison of immunotherapies. While improvement with immunotherapy is typical and long-term outcome is favourable, short-term memory deficits are noted in approximately a third of the patients.

Kawasaki disease in childhood and psychiatric disorders: A population-based case-control prospective study in Taiwan

BACKGROUND

Kawasaki disease (KD) is a common childhood acute inflammatory disease and potentially triggers a chronic inflammation. Although some researches have investigated neurodevelopmental consequences following KD, the findings have been inconsistent. This is the first population-based study targeted on KD and common psychiatric disorders.

OBJECTIVES

We aimed to investigate the association between KD and psychiatric disorders and hypothesized that standard anti-inflammatory treatment by intravenous immunoglobulin (IVIG) may protect against development of psychiatric disorders.

METHOD

We retrieved data from Taiwan's National Health Insurance Research database (NHIRD). Patients (n = 282,513) with psychiatric disorders (the case group) during 1997-2013 were included, and the control group was matched with age, sex, income and urbanization (1:1). We calculated the prevalence of KD in both groups and estimated odd ratios (ORs) and 95% confidence intervals (CIs) in the subgroup analyses for KD in conditions of age, severity, and common psychiatric comorbidity.

RESULTS

Numbers of patients with KD were 460 in the cases and 380 in the controls (p = .006), and the crude OR of KD was 1.21 times greater (95% CI = 1.06-1.39, p = .006) in the case than the control groups. KD patients without IVIG treatment (n = 126) were higher in the cases than those in the controls (n = 54), with the OR of 2.33 (95% CI = 1.70-3.21, p < .0001). Subgroup analyses showed that KD survivors were at significant risk for autism spectrum disorders (ASD) (OR = 2.15, 95% CI = 1.27-3.65; p = .005) and attention deficit and hyperactivity disorders (ADHD) (OR = 1.19, 95% CI = 1.02-1.39; p = 0.03), and a trend of increased risk for anxiety disorders (OR = 1.36, 95%CI = 0.99-1.86; p = 0.05).

CONCLUSIONS

Patients with KD were more likely to have comorbid psychiatric disorders, including ASD and ADHD. Moreover, anti-inflammatory treatment with IVIG may have potential prophylactic effects against the development of psychiatric disorders.

Tocilizumab in the management of posttransfusion hyperhemolysis syndrome in sickle cell disease: The experience so far

BACKGROUND

Posttransfusion hyperhemolysis syndrome is a rare but life-threatening form of delayed hemolytic transfusion reaction with lysis of both transfused and autologous red cells, seen predominantly in patients with sickle cell disease. Macrophage activation is thought to play a major role in its pathophysiology. Standard treatment is with intravenous immunoglobulin and steroids but refractory cases pose a major clinical problem. Tocilizumab is a humanized monoclonal antibody against the IL-6 receptor that can inhibit IL-6 induced macrophage activation.

METHODS AND MATERIALS

We describe the case of a 33-year-old woman with sickle cell anemia and posttransfusion hyper hemolysis syndrome refractory to standard therapy, treated with Tocilizumab. We also review all cases reported in the literature where Tocilizumab was used for posttransfusion hyperhemolysis.

RESULTS

Treatment with Tocilizumab was well tolerated with no observed adverse events. There was no further drop in Hb after day 2 of treatment with subsequent continuous gradual improvement. Her bilirubin dropped significantly after the first dose and continued to improve, while ferritin and LDH reduced significantly after day 2 of treatment with Tocilizumab and continued to drop thereafter. Like in our case, all other cases in the literature where Tocilizumab was used for posttransfusion hyperhemolysis led to rapid clinical responses and no adverse events.

DISCUSSION

Even though the number of cases of posttransfusion hyper hemolysis syndrome treated with Tocilizumab are few, they have all been associated with rapid clinical responses with no observed adverse events suggesting that the role of Tocilizumab in this context needs to be further explored.

Enhanced Immunomodulatory Effect of Intravenous Immunoglobulin by Fc Galactosylation and Nonfucosylation

Intravenous immunoglobulin (IVIG) is used as an immunomodulatory agent in the treatment of various autoimmune/inflammatory diseases although its mechanism of action remains elusive. Recently, nonfucosylated IgG has been shown to be preferentially bound to Fcγ receptor IIIa (FcγRIIIa) on circulating natural killer cells; therefore, we hypothesized that nonfucosylated IVIG may modulate immune responses through FcγRIIIa blockade. Here, homogeneous fucosylated or nonfucosylated glycoforms of normal polyclonal IgG bearing sialylated, galactosylated or nongalactosylated Fc oligosaccharides were generated by chemoenzymatic glycoengineering to investigate whether the IgG glycoforms can inhibit antibody-dependent cellular cytotoxicity (ADCC). Among the six IgG glycoforms, galactosylated, nonfucosylated IgG [(G2)₂] had the highest affinity to FcγRIIIa and 20 times higher potency to inhibit ADCC than native IgG. A pilot study of IVIG treatment in mice with collagen antibody-induced arthritis highlighted the low-dose (G2)₂ glycoform of IVIG (0.1 g/kg) as an effective immunomodulatory agent as the 10-fold higher dose of native IVIG. These preliminary results suggest that the anti-inflammatory activity of IVIG is in part mediated via activating FcγR blockade by galactosylated, nonfucosylated IgG and that such nonfucosylated IgG glycoforms bound to FcγRs on immune cells play immunomodulatory roles in health and disease. This study provides insights into improved therapeutic strategies for autoimmune/inflammatory diseases using glycoengineered IVIG and recombinant Fc.

