Intravenous immunoglobulin G: trends in production methods, quality control and quality assurance

Two Patients with Therapy-Resistant Pemphigus Vulgaris and Severe Underlying Disease Showing Good Response to a New IVIg Preparation

Pemphigus vulgaris is a severe and often therapy-resistant bullous autoimmune disease. Standard therapy with steroids often administered together with another immunosuppressant does not respond in all patients or may not be a good therapeutic option in patients with severe underlying diseases. Intravenous immunoglobulins (IVIgs) represent a treatment alternative, often showing a rapid response which allows one to reduce concomitant immunosuppression. Here, we report on two patients with a complex disease history suffering from severe pemphigus vulgaris who received treatment with a new IVIg preparation (Yimmugo®, 2 g per kg body weight every 4 weeks). IVIg preparations differ regarding manufacturing process and show a varying side effect profile. Both of our patients did not experience any side effects from IVIgs and showed a significant improvement of skin and mucosal erosions. More reports on IVIgs are desirable to help in selecting the optimal preparation and dosing regarding tolerability and effectiveness for individual patients.

Passive Immunisation in the Treatment of Infectious Diseases Related to Highly Potent Bacterial Toxins

The discovery of microbial toxins as the primary factors responsible for disease manifestations and the discovery that these toxins could be neutralised by antitoxins are linked to the birth of immunology. In the late 19th century, the serum or plasma of animals or patients who had recovered from infectious diseases or who had been immunised with a relevant antigen began to be used to treat or prevent infections. Before the advent of widespread vaccination campaigns, antitoxins played a key role in the treatment and prevention of diseases such as diphtheria and tetanus. A significant reduction in mortality following the introduction of antitoxins confirmed their efficacy. Serum therapy remains an important measure for post-exposure prophylaxis and for the treatment of unvaccinated or incompletely vaccinated patients. For the botulinum toxin, antitoxin therapy continues to be the sole available treatment. The manuscript contains a summary of the most important information on the passive immunoprophylaxis used in the treatment of diphtheria, tetanus, and botulism, all representing diseases in which symptoms are driven by the activity of highly potent bacterial toxins.

Non-allergic Hypersensitivity Reactions to Immunoglobulin Preparations in Antibody Deficiencies: What Role for Anti-IgA IgG and Complement Activation?

The presence of IgG anti-IgA in the serum of primary immunodeficiency (PID) patients has long been considered responsible for hypersensitivity (HS) to immunoglobulin preparations (IgPs), but this link is increasingly being questioned. The aim of this work was to describe the prevalence of IgG anti-IgA and its association with HS, and to explore a new pathophysiological hypothesis involving the complement system. We measured IgG anti-IgA, using a standardised commercial technique, in controls and PID patients, and compared our results to a systematic literature review. We measured complement activation in PID patients before and after IgP infusion, and in vitro after incubation of IgP with serum from controls and PID patients. IgG anti-IgA was detected in 6% (n = 2/32) of PID patients, 30% (n = 3/10) of selective IgA deficiency patients and 2% (n = 1/46) of healthy controls. In the literature and our study, 38 PID patients had IgG anti-IgA and HS to IgPs and 9 had IgG anti-IgA but good tolerance to IgPs. In our patients, we observed a constant complement activation after IgP infusion compared to baseline. In vitro, IgP induced significant complement activation with all sera from tested individuals. IgA immunisation is not rare in PID, higher in selective IgA deficiency, but may also occur in healthy controls. Our results question the clinical relevance and pathophysiological implication of IgG anti-IgA in the context of HS with IgPs. Complement activation-related pseudoallergy could explain the clinical characteristics and natural history of HS symptoms.

Assessment of autoantibodies associated with intravenous immunoglobulin replacement therapy in children with primary immunodeficiency

While it is known that immunoglobulin replacement therapy (IgRT) used in the treatment of primary immunodeficiency disorders (PIDs) can lead to the passive transfer of autoantibodies, there is no data indicating that these antibodies can cause clinical symptoms in patients. This study aimed to investigate the presence of autoantibodies and their clinical correlation in patients diagnosed with PIDs receiving IgRT. Paediatric patients who were diagnosed with PIDs, and administered IgRT at our immunology clinic between 1 January 2012 and 31 December 2021, were included in the study. The medical records of these patients were retrospectively analysed, and autoantibodies were screened. Autoantibody screening was conducted at least once in 48 cases. Among these cases, 29 cases (60.4%) demonstrated positivity for at least one of the autoantibodies screened in the study. Among these cases, 23 tested positive for anti-TPO, 9 for anti-TG and 2 for both anti-TPO and anti-TG. Only two of these patients were confirmed to have Hashimoto's thyroiditis. In 30 cases, autoantibodies related to Celiac disease (CD) were screened, with at least one being positive in five different cases; CD was not confirmed. The results of our study suggest that passive transfer of autoantibodies to patients with IgRT does not cause any significant clinical findings. In addition, in cases of PID, autoantibodies detected in the blood passed to patients with IgRT can lead to misdiagnosis. Screening for autoantibodies in patients with PID undergoing IgRT may not yield accurate results in terms of detecting autoimmune diseases.

Towards personalized and rational use of immunoglobulins amid expanding indications and shortages

The development of intravenous IgG (IVIG) formulations in the 1970s enabled expanded use for treating primary antibody deficiency syndromes and autoimmune conditions. Recent advancements include the use of IVIG in secondary immune deficiencies related to hematologic malignancies and stem cell transplantation, along with the newly emerging prophylactic applications following chimeric antigen receptor T-cell (CAR-T) therapies. Novel therapeutic areas such as bispecific antibodies (BsAbs) for lymphoma and myeloma have increased the use of IgG, given the associated risks of infections. Today, the concept of a rational personalized clinical use of IgG in the context of evolving clinical indications in high-income countries (HIC) is emerging, as unmet challenges in line with managing shortages due to increasing demands globally. The current work aims to review and link the indications for IgG to their characteristics and formulations, their dose, route and frequency of administrations and duration of therapy to meet the needs of individual patients. It will also explore the means to rationalize and monitor IgG use in HIC in the time of shortage, while explaining pragmatic strategies to improve supply and use in low- and middle-income countries (LMIC).

