On the dark side of therapies with immunoglobulin concentrates: the adverse events

Real-world experience with CLAIRYG® 50 mg/mL (intravenous immunoglobulin) in children under 12 years with primary immunodeficiency or immmune thrombocytopenia: a post-approval safety study

Introduction

This study presents the results of a real-life, multicenter, prospective, post-approval safety evaluation of Clairyg® 50 mg/mL, a 5% intravenous immunoglobulin (IVIg) liquid, in 59 children (aged < 12 years) with primary immunodeficiency diseases (PID) (n = 32) or immune thrombocytopenia (ITP) (n = 27) in France.

Methods

The primary objective of the study was to assess the safety and tolerability of Clairyg®, recording all serious and non-serious adverse events (AEs), whether related (rAEs) or not related to the product. Secondary objectives aimed at evaluating the administration of Clairyg® under routine conditions and the available efficacy data to better document the benefit/risk ratio in this pediatric population. An exploratory objective was added to evaluate the potential factors associated with the occurrence of rAEs. Patients received Clairyg® according to the approved dosage under normal conditions of prescriptions over a median follow-up period of 11.8 months.

Results

A total of 549 infusions (PID: n = 464 and ITP: n = 85), were administered, of which 58.8% were preceded by premedication. The most frequent rAEs were headache, vomiting, and pyrexia in both indications. Most of them were considered non-serious and mild or moderate in intensity. A severe single rAE was observed (aseptic meningitis) in a 4-year-old girl presenting with chronic ITP. The exploratory multivariate analysis of potential co-factors showed that the occurrence of rAEs is significantly linked to high IVIg doses and possibly to female gender. The annualized rate of serious bacterial infections was 0.11 for patients with PID. For patients with ITP, 74.1% experienced at least one bleeding episode during the follow-up, mostly a cutaneous one, and none had gastrointestinal, genitourinary, or central nervous system bleeding.

Conclusion

Clairyg® was well tolerated and allowed for control of serious bacterial infection in PID and serious bleeding in ITP, which are the main complications in these respective pediatric disorders. No new safety signal was detected in children less than 12 years-old in real-life conditions of use.

Investigation of cardiac adverse effects in COVID-19 ARDS patients treated with intravenous immunoglobulin

OBJECTIVE

The popularity of intravenous immunoglobulin (IVIG) therapy in Acute Respiratory Distress Syndrome (CARDS) secondary to COVID-19 infection is increasing day by day. In this study, we aimed to retrospectively evaluate the possible cardiac effects in our CARDS patients treated with IVIG.

METHODS

Demographic and clinical characteristics, mortality, sequential electrocardiography (ECG), echocardiography, cardiac markers, and other laboratory parameters of CARDS patients who received IVIG treatment were recorded.

RESULTS

The mean age of the patients was 68.7±13.6%, and 70.5% were female. The mean number of days of hospitalization in the intensive care unit was 18.2±9.7, and the mortality rate was recorded as 35.2%. No pathological rhythm or ischemic change was observed in sequential ECG follow-ups. However, in consecutive ECO follow-ups, the sPAP values at the treatment end were numerically lower, although not statistically significant.

CONCLUSION

Our study suggests that IVIG therapy may be used safely in COVID-19 patients with cardiovascular side effects. However, due to the high risk of coagulopathy in these patients, the use of IVIG therapy in COVID-19 infection should be monitored with close monitoring, as it may increase the potential for cardiovascular risk. Furthermore, monitoring cardiac parameters are also essential as it may predict high cardiovascular risk in patients. For this reason, patients need lower infusion rates, steroid combination, adequate hydration, and effective anticoagulation therapy to avoid these side effects.

Use of Structured Electronic Health Records Data Elements for the Development of Computable Phenotypes to Identify Potential Adverse Events Associated with Intravenous Immunoglobulin Infusion

INTRODUCTION

Detection of adverse reactions to drugs and biologic agents is an important component of regulatory approval and post-market safety evaluation. Real-world data, including insurance claims and electronic health records data, are increasingly used for the evaluation of potential safety outcomes; however, there are different types of data elements available within these data resources, impacting the development and performance of computable phenotypes for the identification of adverse events (AEs) associated with a given therapy.

OBJECTIVE

To evaluate the utility of different types of data elements to the performance of computable phenotypes for AEs.