Pathogenesis, Diagnosis and Management of Obstetric Antiphospholipid Syndrome: A Comprehensive Review

Antiphospholipid syndrome is an autoimmune disorder characterized by vascular thrombosis and/or pregnancy morbidity associated with persistent antiphospholipid antibody positivity. Cases fulfilling the Sydney criteria for obstetric morbidity with no previous thrombosis are known as obstetric antiphospholipid syndrome (OAPS). OAPS is the most identified cause of recurrent pregnancy loss and late-pregnancy morbidity related to placental injury. Cases with incomplete clinical or laboratory data are classified as obstetric morbidity APS (OMAPS) and non-criteria OAPS (NC-OAPS), respectively. Inflammatory and thrombotic mechanisms are involved in the pathophysiology of OAPS. Trophoblasts, endothelium, platelets and innate immune cells are key cellular players. Complement activation plays a crucial pathogenic role. Secondary placental thrombosis appears by clot formation in response to tissue factor activation. New risk assessment tools could improve the prediction of obstetric complication recurrences or thromboses. The standard-of-care treatment consists of low-dose aspirin and prophylactic low molecular weight heparin. In refractory cases, the addition of hydroxychloroquine, low-dose prednisone or IVIG improve pregnancy outcomes. Statins and eculizumab are currently being tested for treating selected OAPS women. Finally, we revisited recent insights and concerns about the pathophysiology, diagnosis and management of OAPS.

Systemic Sclerosis: From Pathophysiology to Novel Therapeutic Approaches

Systemic sclerosis (SSc) is a systemic, immune-mediated chronic disorder characterized by small vessel alterations and progressive fibrosis of the skin and internal organs. The combination of a predisposing genetic background and triggering factors that causes a persistent activation of immune system at microvascular and tissue level is thought to be the pathogenetic driver of SSc. Endothelial alterations with subsequent myofibroblast activation, excessive extracellular matrix (ECM) deposition, and unrestrained tissue fibrosis are the pathogenetic steps responsible for the clinical manifestations of this disease, which can be highly heterogeneous according to the different entity of each pathogenic step in individual subjects. Although substantial progress has been made in the management of SSc in recent years, disease-modifying therapies are still lacking. Several molecular pathways involved in SSc pathogenesis are currently under evaluation as possible therapeutic targets in clinical trials. These include drugs targeting fibrotic and metabolic pathways (e.g., TGF-β, autotaxin/LPA, melanocortin, and mTOR), as well as molecules and cells involved in the persistent activation of the immune system (e.g., IL4/IL13, IL23, JAK/STAT, B cells, and plasma cells). In this review, we provide an overview of the most promising therapeutic targets that could improve the future clinical management of SSc.

Nano Differential Scanning Fluorimetry-Based Thermal Stability Screening and Optimal Buffer Selection for Immunoglobulin G

Nano differential scanning fluorimetry (nanoDSF) is a high-throughput protein stability screening technique that simultaneously monitors protein unfolding and aggregation properties. The thermal stability of immunoglobulin G (IgG) was investigated in three different buffers (sodium acetate, sodium citrate, and sodium phosphate) ranging from pH 4 to 8. In all three buffers, the midpoint temperature of thermal unfolding (T_m) showed a tendency to increase as the pH increased, but the aggregation propensity was different depending on the buffer species. The best stability against aggregation was obtained in the sodium acetate buffers below pH 4.6. On the other hand, IgG in the sodium citrate buffer had higher aggregation and viscosity than in the sodium acetate buffer at the same pH. Difference of aggregation between acetate and citrate buffers at the same pH could be explained by a protein-protein interaction study, performed with dynamic light scattering, which suggested that intermolecular interaction is attractive in citrate buffer but repulsive in acetate buffer. In conclusion, this study indicates that the sodium acetate buffer at pH 4.6 is suitable for IgG formulation, and the nanoDSF method is a powerful tool for thermal stability screening and optimal buffer selection in antibody formulations.

The Functional Role of IgA in the IgM/IgA-Enriched Immunoglobulin Preparation Trimodulin

In comparison to human immunoglobulin (Ig) G, antibodies of IgA class are not well investigated. In line with this, the functional role of the IgA component in IgM/IgA-enriched immunoglobulin preparations is also largely unknown. In recent years, powerful anti-pathogenic and immunomodulatory properties of human serum IgA especially on neutrophil function were unraveled. Therefore, the aim of our work is to investigate functional aspects of the trimodulin IgA component, a new plasma-derived polyvalent immunoglobulin preparation containing ~56% IgG, ~23% IgM and ~21% IgA. The functional role of IgA was investigated by analyzing the interaction of IgA with FcαRI, comparing trimodulin with standard intravenous IgG (IVIG) preparation and investigating Fc receptor (FcR)-dependent functions by excluding IgM-mediated effects. Trimodulin demonstrated potent immunomodulatory, as well as anti-pathogenic effects in our neutrophil model (neutrophil-like HL-60 cells). The IgA component of trimodulin was shown to induce a strong FcαRI-dependent inhibitory immunoreceptor tyrosine-based activation motif (ITAMi) signaling, counteract lipopolysaccharide-induced inflammation and mediate phagocytosis of Staphylococcus aureus. The fine-tuned balance between immunomodulatory and anti-pathogenic effects of trimodulin were shown to be dose-dependent. Summarized, our data demonstrate the functional role of IgA in trimodulin, highlighting the importance of this immunoglobulin class in immunoglobulin therapy.

Intravenous Ig Regulates Anti-Desmoglein 3 IgG Production in B220- Antibody-Producing Cells in Mice with Pemphigus Vulgaris

Intravenous Ig (IVIG) is a treatment option for intractable cases of pemphigus vulgaris (PV), an autoimmune blistering disease caused by autoantibodies against desmoglein 3 (DSG3). To investigate the efficacy of IVIG on autoantibody secretion, we produced PV model mice by adoptive transfer of immunized Dsg3^-/- splenocytes to Rag2^-/- mice. We found that circulating anti-DSG3 IgG ELISA titer decreased in PV model mice after 5 days of treatment with IVIG compared with PBS-treated mice, whereas the F(ab')₂ fragment did not suppress the anti-DSG3 IgG titer. enzyme-linked immunospot assay revealed that IVIG treatment reduced the frequency of anti-DSG3 antibody-secreting cells in the spleen but not in lymph nodes and bone marrow. Moreover, this reduction was observed only in the splenic B220^- fraction but not in the B220⁺ fraction. Furthermore, IVIG decreased the serum levels of anti-DSG3 IgG, even after a significant reduction of its titer, owing to antibody-mediated CD20⁺ B cell depletion. In addition, IVIG suppressed anti-DSG3 IgG production in B220^-CD138⁺ plasma cells derived from PV model mice ex vivo. These results indicate that IVIG reduced autoantibody production in B220^- cells containing plasma cells in PV model mice, and this function may indicate one of the mechanisms of action of IVIG on PV.