The role of convalescent plasma and hyperimmune immunoglobulins in the COVID-19 pandemic, including implications for future preparedness

Introduction

When Coronavirus Disease-19 (COVID-19) struck the world in December 2019, initiatives started to investigate the efficacy of convalescent plasma, a readily available source of passive antibodies, collected from recovered patients as a therapeutic option. This was based on historical observational data from previous virus outbreaks.

Methods

A scoping review was conducted on the efficacy and safety of convalescent plasma and hyperimmune immunoglobulins for COVID-19 treatment. This review included the latest Cochrane systematic review update on 30-day mortality and safety. We also covered use in pediatric and immunocompromised patients, as well as the logistic challenges faced in donor recruitment and plasma collection in general. Challenges for low resource countries were specifically highlighted.

Results

A major challenge is the high donation frequency required from first-time donors to ensure a safe product, which minimizes the risk of transfusion-transmitted infectious. This is particularly difficult in low- and middle- income countries due to inadequate infrastructure and insufficient blood product supplies. High-certainty evidence indicates that convalescent plasma does not reduce mortality or significantly improve clinical outcomes in patients with moderate to severe COVID-19 infection. However, CCP may provide a viable treatment for patients unable to mount an endogenous immune response to SARS-CoV-2, based on mostly observational studies and subgroup data of published and ongoing randomized trials. Convalescent plasma has been shown to be safe in adults and children with COVID-19 infection. However, the efficacy in pediatric patients remains unclear.

Discussion

Data on efficacy and safety of CCP are still underway in ongoing (randomized) studies and by reporting the challenges, limitations and successes encountered to-date, research gaps were identified to be addressed for the future.

Conclusion

This experience serves as a valuable example for future pandemic preparedness, particularly when therapeutic options are limited, and vaccines are either being developed or ineffective due to underlying immunosuppression.

Comparative Analysis of Laboratory-Scale Immunoglobulin G Purification Methods from Human Serum

Immunoglobulin G (IgG) purification is a critical process for evaluating its role in autoimmune diseases, which are defined by the occurrence of autoantibodies. Affinity chromatography with protein G is widely considered to be the optimal technique for laboratory-scale purification. However, this technique has some limitations, including the exposure of IgG to low pH, which can compromise the quality of the purified IgG. Here, we show that alternative methods for IgG purification are possible while maintaining the quality of IgG. Different techniques for IgG purification from serum were evaluated and compared with protein G-based approaches: Melon Gel, caprylic acid-ammonium sulfate (CAAS) precipitation, anion-exchange chromatography with diethylamino ethyl (DEAE) following ammonium sulfate (AS) precipitation, and AS precipitation alone. The results demonstrated that the purification yield of these techniques surpassed that of protein G. However, differences in the purity of IgG were observed using GeLC-MS/MS. The avidity of purified IgG against selected targets (SARS-CoV-2 and topoisomerase-I) was similar between purified IgG obtained using all techniques and unpurified sera. Our work provides valuable insights for future studies of IgG function by recommending alternative purification methods that offer advantages in terms of yield, time efficiency, cost-effectiveness, and milder pH conditions than protein G.

Hepatitis B screening in hematology patients receiving intravenous immunoglobulin

BACKGROUND

Transient positivity for hepatitis B core antibody (Anti-HBc) following intravenous immunoglobulin (IVIG) and subcutaneous immunoglobulin exposure is a well-described phenomenon. The aim of this study was to retrospectively review Hepatitis B viral screening practices in IVIG recipients in a hematology specific cohort at a single center.

METHODS

Electronic databases were analyzed to identify all hematology patients who received IVIG from September 2022 to March 2022 at a single Irish center (n = 43). The proportion of patients that had a baseline anti-HBc tested prior to IVIG receipt was assessed as well as the proportion of patients that developed a transiently positive anti-HBc following IVIG exposure. Data were also collected relating to signal cut-off ratios in patients with detectable anti-HBc post-IVIG.

RESULTS

58.1% of patients had at least one serological hepatitis B viral test sent prior to IVIG exposure. Anti-HBc was the least common serological investigation performed prior to IVIG exposure (21% of recipients). A positive or equivocal "low level antibody" was identified in 15% of recipients and this was proven to be transient in all cases.

CONCLUSION

The minority of hematology patients had a baseline anti-HBc assessed prior to IVIG exposure. All patients in this study had the potential to require further immunosuppressive therapies, which could be limited by a misleading anti-HBc result. We therefore advocate for baseline anti-HBc testing to be performed prior to IVIG exposure in hematology patients and for cautious interpretation of anti-HBc results taking into account signal cut-off ratios post-IVIG exposure.

Monoclonal Antibodies and Hyperimmune Immunoglobulins in the Next Pandemic

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

Management of the sensitized pediatric renal transplant candidate

Kidney transplantation is the treatment of choice for patients with ESRD as it is associated with improved patient survival and better quality of life, especially in children. There are several barriers to a successful transplant including organ shortage, anatomic barriers, and immunologic barriers. One of the biggest immunologic barriers that precludes transplantation is sensitization, when patients have antibodies prior to transplantation, resulting in positive crossmatches with donor. 30%-40% of adult patients on the wait list are sensitized. There is a growing number of pediatric patients on the wait list who are sensitized. This poses a unique challenge to the pediatric transplant community. Therefore, attempts to perform desensitization to remove or suppress pathogenic HLA antibodies resulting in acceptable crossmatches, and ultimately a successful transplant, while reducing the risk of acute rejection, are much needed in these children. This review article aims to address the management of such patients both prior to transplantation, with strategies to overcome sensitization, and after transplantation with monitoring for allograft rejection and other complications.

Pregnant Women at Low Risk of Having a Child with Fetal and Neonatal Alloimmune Thrombocytopenia Do Not Require Treatment with Intravenous Immunoglobulin

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a rare condition in which maternal alloantibodies to fetal platelets cause fetal thrombocytopenia that may lead to intracranial hemorrhage (ICH). Off-label intravenous immunoglobulin (IVIg) has for 30 years been the standard of care for pregnant women who previously have had a child with FNAIT. The efficacy of this treatment has never been tested in a placebo-controlled clinical trial. Although IVIg treatment may improve the neonatal outcome in women who previously have had a child with FNAIT-associated ICH, the question is whether IVIg is necessary for all immunized pregnant women at risk of having a child with FNAIT. The results from some recent publications suggest that antenatal IVIg treatment is not necessary for women who are (1) HPA-1a-immunized and HLA-DRB3*01:01-negative, (2) HPA-1a-immunized with a previous child with FNAIT but without ICH or (3) HPA-5b-immunized. If IVIg is not used for these categories of pregnant women, the amount of IVIg used in pregnant women with platelet antibodies would be reduced to less than ¼ of today's use. This is important because IVIg is a scarce resource, and the collection of plasma for the treatment of one pregnant woman is not only extremely expensive but also requires tremendous donor efforts.

