Differences between IGIV products: impact on clinical outcome

Updates in the Understanding of Immunoglobulin Replacement Therapy in Primary Immune Deficiency Disorders: Function, Composition, and Role in Reconstitution and Immunomodulation

Clinical indications for immunoglobulin therapy can be broadly classified into replacement therapy for immunodeficiencies, immunomodulatory treatment of inflammatory conditions, and hyperimmune therapy against specific infectious agents. When starting immunoglobulin therapy, there are important considerations for the clinician including indication and function, composition, dosing, route, and safety. Immunoglobulin therapy should be tailored to an individual patient. This review discusses our current understanding and practical considerations for using immunoglobulin therapy for both humoral immune reconstitution and immunomodulation.

Immunomodulatory and anti-inflammatory properties of immunoglobulin G antibodies

Antibodies provide an essential layer of protection from infection and reinfection with microbial pathogens. An impaired ability to produce antibodies results in immunodeficiency and necessitates the constant substitution with pooled serum antibodies from healthy donors. Among the five antibody isotypes in humans and mice, immunoglobulin G (IgG) antibodies are the most potent anti-microbial antibody isotype due to their long half-life, their ability to penetrate almost all tissues and due to their ability to trigger a wide variety of effector functions. Of note, individuals suffering from IgG deficiency frequently produce self-reactive antibodies, suggesting that a normal serum IgG level also may contribute to maintaining self-tolerance. Indeed, the substitution of immunodeficient patients with pooled serum IgG fractions from healthy donors, also referred to as intravenous immunoglobulin G (IVIg) therapy, not only protects the patient from infection but also diminishes autoantibody induced pathology, providing more direct evidence that IgG antibodies play an active role in maintaining tolerance during the steady state and during resolution of inflammation. The aim of this review is to discuss different conceptual models that may explain how serum IgG or IVIg can contribute to maintaining a balanced immune response. We will focus on pathways depending on the IgG fragment crystallizable (Fc) as pre-clinical data in various mouse model systems as well as human clinical data have demonstrated that the IgG Fc-domain recapitulates the ability of intact IVIg with respect to its ability to trigger resolution of inflammation. We will further discuss how the findings already have or are in the process of being translated to novel therapeutic approaches to substitute IVIg in treating autoimmune inflammation.

Rational use of immunoglobulins (IVIgs and SCIgs) in secondary antibody deficiencies

Immunoglobulins for intravenous use (IVIgs) and subcutaneous use (SCIgs) can prevent recurrent and severe infections in patients with secondary antibody deficiencies that are frequently linked to haematological/oncological malignancies as well as other clinical conditions and their respective treatments. Even so, as IVIgs and SCIgs are costly and their supply is limited, their clinical use must be optimised. The aim of this position paper is to provide structured practical guidance on the optimal use of IVIgs and SCIgs in secondary antibody deficiencies, particularly in haematological and oncological practice. The authors agree that the occurrence of severe infections is a prerequisite for the use of IVIgs. Serum IgG levels in general as well as IgG subclass levels can be additional indicators of whether a patient could benefit from IVIgs. Responsiveness to vaccines can help to identify immunodeficiency. Patients with chronic lymphocytic leukaemia or multiple myeloma who are receiving respective treatment, especially B-cell depletion therapy, but also some patients with autoimmune diseases are prone to antibody deficiencies and need IVIgs. For the optimal use of IVIgs and to maximise their potential benefit, the indication must be individually assessed for each patient. As a primary treatment goal, the authors define a sufficient prophylaxis of severe infections, which can be supported by normalising IgG levels. If the initiated treatment is insufficient or linked to intolerable adverse reactions, switching the product within the class of IVIgs or changing to a different batch of the same product can be considered. Pausing treatment can also be considered if there are no infections, which happens more frequently in summer, but treatment needs to be resumed once infections return. These structured recommendations for IVIg treatment in patients with secondary antibody deficiency may provide guidance for clinical practice and therefore help to allocate IVIgs to those who will benefit the most, without overusing valuable resources.

IgG1 Is the Optimal Subtype for Treating Atherosclerosis by Inducing M2 Macrophage Differentiation, and Is Independent of the FcγRIIA Gene Polymorphism

In recent years, it has been established that atherosclerosis is an autoimmune disease. However, little is currently known about the role of FcγRIIA in atherosclerosis. Herein, we sought to investigate the relationship between FcγRIIA genotypes and the effectiveness of different IgG subclasses in treating atherosclerosis. We constructed and produced different subtypes of IgG and Fc-engineered antibodies. In vitro, we observed the effect of different subtypes of IgG and Fc-engineered antibodies on the differentiation of CD14⁺ monocytes from patients or healthy individuals. In vivo, Apoe^-/- mice were fed a high-fat diet (HFD) for 20 weeks and administered injections of different CVI-IgG subclasses or Fc-engineered antibodies. Flow cytometry was used to assess the polarization of monocytes and macrophages. Although CVI-IgG4 reduced the release of MCP-1 compared to the other subtypes, IgG4 did not yield an anti-inflammatory effect by induction of human monocyte and macrophage differentiation in vitro. Furthermore, genetic polymorphisms of FcγRIIA were not associated with different CVI-IgG subclasses during the treatment of atherosclerosis. In vivo, CVI-IgG1 decreased Ly6C^high monocyte differentiation and promoted M2 macrophage polarization. We also found that the secretion of IL-10 was upregulated in the CVI-IgG1-treated group, whereas V11 and GAALIE exerted no significant effect. These findings highlight that IgG1 is the optimal subtype for treating atherosclerosis, and CVI-IgG1 can induce monocyte/macrophage polarization. Overall, these results have important implications for the development of therapeutic antibodies.

Effect of glioma-derived immunoglobulin on biological function of glioma cells

INTRODUCTION

Glioma is the most common and most invasive primary central nervous system tumour, and it is urgent to develop new specific therapeutic targets. Studies have confirmed that epithelial-derived tumour cells promote tumour cell proliferation and metastasis by secreting a large number of immunoglobulins (Igs), but the role of tumour-derived Igs in glioma has never been reported.

METHODS

The Gene Expression Profiling Interactive Analysis and Chinese Glioma Genome Atlas databases were used to analyse the Ig transcription and its correlation with the prognosis of patients with glioma. Immunohistochemistry and immunofluorescence were used to detect the protein expression of IgG and IgM in the glioma tissues of patients and glioma cell lines. When IgG was knocked down by small interfering RNA or knocked out by CRISPR-Cas9, the function of proliferation and migration of glioma cells were analysed by CCK-8, clone formation, wound healing, and transwell assays. Changes in proteins and their phosphorylation in signalling pathways were detected by western blotting. The nude mouse subcutaneous tumour-bearing model was established to analyse the effect of IgG in vivo.