B and T Immunoregulation: A New Insight of B Regulatory Lymphocytes in Autism Spectrum Disorder

Introduction: Autism Spectrum Disorder (ASD) is a heterogeneous neurodevelopmental disorder characterized by a complex pathogenesis, by impairment social communication and interaction, and may also manifest repetitive patterns of behavior. Many studies have recognized an alteration of the immune response as a major etiological component in ASDs. Despite this, it is still unclear the variation of the function of the immune response.

Aim: Our aim is to investigate the levels of immunological markers in peripheral blood of children with ASD such as: regulatory B and T cells, memory B and natural killer (NK) cells.

Materials and Methods: We assessed various subsets of immune cells in peripheral blood (regulatory B and T cells, B-cell memory and natural killer cells) by multi-parametric flow cytometric analysis in 26 ASD children compared to 16 healthy controls (HCs) who matched age and gender.

Results: No significant difference was observed between B-cell memory and NK cells in ASDs and HCs. Instead, regulatory B cells and T cells were decreased (p < 0.05) in ASD subjects when compared to HCs.

Discussion: Regulatory B and T cells have a strategic role in maintaining the immune homeostasis. Their functions have been associated with the development of multiple pathologies especially in autoimmune diseases. According to our study, the immunological imbalance of regulatory B and T cells may play a pivotal role in the evolution of the disease, as immune deficiencies could be related to the severity of the ongoing disorder.

Cancer-Cell-Derived IgG and Its Potential Role in Tumor Development

Human immunoglobulin G (IgG) is the primary component of the human serum antibody fraction, representing about 75% of the immunoglobulins and 10-20% of the total circulating plasma proteins. Generally, IgG sequences are highly conserved, yet the four subclasses, IgG1, IgG2, IgG3, and IgG4, differ in their physiological effector functions by binding to different IgG-Fc receptors (FcγR). Thus, despite a similarity of about 90% on the amino acid level, each subclass possesses a unique manner of antigen binding and immune complex formation. Triggering FcγR-expressing cells results in a wide range of responses, including phagocytosis, antibody-dependent cell-mediated cytotoxicity, and complement activation. Textbook knowledge implies that only B lymphocytes are capable of producing antibodies, which recognize specific antigenic structures derived from pathogens and infected endogenous or tumorigenic cells. Here, we review recent discoveries, including our own observations, about misplaced IgG expression in tumor cells. Various studies described the presence of IgG in tumor cells using immunohistology and established correlations between high antibody levels and promotion of cancer cell proliferation, invasion, and poor clinical prognosis for the respective tumor patients. Furthermore, blocking tumor-cell-derived IgG inhibited tumor cells. Tumor-cell-derived IgG might impede antigen-dependent cellular cytotoxicity by binding antigens while, at the same time, lacking the capacity for complement activation. These findings recommend tumor-cell-derived IgG as a potential therapeutic target. The observed uniqueness of Ig heavy chains expressed by tumor cells, using PCR with V(D)J rearrangement specific primers, suggests that this specific part of IgG may additionally play a role as a potential tumor marker and, thus, also qualify for the neoantigen category.

Unraveling the mechanisms of IVIG immunotherapy in MIS-C

In The Journal of Clinical Investigation, Zhu et al.¹ report that intravenous immunoglobulin (IVIG) targets IL-1β⁺ neutrophils to exert anti-inflammatory effects in multisystem inflammatory syndrome in children (MIS-C), a post-infectious inflammatory condition associated with COVID-19.

The autoimmune signature of hyperinflammatory multisystem inflammatory syndrome in children

Multisystem inflammatory syndrome in children (MIS-C) manifests as a severe and uncontrolled inflammatory response with multiorgan involvement, occurring weeks after SARS-CoV-2 infection. Here, we utilized proteomics, RNA sequencing, autoantibody arrays, and B cell receptor (BCR) repertoire analysis to characterize MIS-C immunopathogenesis and identify factors contributing to severe manifestations and intensive care unit admission. Inflammation markers, humoral immune responses, neutrophil activation, and complement and coagulation pathways were highly enriched in MIS-C patient serum, with a more hyperinflammatory profile in severe than in mild MIS-C cases. We identified a strong autoimmune signature in MIS-C, with autoantibodies targeted to both ubiquitously expressed and tissue-specific antigens, suggesting autoantigen release and excessive antigenic drive may result from systemic tissue damage. We further identified a cluster of patients with enhanced neutrophil responses as well as high anti-Spike IgG and autoantibody titers. BCR sequencing of these patients identified a strong imprint of antigenic drive with substantial BCR sequence connectivity and usage of autoimmunity-associated immunoglobulin heavy chain variable region (IGHV) genes. This cluster was linked to a TRBV11-2 expanded T cell receptor (TCR) repertoire, consistent with previous studies indicating a superantigen-driven pathogenic process. Overall, we identify a combination of pathogenic pathways that culminate in MIS-C and may inform treatment.

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.