Practise of Immunoglobulin Replacement Therapy in Primary and Secondary Immunodeficiencies: A Single Centre Experience from Malaysia

Background

Intravenous immunoglobulin (IVIG) replacement therapy is increasingly in demand. This study focused on the characteristics of IVIG usage and associated factors toward the frequency status of IVIG among patients in Hospital Kuala Lumpur.

Methods

A retrospective cross-sectional study was performed on patients who received IVIG in Hospital Kuala Lumpur. Data were extracted from the request forms for IVIG recorded in the Pharmacy Department from January 2018 until December 2019. Chi-squared test and t-test analysis were used for statistical analysis, and a P-value of < 0.05 was considered significant.

Results

A total of 482 patients received IVIG in Hospital Kuala Lumpur. There were 243 (50.4%) females and 228 (47.3%) males with median age of the patients was 27 years old. The highest indications for IVIG among all patients were hypogammaglobulinemia and other deficiency states in 127 patients (26.3%). The most common indication for one-off treatment in adults was hypogammaglobulinemia and other deficiency states, 35%; whereas in paediatrics, it was Kawasaki disease, 20.3%. The highest indication for regular therapy among adult patients was chronic inflammatory demyelinating polyneuropathy (23.4%), while in paediatrics it was sepsis (31.1%). The clinical category was associated with the frequency status of IVIG usage in both adult and paediatric cohorts with P = 0.004 and P = 0.017, respectively.

Conclusion

There were significant differences between the indication of one-off treatment and regular therapy among adult and paediatric patients. A national guideline on the prescription of IVIG for patients is instantly needed to help clinicians in prescribing IVIG appropriately.

Validation of Viral Inactivation Protocols for Therapeutic Blood Products against Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-COV-2)

Therapeutic blood products including convalescent plasma/serum and immunoglobulins concentrated from convalescent plasma, such as intravenous immunoglobulins or hyperimmune globulins, and monoclonal antibodies are passive immunotherapy options for novel coronavirus disease 2019 (COVID-19). They have been shown to improve the clinical status and biological and radiological parameters in some groups of COVID-19 patients. However, blood products are still potential sources of virus transmission in recipients. The use of pathogen reduction technology (PRT) should increase the safety of the products. The purpose of this study was to determine the impact of solvent/detergents (S/D) procedures on SARS-COV-2 infectivity elimination in the plasma of donors but also on COVID-19 convalescent serum (CCS) capacity to neutralize SARS-COV-2 infectivity. In this investigation, S/D treatment for all experiments was performed at a shortened process time (30 min). We first evaluated the impact of S/D treatments (1% TnBP/1% TritonX-45 and 1% TnBP/1% TritonX-100) on the inactivation of SARS-COV-2 pseudoparticles (SARS-COV-2pp)-spiked human plasma followed by S/D agent removal using a Sep-Pak Plus C18 cartridge. Both treatments were able to completely inactivate SARS-COV-2pp infectivity to an undetectable level. Moreover, the neutralizing activity of CCS against SARS-COV-2pp was preserved after S/D treatments. Our data suggested that viral inactivation methods using such S/D treatments could be useful in the implementation of viral inactivation/elimination processes of therapeutic blood products against SARS-COV-2.

Diagnosis and treatment for the early stage of cytomegalovirus infection during hematopoietic stem cell transplantation

Cytomegalovirus (CMV) infection remains a frequent complication after hematopoietic stem cell transplantation (HSCT) and causes significant morbidity and mortality in transplantation recipients. In this review, we highlight the role of major risk factors that are associated with the incidence of CMV infection. Advances in immunosurveillance may predict CMV infection, allowing early interventions to prevent severe infection. Furthermore, numerous therapeutic strategies against CMV infection after HSCT are summarized. A comprehensive understanding of the current situation of CMV treatment may provide a hint for clinical practice and even promote the development of novel strategies for precision medicine.

An optimized microplate-based method to evaluate complement-dependent hemolysis mediated by intravenous immunoglobulins (IVIG)

Hemolytic reactions can cause serious complications after administration of Intravenous Immunoglobulin (IVIG), due to passive transfer of anti-A and anti-B IgG antibodies (isoagglutinins). A maximum allowable amount of isoagglutinins is established in the US and EU for licensed IVIG, as measured by a specified direct hemagglutination test (DHAT). Despite this limit, reports of hemolysis have increased over time, raising the question of how well the DHAT predicts clinically significant hemolysis. This study was undertaken to develop a microplate-based complement-dependent hemolysis assay (CDHA) that reproducibly measures functional hemolytic activity of IVIG, for assessment of IVIG products. An IVIG working reference reagent (NIBSC 14/160) was qualified as an assay control and for quantitation purposes. Hemolytic activities of 36 IVIG product lots encompassing seven brands and including 6 clinically hemolytic lots were measured. Hemolytic activity varied among IVIG product brands, and to a lesser extent, from lot-to-lot for individual brands. Correlation between the CDHA and DHAT was not robust which may reflect imprecision of the DHAT method or additional variables that influence complement-dependent hemolysis after opsonization. In conclusion, the CDHA provides a simple, specific, and sensitive tool for IVIG product characterization and investigation of hemolytic events by manufacturers, researchers, and regulatory authorities.