RESULTS

The transcriptional level of IgG was pretty high in glioma tissues and was positively correlated with high WHO grade, recurrence, and poor prognosis. The expression of IgG and IgM was found in tumour tissues and human glioma cell lines U87 and U251, and the main expression form was secreted. Decreased IgG inhibited the proliferation and migration of glioma cells. Knockout or knockdown of IgG downregulated the phosphorylation of the key molecules in the MAPK and PI3K/Akt pathway through the HGF/SF-Met or FAK/Src pathway. In vivo tumourigenesis mouse model confirmed that reduced IgG expression inhibited glioma growth.

CONCLUSION

Ig was expressed in glioma tissues and cell lines, and a high expression level predicted a poor prognosis of patients. Glioma-derived IgG promoted glioma cell proliferation and migration through the HGF/SF-Met or FAK/Src pathway.

Dealing With Immunoglobulin Shortages: A Rationalization Plan From Evidence-Based and Data Collection

Background

The demand and consumption of immunoglobulins (IgGs) are growing, and there are many difficulties in obtaining supplies. The aim of the study was to analyze the evolution of IgG consumption and cost over a decade, describe the measures implemented for clinical management in the context of regional public health system, and evaluate the initial impact of these measures.

Methods

We performed a retrospective longitudinal study including patients of all public health systems in Catalonia. First, we analyzed data on consumption and cost of IgGs during a period between 1 January, 2010 and 31 December 2021. Second, we analyzed the impact of a set of regional measures in terms of annual consumption and cost of IgGs. Regional measures were based on rational evidence-based measures and computer registries. We compared the data of year before applying intervention measures (1 January and 31 December 2020) with data of year after applying clinical management interventions (1 January and 31 December 2021). In addition, detailed information on clinical indications of IgG use between 1 January and 31 December 2021 was collected.

Results

Overall, in terms of population, the consumption of IgGs (g/1,000 inhabitants) increased from 40.4 in 2010 to 94.6 in 2021. The mean cost per patient increased from €10,930 in 2010 to €15,595 in 2021. After implementing the measures, the mean annual estimated consumption per patient in 2021 was statistically lower than the mean annual estimated consumption per patient in 2020 (mean difference −47 g, 95% CI −62.28 g, −31.72 g, p = 0.03). The mean annual estimated cost per patient in 2021 was also lower than the mean annual estimated cost per patient in 2020 (the mean difference was –€1,492, 95% CI –€2,132.12, –€851.88; p = 0.027). In 2021, according to evidence-based classification, 75.66% treatments were prescribed for a demonstrated therapeutic evidence-based indication, 12.17% for a developed therapeutic evidence-based indication, 4.66% for non-evidence-based therapeutic role indication, and 8.1% could not be classified because of lack of information.

Conclusion

The annual consumption and cost of IgGs have grown steadily over the last decade in our regional public health system. After implementing a set of regional measures, the annual consumption of IgGs per patient and annual cost per patient decreased. However, the decrease has occurred in the context of the coronavirus disease 2019 (COVID-19) pandemic, which may have influenced their clinical use. Managing the use of IgGs through a rational plan with strategies including evidence-based and data collection may be useful in a shortage situation with growing demand. Registries play a key role in collection of systematic data to analyze, synthesize, and obtain valuable information for decision support. The action developed needs close monitoring in order to verify its effectiveness.

CIDP: Current Treatments and Identification of Targets for Future Specific Therapeutic Intervention

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired immune-mediated inflammatory disorder of the peripheral nervous system. This clinically heterogeneous neurological disorder is closely related to Guillain–Barré syndrome and is considered the chronic counterpart of that acute disease. Currently available treatments are mostly empirical; they include corticosteroids, intravenous immunoglobulins, plasma exchange and chronic immunosuppressive agents, either alone or in combination. Recent advances in the understanding of the underlying pathogenic mechanisms in CIDP have brought a number of novel ways of possible intervention for use in CIDP. This review summarizes selected pre-clinical and clinical findings, highlights the importance of using adapted animal models to evaluate the efficacy of novel treatments, and proposes the outlines of future directions to ameliorate the conditions of patients with CIDP.

High-Concentration Intravenous Immunoglobulin May Influence the Course of Fever and Rate of Reported Treatment Resistance in Children With Kawasaki Disease: A Single-Center Retrospective Analysis

BACKGROUND

Intravenous immunoglobulin (IVIG) resistance in patients with Kawasaki disease (KD) is defined as persistent or recrudescent fever ≥36 hours after IVIG infusion. We have experienced an increase in IVIG resistance in patients with KD since the substitution of 10% IVIG for 5% IVIG. This study aimed to determine the independent association between increased IVIG resistance and 10% IVIG therapy.

METHODS

Medical records of pediatric patients with KD were retrospectively reviewed. Clinical and laboratory characteristics were compared between patients receiving 5% IVIG therapy and those receiving 10% IVIG therapy. Between IVIG-responsive and IVIG-resistant patients, a multivariate analysis was performed to determine the independent factors for IVIG resistance.

RESULTS

A total of 119 patients were included in this study: 81 (68.1%) and 38 (31.9%) patients received 5% and 10% IVIG therapy, respectively. IVIG resistance was identified in 34 (28.6%) patients: 44.7% of patients receiving 10% IVIG therapy and 21.0% of patients receiving 5% IVIG therapy (p = 0.008). The clinical manifestations and outcomes were comparable between patients who received 5% IVIG therapy and those who received 10% IVIG therapy. IVIG resistance was significantly associated with fewer fever days at IVIG administration (p = 0.032), a higher percentage of neutrophils (p = 0.013), and 10% IVIG treatment (p = 0.004) in the multivariate analysis.

CONCLUSION

10% IVIG therapy was significantly associated with increased reporting of IVIG resistance. However, the increase in patients with fever patterns consistent with IVIG resistance seemed to represent adverse febrile reactions resulting from using high-concentration IVIG rather than increased severity of KD.

A New Intravenous Immune Globulin: Novel or Not?

OBJECTIVE

To assess the clinical use and determine the place in therapy for immune globulin intravenous (IV), human-slra, a recently approved IV immune globulin for the treatment of primary immune deficiency diseases (PIDD).

DATA SOURCES

A PubMed and MEDLINE search (2010 to April 2020) was conducted for relevant articles. Data were also obtained from the package insert.

STUDY SELECTION AND DATA EXTRACTION

English language publications regarding the clinical efficacy and safety of immune globulin-slra were analyzed. Publications focused on use of immune globulin products were also included.

DATA SYNTHESIS

Immune globulin-slra is indicated for patients with PIDD and was specifically developed to include donor plasma with high respiratory syncytial virus (RSV) antibody titers. Efficacy was demonstrated through favorable incidence of infections and infection-related complications. Patients treated with immune globulin-slra had increases in anti-RSV neutralizing antibody titers compared with baseline. Adverse events occurred at rates similar to or less than other available immune globulin products.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review describes a new immune globulin product available for use in patients with PIDD. A novel approach to managing patients at risk of serious infections may be to utilize products with formulations proven to not only boost IgG levels, but also antibodies to specific pathogens.