Recent advances in antibody-based immunotherapy strategies for COVID-19

The emergence of a new acute respiratory syndrome Coronavirus 2 (SARS-CoV-2), the cause of the 2019-nCOV disease (COVID-19), has caused a pandemic and a global health crisis. Rapid human-to-human transmission, even from asymptomatic individuals, has led to the quick spread of the virus worldwide, causing a wide range of clinical manifestations from cold-like symptoms to severe pneumonia, acute respiratory distress syndrome (ARDS), multiorgan injury, and even death. Therefore, using rapid and accurate diagnostic methods to identify the virus and subsequently select appropriate and effective treatments can help improvement of patients and control the pandemic. So far, various treatment regimens along with prophylactic vaccines have been developed to manage COVID-19-infected patients. Among these, antibody-based therapies, including neutralizing antibodies (against different parts of the virus), polyclonal and monoclonal antibodies, plasma therapy, and high-dose intravenous immunoglobulin (IVIG) have shown promising outcomes in accelerating and improving the treatment process of patients, avoiding the viral spreading widely, and managing the pandemic. In the current review paper, different types and applications of therapeutic antibodies in the COVID-19 treatment are comprehensively discussed.

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.

A monocyte/dendritic cell molecular signature of SARS-CoV-2-related multisystem inflammatory syndrome in children with severe myocarditis

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children is generally milder than in adults, but a proportion of cases result in hyperinflammatory conditions often including myocarditis.

Methods

To better understand these cases, we applied a multiparametric approach to the study of blood cells of 56 children hospitalized with suspicion of SARS-CoV-2 infection. Plasma cytokine and chemokine levels and blood cellular composition were measured, alongside gene expression at the bulk and single-cell levels.

Findings

The most severe forms of multisystem inflammatory syndrome in children (MIS-C) related to SARS-CoV-2 that resulted in myocarditis were characterized by elevated levels of pro-angiogenesis cytokines and several chemokines. Single-cell transcriptomics analyses identified a unique monocyte/dendritic cell gene signature that correlated with the occurrence of severe myocarditis characterized by sustained nuclear factor κB (NF-κB) activity and tumor necrosis factor alpha (TNF-α) signaling and associated with decreased gene expression of NF-κB inhibitors. We also found a weak response to type I and type II interferons, hyperinflammation, and response to oxidative stress related to increased HIF-1α and Vascular endothelial growth factor (VEGF) signaling.

Conclusions

These results provide potential for a better understanding of disease pathophysiology.

Funding

Agence National de la Recherche (Institut Hospitalo-Universitaire Imagine, grant ANR-10-IAHU-01; Recherche Hospitalo-Universitaire, grant ANR-18-RHUS-0010; Laboratoire d’Excellence ‘‘Milieu Intérieur,” grant ANR-10-LABX-69-01; ANR-flash Covid19 “AIROCovid” and “CoVarImm”), Institut National de la Santé et de la Recherche Médicale (INSERM), and the “URGENCE COVID-19” fundraising campaign of Institut Pasteur.

Children with SARS-CoV-2 infection were initially thought to have only mild COVID-19 symptoms. However, several weeks into the first wave of SARS-CoV-2 infections, there was a surge of a postacute pathology called multisystem inflammatory syndrome in children (MIS-C). The authors recruited a cohort of children with suspicion of SARS-CoV-2 infection and uncovered hyperinflammation, hypoxic conditions, exacerbation of TNF-α signaling via NF-κB, and absence of responses to type I and type II IFN secretion in the most severe forms of MIS-C with severe myocarditis. This work led the authors to identify in monocytes and validate in peripheral blood mononuclear cells a molecular signature of 25 genes that allows discrimination of the most severe forms of MIS-C with myocarditis.

Intravenous immunoglobulin for corticosteroid-resistant intestinal Henoch-Schönlein purpura: worth a controlled trial against corticosteroids?

OBJECTIVES

Henoch-Schönlein purpura (HScP) may present in children with severe, occasionally refractory, gastrointestinal (GI) involvement. The use of corticosteroids (CSs) is commonplace in the management of the disease, but to date no standardized protocol is available and, although rare, resistance to CS therapy may be challenging to clinicians. IVIG has been proposed as an effective alternative to CSs, but to date no controlled trial has been conducted to ascertain their real efficacy. We share our personal experience of successful IVIG treatment in two cases of GI HScP, comparing it with similar experiences reported in literature.

METHODS

Retrospective clinical data collection, comparison with available literature.

RESULTS

We describe two children with severe HScP GI vasculitis refractory to high-dose intravenous CSs that responded rapidly to IVIG administration, with complete recovery within a few days. Patient characteristics and response to IVIG administration were comparable to those of other previously reported cases.

CONCLUSION

Our observation confirms that IVIG may be useful in the treatment of CS-resistant HScP-related GI vasculitis in children, and highlights the need for more structured research, including a randomized trial against CSs, in order to ascertain their real effectiveness.

Severe COVID-19: Immunosuppression or Hyperinflammation?

ABSTRACT

The ongoing coronavirus disease 2019 (COVID-19) pandemic has swept over the world and causes thousands of deaths. Although the clinical features of COVID-19 become much clearer than before, there are still further problems with the pathophysiological process and treatments of severe patients. One primary problem is with the paradoxical immune states in severe patients with COVID-19. Studies indicate that Severe Acute Respiratory Syndrome Coronavirus 2 can attack the immune system, manifested as a state of immunosuppression with a decrease in lymphocytes, whereas a state of hyperinflammation, presenting as elevated cytokine levels, is also detected in COVID-19. Therefore, discussing the specific status of immunity in COVID-19 will contribute to the understanding of its pathophysiology and the search for appropriate treatments. Here, we review all the available literature concerning the different immune states in COVID-19 and the underlying pathophysiological mechanisms. In addition, the association between immune states and the development and severity of disease as well as the impact on the selection of immunotherapy strategies are discussed in our review.