Efficient and Sustainable Platform for Preparation of a High-Quality Immunoglobulin G as an Urgent Treatment Option During Emerging Virus Outbreaks

During the pre-vaccine era of the COVID-19 pandemic convalescent plasma has once again emerged as a major potential therapeutic form of passive immunization that in specific cases still represents irreplaceable treatment option. There is a growing concern that variable concentration of neutralizing antibodies, present in convalescent plasma which originates from different donors, apparently affects its effectiveness. The drawback can be overcome through the downstream process of immunoglobulin fraction purification into a standardized product of improved safety and efficacy. All modern procedures are quite lengthy processes. They are also based on fractionation of large plasma quantities whose collection is not attainable during an epidemic. When outbreaks of infectious diseases are occurring more frequently, there is a great need for a more sustainable production approach that would be goal-oriented towards assuring easily and readily available immunoglobulin of therapeutic relevance. We propose a refinement strategy for the IgG preparation achieved through simplification and reduction of the processing steps. It was designed as a small but scalable process to offer an immediately available treatment option that would simultaneously be harmonized with an increased availability of convalescent plasma over the viral outbreak time-course. Concerning the ongoing pandemic status of the COVID-19, the proof of concept was demonstrated on anti-SARS-CoV-2 convalescent plasma but is likely applicable to any other type depending on the current needs. It was guided by the idea of persistent keeping of IgG molecules in the solution, so that protection of their native structure could be assured. Our manufacturing procedure provided a high-quality IgG product of above the average recovery whose composition profile was analyzed by mass spectrometry as quality control check. It was proved free from IgA and IgM as mediators of adverse transfusion reactions, as well as of any other residual impurities, since only IgG fragments were identified. The proportion of S protein-specific IgGs remained unchanged relative to the convalescent plasma. Undisturbed IgG subclass composition was accomplished as well. However, the fractionation principle affected the final product's capacity to neutralize wild-type SARS-CoV-2 infectivity, reducing it by half. Decrease in neutralization potency significantly correlated with the amount of IgM in the starting material.

Opto-Microfluidic Integration of the Bradford Protein Assay in Lithium Niobate Lab-on-a-Chip

This paper deals with the quantification of proteins by implementing the Bradford protein assay method in a portable opto-microfluidic platform for protein concentrations lower than 1.4 mg/mL. Absorbance is measured by way of optical waveguides integrated to a cross-junction microfluidic circuit on a single lithium niobate substrate. A new protocol is proposed to perform the protein quantification based on the high correlation of the light absorbance at 595 nm, as commonly used in the Bradford method, with the one achieved at 633 nm with a cheap commercially available diode laser. This protocol demonstrates the possibility to quantify proteins by using nL volumes, 1000 times less than the standard technique such as paper-analytical devices. Moreover, it shows a limit of quantification of at least 0.12 mg/mL, which is four times lower than the last literature, as well as a better accuracy (98%). The protein quantification is obtained either by using one single microfluidic droplet as well by performing statistical analysis over ensembles of several thousands of droplets in less than 1 min. The proposed methodology presents the further advantage that the protein solutions can be reused for other investigations and the same pertains to the opto-microfluidic platform.

Determination of total protein content in biomedical products by the PDMS-assisted lab-in-a-syringe assay using 3D printed scaffolds removal

The aim of our work was to develop a low-cost, portable device for the fast and easy determination of total protein content by using PDMS-based lab-in-a-syringe technology with removal of 3D-printed channels. We proposed two designs with a one-step PDMS curing and a two-step PDMS-curing fabrication procedure. The one-step PDMS microdevices were found to be the best in the view of preparation, repeatability, and stability of the reagent. This design was then applied for the determination of total protein content in biomedical products using the Bradford assay.

An overview on the investigation of nanomaterials' effect on plasma components: immunoglobulins and coagulation factor VIII, 2010-2020 review

FVIII and immunoglobulins (Igs) are the most prominent plasma proteins, which play a vital role in plasma hemostasis. These proteins have been implemented frequently in protein therapy. Therefore, their maintenance, durability, and stability are highly essential. Herein, various approaches to improve protein functions have been investigated, such as using recombinant protein replacement. In comparison, advances in nanotechnology have provided adequate context to boost biomaterial utilization. In this regard, the applications of various nanoparticles such as polymeric nanomaterials (PEG and PLGA), metal nanoparticles, dendrimers, and lipid based nanomaterials (liposomes and lipid nanoparticles) in stability and the functional improvement of antibodies and coagulation factor VIII (FVIII) have been reviewed from 2010 to 2020. Reviewing related articles has shown that not only can nanomaterials adequately protect the structure of proteins, but have also improved proteins' functions in some cases. For example, the high rate of FVIII instability has been successfully enhanced by bio-PEGylation. Also, utilizing PEGylated liposomes, using the PEG-lip technique for coating nanostructures, leads to FIIIV half-life prolongation. Hence, PEGylation had most impact on the stability of FVIII. Likewise, PEG-coated liposome nano-carriers also presented such a good effect on stability improvements for FVIII due to their ability to tune the immune system by reducing FVIII immunogenicity. Similarly, Ig PEGylation and conjugation to magnetic nanoparticles resulted in increased half-life and better purification of Igs, respectively, without any loss in structural or functional features. Consequently, metal-organic frameworks and recent hybrid systems have been introduced as promising nanomaterials in biomedical applications. As far as we know, this is the first study in this field, which considers the applications of nanoparticles for improving the storage and stability of antibodies and coagulation FVIII.

Effects of compaction and storage conditions on stability of intravenous immunoglobulin - Implication on developing oral tablets of biologics

Biological products, such as therapeutic proteins, vaccines and cell - based therapeutics have a rapidly growing global market. Monoclonal antibody represents a major portion of the biologics market. For biologics that target gastrointestinal tract, the oral delivery route offers many advantages, such as better patient compliance, easy administration and increased stability, over the parental route of administration. To lay the ground work for the oral delivery of biologics, we studied the solid state properties and effects of compaction pressure, particle size, and storage relative humidity on the stability of immunoglobulin G (IVIG). We employed complementary analytical and biophysical techniques, such as size exclusion chromatography and Dynamic light scattering to characterize the aggregates, circular dichroism and solid state Fourier-transform infrared spectroscopy to evaluate protein secondary structure and nano-DSC to probe thermal stability of protein conformations. Our results showed storage relative humidity could induce conformational changes and aggregation of IVIG. However, the IVIG binding activity did not significantly change with relative humidity. The commonly used compaction pressures did not promote protein aggregation, but noticeably reduced binding activity.

