High dose intravenous immunoglobulin treatment: mechanisms of action

A 21-bp deletion in the complement regulator CD55 promotor region is associated with multifocal motor neuropathy and its disease course

BACKGROUND AND AIMS

To further substantiate the role of antibody-mediated complement activation in multifocal motor neuropathy (MMN) immunopathology, we investigated the distribution of promotor polymorphisms of genes encoding the membrane-bound complement regulators CD46, CD55, and CD59 in patients with MMN and controls, and evaluated their association with disease course.

METHODS

We used Sanger sequencing to genotype five common polymorphisms in the promotor regions of CD46, CD55, and CD59 in 133 patients with MMN and 380 controls. We correlated each polymorphism to clinical parameters.

RESULTS

The genotype frequencies of rs28371582, a 21-bp deletion in the CD55 promotor region, were altered in patients with MMN as compared to controls (p .009; Del/Del genotype 16.8% vs. 7.7%, p .005, odds ratio: 2.43 [1.27-4.58]), and patients carrying this deletion had a more favorable disease course (mean difference 0.26 Medical Research Council [MRC] points/year; 95% confidence interval [CI]: 0.040-0.490, p .019). The presence of CD59 rs141385724 was associated with less severe pre-diagnostic disease course (mean difference 0.940 MRC point/year; 95% CI: 0.083-1.80, p .032).

INTERPRETATION

MMN susceptibility is associated with a 21-bp deletion in the CD55 promotor region (rs2871582), which is associated with lower CD55 expression. Patients carrying this deletion may have a more favorable long-term disease outcome. Taken together, these results point out the relevance of the pre-C5 level of the complement cascade in the inflammatory processes underlying MMN.

Clinical Effect Analysis of Different Doses of Creatine Phosphate Sodium Combined with Immunoglobulin in the Treatment of Pediatric Viral Myocarditis

The purpose of this paper was to unravel the clinical effect analysis of different doses of creatine phosphate sodium (CPS) combined with immunoglobulin in the treatment of pediatric viral myocarditis (VMC). One hundred and twenty children with VMC were recruited and randomized into three groups (40 patients each). Group I received 1.0 g of CPS dissolved in 100 mL of 5% glucose injection intravenously 1 time/day; group II received 1.25 g of CPS dissolved in 125 mL of 5% glucose injection intravenously 1 time/day; group III received 1.5 g of CPS dissolved in 150 mL of 5% glucose injection intravenously 1 time/day; then all three groups were treated with combined use of immunoglobulin (300-400 mg/day) intravenously once a day; and all three groups were treated for 14 days. The clinical efficacy, cardiac function, serum inflammatory factor levels, immune function, and the occurrence of drug toxicity and adverse effects of the children in the three groups were compared after 14 days of treatment. All three groups achieved better therapeutic effects after treatment, in which the effective rate of the Group II and Group III was notably higher versus the Group I. Lower levels of cTnI, CK-MB, LDH, AST, IL-18, IL-6, IFN-γ, and LVEDD and higher CD3+, CD4+, and CD4+/CD8+, FS, and LVEF values were noted in the Group II and Group III versus the Group I, and the results were more pronounced in the high-dose group. The liver and kidney functions of the children in the three groups before and after treatment did not show any significant changes and the incidence of adverse reactions during the treatment period was low in all three groups. Children with VMC can be treated with high-dose CPS in combination with immunoglobulin, which can improve their cardiac function and immune function and reduce the inflammatory response with good overall therapeutic efficacy and fewer adverse effects.

Use of human intravenous immunoglobulin for the treatment of 12 dogs with newly diagnosed malignant disease and presumed secondary immune-mediated thrombocytopenia

OBJECTIVES

To evaluate the safety and efficacy of human intravenous immunoglobulin in dogs with newly diagnosed malignancy and presumed secondary immune-mediated thrombocytopenia.

MATERIALS AND METHODS

Twelve client-owned dogs with newly diagnosed malignant disease and presumed secondary immune-mediated thrombocytopenia were prospectively enrolled to receive a single infusion of human intravenous immunoglobulin at a dose of 0.5 to 1 mg/kg intravenous over 8 hours. A complete treatment response was defined as a platelet estimation of ≥40,000 platelets/μL within 24 hours and a partial response within 48 hours from the completion of human intravenous immunoglobulin infusion. No treatment response was defined as a platelet estimation remaining <40,000 platelets/μL over 48 hours from the completion of the human intravenous immunoglobulin infusion. This pilot study had a prospective, open-label, uncontrolled design.

RESULTS

Out of the 12 enrolled dogs, seven completed the study. A complete treatment response to human intravenous immunoglobulin was identified in one lymphoma dog and a partial response was noted in another lymphoma dog. The remaining 10 dogs had no response to human intravenous immunoglobulin. No clinically relevant adverse reactions to human intravenous immunoglobulin occurred in any of the 12 initially enrolled dogs during the infusion and over a 3-month follow-up period for the seven surviving dogs.

CLINICAL SIGNIFICANCE

The results of this study suggest that the use of human intravenous immunoglobulin in dogs with newly diagnosed malignant disease and presumed secondary immune-mediated thrombocytopenia appears safe, but not effective for the treatment of thrombocytopenia. Larger multi-centre, prospective, double-blinded, placebo-controlled, outcome-based, malignancy-specific studies are needed to further evaluate these preliminary findings.