Rapid and regenerable surface plasmon resonance determinations of biomarker concentration and biomolecular interaction based on tris-nitrilotriacetic acid chips

The tris-nitrilotriacetic acid (tris-NTA) chip has been used for surface plasmon resonance (SPR) kinetic studies involving histidine (His)-tagged proteins. However, its full potential, especially for analyte quantification in complex biological media, has not been realized due to a lack of systematic studies on the factors governing ligand immobilization, surface regeneration, and data analysis. We demonstrate that the tris-NTA chip not only retains His-tagged proteins more strongly than its mono-NTA counterpart, but also orients them more uniformly than protein molecules coupled to carboxymethylated dextran films. We accurately and rapidly quantified immunoglobulin (IgG) molecules in sera by using the initial association phase of their conjugation with His-tagged protein G densely immobilized onto the tris-NTA chip, and established criteria for selecting the optimal time for constructing the calibration curve. The method is highly reproducible (less than 2% RSD) and three orders of magnitude more sensitive than immunoturbidimetry. In addition, we found that the amount of His-protein immobilized is highly dependent on the protein isoelectric point (pI). Reliable kinetic data in a multi-channel SPR instrument can also be rapidly obtained by using a low density of immobilized His-tagged protein. The experimental parameters and procedures outlined in this study help expand the range of SPR applications involving His-tagged proteins.

Intravenous immunoglobulins do not prove beneficial to reduce alloimmunity among kidney transplant recipients with BKV-associated nephropathy

Reduced immunosuppression during BKV-DNAemia has been associated with T-cell mediated rejection (TCMR), de novo donor-specific antibodies (DSA) and antibody-mediated rejection (ABMR). Intravenous immunoglobulins (IVIG) may reduce alloimmunity. We studied 860 kidney transplant recipients (KTRs) for the development of BKV-DNAuria and BKV-DNAemia (low-level <10 000 IE/ml, high-level >10 000 IE/ml). 52/131 KTRs with high-level BKV-DNAemia received IVIG. The HLA-related immunological risk was stratified by the Predicted Indirectly Recognizable HLA Epitopes (PIRCHE) algorithm. BKV-DNAuria only was observed in 86 KTRs (10.0%), low-level BKV-DNAemia in 180 KTRs (20.9%) and high-level BKV-DNAemia in 131 KTRs (15.2%). KTRs with low-level BKV-DNAemia showed significantly less TCMR compared to KTRs with high-level BKV-DNAemia (5.2% vs. 25.5%; P < 0.001) and no BKV-replication (13.2%; P = 0.014), lowest rates of de novo DSA (21.3%), ABMR (9.2%) and flattest glomerular filtration rate (GFR) slope (-0.8 ml/min). KTRs with low-level BKV-DNAemia showed significantly higher median (interquartile range) total PIRCHE if they developed TCMR [100.22 (72.6) vs. 69.52 (49.97); P = 0.020] or ABMR [128.86 (52.99) vs. 69.52 (49.96); P = 0.005]. Administration of IVIG did not shorten duration of BKV-DNAemia (P = 0.798) or reduce TCMR, de novo DSA and ABMR (P > 0.05). KTRs with low-level BKV-DNAemia showed best protection against alloimmunity, with a high number of PIRCHE co-determining the remaining risk. The administration of IVIG, however, was not beneficial in reducing alloimmunity.

Thromboembolic complications following intravenous immunoglobulin therapy in immune-mediated neurological disorders

BACKGROUND

Minor adverse events of intravenous immunoglobulin (IVIg) include flu-like symptoms, eczematous skin reaction, electrolyte disturbance, and transient leukopenia. On rare occasions, serious complications such as aseptic meningitis, arrhythmia, decrease in blood pressure, and thromboembolic complications (TEC) have been described. The current study aimed to understand the frequency and clinical features of TEC related to IVIg administration in patients with immune-mediated neurological disorders.

METHODS

We conducted a retrospective chart review of hospitalized patients with immune-mediated neuromuscular or neuroimmunological disorders treated with IVIg from January 2018 to March 2020 in a single tertiary hospital.

RESULTS

During the study period, 61 patients were treated with a total of 364 IVIg infusions over 84 treatment courses. Among them, we identified 3 TEC cases that occurred during or after the completion of IVIg therapy: two patients with myasthenia gravis (F/60 and F/80) and one patient with Guillain-Barré syndrome (F/79) had undergone arterial TEC (two for ischemic stroke and one for pulmonary thromboembolism). The rates of TEC per patient, per treatment course, and per infusion were 4.91% (3/61), 3.57% (3/84), and 0.82% (3/364), respectively.

CONCLUSION

The risk of developing TEC upon receiving IVIg infusions is generally low in patients with immune-mediated neurological disorders; however, IVIg-related TEC should be cautiously monitored for in critically ill elderly patients with vascular risk factors, especially those suffering from myasthenic crisis.

Immunomodulation: Immunoglobulin Preparations Suppress Hyperinflammation in a COVID-19 Model via FcγRIIA and FcαRI

The rapid spread of SARS-CoV-2 has induced a global pandemic. Severe forms of COVID-19 are characterized by dysregulated immune response and "cytokine storm". The role of IgG and IgM antibodies in COVID-19 pathology is reasonably well studied, whereas IgA is neglected. To improve clinical outcome of patients, immune modulatory drugs appear to be beneficial. Such drugs include intravenous immunoglobulin preparations, which were successfully tested in severe COVID-19 patients. Here we established a versatile in vitro model to study inflammatory as well as anti-inflammatory processes by therapeutic human immunoglobulins. We dissect the inflammatory activation on neutrophil-like HL60 cells, using an immune complex consisting of latex beads coated with spike protein of SARS-CoV-2 and opsonized with specific immunoglobulins from convalescent plasma. Our data clarifies the role of Fc-receptor-dependent phagocytosis via IgA-FcαRI and IgG-FcγR for COVID-19 disease followed by cytokine release. We show that COVID-19 associated inflammation could be reduced by addition of human immunoglobulin preparations (IVIG and trimodulin), while trimodulin elicits stronger immune modulation by more powerful ITAMi signaling. Besides IgG, the IgA component of trimodulin in particular, is of functional relevance for immune modulation in this assay setup, highlighting the need to study IgA mediated immune response.