CONCLUSIONS

The choice of which immune globulin product to select for a patient or formulary is complex. Each product is unique, and differences between products should be taken into consideration, along with cost and availability.

Mouse Models of Rheumatoid Arthritis for Studies on Immunopathogenesis and Preclinical Testing of Fc Receptor-Targeting Biologics

<b><i>Background:</i></b> Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes inflammation, swelling, and pain in the joints and involves systemic complications. Mouse models of RA have been extensively used to model the pathogenesis of RA and to develop effective therapies. Although many components of the immune system have been studied in these models, the role of crystallizable fragment (Fc) gamma receptors (FcγRs) in RA has been sorely neglected. The aim of this review was to introduce the different mouse models of RA and to describe the different drug development strategies that have been tested in these models to target FcγR function, with the focus being on drugs that have been made from the Fc of immunoglobulin G (IgG). <b><i>Summary:</i></b> Evidence suggests that FcγRs play a major role in immune complex-induced inflammation in autoimmune diseases, such as RA. However, there is limited knowledge on the importance of FcγRs in the human disease even though there has been extensive work in mouse models of RA. Numerous mouse models of RA are available, with each model depicting certain aspects of the disease. Induced models of RA have nonspecific immune activation with cartilage-directed autoimmunity, whereas spontaneous models of RA develop without immunization, which results in a more chronic form of arthritis. These models have been used to test FcγR-targeting monoclonal antibodies, intravenous immunoglobulin (IVIg), subcutaneously administered IVIg, and recombinant Fcs for their ability to interact with and modify FcγR function. Recombinant Fcs avidly bind FcγRs and exhibit enhanced therapeutic efficacy in mouse models of RA. <b><i>Key Message:</i></b> The therapeutic utility of targeting FcγRs with recombinant Fcs is great and should be explored in human clinical trials for autoimmune diseases, such as RA.

The growing importance of achieving national self-sufficiency in immunoglobulin in Italy. The emergence of a national imperative

Since the inception of industrial plasma fractionation during the Second World War, a succession of protein therapies isolated from plasma have determined the volume of plasma requiring collection, and have also shaped the economics of the industry. These so-called plasma drivers have successively included albumin, coagulation Factor VIII (FVIII) and, for the past thirty years, intravenously (IV) and subcutaneously (SC) administered immunoglobulin (IG) solutions. The sale of IG underpins the profitability of the industry and has experienced continuous growth over the past decades, as the result of growing clinical demand. Modelling this demand using decision analysis indicates that supplying the evidence-based indications for IG therapies will generate a need for IG which exceeds the current plasma collection capacity of most countries. A notable exception to this situation is the United States (US) of America, whose population of compensated plasma donors generates two thirds of the global supply of plasma for fractionation. The US is also the leading consumer of IG, and its health care providers pay the highest price for the product globally. Shortages of IG occur whenever the demand for the product outstrips the supply. Current shortages, following other historical periods of shortage, threaten the well-being of patients dependant on these products and incur heavy costs on health systems. In Italy, the national blood system, which is based on voluntary unpaid donors, reflects a policy of national self-sufficiency in blood-derived therapies (a strategic objective of the national blood system itself), based on solidarity as an ethical principle. This system has increased the collection of plasma for fractionation by 3.8% per annum over 2008-2017, in accordance to a plan for plasma procurement targeting a collection rate of 14.1 L of plasma per thousand (10³) population by 2020. Over the same period, IG usage has increased by 8.5/per annum, to 89.2 g IG/10³ population. In this paper, we review the factors which, increasingly, are causing an imbalance between the global supply and demand for IG, and we assess Italy's capacity to ensure that increasing this level of independence is no longer simply an ethical, but also an economic imperative, with implications for the security of Italy's health system.

Treatment with intravenous immunoglobulins in systemic lupus erythematosus: a single-center experience with 63 patients

BACKGROUND

Intravenous immunoglobulin (IVIG) is prepared using purified human plasma. IVIG therapy has immunomodulatory effects on autoimmune diseases, including severe systemic lupus erythematosus (SLE). However, reports of its effects on large cohorts are scarce.

METHODS

This single-center retrospective study included SLE patients treated with at least one IVIG cycle for SLE complications. Demographic data, indications, cycle numbers, and clinical improvement with IVIG were evaluated. SLE Disease Activity Index 2000 (SLEDAI-2K) scores were calculated at admission and after IVIG treatment in order to measure clinical improvement.

RESULTS

Sixty-three SLE patients treated with IVIG (median age: 29 years; interquartile range 21-36 years; 84.13% female) were included, who received 2 g/kg IVIG for two to five days. Main indications were immune thrombocytopenia, hypogammaglobulinemia, infection during a SLE flare, bicytopenia, and immune hemolytic anemia. Seven patients received more than one IVIG cycle without severe adverse effects. Significant differences were found in SLEDAI-2K scores when the indications were immune thrombocytopenia and hypogammaglobulinemia, with a trend for hemolytic anemia. Patients with concomitant infection, myopathy, and gastrointestinal involvement showed a considerable reduction in their last SLEDAI-2K scores. Fourteen patients died during hospitalization, mainly due to septic shock and active SLE.

CONCLUSIONS

IVIG showed adequate tolerance and effectiveness in selected severe SLE manifestations, mainly hematological involvement. It was useful for concomitant infection.

High level antibodies to TORCH in the IVIG preparation from Taiwanese

BACKGROUND

Congenital TORCH (toxoplasmosis, other viruses [varicella-zoster virus, VZV, etc.], rubella, cytomegalovirus [CMV], Herpes simplex virus [HSV]) infections are major causes of prenatal, perinatal, and postnatal morbidity and mortality. Although treatment or prevention strategies are available for these pathogens, all drugs may not be safe during the pregnancy. The aim of this study is to measure the antibodies (Abs) concentration in the intravenous immunoglobulin (IVIG) preparation to evaluate the therapeutic potential for TORCH infection.

METHODS

We tested the only one commercial IVIG preparation from Taiwanese for the presence of Abs against Toxoplasma gondii, VZV, Epstein-Barr virus (EBV), measles, mumps, rubella, CMV, HSV type 1 (HSV-1), and HSV type 2 (HSV-2) by using enzyme-linked immunosorbent assay or chemiluminescent microparticle immunoassay.

RESULTS

In our study, the median level (range) of anti-CMV immunoglobulin G (IgG) is > 250 (All > 250) (arbitrary unit, AU)/mL, anti-EBV > 200 (All > 200) (relative unit, RU)/mL, anti-HSV > 200 (152.75 to >200) RU/mL, anti-VZV > 5000 (All > 5000) IU/L, anti-measles > 5000 (All > 5000) IU/L, anti-mumps > 200 (156.5 to > 200) RU/mL, anti-rubella 209.8 IU/mL (192.7 to 238.5), and anti-Toxoplasma is 14.05 (12.3 to 16) IU/mL. There was not any immunoglobulin M (IgM) against HSV, VZV, mumps, measles, rubella, CMV, EBV, and Toxoplasma in the "Taiwan Blood Services Foundation" IVIG preparations.