Immunoglobulin repletion during blinatumomab therapy does not reduce the rate of secondary hypogammaglobulinemia and associated infectious risk

Background

Blinatumomab has demonstrated efficacy in minimal residual disease (MRD) positive and relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL) by inciting rapid and sustained B-cell depletion.

Methods

Owing to its effect on B-cells, blinatumomab is associated with a higher rate of secondary hypogammaglobulinemia compared to chemotherapy. To mitigate blinatumomab-induced hypogammaglobulinemia, patients were pre-emptively repleted with intravenous immune globulin (IVIG) during blinatumomab therapy. In this retrospective study, we compared outcomes of 23 blinatumomab treated adults with ALL. Seventeen patients routinely received IVIG and 6 patients were in the control cohort.

Results

Our findings demonstrated no difference between the two cohorts in immunoglobulin G (IgG) nadir (338 mg/dL vs. 337 mg/dL, P=0.641), days to IgG nadir (120.5 vs. 85.5 days, P=0.13), infection rate (82.4% vs. 66.7%, P=0.58), infections requiring ICU admission (23.5% vs. 16.7%, P=1), and infection related mortality (17.6% vs. 16.7%, P=1).

Conclusion

Pre-emptive IVIG repletion during blinatumomab did not prevent hypogammaglobulinemia and associated infection risk.

Non-pharmacological treatments for COVID-19: current status and consensus

Purpose

COVID-19 is a disease caused by SARS-CoV-2 (coronavirus type 2 of the severe acute respiratory syndrome), isolated in China, in December 2019. The strategy currently used by physicians is to control disease and to treat symptoms, including non-pharmacological treatments, as there is still no specific treatment for COVID-19. Thus, the aim of this article is to carry out a systematic review about non-pharmacological treatments used for COVID-19, addressing current status and consensus found in the literature.

Methods

Three databases were consulted for evidence referring to the drugs indicated for COVID-19 (Cochrane Central, MEDLINE and Embase). The following terms and combinations were used: ((“2019-nCoV” OR 2019nCoV OR nCoV2019 OR “nCoV-2019” OR “COVID-19” OR COVID19 OR “HCoV-19” OR HCoV19 OR CoV OR “2019 novel*” OR Ncov OR “n-cov” OR “SARS-CoV-2” OR “SARSCoV-2” OR “SARSCoV2” OR “SARSCoV2” OR SARSCov19 OR “SARS-Cov19” OR “SARS-Cov-19”) OR “severe acute respiratory syndrome*” OR ((corona* OR corono*) AND (virus* OR viral* OR virinae*)) AND ((“lung injury”) OR (“ventilation use”) OR (“respiratory injuries” OR prone)) AND (treatment)) NOT Drugs NOT medicines NOT antivirals.

Results

A total of 28 articles were selected. These articles adopted one or more treatment methods for patients with severe cases of COVID-19, i.e., oxygen therapy, prone position, inhaled nitric oxide, intravenous infusion, passive immunotherapy, mesenchymal stem cells (MSC).

Conclusion

There is still no specific treatment approved for patients with COVID-19. The available evidence is not able yet to indicate the benefits or harms of non-pharmacological treatments, but some studies show that some treatments can play an important role in relation to COVID-19. The current consensus among researchers is that several studies using a randomized clinical trial should be carried out to provide evidence of safety and efficacy of the proposed treatments.

Current Desensitization Strategies in Heart Transplantation

Heart transplant candidates sensitized to HLA antigens wait longer for transplant, are at increased risk of dying while waiting, and may not be listed at all. The increasing prevalence of HLA sensitization and limitations of current desensitization strategies underscore the urgent need for a more effective approach. In addition to pregnancy, prior transplant, and transfusions, patients with end-stage heart failure are burdened with unique factors placing them at risk for HLA sensitization. These include homograft material used for congenital heart disease repair and left ventricular assist devices (LVADs). Moreover, these risks are often stacked, forming a seemingly insurmountable barrier in some cases. While desensitization protocols are typically implemented uniformly, irrespective of the mode of sensitization, the heterogeneity in success and post-transplant outcomes argues for a more tailored approach. Achieving this will require progress in our understanding of the immunobiology underlying the innate and adaptive immune response to these varied allosensitizing exposures. Further attention to B cell activation, memory, and plasma cell differentiation is required to establish methods that durably abrogate the anti-HLA antibody response before and after transplant. The contribution of non-HLA antibodies to the net state of sensitization and the potential implications for graft longevity also remain to be comprehensively defined. The aim of this review is to first bring forth select issues unique to the sensitized heart transplant candidate. The current literature on desensitization in heart transplantation will then be summarized providing context within the immune response. Building on this, newer approaches with therapeutic potential will be discussed emphasizing the importance of not only addressing the short-term pathogenic consequences of circulating HLA antibodies, but also the need to modulate alloimmune memory.

The Possible Role of IVIG in the Treatment of Atrial Fibrillation Accompanied by Fulminant Myocarditis in a 12-Year-Old Pediatric Patient

Background

Fulminant myocarditis (FM) is a potentially lethal condition in children due to rapid progressive hemodynamic instability and cardiogenic shock. Patients with FM might show different clinical manifestations on emergency department admission.