Production of hyperimmune anti-SARS-CoV-2 intravenous immunoglobulin from pooled COVID-19 convalescent plasma

Background: This study assesses the feasibility of producing hyperimmune anti-COVID-19 intravenously administrable immunoglobulin (C-IVIG) from pooled convalescent plasma (PCP) to provide a safe and effective passive immunization treatment option for COVID-19. Materials & methods: PCP was fractionated by modified caprylic acid precipitation followed by ultrafiltration/diafiltration to produce hyperimmune C-IVIG. Results: In C-IVIG, the mean SARS-CoV-2 antibody level was found to be threefold (104 ± 30 cut-off index) that of the PCP (36 ± 8.5 cut-off index) and mean protein concentration was found to be 46 ± 3.7 g/l, comprised of 89.5% immunoglobulins. Conclusion: The current method of producing C-IVIG is feasible as it uses locally available PCP and simpler technology and yields a high titer of SARS-CoV-2 antibody. The safety and efficacy of C-IVIG will be evaluated in a registered clinical trial (NCT04521309).

Characterization of antibodies in human immunoglobulin products from different regions worldwide

AIM

The antibody levels against a broad spectrum of pathogens were assessed in commercial intravenous immunoglobulin (IVIG) manufactured from pooled plasma obtained from different global regions.

METHODS

Twenty-four IVIG commercial lots from eight manufacturers corresponding to 12 brands were analyzed. The plasma was collected in 10 countries/regions. Depending on each pathogen, antibody levels were measured using specific commercial IgG-specific enzyme immunoassay kits or by cell culture neutralization test and guinea pig skin neutralization test. A principal component analysis was performed.

RESULTS

For polio and diphtheria (reference markers of the US authorities), all IVIGs had relevant titers in accordance with reference levels. IVIGs from Canada, Australia, and the USA were positive for titers against globally distributed pathogens or those under vaccination programs in the developed world (parainfluenza, Epstein-Barr, varicella-zoster, influenza B, parvovirus B19, and measles viruses). IVIG from Taiwan and Hong Kong showed low antibody titers for these pathogens but high titers for Pseudomonas aeruginosa. IVIG from India had high titers for pathogens frequently found in developing countries (West Nile, dengue, chikungunya, and hepatitis E viruses and Streptococcus pneumoniae). IVIGs from Argentina, Spain, Israel, and Czechia showed intermediate antibody concentrations.

CONCLUSION

The antibody profile in IVIG was greatly influenced by regional characteristics including climate, vaccination programs, and the prevalence of pathogens in the different countries and regions.

Importance of immunoglobulin therapy for COVID-19 patients with lymphocytopenia

BACKGROUND

The global coronavirus disease 2019 (COVID-19) was announced as pandemic by the World Health Organization (WHO). With the increased number of infected and dead victims daily all over the world, it becomes necessary to stop or overcome its rapid spread.Main bodyAlthough the production of vaccine or even specified effective anti-virus may take about six months to a year, intravenous immunoglobulin (IVIg) may be clinically used as a safe treatment to save and improve the quality of life of patients with a variety of immunodeficiency diseases such as lymphocytopenia, which is a common clinical feature in COVID-19.

CONCLUSION

Through the current review, it was concluded that this passive immunization may promote the immunity to better fight against the virus, so the survival of the patients could be kept longer. The efficacy of immunotherapy with IVIg would be greater if the immune IgG antibodies were collected from convalescent plasma therapy.

The Road towards Polyclonal Anti-SARS-CoV-2 Immunoglobulins (Hyperimmune Serum) for Passive Immunization in COVID-19

Effective treatments specific for COVID-19 are still lacking. In the setting of passive immunotherapies based on neutralizing antibodies (nAbs), randomized controlled trials of COVID-19 convalescent plasma (CCP) anti-SARS-CoV-2 Spike protein monoclonal antibodies (mAb), which have been granted emergency use authorization, have suggested benefit in early disease course (less than 72 hours from symptoms and seronegative). Meanwhile, polyclonal immunoglobulins (i.e., hyperimmune serum), derived either from CCP donations or from animals immunized with SARS-CoV-2 antigens, are likely to become the next nAb-derived candidate. We here discuss the pros and cons of hyperimmune serum versus CCP and mAb, and summarize the ongoing clinical trials of COVID-19 hyperimmune sera.

A systemic review of intravenous immunoglobulin G treatment in women with recurrent implantation failures and recurrent pregnancy losses

Over the last few decades, the advancement in reproductive technologies and protocols to improve embryo quality through culture techniques and genetic testing to eliminate chromosomally abnormal embryos resulted in better pregnancy rates and outcomes after fertility treatments. Unfortunately, some patients still struggle with recurrent implantation failures (RIFs) and recurrent pregnancy losses (RPLs). Immune etiologies have been attributed to play an important role in some of those patients. Maintaining a pre-conceptional anti-inflammatory environment for implantation and pregnancy continuation yields superior results. Intravenous immunoglobulin G (IVIG) treatment has been reported to enhance reproductive outcome in patients with RIF and RPL with immune dysregulations. In this systemic review, we analyzed outcomes of IVIG trials for RIF and RPL, its mechanism of action, dosing, administration, side-effects, and evidence for its use in women with RIF and RPL.

The SARS-Coronavirus Infection Cycle: A Survey of Viral Membrane Proteins, Their Functional Interactions and Pathogenesis

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is a novel epidemic strain of Betacoronavirus that is responsible for the current viral pandemic, coronavirus disease 2019 (COVID-19), a global health crisis. Other epidemic Betacoronaviruses include the 2003 SARS-CoV-1 and the 2009 Middle East Respiratory Syndrome Coronavirus (MERS-CoV), the genomes of which, particularly that of SARS-CoV-1, are similar to that of the 2019 SARS-CoV-2. In this extensive review, we document the most recent information on Coronavirus proteins, with emphasis on the membrane proteins in the Coronaviridae family. We include information on their structures, functions, and participation in pathogenesis. While the shared proteins among the different coronaviruses may vary in structure and function, they all seem to be multifunctional, a common theme interconnecting these viruses. Many transmembrane proteins encoded within the SARS-CoV-2 genome play important roles in the infection cycle while others have functions yet to be understood. We compare the various structural and nonstructural proteins within the Coronaviridae family to elucidate potential overlaps and parallels in function, focusing primarily on the transmembrane proteins and their influences on host membrane arrangements, secretory pathways, cellular growth inhibition, cell death and immune responses during the viral replication cycle. We also offer bioinformatic analyses of potential viroporin activities of the membrane proteins and their sequence similarities to the Envelope (E) protein. In the last major part of the review, we discuss complement, stimulation of inflammation, and immune evasion/suppression that leads to CoV-derived severe disease and mortality. The overall pathogenesis and disease progression of CoVs is put into perspective by indicating several stages in the resulting infection process in which both host and antiviral therapies could be targeted to block the viral cycle. Lastly, we discuss the development of adaptive immunity against various structural proteins, indicating specific vulnerable regions in the proteins. We discuss current CoV vaccine development approaches with purified proteins, attenuated viruses and DNA vaccines.