CONCLUSION

There was high activity against T. gondii, VZV, EBV, measles, mumps, rubella, CMV, HSV-1, and HSV-2 in all IVIG batches. Further investigation is warranted to confirm the efficacy of IVIG from Taiwanese for congenital TORCH infections.

Two comparative assessments of intravenous immunoglobulin therapy switching patterns in the treatment of chronic inflammatory demyelinating polyneuropathy in the US

Purpose: For chronic inflammatory demyelinating polyneuropathy (CIDP) patients, each branded intravenous immunoglobulin (IVIG) treatment differs in production processes, virus elimination, formulation, and composition. Given the limited availability of real-world data comparing IVIGs for CIDP, this study evaluated switching patterns between IVIG products in 2 separate retrospective databases. Patients and methods: Two independent analytic teams retrospectively evaluated IVIG treatment-naïve patients with an ICD diagnosis code for CIDP. Study 1 used integrated healthcare claims from IMS LifeLink PharMetrics Plus™ and Study 2 used the Truven MarketScan® Database. All analyses were descriptive, with outcomes assessed during the 2-year post-index period. Results: One-quarter of IVIG patients switched therapies within the 2-year study period. In both studies, switching rates were lowest for IVIG-G (Gamunex®-C) (Study 1: 9.8%, Study 2: 8.9%), followed by IVIG-F (Flebogamma®) (Study 1: 25.0%, Study 2: 18.2%), and highest for IVIG-other (Octagam®/Gammaplex®) (Study 1: 50.0%, Study 2: 33.3%). When patients were switched, most switched to IVIG-G (Study 1: 51.6%, Study 2: 54.3%). Conclusion: The small proportion of CIDP switchers in 2 independent studies suggests that IVIG therapy is generally well tolerated. However, differences existed in switch rates for different IVIG products. The reason for low switching rates could not be assessed in this study; therefore, further studies are required to detect possible relevant differences in effectiveness and tolerability.

Analysis of sialic acid levels in Chinese intravenous immunoglobulins by high-performance liquid chromatography with fluorescence detection

Intravenous immunoglobulin (IVIg) is increasingly used for the treatment of autoimmune and systemic inflammatory diseases with both licensed and off-label indications. Recent studies indicated that IVIg-mediated immunomodulation and anti-inflammation are closely associated with the IgG sialylation, especially with IgG crystallizable fragment (Fc) sialylation. The sialic acid levels of the IgG molecules and Fc fragments in 12 IVIg preparations from six Chinese manufacturers were evaluated. The Fc fragments were derived from the papain digestion of IVIg, followed by affinity and size exclusion chromatography. The sialic acid levels in Fc fragments and IVIg preparations were determined by high-performance liquid chromatography with fluorescence detection, after the sialic acid residues were released from the proteins. The results showed that the sialic acid levels in Chinese IVIg preparations ranged from 0.875 (mol/mol IgG) to 1.085 (mol/mol IgG), and the sialic acid levels in Fc fragments were from 0.321 (mol/mol Fc) to 0.361 (mol/mol Fc). Furthermore, the sialic acid levels of IVIg preparations and Fc fragments from different Chinese manufactures were significantly different. These findings will contribute to an increased understanding of Chinese IVIg preparations and the relationship between the sialic acid levels in IVIg preparations and their clinical efficacy in future clinical studies.

Low Rates of Poliovirus Antibodies in Primary Immunodeficiency Patients on Regular Intravenous Immunoglobulin Treatment

PURPOSE

Poliovirus has been nearly eliminated as part of a world-wide effort to immunize and contain circulating wild-type polio. Nevertheless, poliovirus has been detected in water supplies and represents a threat to patients with humoral immunodeficiencies where infection can be fatal. To define the risk, we analyzed antibodies to poliovirus 1, 2, and 3 in serum samples collected over a year from patients with primary immunodeficiency diseases (PID) on regular intravenous immunoglobulin (IVIG) replacement.

METHODS

Twenty-one patients on regular IVIG replacement therapy were evaluated: Twelve patients with common variable immune deficiency (CVID), six with X-linked agammaglobulinemia (XLA), and three with hyper IgM syndrome (HIGM). Over 1 year, four blood samples were collected from each of these patients immediately before immunoglobulin infusion. One sample of IVIG administered to each patient in the month before blood collection was also evaluated. Poliovirus antibodies were quantified by seroneutralization assay.

RESULTS

All IVIG samples had detectable antibodies to the three poliovirus serotypes. Despite that, only 52.4, 61.9, and 19.0% of patients showed protective antibody titers for poliovirus 1, 2, and 3, respectively. Only two patients (9.5%) had protective antibodies for the three poliovirus serotypes on all samples. Most patients were therefore susceptible to all three poliovirus serotypes.

CONCLUSIONS

This study demonstrates the need for ongoing vigilance regarding exposure of patients with PID to poliovirus in the community.

A Retrospective Analysis of the Safety Profile of Intravenous Immunoglobulin in 1176 Patients Receiving Home Infusion Therapy

OBJECTIVES

This analysis assessed the safety of intravenous immunoglobulin (IVIg) in the treatment of patients with neuroimmunological and immunological disorders in a home-based setting.

METHODS

Adverse reactions (ARs) were assessed in a retrospective review of 1176 patients receiving 28,677 home-based IVIg infusions between 1996 and 2013.

RESULTS

Of 1176 patients, 648 (55.1%) experienced IVIg-related ARs; 536 (45.6%) were mild, 78 (6.6%) moderate, and 34 (2.9%) severe. Thirty-seven (3.1%) patients were hospitalized because of ARs; of these, headache was most common (51.4%). Mean number of ARs per patient increased from 1.4 (low dose) to 3.6 (high dose). Incidence of ARs increased from 41% in the first 5-year moving average in 2003 to 65% in 2008. The number of ARs correlated with the number of infusions (ρ = 0.24; P < 0.001) and the average IVIg dose (ρ = 0.10; P < 0.001).

CONCLUSIONS

Low- and high-dose IVIg were safe and well tolerated with a few serious ARs in patients with neuroimmunological and immunological disorders.