Case

Herein, we describe the case of a 12-year-old girl who was admitted to our institution's emergency department due to complaints of abdominal pain and incessant vomiting. However, we detected an early onset of atrial fibrillation (AF) accompanied by FM. The patient's condition of AF and severe hemodynamic disorder was successfully treated in our institution's pediatric intensive care unit.

Conclusion

To the best of our knowledge, this is the first report of the co-occurrence of FM and AF successfully treated in childhood. This case report will serve as a guide for the treatment of cases with FM accompanied by AF.

Acquired von Willebrand syndrome in monoclonal gammopathy - A scoping review on hemostatic management

BACKGROUND

Acquired von Willebrand syndrome (AVWS) has been associated with monoclonal gammopathy of undetermined significance (MGUS), with limited data on its management.

METHODS

We conducted a systematic literature search in Medline (Ovid), Embase, and Scopus up to September 11, 2019, for studies reporting on the management of AVWS associated with MGUS (AVWS-MGUS). Data on patient characteristics, laboratory parameters at presentation, and clinical and laboratory outcomes were extracted.

OBJECTIVES

To describe the clinical presentation and outcomes of different therapeutic approaches.

RESULTS

Seventy-five studies were included in the final review, for a total of 137 patients. Most patients had von Willebrand factor ristocetin cofactor activity <30 IU/dL (86.6%) and factor VIII levels <50 IU/dL (91.8%). Bleeding severity ranged from no bleeding (16.1%) to minor bleeding (46.4%) and major bleeding (37.5%). The overall clinical success rates for 1-deamino-8-D-arginine vasopressin (DDAVP), factor replacement therapy, and intravenous immunoglobulin (IVIG) were 43.8%, 33.3%, and 85.4%, respectively. The laboratory response rates for DDAVP, factor replacement therapy, and IVIG were 39.0%, 62.9%, and 88.6%, respectively. Several other treatments were also reported in small numbers, out of which myeloma-directed therapies, plasma exchange, recombinant factor VIIa, and antifibrinolytics appeared most successful, while immunosuppressive agents were largely ineffective.

CONCLUSION

IVIG appears to be an effective treatment for AVWS-MGUS bleeding, conferring a high clinical success rate with measurable laboratory outcomes; albeit temporary. DDAVP and factor replacement therapy may be partially successful in controlling minor bleeds, but not major bleeds. Other less commonly used agents may be effective in certain cases, although data are limited.

Antibodies Inhibiting the Type III Secretion System of Gram-Negative Pathogenic Bacteria

Pathogenic bacteria are a global health threat, with over 2 million infections caused by Gram-negative bacteria every year in the United States. This problem is exacerbated by the increase in resistance to common antibiotics that are routinely used to treat these infections, creating an urgent need for innovative ways to treat and prevent virulence caused by these pathogens. Many Gram-negative pathogenic bacteria use a type III secretion system (T3SS) to inject toxins and other effector proteins directly into host cells. The T3SS has become a popular anti-virulence target because it is required for pathogenesis and knockouts have attenuated virulence. It is also not required for survival, which should result in less selective pressure for resistance formation against T3SS inhibitors. In this review, we will highlight selected examples of direct antibody immunizations and the use of antibodies in immunotherapy treatments that target the bacterial T3SS. These examples include antibodies targeting the T3SS of Pseudomonas aeruginosa, Yersinia pestis, Escherichia coli, Salmonella enterica, Shigella spp., and Chlamydia trachomatis.

Immunoglobulin for Treating Bacterial Infections: One More Mechanism of Action

The mechanisms underlying the effects of immunoglobulins on bacterial infections are thought to involve bacterial cell lysis via complement activation, phagocytosis via bacterial opsonization, toxin neutralization, and antibody-dependent cell-mediated cytotoxicity. Nevertheless, recent advances in the study of the pathogenicity of Gram-negative bacteria have raised the possibility of an association between immunoglobulin and bacterial toxin secretion. Over time, new toxin secretion systems like the type III secretion system have been discovered in many pathogenic Gram-negative bacteria. With this system, the bacterial toxins are directly injected into the cytoplasm of the target cell through a special secretory apparatus without any exposure to the extracellular environment, and therefore with no opportunity for antibodies to neutralize the toxin. However, antibodies against the V-antigen, which is located on the needle-shaped tip of the bacterial secretion apparatus, can inhibit toxin translocation, thus raising the hope that the toxin may be susceptible to antibody targeting. Because multi-drug resistant bacteria are now prevalent, inhibiting this secretion mechanism is an attractive alternative or adjunctive therapy against lethal bacterial infections. Thus, it is not unreasonable to define the blocking effect of anti-V-antigen antibodies as the fifth mechanism for immunoglobulin action against bacterial infections.