METHODS

We used intravenous immunoglobulin (IVIG) as a model therapeutic agent and conducted a single-center, retrospective study of 3897 individuals who had at least one IVIG administration between 1 January 2014 and 31 December 2019. We identified the potential occurrence of four different AEs, including two proximal AEs (anaphylaxis and heart rate alterations) and two distal AEs (thrombosis and hemolysis). We considered three different computable phenotypes: (1) an International Classification of Disease (ICD)-based phenotype; (2) a phenotype-based on EHR-derived contextual information based on structured data elements, including laboratory values, medication administrations, or vital signs; and (3) a compound phenotype that required both an ICD code for the AE in combination with additional EHR-derived structured data elements. We evaluated the performance of each of these computable phenotypes compared with chart review-based identification of AEs, assessing the positive predictive value (PPV), specificity, and estimated sensitivity of each computable phenotype method.

RESULTS

Compound computable phenotypes had a high positive predictive value for acute AEs such as anaphylaxis and bradycardia or tachycardia; however, few patients had both ICD codes and the relevant contextual data, which decreased the sensitivity of these computable phenotypes. In contrast, computable phenotypes for distal AEs (i.e., thrombotic events or hemolysis) frequently had ICD codes for these conditions in the absence of an AE due to a prior history of such events, suggesting that patient medical history of AEs negatively impacted the PPV of computable phenotypes based on ICD codes.

CONCLUSIONS

These data provide evidence for the utility of different structured data elements in computable phenotypes for AEs. Such computable phenotypes can be used across different data sources for the detection of infusion-related adverse events.

Immunoglobulin replacement in hematological malignancies: a focus on evidence, alternatives, dosing strategy, and cessation rule

Acquired hypogammaglobulinemia or secondary immunodeficiency (SID) occurs commonly in hematological malignancies with increasing incidence and complexity in the era of modern therapies. Despite current practice of immunoglobulin replacement (IgRT) in SID, the evidence is lacking, especially for newer treatments. We discuss the current evidence for IgRT in various disease groups including issues, such as actual or ideal body weight (IBW)-based dosing, length of treatment, antibiotic prophylaxis, and vaccination. Incidence of SID with newer treatment is lacking. While there is a trend toward decreased respiratory infections and hospitalizations with IgRT, this is not consistent across all disease course or treatment groups. Dosing and indications for cessation of IgRT are also inadequately characterized. Further randomized controlled trials (RCTs) and observational studies are required to assess the optimal indications, timing, and duration of IgRT to improve the efficacy, safety, and cost-effectiveness. Assessment of alternative and adjunctive therapies, such as vaccination and antibiotic prophylaxis could also improve the outcomes and costs.

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.

[Thrombosis with Thrombocytopenia Syndrome after ChAdOx1 nCoV-19 vaccination]

A 48-year-old Japanese man who had no previous medical history received his first dose of the ChAdOx1 nCoV-19 vaccine. Ten days after the vaccine administration, he developed a headache. Laboratory results indicated throm-bocytopenia and DIC. A head CT revealed microbleeding in the left parietal lobe. Contrast-enhanced CT showed thrombus in the left transverse sinus and left sigmoid sinus. A brain MRI demonstrated venous hemorrhagic infarction and subarachnoid hemorrhages in the left parietal lobe, and whole-body enhanced CT also revealed portal vein embolism and renal infarction. He was diagnosed with thrombosis with thrombocytopenia syndrome, and was treated according to the guideline. He has been recovering with the treatments. This is the first reported case of TTS associated with the ChAdOx1 nCoV-19 vaccine in Japan.

Intravenous Immunoglobulin Combined With Corticosteroids for the Treatment of Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis: A Propensity-Matched Retrospective Study in China