The Perfect Storm: A Rheumatologist's Point of View on COVID-19 Infection

The new coronavirus infection (Covid-19) is a pandemic that has affected the whole world and progresses with high morbidity and mortality. It has a high contagion rate and a course capable of rapid lung involvement with severe acute respiratory distress syndrome (ARDS) and pulmonary insufficiency. A severe clinical picture develops as a result of a "perfect cytokine storm" which results from possible immunological mechanisms triggered by the viral infection. Immune system dysregulation and possible autoinflammatory and autoimmune mechanisms are responsible for a higher amount of cytokines release from immune cells. Although no clear treatment of Covid-19 infection has emerged yet, it is argued that some disease-modifying anti-rheumatic drugs (DMARDs) may be effective in addition to anti-viral treatments. These drugs (anti-malarial drugs, colchicum dispert, biologics) have been well known to rheumatologists for years because they are used in the treatment of many inflammatory rheumatologic diseases. Another important issue is whether DMARDs, which can cause severe immunosuppression, pose a risk for Covid-19 infection and whether they have been discontinued beforehand. Although there are insufficient data on this subject, considering the risk of disease reactivation, patients may continue their DMARDs treatment under the supervision of a rheumatologist. In this article, the possible immunological mechanisms in the pathogenesis of Covid-19 infection and the efficacy and safety of various DMARDs used in the treatment are discussed from a rheumatologist's perspective in the light of recent literature data.

The "Intermediate" CD14 + CD16 + monocyte subpopulation plays a role in IVIG responsiveness of children with Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is an acute, self-limited febrile illness of unknown cause. Intravenous immunoglobulin (IVIG)-resistance are related to greater risk for permanent cardiac complications. We aimed to determine the correlation between monocytes and the phenotype of KD in relation to IVIG responsiveness in children.

MATERIALS AND METHODS

The study cohort included 62 patients who were diagnosed with KD, 20 non febrile healthy controls (NFC), and 15 other febrile controls (OFC). In all enrolled patients, blood was taken at least 4 times and laboratory tests were performed. In addition, subtypes of monocytes were characterized via flow cytometry.

RESULTS

The numbers of intermediate monocytes were significantly lower in IVIG-resistant group compared to IVIG-responsive group before IVIG infusion (p < 0.0001). After infusion, intermediate monocytes decreased in the responsive group, while a trend of increase was observed in the resistant group. Only intermediate monocytes were significant in logistic regression with adjusted OR of 0.001 and p value of 0.03.

CONCLUSIONS

CD14 + CD16 + intermediate monocyte may play an important role in IVIG responsiveness among KD children. Low starting levels of intermediate monocytes, followed by a dramatic increase post-IVIG infusion during acute phase of KD are associated with IVIG-resistance. Functional studies on intermediate monocyte may help to reveal the pathophysiology.

The Trilogy of SARS-CoV-2 in Pediatrics (Part 2): Multisystem Inflammatory Syndrome in Children

Multisystem Inflammatory Syndrome in Children (MIS-C) was first recognized as a novel illness in 2020 with manifestations similar to other hyperinflammatory syndromes, such as Kawasaki disease or macrophage activation syndrome. Severity varies from a self-limited febrile illness to shock requiring inotropes and mechanical ventilation. Gastrointestinal symptoms and persistent fevers are the most common clinical symptoms, with the addition of cardiac manifestations inclusive of ventricular dysfunction and coronary artery aneurysms. With no controlled trials or comparative effectiveness studies evaluating treatment of MIS-C to date, current treatment with immunomodulatory agents has mainly been derived from previous experience treating Kawasaki disease. This article provides a comprehensive review summarizing published data for the evaluation and management of MIS-C, with a focus on pharmacotherapy treatment considerations.

Immune-Based Therapy for COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel zoonotic virus identified as the cause of coronavirus disease 2019 (COVID-19) that has crossed species and infected humans. In order to develop new insights on the immune-based treatments against this disease, it is vital to understand the immunopathology of the COVID-19, implications of the immune response to SARS-CoV-2, and immune dysfunction in response to SARS-CoV-2. There is no approved drug for the treatment of COVID-19. It is, thus, promising to design immune-based treatments that inhibit the infectious mechanism of the virus, improve the inadequate immune response, or regulate the hyperactivated immune response in severely ill patients. According to the antiviral immune response against the virus, antibody-based immunotherapies of COVID-19 include injection of convalescent plasma from recovered patients, high-dose intravenous immunoglobulins (IVIG), monoclonal antibodies, and polyclonal antibodies. Also, cell-based treatment, vaccine-based approaches, cytokine-based immunotherapy, immune checkpoint inhibitors, JAK inhibitors, decoy receptors, and immunosuppressive drugs are discussed in this chapter.

Boolean analysis of the transcriptomic data to identify novel biomarkers of IVIG response

Intravenous immunoglobulin (IVIG) is used to treat several autoimmune and inflammatory diseases, but some patients are refractory to IVIG and require alternative treatments. Identifying a biomarker that could segregate IVIG responders from non-responders has been a subject of intense research. Unfortunately, previous transcriptomic studies aimed at addressing IVIG resistance have failed to predict a biomarker that could identify IVIG-non-responders. Therefore, we used a novel data mining technique on the publicly available transcriptomic data of Kawasaki disease (KD) patients treated with IVIG to identify potential biomarkers of IVIG response. By studying the boolean patterns hidden in the expression profiles of KD patients undergoing IVIG therapy, we have identified new metabolic pathways implicated in IVIG resistance in KD. These pathways could be used as biomarkers to segregate IVIG non-responders from responders prior to IVIG infusion. Also, boolean analysis of the transcriptomic data could be further extended to identify a universal biomarker that might predict IVIG response in other autoimmune diseases.