Role of intravenous immunoglobulin therapy in the survival rate of pediatric patients with acute myocarditis: A systematic review and meta-analysis

The treatment of pediatric myocarditis is controversial, and the benefits of intravenous immunoglobulin (IVIG) are inconclusive due to limited data. We searched studies from PubMed, MEDLINE, Embase, and Cochrane Library databases since establishment until October 1st, 2018. Thirteen studies met the inclusion criteria. We included a total of 812 patients with IVIG treatment and 592 patients without IVIG treatment. The meta-analysis showed that the survival rate in the IVIG group was higher than that in the non-IVIG group (odds ratio = 2.133, 95% confidence interval (CI): 1.32-3.43, p = 0.002). There was moderate statistical heterogeneity among the included studies (I² = 35%, p = 0.102). However, after adjustment using Duval and Tweedie's trim and fill method, the point estimate of the overall effect size was 1.40 (95% CI 0.83, 2.35), which became insignificant. Moreover, the meta-regression revealed that age (coefficient = -0.191, 95% CI (-0.398, 0.015), p = 0.069) and gender (coefficient = 0.347, 95% CI (-7.586, 8.279), p = 0.93) were not significantly related to the survival rate. This meta-analysis showed that IVIG treatment was not associated with better survival. The use of IVIG therapy in acute myocarditis in children cannot be routinely recommended based on current evidence. Further prospective and randomized controlled studies are needed to elucidate the effects of IVIG treatment.

Tick-borne encephalitis in Europe and Russia: Review of pathogenesis, clinical features, therapy, and vaccines

Tick-borne encephalitis (TBE) is an illness caused by tick-borne encephalitis virus (TBEV) infection which is often limited to a febrile illness, but may lead to very aggressive downstream neurological manifestations. The disease is prevalent in forested areas of Europe and northeastern Asia, and is typically caused by infection involving one of three TBEV subtypes, namely the European (TBEV-Eu), the Siberian (TBEV-Sib), or the Far Eastern (TBEV-FE) subtypes. In addition to the three main TBEV subtypes, two other subtypes; i.e., the Baikalian (TBEV-Bkl) and the Himalayan subtype (TBEV-Him), have been described recently. In Europe, TBEV-Eu infection usually results in only mild TBE associated with a mortality rate of <2%. TBEV-Sib infection also results in a generally mild TBE associated with a non-paralytic febrile form of encephalitis, although there is a tendency towards persistent TBE caused by chronic viral infection. TBE-FE infection is considered to induce the most severe forms of TBE. Importantly though, viral subtype is not the sole determinant of TBE severity; both mild and severe cases of TBE are in fact associated with infection by any of the subtypes. In keeping with this observation, the overall TBE mortality rate in Russia is ∼2%, in spite of the fact that TBEV-Sib and TBEV-FE subtypes appear to be inducers of more severe TBE than TBEV-Eu. On the other hand, TBEV-Sib and TBEV-FE subtype infections in Russia are associated with essentially unique forms of TBE rarely seen elsewhere if at all, such as the hemorrhagic and chronic (progressive) forms of the disease. For post-exposure prophylaxis and TBE treatment in Russia and Kazakhstan, a specific anti-TBEV immunoglobulin is currently used with well-documented efficacy, but the use of specific TBEV immunoglobulins has been discontinued in Europe due to concerns regarding antibody-enhanced disease in naïve individuals. Therefore, new treatments are essential. This review summarizes available data on the pathogenesis and clinical features of TBE, plus different vaccine preparations available in Europe and Russia. In addition, new treatment possibilities, including small molecule drugs and experimental immunotherapies are reviewed. The authors caution that their descriptions of approved or experimental therapies should not be considered to be recommendations for patient care.

Dermatologic manifestations in end stage renal disease

Skin manifestations are commonly seen in end stage renal disease (ESRD). Skin involvement in this population can be extensive and dramatically worsen quality of life. Close observation of the skin and nails of ESRD patients by clinicians allows for timely diagnosis and treatment, which ultimately improves quality of life and reduces mortality. In this article we focus on the cutaneous changes most commonly seen in ESRD patients. PubMed/Medline database search was done for published literature on skin manifestations in ESRD patients. All the available literature was reviewed and relevant articles were used to discuss about clinical features, pathogenesis, histology and treatment of each skin disorder in ESRD patients. Most commonly encountered skin manifestations in patients with ESRD are pruritus, xerosis, pigmentation changes, nail changes, perforating disorders, calcifying disorders, bullous dermatoses and nephrogenic systemic fibrosis. Skin manifestations in ESRD can be difficult to treat and multiple comorbidities in this patient population can exacerbate these disorders. Many of the treatment options are experimental with evidence largely derived from the case reports and small clinical trials. More large-scale trials are needed to firmly establish evidence based treatment guidelines. Prompt evaluation and management of these disorders improve morbidity and quality of life in ESRD patients.

A 6-month mixed-effect pharmacokinetic model for post-transplant intravenous anti-hepatitis B immunoglobulin prophylaxis

Background

Although individualized dosage regimens for anti-hepatitis B immunoglobulin (HBIG) therapy have been suggested, the pharmacokinetic profile and factors influencing the basis for individualization have not been sufficiently assessed. We sought to evaluate the pharmacokinetic characteristics of anti-HBIG quantitatively during the first 6 months after liver transplantation.

Methods

Identical doses of 10,000 IU HBIG were administered to adult liver transplant recipients daily during the first week, weekly thereafter until 28 postoperative days, and monthly thereafter. Blood samples were obtained at days 1, 7, 28, 84, and 168 after transplantation. Plasma HBIG titer was quantified using 4 different immunoassay methods. The titer determined by each analytical method was used for mixed-effect modeling, and the most precise results were chosen. Simulations were performed to predict the plausible immunoglobulin maintenance dose.

Results

HBIG was eliminated from the body most rapidly in the immediate post-transplant period, and the elimination rate gradually decreased thereafter. In the early post-transplant period, patients with higher DNA titer tend to have lower plasma HBIG concentrations. The maintenance doses required to attain targets in 90%, 95%, and 99% of patients were ~15.3, 18.2, and 25.1 IU, respectively, multiplied by the target trough level (in IU/L).