Global immunoglobulin supply: steaming towards the iceberg?

PURPOSE OF REVIEW

This review describes how plasma is sourced for fractionation into plasma-derived medicinal products (PDMPs), such as immunoglobulin (Ig) together with differences between plasma from whole blood (recovered plasma) and from plasmapheresis (source plasma) in terms of global plasma supply. Specific areas of growth in immunoglobulin use are identified alongside novel therapies, which may reduce demand for some immunoglobulin indications.

RECENT FINDINGS

There has been a 6--8% annual growth in immunoglobulin use. Secondary immunodeficiency alongside improved recognition and diagnosis primary immunodeficiency disorders are drivers whereas the novel neonatal Fc receptor inhibitors (FcRni) may reduce demand for some immunomodulatory indications.

SUMMARY

There is a significant geographical imbalance in global supply of plasma with 65% collected in the United States. This results in a dependency of other countries on United States supply and argues for both more plasma supply and greater regionally balanced plasma collection. In addition, progress towards a transparent, regulated and well tolerated framework for the coexistence of unpaid and compensated plasma donations is needed as unpaid donation will not be sufficient. These discussions should be informed by the needs of patients for this life-saving therapy, the care of donors and the safety of plasma and PDMPs.

Convalescent Plasma Therapy for COVID-19: State of the Art

Convalescent plasma (CP) therapy has been used since the early 1900s to treat emerging infectious diseases; its efficacy was later associated with the evidence that polyclonal neutralizing antibodies can reduce the duration of viremia. Recent large outbreaks of viral diseases for which effective antivirals or vaccines are still lacking has renewed the interest in CP as a life-saving treatment. The ongoing COVID-19 pandemic has led to the scaling up of CP therapy to unprecedented levels. Compared with historical usage, pathogen reduction technologies have now added an extra layer of safety to the use of CP, and new manufacturing approaches are being explored. This review summarizes historical settings of application, with a focus on betacoronaviruses, and surveys current approaches for donor selection and CP collection, pooling technologies, pathogen inactivation systems, and banking of CP. We additionally list the ongoing registered clinical trials for CP throughout the world and discuss the trial results published thus far.

Antibody-enhanced hepatitis E virus nanofiltration during the manufacture of human immunoglobulin

BACKGROUND

Circulation of hepatitis E virus (HEV) in areas where plasma is sourced for the manufacture of plasma-derived medicinal products (PDMPs) has prompted verification of HEV clearance. HEV exists as quasi lipid-enveloped (LE) and non-lipid-enveloped (NLE) forms, which might be of relevance for HEV clearance from manufacturing processes of antibody-containing PDMPs with solvent/detergent (S/D) treatment upstream of further clearance steps.

STUDY DESIGN AND METHODS

Presence of different HEV particles in stocks used in clearance studies was investigated, with nanofilters graded around the assumed HEV particle sizes and by gradient centrifugation. HEV removal by 35-nm nanofiltration was investigated in the presence or absence of HEV antibodies, in buffer as well as in immunoglobulin (IG) manufacturing process intermediates.

RESULTS

HEV particles consistent with LE, NLE, and an "intermediate" (IM) phenotype, obtained after S/D treatment, were seen in different HEV stocks. In the absence of HEV antibodies, log reduction factors (LRFs) of 4.0 and 2.5 were obtained by 35-nm nanofiltration of LE and IM HEV, consistent with the larger and smaller sizes of these phenotypes. Addition of HEV antibodies enhanced IM HEV removal around 1000-fold (LRF, 5.6). Effective (LRF, >4.8 and >4.0) HEV removal was obtained for the nanofiltration processing step for IG intermediates with varying HEV antibody content.

CONCLUSION

HEV spikes used in clearance studies should be carefully selected, as differences in physicochemical properties might affect HEV clearance. Antibody-mediated enhancement of HEV nanofiltration was demonstrated in IG process intermediates even at low HEV antibody concentration, illustrating the robustness of this manufacturing step.

Polysaccharide-based chromatographic adsorbents for virus purification and viral clearance

Viruses still pose a significant threat to human and animal health worldwide. In the fight against viral infections, high-purity viral stocks are needed for manufacture of safer vaccines. It is also a priority to ensure the viral safety of biopharmaceuticals such as blood products. Chromatography techniques are widely implemented at both academic and industrial levels in the purification of viral particles, whole viruses and virus-like particles to remove viral contaminants from biopharmaceutical products. This paper focuses on polysaccharide adsorbents, particulate resins and membrane adsorbers, used in virus purification/removal chromatography processes. Different chromatographic modes are surveyed, with particular attention to ion exchange and affinity/pseudo-affinity adsorbents among which commercially available agarose-based resins (Sepharose®) and cellulose-based membrane adsorbers (Sartobind®) occupy a dominant position. Mainly built on the development of new ligands coupled to conventional agarose/cellulose matrices, the development perspectives of polysaccharide-based chromatography media in this antiviral area are stressed in the conclusive part.

A Versatile Toolkit for Controllable and Highly Selective Multifunctionalization of Bacterial Magnetic Nanoparticles

Their unique material characteristics, i.e. high crystallinity, strong magnetization, uniform shape and size, and the ability to engineer the enveloping membrane in vivo make bacterial magnetosomes highly interesting for many biomedical and biotechnological applications. In this study, a versatile toolkit is developed for the multifunctionalization of magnetic nanoparticles in the magnetotactic bacterium Magnetospirillum gryphiswaldense, and the use of several abundant magnetosome membrane proteins as anchors for functional moieties is explored. High-level magnetosome display of cargo proteins enables the generation of engineered nanoparticles with several genetically encoded functionalities, including a core-shell structure, magnetization, two different catalytic activities, fluorescence and the presence of a versatile connector that allows the incorporation into a hydrogel-based matrix by specific coupling reactions. The resulting reusable magnetic composite demonstrates the high potential of synthetic biology for the production of multifunctional nanomaterials, turning the magnetosome surface into a platform for specific versatile display of functional moieties.