Lupus acute cardiomyopathy is highly responsive to intravenous immunoglobulin treatment: Case series and literature review

INTRODUCTION

Intravenous immunoglobulin (IVIg) is currently used with considerable success for the treatment of many autoimmune diseases, including systemic lupus erythematosus (SLE). Among its various indications, IVIg has also been found to be beneficial in myocarditis, whether or not it is associated with an autoimmune disease. Nevertheless, data regarding IVIg treatment for myocarditis/cardiomyopathy in patients with SLE are sparse. The objective of this case series was to describe our experience with IVIg as a treatment for lupus myocarditis and to review the literature for IVIg for this indication.

PATIENT CONCERNS

We report 5 female patients with SLE, who presented with signs of acute heart failure including pulmonary congestion and arrhythmias.

DIAGNOSIS

Echocardiography demonstrated new reduced left ventricular ejection fraction of 20% to 30%. Two patients underwent coronary artery angiography, which demonstrated normal coronary arteries, supporting the diagnosis of myocarditis or nonischemic cardiomyopathy.

INTERVENTIONS

High-dose IVIg treatment was initiated in all 5 patients.

OUTCOMES

Following the treatment, clinical and echocardiographic improvement in cardiac function occurred within a few days to 1 month. This dramatic improvement persisted for several years.

CONCLUSION

Based on our case series, we believe that IVIg has an important role in the management of lupus acute cardiomyopathy. This safe, well-tolerated optional treatment should be considered, especially in severe cases.

A Narrative Review of a Pulmonary Aerosolized Formulation or a Nasal Drop Using Sera Containing Neutralizing Antibodies Collected from COVID-19-Recovered Patients as a Probable Therapy for COVID-19

Coronavirus disease 2019 (COVID-19) emerged as a new contagion during December 2019, since which time it has triggered a rampant spike in fatality rates worldwide due to insufficient medical treatments and a lack of counteragents and prompted the World Health Organization to declare COVID-19 a public health emergency. It is, therefore, vital to accelerate the screening of new molecules or vaccines to win the battle against this pandemic. Experiences from previous epidemiological data on coronaviruses guide investigators in designing and exploring new compounds for a safe and cost-effective treatment. Several reports on the severe acute respiratory syndrome (SARS) epidemic indicate that severe acute respiratory syndrome coronavirus (SARS-CoV) and the novel COVID-19 use angiotensin-converting enzyme 2 (ACE2) as a receptor for binding to the host cell in the lung epithelia through the spike protein on their virion surface. ACE2 is a mono-carboxypeptidase best known for cleaving major peptides and substrates. Its degree in human airway epithelia positively correlates with coronavirus infection. The treatment approach can be the neutralization of the virus entering lung epithelial cells by using sera containing antibodies collected from COVID-19-recovered patients. Hence, we herein propose a pulmonary aerosolized formulation or a nasal drop using sera, which contain antibodies to prevent, treat, or immunize against COVID-19 infection.

The Role of Lectin Receptors and Their Ligands in Controlling Allergic Inflammation

More than fifty c-type lectin receptors (CLR) are known and have been identified so far. Moreover, we know the group of galectins and sialic acid-binding immunoglobulin-type lectins that also belong to the carbohydrate-binding receptors of the immune system. Thus, the lectin receptors form the largest receptor family among the pathogen recognition receptors. Similar to the toll-like receptors (TLRs), the CLR do not only recognize foreign but also endogenous molecules. In contrast to TLRs, which have a predominantly activating effect on the immune system, lectin receptors also mediate inhibitory signals. They play an important role in innate and adaptive immunity for the induction, regulation and shaping of the immune response. The hygiene hypothesis links enhanced infection to protection from allergic disease. Yet, the microbial substances that are responsible for mediating this allergy-protective activity still have to be identified. Microbes contain both ligands binding to TLRs and carbohydrates that are recognized by CLR and other lectin receptors. In the current literature, the CLR are often recognized as the ‘bad guys’ in allergic inflammation, because some glycoepitopes of allergens have been shown to bind to CLR, facilitating their uptake and presentation. On the other hand, there are many reports revealing that sugar moieties are involved in immune regulation. In this review, we will summarize what is known about the role of carbohydrate interaction with c-type lectins and other sugar-recognizing receptors in anti-inflammation, with a special focus on the regulation of the allergic immune response.

Therapies for Chronic Allograft Rejection

Remarkable advances have been made in the pathophysiology, diagnosis, and treatment of antibody-mediated rejection (ABMR) over the past decades, leading to improved graft outcomes. However, long-term failure is still high and effective treatment for chronic ABMR, an important cause of graft failure, has not yet been identified. Chronic ABMR has a relatively different phenotype from active ABMR and is a slowly progressive disease in which graft injury is mainly caused by de novo donor specific antibodies (DSA). Since most trials of current immunosuppressive therapies for rejection have focused on active ABMR, treatment strategies based on those data might be less effective in chronic ABMR. A better understanding of chronic ABMR may serve as a bridge in establishing treatment strategies to improve graft outcomes. In this in-depth review, we focus on the pathophysiology and characteristics of chronic ABMR along with the newly revised Banff criteria in 2017. In addition, in terms of chronic ABMR, we identify the reasons for the resistance of current immunosuppressive therapies and look at ongoing research that could play a role in setting better treatment strategies in the future. Finally, we review non-invasive biomarkers as tools to monitor for rejection.

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, was being reported as a 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.

Human immunology and immunotherapy: main achievements and challenges

The immune system is a fascinating world of cells, soluble factors, interacting cells, and tissues, all of which are interconnected. The highly complex nature of the immune system makes it difficult to view it as a whole, but researchers are now trying to put all the pieces of the puzzle together to obtain a more complete picture. The development of new specialized equipment and immunological techniques, genetic approaches, animal models, and a long list of monoclonal antibodies, among many other factors, are improving our knowledge of this sophisticated system. The different types of cell subsets, soluble factors, membrane molecules, and cell functionalities are some aspects that we are starting to understand, together with their roles in health, aging, and illness. This knowledge is filling many of the gaps, and in some cases, it has led to changes in our previous assumptions; e.g., adaptive immune cells were previously thought to be unique memory cells until trained innate immunity was observed, and several innate immune cells with features similar to those of cytokine-secreting T cells have been discovered. Moreover, we have improved our knowledge not only regarding immune-mediated illnesses and how the immune system works and interacts with other systems and components (such as the microbiome) but also in terms of ways to manipulate this system through immunotherapy. The development of different types of immunotherapies, including vaccines (prophylactic and therapeutic), and the use of pathogens, monoclonal antibodies, recombinant proteins, cytokines, and cellular immunotherapies, are changing the way in which we approach many diseases, especially cancer.