Conclusion

The variability (explained and unexplained) in HBIG pharmacokinetics was relatively larger in the early post-transplant period. Dose individualization based upon patient characteristics should be adjusted focusing quantitatively on the early post-transplant period.

Proposed Relationship Between Intravenous Immunoglobulin and Thrombosis in Renal Transplant Recipients

Objective:

To report 2 cases of intravenous human immunoglobulin (IVIG)–associated thrombosis in kidney transplant patients.

Case Summary:

Both cases involved female patients presenting to Henry Ford Hospital in Detroit for renal transplantation. Patient 1 presented with systemic lupus erythematosus, positive for both anticardiolipin and anti-DNA antibody. Patient 2, post nephrectomy, was found to have moderate hyperhomocysteinemia, with a total plasma homocysteine level of 3.9 mg/L. Both patients were considered highly sensitized and at high risk for rejection due to the presence of either high panel reactive antibody or a positive B cell flow cytometry crossmatch, in addition to other risk factors. Therefore, IVIG was considered a viable treatment option to be included in induction therapy. IVIG was administered both peri- and postoperatively, and both patients experienced immediate graft function with good urine output. Within 24 hours following transplantation, elevations in serum creatinine and decreases in urine output were seen. Subsequently, kidney exploration was performed and palpable thrombi in renal arteries and veins were detected. Immediate nephrectomy was performed in both cases.

Discussion:

Currently, evidence derived from case reports highlights numerous risk factors for IVIG-associated thrombosis, one of which appears to be a hypercoagulable state. It has also been reported that some IVIG products contain amounts of anticardiolipin antibodies; these antibodies may potentiate thrombosis in the presence of hypercoagulable states, such as hyperhomocysteinemia or antiphospholipid syndrome, in these 2 patients, the Naranjo probability scale indicated that there was a possible association between the thrombotic events and the use of IVIG.

Conclusions:

Prospective trials evaluating the safety of IVIG in highly sensitized transplant patients are scarce. Therefore, it is imperative that the benefits and risks be weighed when considering the use of IVIG in highly sensitized transplant patients.

Emerging pharmacologic targets and treatments for myocarditis

Myocarditis is a heterogeneous group of disorders defined by inflammation of the heart muscle. The primary clinical manifestations of myocarditis are heart failure and sudden death in children and young adults. Numerous interventions have been investigated for the treatment of myocarditis, including broad spectrum alteration of the immune response and antiviral treatments; however, success has been limited. Since the myocarditis treatment trials in the 1990s there has been an improved understanding of disease progression and new facets of the immune response have been discovered. This new information provides fresh opportunities to develop therapeutics to treat myocarditis. This review analyzes previous pharmacologic approaches including immunosuppression, high dose intravenous immunoglobulin treatment, immunoadsorption and antiviral treatments, and looks forward toward recently identified immune factors that can be exploited as targets for new treatments. Such strategies include bolstering beneficial regulatory T cells or mitigating the detrimental Th17 T cells which can drive autoimmunity in the heart. The surging interest of the application of humanized monoclonal antibodies makes targeting deleterious arms of the immune response like Th17 cells a tangible goal in the near future. Promising constituents of herbal remedies have also been identified that may hold potential as new pharmacological treatments for myocarditis, however, significant work remains to elucidate the pharmacokinetics and side-effects of these compounds. Finally, advances in our understanding of the function of Matrix Metalloproteinases yield another target for altering disease progression given their role in the development of fibrosis during Dilated Cardiomyopathy. In bringing to light the various new targets and treatments available since the last myocarditis treatment trials, the aim of this review is to explore the new treatments that are possible in new myocarditis treatment trials.

The Cost of Transplant Immunosuppressant Therapy: Is This Sustainable?

A solid organ transplant is life-saving therapy that engenders the use of immunosuppressive medications for the lifetime of the transplanted organ and its recipient. Conventional therapy includes both induction therapy (a biologic that is infused peri-operatively) followed by maintenance therapy. The cost of these medications is a constant concern and the advent of generics has brought this cost down modestly. For those lacking long term insurance coverage, this may be a significant out of pocket expense that is not affordable. Moreover, transplant Centers are managing higher risk transplant recipients that require more complex induction regimens and longer term use of such biologic agents in the context of desensitization or abrogation of de novo antibody mediated injury. While in kidney transplantation, Medicare part B covers three years of medication, there is frequent non-adherence due to cost after that time-point. The impact of the Affordable Care Act remains uncertain at this time. Finally the pipeline of new therapies is limited due to the cost of development of a drug, the inherent cost of clinical studies, and lack of defined endpoints for newer therapies in high risk patients. These new therapies are of high value to the community but will contribute additional burden to current drug costs.