In vitro evaluation of the biological activities of IgG in seven Chinese intravenous immunoglobulin preparations

The IgG activities of antigen recognition, Fc-mediated complement activation and cellular Fcγ-receptors (FcγRs) binding are critical for intravenous immunoglobulin (IVIg) immunotherapy in a variety of immune deficiency diseases. Further, these activities could be influenced by different plasma sources and the IVIg manufacturing processes of different manufacturers. This study evaluated and compared the biological activities of IgG in 7 IVIg preparations produced by different Chinese manufacturers. By using ELISA and two-dimensional immunoblotting, the binding capacity and antibody repertoire of IVIg against typical pathogenic antigens were investigated. Further, Fc-mediated complement activation and receptor binding activities were measured by the haemolysis method and flow-cytometric assay respectively. The results showed that all of the preparations tested have a broad spectrum of antibodies against the E. coli O157:H7 proteome, and each IVIg has its own distinct antibody repertoire. Compared to the European Pharmacopoeia IgG standard, the mean indices of the pathogenic antigen binding capacity, complement activation activity and FcγRs binding activity in Chinese preparations were 152%, 143% and 87%. The biological activities varied widely among the 7 IVIg preparations, and no significant differences were observed between the different batches of most IVIgs from the same manufacturer. This study will contribute to the improvement of the IVIg product quality evaluation system and an increased understanding of the variety of IgG biological activities in Chinese IVIg preparations.

Historical Aspects of Polyclonal IgG Preparations

Today we can choose between several polyclonal IgG products for both replacement and immunomodulation. However, it was a long way to go to reach this stage. In this chapter, we try to illustrate the major stages of IgG product development which began more than 70 years ago.

Demonstration of the IgG antibody repertoire against the bacteria Escherichia coli in Chinese intravenous immunoglobulins

Intravenous immunoglobulin (IVIg) is produced by pooling plasma from thousands of healthy blood donors, and the diversity of the antibody is critical for the clinical efficacy of IVIg. This study investigated the antibody diversity of Chinese IVIg. Firstly, 2-dimensional gel electrophoresis and immunoblotting with protein extracts of Escherichia coli (E. coli) O157:H7 were used to study IgG antibody repertoire of 8 IVIg preparations from different Chinese manufacturers. This was followed by the identification of the antibody-reactive proteins of E. coli by mass spectrometry and the sequence similarity of the proteins was aligned by bioinformatics analysis. The results showed that all IVIg preparations expressed a large range of antibody reactivities against E. coli proteins. 94-238 antigens were recognized by the 8 IVIg preparations. 33 interesting target antigens were selected and identified as 29 different proteins, mainly including membrane proteins, molecular chaperones, metabolism enzymes, and proteins involved in cell cycle processes. Additionally, these antigens were highly conserved proteins which were found extensively in a variety of other pathogenic microorganisms. Our study indicated that Chinese IVIg preparations recognized a large range of high conserved proteins which play key roles in pathogenic microorganisms, and showed each IVIg had its own distinct antibody repertoire.

Immune recruitment or suppression by glycan engineering of endogenous and therapeutic antibodies

Human serum IgG contains multiple glycoforms which exhibit a range of binding properties to effector molecules such as cellular Fc receptors. Emerging knowledge of how the Fc glycans contribute to the antibody structure and effector functions has opened new avenues for the exploitation of defined antibody glycoforms in the treatment of diseases. Here, we review the structure and activity of antibody glycoforms and highlight developments in antibody glycoengineering by both the manipulation of the cellular glycosylation machinery and by chemoenzymatic synthesis. We discuss wide ranging applications of antibody glycoengineering in the treatment of cancer, autoimmunity and inflammation. This article is part of a Special Issue entitled "Glycans in personalised medicine" Guest Editor: Professor Gordan Lauc.

PROTECTIVE LEVELS OF VARICELLA-ZOSTER ANTIBODY DID NOT EFFECTIVELY PREVENT CHICKENPOX IN AN X-LINKED AGAMMAGLOBULINEMIA PATIENT

We describe the case of an eight-year-old boy with X-linked agammaglobulinemia who developed mild varicella despite regular intravenous immunoglobulin (IVIG) therapy. He maintained protective antibody levels against varicella and the previous batches of IVIG that he received had adequate varicella-specific IgG levels. The case illustrates that IVIG may not prevent VZV infection.

Protection from experimental autoimmune encephalomyelitis by polyclonal IgG requires adjuvant-induced inflammation

Background

Intravenous immunoglobulin (IVIG) proved to be an efficient anti-inflammatory treatment for a growing number of neuroinflammatory diseases and protects against the development of experimental autoimmune encephalomyelitis (EAE), a widely used animal model for multiple sclerosis (MS).

Methods

The clinical efficacy of IVIG and IVIG-derived F(ab’)₂ fragments, generated using the streptococcal cysteine proteinase Ide-S, was evaluated in EAE induced by active immunization and by adoptive transfer of myelin-specific T cells. Frequency, phenotype, and functional characteristics of T cell subsets and myeloid cells were determined by flow cytometry. Antibody binding to microbial antigen and cytokine production by innate immune cells was assessed by ELISA.

Results

We report that the protective effect of IVIG is lost in the adoptive transfer model of EAE and requires prophylactic administration during disease induction. IVIG-derived Fc fragments are not required for protection against EAE, since administration of F(ab’)₂ fragments fully recapitulated the clinical efficacy of IVIG. F(ab’)₂-treated mice showed a substantial decrease in splenic effector T cell expansion and cytokine production (GM-CSF, IFN-γ, IL-17A) 9 days after immunization. Inhibition of effector T cell responses was not associated with an increase in total numbers of Tregs but with decreased activation of innate myeloid cells such as neutrophils, monocytes, and dendritic cells. Therapeutically effective IVIG-derived F(ab’)₂ fragments inhibited adjuvant-induced innate immune cell activation as determined by IL-12/23 p40 production and recognized mycobacterial antigens contained in Freund’s complete adjuvant which is required for induction of active EAE.

Conclusions

Our data indicate that F(ab’)₂-mediated neutralization of adjuvant contributes to the therapeutic efficacy of anti-inflammatory IgG. These findings might partly explain the discrepancy of IVIG efficacy in EAE and MS.

Comparison of Fc N-Glycosylation of Pharmaceutical Products of Intravenous Immunoglobulin G

Intravenous immunoglobulin (IVIg) products from different pharmaceutical companies vary in composition, in part because of the selected blood donors and production process. N-glycosylation of the Fc-portion of IgG varies between blood donors and may influence both the side-effects and therapeutic effectiveness of IVIg. At present, the variation in Fc N-glycosylation between IVIg products has not been defined. Utilizing mass spectrometry, we performed relative quantitation of the Fc N-glycosylation of IgG, assessing a total of 154 unique lot numbers of IVIg. Seven products showed comparable Fc N-glycosylation, with only one product differing from the others in all glycosylation features (galactosylation, sialylation, fucosylation and bisecting N-acetylglucosamine). However, the mean difference did not exceed 3%. Within product variation was present to a minor degree, but largely indistinguishable from analytical variation. In conclusion, we expect that the minor variation in Fc N-glycosylation between IVIg products has a small effect, if any, on the biological activity.