Case Report: Improvement Following Immunotherapy in an Individual With Seronegative Down Syndrome Disintegrative Disorder

Down syndrome disintegrative disorder (DSDD) is a condition of unknown etiology characterized by acute cognitive decline, catatonia, insomnia, and autistic features in individuals with Down syndrome. A prior report of four patients with DSDD suggested a potential autoimmune etiology based on the presence of autoantibodies and on successful treatment with immunotherapy that included intravenous immunoglobulin (IVIG). Herein, we present the case of an 8-year old girl who developed acute cognitive decline to a dementia-like state, insomnia, catatonia, and autistic features. In contrast to the four patients with DSDD above, she had no evidence of autoimmunity and presented at a younger age. Given the gravity of her acute deterioration and the exclusion of other etiologies, she was treated with immunotherapy presumptively. She responded with near complete resolution of symptoms, but demonstrated a pattern of mild decline as she approached each monthly dosing of IVIG and steroids, reversed by treatment. Mycophenolate mofetil (MMF) was therefore added, with stability throughout the month and the ability to taper off IVIG. After stopping IVIG, she had a mild recurrence of symptoms that again resolved with repeat IVIG followed by tapering off. Outcome was assessed at 2.5 years after presentation, at which time she was back to her premorbid condition, except for persistent tics off immunotherapy. This case supports the contention that patients with a rapid onset of severe symptoms consistent with DSDD, who have a thorough evaluation with the exclusion of other etiologies, may warrant a trial of immunotherapy with steroids, IVIG and/or other agents like MMF even in the absence of evidence of autoimmunity on standard evaluation.

Immunoglobulin Expression in Cancer Cells and Its Critical Roles in Tumorigenesis

Traditionally, immunoglobulin (Ig) was believed to be produced by only B-lineage cells. However, increasing evidence has revealed a high level of Ig expression in cancer cells, and this Ig is named cancer-derived Ig. Further studies have shown that cancer-derived Ig shares identical basic structures with B cell-derived Ig but exhibits several distinct characteristics, including restricted variable region sequences and aberrant glycosylation. In contrast to B cell-derived Ig, which functions as an antibody in the humoral immune response, cancer-derived Ig exerts profound protumorigenic effects via multiple mechanisms, including promoting the malignant behaviors of cancer cells, mediating tumor immune escape, inducing inflammation, and activating the aggregation of platelets. Importantly, cancer-derived Ig shows promising potential for application as a diagnostic and therapeutic target in cancer patients. In this review, we summarize progress in the research area of cancer-derived Ig and discuss the perspectives of applying this novel target for the management of cancer patients.

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

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

COVID-19 treatment options: a difficult journey between failed attempts and experimental drugs

Since its outbreak in China in December 2019 a novel Coronavirus, named SARS-CoV-2, has spread worldwide causing many cases of severe pneumonia, referred to as COVID-19 disease, leading the World Health Organization to declare a pandemic emergency in March 2020. Up to now, no specific therapy against COVID-19 disease exists. This paper aims to review COVID-19 treatment options currently under investigation. We divided the studied drugs into three categories (antiviral, immunomodulatory and other drugs). For each molecule, we discussed the putative mechanisms by which the drug may act against SARS-CoV-2 or may affect COVID-19 pathogenesis and the main clinical studies performed so far. The published clinical studies suffer from methodological limitations due to the emergency setting in which they have been conducted. Nevertheless, it seems that the timing of administration of the diverse categories of drugs is crucial in determining clinical efficacy. Antiviral drugs, in particular Remdesivir, should be administered soon after symptoms onset, in the viraemic phase of the disease; whereas, immunomodulatory agents, such as tocilizumab, anakinra and steroids, may have better results if administered in pneumonia/hyperinflammatory phases. Low-molecular-weight heparin may also have a role when facing COVID-19-related coagulopathy. Up to now, treatment choices have been inferred from the experience with other coronaviruses or viral infection outbreaks. Hopefully, in the near future, new treatment strategies will be available thanks to increased knowledge on SARS-CoV2 virus and COVID-19 pathogenesis. In the meanwhile, further well-designed clinical trials are urgently needed to establish a standard of care in COVID-19 disease.

COVID-19: Immunology, Immunopathogenesis and Potential Therapies

The Coronavirus Disease-2019 (COVID-19) imposed public health emergency and affected millions of people around the globe. As of January 2021, 100 million confirmed cases of COVID-19 along with more than 2 million deaths were reported worldwide. SARS-CoV-2 infection causes excessive production of pro-inflammatory cytokines thereby leading to the development of "Cytokine Storm Syndrome." This condition results in uncontrollable inflammation that further imposes multiple-organ-failure eventually leading to death. SARS-CoV-2 induces unrestrained innate immune response and impairs adaptive immune responses thereby causing tissue damage. Thus, understanding the foremost features and evolution of innate and adaptive immunity to SARS-CoV-2 is crucial in anticipating COVID-19 outcomes and in developing effective strategies to control the viral spread. In the present review, we exhaustively discuss the sequential key immunological events that occur during SARS-CoV-2 infection and are involved in the immunopathogenesis of COVID-19. In addition to this, we also highlight various therapeutic options already in use such as immunosuppressive drugs, plasma therapy and intravenous immunoglobulins along with various novel potent therapeutic options that should be considered in managing COVID-19 infection such as traditional medicines and probiotics.