What has happened in the last 50 years in immunology

Fifty years ago, in 1964, our understanding of the immune system was very rudimentary. Gell and Coombs had just described classes of hypersensitivity reactions, and Bruton had described and commenced immunoglobulin replacement in agammaglobulinaemia. The distinction between T and B cells was not identified and characterised until the 1960s and 1970s. This was followed by increasing recognition of T and B cell collaboration in immune responses and identification of significant immunodeficiencies. CD4 and CD8 T cells were only recognised in the 1970s and 1980s. We now know of five CD4 subsets; dysfunction of each is associated with different disorders. By 2014, advances in technology have enabled identification of the genetic basis of over 240 primary immunodeficiencies. Research into the gut microbiome and vitamin D holds promise for the understanding, treatment and prevention of autoimmune and allergic diseases. Immunoglobulin preparations for the treatment of antibody deficiencies improved with the development of preparations for intravenous then subcutaneous administration, giving patients choice and the ability for home-based treatment, especially if experiencing infusion associated adverse effects. Newborn screening for severe combined immunodeficiency is a reality. Improvements in haemopoietic stem cell transplantation and now gene therapy, albeit still only available in the research setting, are improving long-term survival in primary immunodeficiencies. Biologic therapeutic agents are improving the control of autoimmune disease but potentially leading to secondary immunodeficiency, increasing the risk of opportunistic infection and malignancy. It is an exciting time.

Induction of PD-L1 on monocytes: a new mechanism by which IVIg inhibits mixed lymphocyte reactions

Allograft rejection and graft-versus-host disease (GvHD) are frequent complications following solid organ or stem cell transplantation in which T cell activation plays a central role. Despite the development of new immunosuppressive drugs that improve the success rate of transplantation, allograft survival continues to be a challenge. Recently, intravenous immunoglobulin (IVIg) has been proposed as prophylaxis and post-transplant treatment to reduce acute rejection episodes. IVIg is a therapeutic agent that is known to down-modulate T cell functions in patients with autoimmune disorders. To test the hypothesis that this immunomodulatory effect could be beneficial in the context of transplantation, we used mixed lymphocyte reactions (MLR) as an in vitro model of allograft rejection and GvHD. Our results show that IVIg strongly inhibits the MLR as evaluated by IL-2 secretion, a well-known marker of T cell activation. IVIg also modulates the secretion of other pro-(IL-6, IFN-γ) and anti-inflammatory (IL-1RA) cytokines. More importantly, we show that IVIg induces monocytes with a CD80(low) PD-L1(high) phenotype and that blockade of PD-L1 partially abrogates the inhibitory effect of IVIg. We have thus identified a new mechanism by which IVIg inhibits T cell functions in the context of transplantation, supporting the potential usefulness of IVIg in the prevention or treatment of graft rejection and GvHD.

Recombinant IgG2a Fc (M045) multimers effectively suppress experimental autoimmune myasthenia gravis

Myasthenia gravis (MG) is an autoimmune disorder caused by target-specific pathogenic antibodies directed toward postsynaptic neuromuscular junction (NMJ) proteins, most commonly the skeletal muscle nicotinic acetylcholine receptor (AChR). In MG, high-affinity anti-AChR Abs binding to the NMJ lead to loss of functional AChRs, culminating in neuromuscular transmission failure and myasthenic symptoms. Intravenous immune globulin (IVIg) has broad therapeutic application in the treatment of a range of autoimmune diseases, including MG, although its mechanism of action is not clear. Recently, the anti-inflammatory and anti-autoimmune activities of IVIg have been attributed to the IgG Fc domains. Soluble immune aggregates bearing intact Fc fragments have been shown to be effective treatment for a number of autoimmune disorders in mice, and fully recombinant multimeric Fc molecules have been shown to be effective in treating collagen-induced arthritis, murine immune thrombocytopenic purpura, and experimental inflammatory neuritis. In this study, a murine model of MG (EAMG) was used to study the effectiveness of this novel recombinant polyvalent IgG2a Fc (M045) in treating established myasthenia, with a direct comparison to treatment with IVIg. M045 treatment had profound effects on the clinical course of EAMG, accompanied by down-modulation of pathogenic antibody responses. These effects were associated with reduced B cell activation and T cell proliferative responses to AChR, an expansion in the population of FoxP3(+) regulatory T cells, and enhanced production of suppressive cytokines, such as IL-10. Treatment was at least as effective as IVIg in suppressing EAMG, even at doses 25-30 fold lower. Multimeric Fc molecules offer the advantages of being recombinant, homogenous, available in unlimited quantity, free of risk from infection and effective at significantly reduced protein loads, and may represent a viable therapeutic alternative to polyclonal IVIg.

A review of current indications, adverse effects, and administration recommendations for intravenous immunoglobulin

OBJECTIVE

To review and summarize the body of literature regarding human intravenous immunoglobulin (hIVIG) therapy in veterinary medicine. Mechanism of action, usage in human medicine, adverse effects of therapy, implications for veterinary use, and administration recommendations are discussed.

DATA SOURCES

Current human and veterinary peer-reviewed medical literature including original research articles and scientific reviews.

HUMAN DATA SYNTHESIS

There are currently 6 labeled uses for hIVIG in human medicine, but preparations are used off-label to successfully treat multiple immune-mediated conditions. To maximize the potential of hIVIG use in animals and identify areas deficient in research, a review of the current literature is warranted.

VETERINARY DATA SYNTHESIS

Investigation of hIVIG therapy in veterinary patients has been limited to the subjects of immune-mediated hemolytic anemia (IMHA), immune-mediated thrombocytopenia (ITP), Evan's syndrome, cutaneous disease, myasthenia gravis (MG), and sudden acquired retinal degeneration (SARDS). Proponents of veterinary hIVIG use believe administration may reduce transfusion requirements and decrease hospitalization time.