[Intravenous immunoglobulin in treatment of autoimmune neurological diseases in children]

Though the mechanisms of action of intravenous immunoglobulins (IVIG) are not completely understood, these drugs are widely used in treatment of autoimmune diseases. In this review, we have analyzed the literature on the use of IVIG in the treatment of autoimmune diseases of the nervous system in children and discuss the management of patients basing on the recommendation of the European Federation of Neurological Societies. The efficacy of IVIG in children has been shown as first line treatment in Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, dermatomyositis as a second-line drug in the combination with prednisolone or immunosuppressors in patients refractory to treatment with corticosteroids and cytostatics, myasthenic crisis in myasthenia gravis, exacerbations and short-term treatment of severe forms, non-responsiveness to acetylcholinesterase inhibitors, multiple sclerosis as second or third line of treatment in patients with relapsing-remitting course with intolerance to standard immunomodulatory therapy, acute multiple encephalomyelitis with no response to the treatment with high doses of corticosteroids, paraneoplastic syndromes, pharmacoresistant epilepsy and autoimmune encephalitis. Because the right choice of the drug plays a key role, in particular, in children, that determines the efficacy and safety of the treatment, we present the main approaches to the choice of the drug and schemes of treatment of autoimmune diseases of the nervous system in children.

Controlled tetra-Fc sialylation of IVIg results in a drug candidate with consistent enhanced anti-inflammatory activity

Despite the beneficial therapeutic effects of intravenous immunoglobulin (IVIg) in inflammatory diseases, consistent therapeutic efficacy and potency remain major limitations for patients and physicians using IVIg. These limitations have stimulated a desire to generate therapeutic alternatives that could leverage the broad mechanisms of action of IVIg while improving therapeutic consistency and potency. The identification of the important anti-inflammatory role of fragment crystallizable domain (Fc) sialylation has presented an opportunity to develop more potent Ig therapies. However, translating this concept to potent anti-inflammatory therapeutics has been hampered by the difficulty of generating suitable sialylated products for clinical use. Therefore, we set out to develop the first, to our knowledge, robust and scalable process for generating a well-qualified sialylated IVIg drug candidate with maximum Fc sialylation devoid of unwanted alterations to the IVIg mixture. Here, we describe a controlled enzymatic, scalable process to produce a tetra-Fc-sialylated (s4-IVIg) IVIg drug candidate and its qualification across a wide panel of analytic assays, including physicochemical, pharmacokinetic, biodistribution, and in vivo animal models of inflammation. Our in vivo characterization of this drug candidate revealed consistent, enhanced anti-inflammatory activity up to 10-fold higher than IVIg across different animal models. To our knowledge, this candidate represents the first s4-IVIg suitable for clinical use; it is also a valuable therapeutic alternative with more consistent and potent anti-inflammatory activity.

Structural characterization of anti-inflammatory immunoglobulin G Fc proteins

Immunoglobulin G (IgG) is a central mediator of host defense due to its ability to recognize and eliminate pathogens. The recognition and effector responses are encoded on distinct regions of IgGs. The diversity of the antigen recognition Fab domains accounts for IgG's ability to bind with high specificity to essentially any antigen. Recent studies have indicated that the Fc effector domain also displays considerable heterogeneity, accounting for its complex effector functions of inflammation, modulation, and immune suppression. Therapeutic anti-tumor antibodies, for example, require the pro-inflammatory properties of the IgG Fc to eliminate tumor cells, while the anti-inflammatory activity of intravenous IgG requires specific Fc glycans for activity. In particular, the anti-inflammatory activity of intravenous IgG is ascribed to a small population of IgGs in which the Asn297-linked complex N-glycans attached to each Fc CH2 domain include terminal α2,6-linked sialic acids. We used chemoenzymatic glycoengineering to prepare fully disialylated IgG Fc and solved its crystal structure. Comparison of the structures of asialylated Fc, sialylated Fc, and F241A Fc, a mutant that displays increased glycan sialylation, suggests that increased conformational flexibility of the CH2 domain is associated with the switch from pro-inflammatory to anti-inflammatory activity of the Fc.

Antibody levels to tetanus, diphtheria, measles and varicella in patients with primary immunodeficiency undergoing intravenous immunoglobulin therapy: a prospective study

BACKGROUND

Patients with antibody deficiencies depend on the presence of a variety of antibody specificities in intravenous immunoglobulin (IVIG) to ensure continued protection against pathogens. Few studies have examined levels of antibodies to specific pathogens in IVIG preparations and little is known about the specific antibody levels in patients under regular IVIG treatment. The current study determined the range of antibodies to tetanus, diphtheria, measles and varicella in IVIG products and the levels of these antibodies in patients undergoing IVIG treatment.

METHODS

We selected 21 patients with primary antibody deficiencies who were receiving regular therapy with IVIG. Over a period of one year, we collected four blood samples from each patient (every 3 months), immediately before immunoglobulin infusion. We also collected samples from the IVIG preparation the patients received the month prior to blood collection. Antibody levels to tetanus, diphtheria, measles and varicella virus were measured in plasma and IVIG samples. Total IgG levels were determined in plasma samples.

RESULTS

Antibody levels to tetanus, diphtheria, varicella virus and measles showed considerable variation in different IVIG lots, but they were similar when compared between commercial preparations. All patients presented with protective levels of antibodies specific for tetanus, measles and varicella. Some patients had suboptimal diphtheria antibody levels. There was a significant correlation between serum and IVIG antibodies to all pathogens, except tetanus. There was a significant correlation between diphtheria and varicella antibodies with total IgG levels, but there was no significant correlation with antibodies to tetanus or measles.

CONCLUSIONS

The study confirmed the variation in specific antibody levels between batches of the same brand of IVIG. Apart from the most common infections to which these patients are susceptible, health care providers must be aware of other vaccine preventable diseases, which still exist globally.

Guidelines for the use of human immunoglobulin therapy in patients with primary immunodeficiencies in Latin America

Antibodies are an essential component of the adaptative immune response and hold long-term memory of the immunological experiences throughout life. Antibody defects represent approximately half of the well-known primary immunodeficiencies requiring immunoglobulin replacement therapy. In this article, the authors review the current indications and therapeutic protocols in the Latin American environment. Immunoglobulin replacement therapy has been a safe procedure that induces dramatic positive changes in the clinical outcome of patients who carry antibody defects.

Comparative effectiveness of intravenous immunoglobulin from different manufacturing processes on Kawasaki disease

BACKGROUND

The comparative effectiveness of intravenous immunoglobulin (IVIG) for Kawasaki disease was regarded as inconclusive in the international guidelines. However, several new evidences have been published in recent years.

DATA SOURCES

A literature search of PubMed was conducted using key words of "Kawasaki disease or mucocutaneous lymph node syndrome" and "immunoglobulin" in combination. Only original articles published after 2004 were selected. A total of 813 papers were found in PubMed. These papers were screened manually by their titles and abstracts.

RESULTS

Patients treated with IVIG prepared by betapropiolactonation might have worse outcome (a higher non-responsive rate in one report and a higher rate of coronary aneurysm in two reports). Storage of IVIG in acidic solution might be correlated with a higher rate of coronary aneurysm (two reports).