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.

Intravenous immunoglobulin therapy: a snapshot for the internist

Intravenous immunoglobulins are the cornerstone for the treatment of primary humoral immunodeficiencies and may be used for a great number of other autoimmune, neurological and hematological conditions as well. Given their wide application, the possibility of running across a patient who needs this kind of therapy is becoming increasingly common. Generally, intravenous immunoglobulins are well tolerated. However, numerous adverse reactions ranging from mild to severe have been reported and linked to patient- and product-related factors. For all these reasons, we present herein a comprehensive review of the on- and off-label applications of intravenous immunoglobulins and provide a guide for the internist how to minimize the risk of adverse reactions and manage them.

Efficacy and patient satisfaction in the use of subcutaneous immunoglobulin immunotherapy for the treatment of auto-immune neuromuscular diseases

We reviewed the efficacy of SCIg administration in terms of muscle strength maintenance and patient satisfaction comparing with IVIg in the treatment of auto-immune neuromuscular diseases. A systematic review was conducted, and identified studies from databases (PUBMED, EMBASE, EBSCO, Web of Science and Google Scholar) which were analyzed. The methodological quality of the selected publications was evaluated using the Newcastle-Ottawa Scale. Data were extracted from a total of 11 studies Fixed and random-effect model meta-analyses were performed. For the maintenance of muscle strength, Overall Neuropathy Limitations Scale (ONLS) data from 100 patients diagnosed with multifocal mononeuropathy (MMN) or chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) were pooled together. Switching to subcutaneous immunoglobulin administration led to a significant improvement (fixed effects model, p = 0.002). In data collected using the Medical Research Council Scale for Muscle Strength data from 140 patients with a wider range of disorders, a small but significant improvement in overall strength was observed in the SCIg group (p < 0.0001). In addition, the results of two studies measuring health-related quality of life and patient satisfaction were pooled. Data from 49 patients suffering from MMN, CIDP, and a variety of different myopathies demonstrated a small but significant increase in the mean 36-Item Short Form Survey (SF-36) scores (p < 0.0001). A highly significant difference was revealed when comparing data from 119 patients' responses to the Life Quality Index questionnaire (LQI) assessing patient satisfaction (p < 0.0001). This is the first analysis showing that SCIg is more effective than IVIg in improving Patient Reported Outcomes in auto-immune neuromuscular disease. These results should permit a broad range of patients to self-administer immunoglobulin treatments at home, potentially improving patient acceptability while reducing hospital visits and healthcare costs for the treatment of chronic auto-immune neuropathies.

Effectiveness of immunoglobulin prophylaxis in reducing clinical complications of hematopoietic stem cell transplantation: a systematic review and meta-analysis

BACKGROUND

Prophylactic immunoglobulin has been used with varying efficacy to reduce complications in hematopoietic stem cell transplant recipients.

STUDY DESIGN AND METHODS

A systematic review and meta-analysis was conducted of randomized controlled trials that assessed clinical outcomes (overall survival, transplant-related mortality, graft-versus-host disease [GVHD], veno-occlusive disease [VOD], interstitial pneumonitis, disease relapse, cytomegalovirus [CMV] infection and disease, non-CMV infection) of immunoglobulin prophylaxis versus placebo in hematopoietic stem cell transplant recipients. MEDLINE, EMBASE, EBM Reviews, and the Cochrane Central Register of Controlled Trials were searched up to June 2017. Quality of included studies and outcomes were evaluated via Risk of Bias assessment and Grading of Recommendations, Assessment, Development and Evaluation criteria, respectively.

RESULTS

Of 899 citations screened, 27 studies (n = 3934) were included. Immunoglobulin prophylaxis had no impact on survival (risk ratio [RR], 0.94; 95% confidence interval [CI], 0.88-1.01; 11 studies, n = 1962) but decreased risk of acute GVHD (RR, 0.78; 95% CI, 0.65-0.94; eight studies, n = 1097) and CMV disease (RR, 0.52; 95% CI, 0.28-0.97; two studies, n = 167). Meta-analysis revealed increased risk of VOD (RR, 3.04; 95% CI, 1.10-8.41; three studies, n = 384) and disease relapse (RR, 1.26; 95% CI, 1.07-1.49; seven studies, n = 1647). Other outcomes were small in sample size or nonsignificant. Results should be interpreted cautiously given the low quality of studies and evidence of outcomes.

CONCLUSION

Immunoglobulin prophylaxis did not have a significant effect on survival. Positive clinical effects were shown for acute GVHD and CMV disease and negative effects against VOD and disease relapse. No studies examined the effect of immunoglobulin treatment in hypogammaglobulinemic patients despite current guidelines, warranting further studies in this population.

Efficacy and Safety of a New 10% Intravenous Immunoglobulin Product in Patients with Primary Immune Thrombocytopenia (ITP)

BACKGROUND

In the current study, we aimed to investigate the efficacy and safety of intravenous immunoglobulin (IVIg)-SN 10%, a new 10% IVIg formulation, in adult patients with severe primary immune thrombocytopenia (ITP; platelet count < 20 × 10⁹/L).

METHODS

Patients diagnosed as primary ITP, aged 19 years old or more, and had a platelet count of < 20 × 10⁹/L by screening complete blood cell count performed within 2 weeks of study commencement were eligible. Patients received IVIg-SN 10% at a dose of 1 g/kg/day for two consecutive days. Response was defined as the achievement of a platelet count of ≥ 50 × 10⁹/L at day 8.

RESULTS

Out of 81 eligible patients, 31 patients were newly diagnosed, 7 patients had persistent ITP, and 43 patients had chronic ITP. In intent-to-treat analysis, 61.3 patients (75.7%) achieved response and satisfied the pre-defined non-inferiority condition. Median time to response was 2 days and mean duration of maintaining response after the completion of IVIg therapy was 9.13 ± 8.40 days. Response rates were not found to be dependent on the phase of ITP or previous treatment for ITP. The drug was well tolerated and the frequency of mucocutaneous bleeding decreased during the study period.

CONCLUSION

In summary, IVIg-SN 10% formulation was found to be safe and effective in adult ITP patients (Trial registry at ClinicalTrials.gov, NCT02063789).