CONCLUSION

Immunoglobulin (Ig) has not been shown to decrease transfusion requirements in IMHA patients, but shows great promise for treatment of ITP and dermatological diseases. Although serial transfusion of hIVIG is employed in human medicine, repeated transfusion is not recommended in animals due to risk of severe allergic reaction. Other potential adverse effects of transfusion include delayed hypersensitivity reactions, thromboembolism, renal failure, hypotension, and aseptic meningitis.

The role of intravenous immunoglobulin in the treatment of cerebral vasospasm induced by subarachnoid haemorrhage: an experimental study

OBJECTIVES

The aim of this study was to determine whether intravenous immunoglobulin (IVIG) prevents cerebral vasospasm in rabbits with induced subarachnoid haemorrhage (SAH). The effect of IVIG on apoptosis in the endothelial cells of the basilar artery was also evaluated.

METHODS

Eighteen New Zealand white rabbits were allocated randomly into three groups. SAH was induced by injecting autologous blood into the cisterna magna. Group 1, the control group, was subjected to sham surgery (no induction of SAH). Group 2 had SAH alone and Group 3 had SAH plus IVIG. Three days after treatment, the animals were sacrificed. The basilar artery tissues were analysed histologically and the malondialdehyde levels in the brain stem tissues were evaluated biochemically.

RESULTS

Differences in the histopathological luminal areas and full wall thicknesses in the SAH plus IVIG group and the SAH group were statically insignificant (p > 0.005). The malondialdehyde level was also found to be lower in the IVIG group than in the SAH group, although this difference was not significant (p > 0.005).

CONCLUSION

Although the IVIG treatment was revealed to have no vasodilator effect on the SAH-induced spastic basilar artery, it was shown to have a beneficial effect on the apoptosis of endothelial cells, probably via anti-inflammatory mechanisms.

Treatment with immunoglobulin improves outcome for pediatric liver transplant recipients

Immunoglobulin mitigates autoimmune disease and facilitates acceptance of ABO-incompatible transplanted organs. To test the hypothesis that treatment with immunoglobulin is associated with improved graft survival and a decreased rate of allograft rejection, a cohort study of primary liver transplant recipients in the Studies of Pediatric Liver Transplantation registry was performed. The outcomes of 336 pediatric liver transplant recipients who received immunoglobulin within 7 days of liver transplantation were compared with the outcomes of 1612 recipients who did not receive immunoglobulin. The outcome measures were patient survival, death-free graft survival, and allograft rejection. The Kaplan-Meier probability of patient survival was not different between patients treated with immunoglobulin and patients who did not receive immunoglobulin. Death-free graft survival was increased in patients treated with immunoglobulin (hazard ratio of death-free survival = 0.57, P = 0.014). The probability of allograft rejection at 3 months was 31% for patients treated with immunoglobulin versus 40% for patients who did not receive immunoglobulin (hazard ratio = 0.81, P = 0.02). The proportion of patients with 2 or more episodes of allograft rejection was lower in patients treated with immunoglobulin (13.1% with immunoglobulin versus 19.2% with no immunoglobulin, P = 0.009). Treatment with immunoglobulin was associated with a decreased risk for allograft rejection, whereas use of cyclosporine as the initial immunosuppression and transplantation before 2002 were independently associated with an increased risk of allograft rejection in pediatric liver transplantation recipients. A trend toward a decreased rate of retransplantation was detected in the population that received treatment with immunoglobulin.

Neuroprotection in stroke by complement inhibition and immunoglobulin therapy

Activation of the complement system occurs in a variety of neuroinflammatory diseases and neurodegenerative processes of the CNS. Studies in the last decade have demonstrated that essentially all of the activation components and receptors of the complement system are produced by astrocytes, microglia, and neurons. There is also rapidly growing evidence to indicate an active role of the complement system in cerebral ischemic injury. In addition to direct cell damage, regional cerebral ischemia and reperfusion (I/R) induces an inflammatory response involving complement activation and generation of active fragments, such as C3a and C5a anaphylatoxins, C3b, C4b, and iC3b. The use of specific inhibitors to block complement activation or their mediators such as C5a, can reduce local tissue injury after I/R. Consistent with therapeutic approaches that have been successful in models of autoimmune disorders, many of the same complement inhibition strategies are proving effective in animal models of cerebral I/R injury. One new form of therapy, which is less specific in its targeting of complement than monodrug administration, is the use of immunoglobulins. Intravenous immunoglobulin (IVIG) has the potential to inhibit multiple components of inflammation, including complement fragments, pro-inflammatory cytokine production and leukocyte cell adhesion. Thus, IVIG may directly protect neurons, reduce activation of intrinsic inflammatory cells (microglia) and inhibit transendothelial infiltration of leukocytes into the brain parenchyma following an ischemic stroke. The striking neuroprotective actions of IVIG in animal models of ischemic stroke suggest a potential therapeutic potential that merits consideration for clinical trials in stroke patients.