CONCLUSIONS

Different processes of preparation and conditions of preservation of IVIG may have profound effects on its clinical effectiveness. Randomized controlled studies are needed to further elucidate this issue.

Development, manufacturing and characterization of a highly purified, liquid immunoglobulin g preparation from human plasma

BACKGROUND

The use of plasma-derived immunoglobulin G (IgG) is increasing, and the number of diseases, including immunodeficiencies, neurological diseases and autoimmune conditions, treated with intravenous IgG (IVIG) is expanding. Consequently, there is a great need for high-yield production processes for plasma-derived IgG. The aim of this work was to develop a high-yield process leading to a highly purified, liquid, ready-to-use IgG for intravenous use.

METHODS

Plasma from healthy, voluntary, non-remunerated donors was fractionated by ethanol precipitation. IgG was extracted from fraction II + III using a phosphate/acetate buffer, pH 4, and purified by chromatography.

RESULTS

Precipitation with 6% polyethylene glycol at pH 7 removed high molecular-weight contaminating proteins, aggregates and contaminating viruses. Ion exchange chromatography at pH 5.7 on serially connected anion and cation exchange columns allowed for elution of IgG from the cation exchange column in good yield and high purity. Further safety was achieved by solvent/detergent treatment and repeated ion exchange chromatography. The product consisted of essentially only IgG monomers and dimers, and had a high purity with very low levels of IgM and IgA.

CONCLUSION

A process providing highly purified IVIG in good yield was developed.

The expanding role of therapeutic antibodies

Therapeutic antibodies have been used since the end of nineteenth century, but their use is progressively increased and recently, with the availability of monoclonal antibodies, they are successfully employed in a large disease spectrum, which transversally covers different fields of medicine. Hyperimmune polyclonal immune globulin has been used against infectious diseases, in a period in which anti-microbial drugs were not yet available, and it still maintains a relevant place in prophylaxis/therapy. Although immune globulin should be considered life-saving as replacement therapy in humoral immunodeficiencies, its place in the immune-modulating treatment is not usually first-choice, but it should be considered as support to standard approved treatments. Despite therapeutic monoclonal antibodies have been lastly introduced in therapy, their extreme potentiality is reflected by the large number of approved molecules, addressed toward different immunological targets and able to heavily influence the prognosis and quality of life of a wide range of different diseases.

Polyclonal and monoclonal antibodies in clinic

Immunoglobulins (Ig) or antibodies are heavy plasma proteins, with sugar chains added to amino-acid residues by N-linked glycosylation and occasionally by O-linked glycosylation. The versatility of antibodies is demonstrated by the various functions that they mediate such as neutralization, agglutination, fixation with activation of complement and activation of effector cells. Naturally occurring antibodies protect the organism against harmful pathogens, viruses and infections. In addition, almost any organic chemical induces antibody production of antibodies that would bind specifically to the chemical. These antibodies are often produced from multiple B cell clones and referred to as polyclonal antibodies. In recent years, scientists have exploited the highly evolved machinery of the immune system to produce structurally and functionally complex molecules such as antibodies from a single B clone, heralding the era of monoclonal antibodies. Most of the antibodies currently in the clinic, target components of the immune system, are not curative and seek to alleviate symptoms rather than cure disease. Our group used a novel strategy to identify reparative human monoclonal antibodies distinct from conventional antibodies. In this chapter, we discuss the therapeutic relevance of both polyclonal and monoclonal antibodies in clinic.

A controlled trial of intravenous immunoglobulin in multifocal motor neuropathy

Intravenous immunoglobulin (IVIG) has become the standard treatment for multifocal motor neuropathy (MMN) based on limited data. To critically assess the efficacy, safety, and tolerability of 10% liquid IVIG (IVIG), 44 adults with MMN were randomized 1 : 1 to either double-blind treatment of IVIG followed by placebo for 12 weeks each or the reverse. Open-label IVIG was administered for 12 weeks at the beginning and end of the study for clinical stabilization, and between double-blinded periods to prevent a carry-over effect. To avoid potential worsening, switching to open-label IVIG was permitted if deterioration occurred during blinded treatment. Mean maximal grip strength of the more affected hand declined 31.38% during placebo and increased 3.75% during IVIG (p = 0.005). In 35.7% of participants, Guy's Neurological Disability scores for upper limbs worsened during placebo and not during IVIG, whereas the converse was true in 11.9% (p = 0.021). Sixty-nine percent (69.0%) switched prematurely from placebo to open-label IVIG and 2.4% switched from blinded to open-label IVIG (p < 0.001). One serious adverse reaction (pulmonary embolism) and 100 non-serious reactions (69 mild, 20 moderate, and 11 severe) to IVIG occurred. IVIG was effective in improving disability and muscle strength, and was safe and well tolerated in adults with MMN.

Production of intravenous human dengue immunoglobulin from Brazilian-blood donors

Dengue represents an important health problem in Brazil and therefore there is a great need to develop a vaccine or treatment. The neutralization of the dengue virus by a specific antibody can potentially be applied to therapy. The present paper describes, for the first time, the preparation of Immunoglobulin specific for the dengue virus (anti-DENV IgG), collected from screened Brazilian blood-donations. Production was performed using the classic Cohn-Oncley process with minor modifications. The anti-DENV IgG was biochemically and biophysically characterized and fulfilled the requirements defined by the European Pharmacopoeia. The finished product was able to neutralize different virus serotypes (DENV-1, DENV-2, and DENV-3), while a commercial IgG collected from American blood donations was found to have low anti-dengue antibody titers. Overall, this anti-DENV IgG represents an important step in the study of the therapeutic potential and safety of a specific antibody that neutralizes the dengue virus in humans.

Polyclonal immunoglobulin G for autoimmune demyelinating nervous system disorders

Demyelinating diseases with presumed autoimmune pathogenesis are characterised by direct or indirect immune-mediated damage to myelin sheaths, which normally surround nerve fibres to ensure proper electrical nerve conduction. Parenteral administration of polyclonal IgG purified from multi-donor human plasma pools may beneficially modulate these misguided immune reactions via several mechanisms that are outlined in this review. Convincing therapeutic evidence from controlled trials now exists for certain disorders of the peripheral nervous system, including Guillain-Barré syndrome, chronic inflammatory demyelinating polyradiculoneuropathy, and multifocal motor neuropathy. In addition, there is evidence for potential therapeutic benefits of IgG in patients with chronic inflammatory demyelinating diseases of the central nervous system, including multiple sclerosis and neuromyelitis optica. This review introduces these disorders, briefly summarises the established treatment options, and discusses therapeutic evidence for the use of polyclonal immunoglobulins with a particular emphasis on recent clinical trials and meta-analyses.

Intravenous immunoglobulin and Alzheimer's disease: what now?