Seroprevalence of Opsonophagocytic Antibodies against Serotype Ia, Ib, II, III, and V Group B Streptococcus among Korean Population

BACKGROUND

Invasive Streptococcus agalactiae (group B streptococcus, GBS) infection most commonly occurs in infants; however, cases of GBS infection in adults, particularly in the elderly with significant underlying diseases, are being increasingly reported. We analyzed the serotype specific opsonophagocytic antibodies (the major mechanism of protection against GBS) in infants, adults, and the elderly.

METHODS

The opsonization indices (OIs) of antibodies against serotype Ia, Ib, II, III, and V GBS were studied in 89 infants, 35 adults (age, 30-50 years), and 62 elderly individuals (age, 65-85 years) according to the University of Alabama at Birmingham GBS opsonophagocytic killing assay protocol (www.vaccine.uab.edu).

RESULTS

In infants, adults, and elderly groups respectively, geometric mean of OI against GBS serotype Ia were 3, 7, and 32; against GBS serotype Ib were 7, 242, and 252; against serotype II were 93, 363, and 676; against serotype III were 8, 212, and 609; and against serotype V were 4, 639, and 610. The seropositive rate (% of subjects with OI ≥ 4) increased significantly in older age group for all five serotypes.

CONCLUSION

During infancy, only a limited proportion of infants have functional immunity against serotype Ia, Ib, II, III, and V GBS. Furthermore, a lack of opsonic activities against GBS observed in some adults and the elderly might predispose such individuals to the risk of invasive GBS infection. Epidemiological monitoring and development of suitable vaccine for these populations are needed.

Dimeric IgG complexes from IVIg are incapable of inducing in vitro neutrophil degranulation or complement activation

Purpose

Intravenous immunoglobulin (IVIg) products contain various amounts of dimeric IgG complexes. Current insights into the possible biological activities of these dimers remain controversial, and both immunemodulating and immune-activating effects have been reported. Here, we analyzed the putative immune-activating effects of dimers isolated from IVIg.

Methods

Dimers isolated from IVIg were purified by high-performance size-exclusion chromatography (HP-SEC) and tested for the ability to induce neutrophil degranulation in vitro.

Results

Dimers isolated from IVIg were found to be incapable of inducing in vitro neutrophil degranulation or complement activation, even at concentrations exceeding those expected to be reached upon administration in patients. These results depend on the removal of artefactual activation by using 0.1 micron filtration and the use of poloxamer to prevent adsorption of IgG onto the solid phase.

Conclusions

The data suggest dimeric IgG found in IVIg may bind to Fc-receptors without causing activation.

What can be learned in the snake antivenom field from the developments in human plasma derived products?

Human plasma-derived medicinal products and snake antivenom immunoglobulins are unique and complex therapeutic protein products. Human plasma products are obtained by fractionating large pools of plasma collected from blood plasma donors. They comprise a wide range of protein products, including polyvalent and hyperimmune immunoglobulins, coagulation factors, albumin, and various protease inhibitors that are transfused to patients affected by congenital or acquired protein deficiencies, immunological disorders, or metabolic diseases. Snake antivenoms are manufactured from pools of plasma collected from animals, typically horses, which have been immunized against snake venoms. Transfusing antivenoms is the cornerstone therapy to treat patients affected by snakebite envenoming. Over the last thirty years, much technical and regulatory evolution has been implemented to ensure that this class of biologicals meets modern quality requirements. The purpose of this review is to compare the main developments that took place in plasma production, protein fractionation, pathogen safety, quality control, preclinical and clinical studies, and regulations of these products. We also analyze whether both fields have been influencing and cross-fertilizing each other technically and in regulatory aspects to reach modern safety and efficacy standards at global levels, and how experience in the human plasma fractionation industry can further impact the manufacture of snake antivenom and that of other animal-derived antisera.

High-dose intravenous immunoglobulins for the treatment of dermatological autoimmune diseases

Based on their immunomodulatory properties, high-dose intravenous immunoglobulins (IVIGs) are successfully used in the treatment of various dermatological autoimmune diseases, in particular pemphigus vulgaris and dermatomyositis. In autoimmune bullous diseases, IVIGs can be used in an adjuvant setting (second- or third-line therapy) once combined immunosuppressive regimens have failed. In dermatomyositis, IVIGs may already be employed as an adjuvant second-line therapy after failure of corticosteroid monotherapy. In scleromyxedema, IVIGs may be considered as first-line treatment, given the lack of effective and safe alternatives. Other potential indications for IVIGs may include severe recalcitrant cases of systemic vasculitis and systemic lupus erythematosus. Toxic epidermal necrolysis may be an indication for high-dose IVIGs if administered early. Common, readily manageable side effects include nausea, headache, fatigue, and febrile infusion reactions. Severe adverse events such as thromboembolic events, anaphylaxis, and acute renal failure are very uncommon. The risk of viral transmission is very low. Potential mechanisms of action include upregulation of inhibitory Fc receptors, reduction of the half-life of endogenous immunoglobulins due to displacement from protective receptor sites, neutralization of autoantibodies by anti-idiotypic antibodies, as well as inhibition of complement activation.

High-resolution physicochemical characterization of different intravenous immunoglobulin products

Intravenous immunoglobulin (IVIg) is a complex mixture drug comprising diverse immunoglobulins and non-IgG proteins purified from the plasma of thousands of healthy donors. Approved IVIg products on the market differ regarding source of plasma, isolation process, and formulation. These products are used widely, and often interchangeably, for the treatment of immunodeficiency and autoimmune and inflammatory diseases, but their mechanisms of action in different indications are not well understood. A primary limitation to understanding the therapeutic relevance of specific components within IVIg has been the limited resolution of analytics historically implemented to characterize its complex mixture. In this study, high-resolution analytics were applied to better understand the composition of IVIg and product variations. We characterized three approved IVIg products: Gammagard®, Privigen®, and Octagam®. Differences in the distribution of molecular weight species, IgG sequence variants, isoforms, glycoforms, and the repertoire of previously reported antibody specificities were identified. We also compared the effect of aging on these products to identify changes in size distribution and posttranslational modifications. This type of characterization may provide insights into the specific factors and components of IVIg that may influence its activity and ultimately lead to optimization of IVIg products for use in autoimmune diseases.