Self-Reactivity in the Dimeric Intravenous Immunoglobulin Fraction

Therapeutic intravenous immunoglobulin (IVIg) preparations contain antibodies reflecting the cumulative antigen experience of the donor population. IVIg contains variable amounts of monomeric and dimeric IgG, but there is little information available on their comparative antibody specificities. We have isolated highly purified fractions of monomeric and dimeric IgG by size-exclusion chromatography. Following treatment of all fractions at pH4, analyses by immunodot and immunocytology on human cell lines showed a preferential recognition of autoantigens in the dimeric IgG fraction. Investigation of the HEp-2 cytoplasmic proteome by 2D-PAGE, Western blot, and subsequent identification of IVIg reactive spots by mass spectrometry (LC-MS/MS) showed that IVIg recognized only a restricted set of the total proteins. Similar experiments showed that more antigens were recognized by the dimeric IgG fraction, especially when the dissociated dimer fraction was used, as compared to its monomeric counterpart. These observations are consistent with idiotype-anti-idiotype masking of auto-specific Abs in the dimeric fraction of IVIg.

Variations in serum hemoglobin, albumin, and electrolytes in patients receiving intravenous immunoglobulin therapy: a real clinical threat?

BACKGROUND AND OBJECTIVE

Intravenous immunoglobulin (IVIg) is a solution of globulins containing antibodies derived from pooled human plasma of donors and used in the treatment of a number of immune deficiencies and autoimmune diseases. However, several investigators have reported biochemical alterations with use of IVIg. The objective of this study was to evaluate the effects of IVIg therapy on selected biochemical and hematologic parameters in patients with autoimmune mucocutaneous blistering diseases (AMBDs).

METHODS

In this preliminary clinical study, ten patients with AMBDs (seven with pemphigus vulgaris and three with mucous membrane pemphigoid) received 133 cycles of IVIg for a total of 399 infusions. We evaluated the effects of IVIg therapy on serum hemoglobin (Hb), albumin, and electrolyte levels, including sodium (Na+), potassium (K+), chloride (Cl-) and calcium (Ca2+). Values of these parameters were measured 24 hours before, during, and 24 hours and 4 weeks after the 3-day infusion period.

RESULTS

The observed variations in serum electrolyte levels were physiologically and clinically negligible. Furthermore, 24 hours after the last infusion, mean electrolyte values had spontaneously returned to normal levels without the need for additional supplementation: Na+ 137.59+/-1.42 mmol/L (p=0.6091 vs baseline); K+ 3.97+/-0.5 mmol/L (p=0.2689); Cl- 103.4+/-2.69 mmol/L (p=0.0388); and Ca2+ 9.07+/-0.44 mg/dL (p=0.5332). Conversely, significant variations in mean Hb and albumin levels were observed. When measured 24 hours after the last infusion, mild/moderate decreases in Hb (11.62+/-2.12 g/dL; p=0.009 vs baseline) and/or albumin (mean 3.14+/-0.24 g/dL; p=0.0016 vs baseline) were evident. Such changes may, albeit very rarely, be of sufficient clinical significance in individual patients as to necessitate additional treatment.

CONCLUSION

In patients receiving intravenous IVIg for AMBDs, electrolyte values should be monitored but do not represent a real clinical threat. Hemoglobin and albumin values may be altered sufficiently to require additional treatment but this is a very rare occurrence. These findings confirm and extend previous reports of the safety of IVIg therapy.

Immunologic and functional evidence for anti–Siglec-9 autoantibodies in intravenous immunoglobulin preparations

Human intravenous immunoglobulin (IVIg) preparations are increasingly used for the treatment of autoimmune diseases. Earlier work demonstrated the presence of autoantibodies against Fas in IVIg, suggesting that IVIg might be able to induce caspase-dependent cell death in Fas-sensitive cells. In this study, we demonstrate that sialic acid–binding Ig-like lectin 9 (Siglec) represents a surface molecule on neutrophils that is activated by IVIg, resulting in caspase-dependent and caspase-independent forms of cell death. Neutrophil death was mediated by naturally occurring anti–Siglec-9 autoantibodies present in IVIg. Moreover, the efficacy of IVIg-mediated neutrophil killing was enhanced by the proinflammatory cytokines granulocyte/macrophage colony-stimulating factor (GM-CSF) and interferon-γ (IFN–γ), and this additional cell death required reactive oxygen species (ROSs) but not caspases. Anti– Siglec-9 autoantibody–depleted IVIg failed to induce this caspase-independent neutrophil death. These findings contribute to our understanding of how IVIg preparations exert their immunoregulatory effects under pathologic conditions and may provide a possible explanation for the neutropenia that is sometimes seen in association with IVIg therapy.

Pretransplant immunomodulation of highly sensitized small bowel transplant candidates with intravenous immune globulin

Presence of preformed lymphocytotoxic antibodies may represent a barrier to isolated intestinal transplantation (IITx). We developed an intravenous immunoglobulins (IVIg) based desensitization protocol for candidates with high panel-reactive antibodies (PRA). Six patients with a mean PRA of 72+/-22% were included in a four-level (L) protocol with escalating doses of IVIg (L1, L2), addition of mycophenolate mofetil (MMF) or plasmapheresis (L3); and anti-CD20 (Rituximab) (L4). Four of six candidates improved their PRAs (from a mean of 66.2% to 25.5%; P=0.01) and were successfully transplanted. At a mean follow-up of 8 months, number and severity of rejection episodes of protocol patients did not differ from patients with low PRA transplanted during the same period. These data support the use of IVIg to desensitize patients waiting for IITx. It increases the applicability of IITx, and reduces the waiting time and mortality on the waiting list with outcomes comparable to nonsensitized recipients.