Intravenous immunoglobulin (IVIG) products are prepared from purified plasma immunoglobulins from large numbers of healthy donors. Pilot studies with the IVIG preparations Octagam and Gammagard in individuals with mild-to-moderate Alzheimer’s disease (AD) suggested stabilization of cognitive functioning in these patients, and a phase II trial with Gammagard reported similar findings. However, subsequent reports from Octagam’s phase II trial and Gammagard’s phase III trial found no evidence for slowing of AD progression. Although these recent disappointing results have reduced enthusiasm for IVIG as a possible treatment for AD, it is premature to draw final conclusions; a phase III AD trial with the IVIG product Flebogamma is still in progress. IVIG was the first attempt to use multiple antibodies to treat AD. This approach should be preferable to administration of single monoclonal antibodies in view of the multiple processes that are thought to contribute to AD neuropathology. Development of “AD-specific” preparations with higher concentrations of selected human antibodies and perhaps modified in other ways (such as increasing their anti-inflammatory effects and/or ability to cross the blood–brain barrier) should be considered. Such preparations, if generated with recombinant technology, could overcome the problems of high cost and limited supplies, which have been major concerns relating to the possible widespread use of IVIG in AD patients. This review summarizes the recent AD IVIG trials and discusses the major issues relating to possible use of IVIG for treating AD, as well as the critical questions which remain.

Comparative effectiveness of intravenous immunoglobulin for children with Kawasaki disease: a nationwide cohort study

Introduction

Different immunoglobulin manufacturing processes may influence its effectiveness for Kawasaki disease. However, nationwide studies with longitudinal follow-up are still lacking. The aim of this study was to evaluate the comparative effectiveness of immunoglobulin preparations from a nationwide perspective.

Materials and Methods

This is a nationwide retrospective cohort study with a new user design. Data came from the National Health Insurance Research Database of Taiwan. From 1997 to 2008, children under 2 years old who received immunoglobulin therapy for the first time under the main diagnosis of Kawasaki disease were enrolled. The manufacturing processes were divided into β-propiolactonation, acidification and those containing IgA. The endpoints were immunoglobulin non-responsiveness, acute aneurysm, prolonged use of anti-platelets or anti-coagulants, and recurrence.

Results

In total, 3830 children were enrolled. β-propiolactonation had a relative risk of 1.45 (95% CI 1.08∼1.94) of immunoglobulin non-responsiveness, however, the relative risks for acidification and containing IgA were non-significant. For acute aneurysms, acidification had a relative risk of 1.49 (95% CI 1.17∼1.90), however the relative risks for β-propiolactonation and containing IgA were non-significant. For prolonged use of anti-platelets or anti-coagulants, β-propiolactonation had a relative risk of 1.44 (95% CI 1.18∼1.76), and acidification protected against them both with a relative risk of 0.82 (95% CI 0.69∼0.97), whereas the relative risk for containing IgA was non-significant. For recurrence, all three factors were non-significant.

Conclusions

The effectiveness of immunoglobulin may differ among different manufacturing processes. β-propiolactonation had a higher risk of treatment failure and prolonged use of anti-platelets or anti-coagulants. Acidification may increase the risk of acute coronary aneurysms.

Intravenous immunoglobulin therapy: how does IgG modulate the immune system?

Intravenous immunoglobulin (IVIG) preparations comprise pooled IgG antibodies from the serum of thousands of donors and were initially used as an IgG replacement therapy in immunocompromised patients. Since the discovery, more than 30 years ago, that IVIG therapy can ameliorate immune thrombocytopenia, the use of IVIG preparations has been extended to a wide range of autoimmune and inflammatory diseases. Despite the broad efficacy of IVIG therapy, its modes of action remain unclear. In this Review, we cover the recent insights into the molecular and cellular pathways that are involved in IVIG-mediated immunosuppression, with a particular focus on IVIG as a therapy for IgG-dependent autoimmune diseases.

Nursing guidelines for administration of immunoglobulin replacement therapy

Immunoglobulin (Ig) replacement therapy, given as regular infusions of pooled human Ig, is the recognized treatment of humoral immunodeficiencies characterized by hypogammaglobulinemia and impaired antibody responses. It is a safe, effective therapy when delivered by nurses who have been educated to oversee and/or provide these infusions. Guidelines for administration have been developed by the Immune Deficiency Foundation Nurse Advisory Committee to provide a framework and guidance to those nurses administering this therapy.

In vitro and in vivo properties differ among liquid intravenous immunoglobulin preparations

Objective To compare in vitro and in vivo biological and biochemical properties of five liquid intravenous immunoglobulin (IVIg) preparations licensed for therapeutic use in Europe.

Methods ClairYg® was compared in a blinded manner to four other liquid IVIg preparations licensed in Europe (Octagam®, Kiovig®, Gamunex®, Privigen®). Three batches of each preparation were tested, except for the IgG repertoires and the animal model.

Results Levels of anti-A and anti-B antibodies were lower in ClairYg® (0·11/0·11) relative to a positive EDQM standard and Octagam® (0·11/0·08) than in other preparations (0·33–0·69/0·42–0·46). IgG in ClairYg® recognized 365 and 416 protein spots in HEp-2 cell and Escherichia coli protein extracts vs. 230–330 and 402–842 protein spots, respectively, for IgG in other preparations. IgA content (301 vs. 165–820 ng/mg of IgG), Factor XI and Factor XII antigen (0·46 vs. 0·85–2·40 mU/mg of IgG and 7·8 vs. 20·0–46·2 lU/mg of IgG) C1q binding (0·42 vs. 0·67–1·89 arbitrary units) and C5a uptake (0·41 vs. 0·45–0·66% of activation) were lower in ClairYg® than in other preparations. Finally, intravenous infusion of ClairYg®, Gamunex® and Privigen® had no major effect on arterial blood pressure in spontaneously hypertensive rats.

Conclusions Our results evidence some differences in the biological and biochemical properties among licensed liquid IVIg preparations.

Payor issues: barriers to optimal management of patients with primary immunodeficiency

Since 2005, when changes in Medicare reimbursement for IgG replacement therapy went into effect, physicians and patients with primary immunodeficiency disease (PIDD) have encountered a number of challenges to administering and receiving appropriate immunoglobulin therapy. A 2006 membership survey conducted by the American Academy of Allergy, Asthma & Immunology found that 95 % of responders thought that the health of their patients was at risk due to Medicare changes; many patient surveys also found a significant number adversely affected by these changes. Decisions critical for optimal care being made by third-party payors are often in conflict with guidelines on recommended standard of care. Many payors, for example, are dictating where infusions can occur despite evidence clearly demonstrating that choice of the site of care needs to be determined by the particular patient's circumstance and experience. Another critical issue is the lack of product availability due to the determination by payors of which IgG products appear on formularies. Patients, physicians, and payors all bring their own perspective to these issues, and finding a solution to these challenges requires balancing the needs of all three groups.