Background: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but life-threatening severe adverse drug reactions. The use of corticosteroids and intravenous immunoglobulin (IVIg) in SJS/TEN remains controversial. Methods: In this single-center, observational, propensity-matched, retrospective study, we collected a total of 224 patients with SJS/TEN who were hospitalized in our department from 2008 to 2019; according to treatment with IVIg combined with corticosteroids or with corticosteroids alone, patients were divided into combination therapeutic group (163 patients) and monotherapeutic group (61 patients). Patients from the two groups were matched by their propensity score in blocks of 2:1. Comparisons of the clinical characteristics and prognoses between propensity-matched SJS/TEN patients treated with IVIg combined with corticosteroids and corticosteroids alone were made. Results: After our propensity matching, a total of 145 patients were yielded, including 93 patients treated with IVIg and 52 patients not treated with IVIg. All of the 23 variables reflected good matching between patients treated with/without IVIg, and no significant difference was observed. Although there was no significant difference between the totally predicted and actual mortality in both of our groups, the actual mortality was lower than it was predicted in patients treated with IVIg [p > 0.250, the standardized mortality ratio (SMR) was 0.38, 95% CI 0.00-0.91] and patients treated without IVIg (p = 1.000, the SMR was 0.75, 95% CI 0.00-1.76). IVIg tended toward reducing the time to arrest of progression by 1.56 days (p = 0.000) and the length of hospital stay by 3.37 days (p = 0.000). The mortality rate was 45% lower for patients treated with IVIg combined with corticosteroids than those only treated with corticosteroid therapy, although it was not statistically significant (p = 0.555). The incidence of skin infections was significantly lower in the combined therapy group (p < 0.025), and the total infection rate of patients treated with combination therapy tended to decrease by 67% compared to patients treated with corticosteroids alone (p = 0.047). Conclusion: The actual mortality rate of patients treated with corticosteroids alone or IVIg combined with corticosteroids tended to be lower than those predicted by TEN-specific severity-of-illness score (SCORTEN), although there was no significance. Compared with those treated by corticosteroids alone, combination therapy was prone to bring a better prognosis for SJS/TEN patients.

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.

Treatment-associated hemolysis in Kawasaki disease: association with blood-group antibody titers in IVIG products

Hemolytic anemia resulting from IV Immunoglobulin (IVIG) treatment can be a serious complication, especially for those with underlying conditions with a high level of inflammation and after administration of high IVIG dosages, such as Kawasaki disease (KD), a multisystem vasculitis affecting young children. This hemolysis is caused by antibodies against blood groups A and B, but the precise mechanism for hemolysis is not known. We performed a single center, partly retrospective, partly prospective study of a cohort of 581 patients who received IVIG for treatment of KD from 2006 to 2013. Factors associated with hemolysis were identified through univariable and multivariable logistic regression. Six IVIG preparations were assayed for their hemolytic effect with serological and cellular assays to clarify the mechanism of red cell destruction. During the study period, a sudden increase in the incidence of hemolysis was observed, which coincided with the introduction of new IVIG preparations in North America that contained relatively high titers of anti-A and anti-B. These blood-group-specific antibodies were of the immunoglobulin G2 (IgG2) subclass and resulted in phagocytosis by monocyte-derived macrophages in an FcγRIIa-dependent manner. Phagocytosis was increased in the presence of proinflammatory mediators that mimicked the inflammatory state of KD. An increased frequency of severe hemolysis following IVIG administration was caused by ABO blood-group-specific IgG2 antibodies leading to FcγRIIa-dependent clearance of erythrocytes. This increase in adverse events necessitates a reconsideration of the criteria for maximum titer (1:64) of anti-A and anti-B in IVIG preparations.

Neutropenia resulting from high-dose intravenous immunoglobulin in dermatological patients

BACKGROUND AND OBJECTIVES

Current guidelines recommend high-dose intravenous immunoglobulin (IVIG) as a rescue therapy to treat severe cutaneous autoimmune disorders. Data on IVIG-induced hematological adverse events are limited in dermatological patients. We assessed the incidence and clinical implications of IVIG-induced neutropenia.

PATIENTS AND METHODS

Patients who received one or several cycles of IVIG between 2014 and 2019 were retrospectively evaluated. IVIG was given according to standardized infusion protocols. Daily differential blood counts were performed. Information on clinical baseline data, dermatological diagnosis, immunosuppressive pre-treatment, and IVIG-related adverse events was retrieved from patient files.

RESULTS

Seventeen patients received 106 IVIG treatment cycles. Neutrophil counts below 1,500/μL were documented during 36 (34.0 %) cycles, and neutrophils fell below 1,000/μL in 14 (13.2 %) cases. The average drop of neutrophils from day one (pre-dose) to days 2 and 3 of IVIG therapy was statistically significant (p = 0.006, and p = 0.002, respectively) despite correction for hemodilution, and so was a slight decrease of thrombocytes (p = 0.029, and p = 0.011, respectively). Four patients developed seven episodes of bacterial infections during or immediately after IVIG therapy.

CONCLUSIONS

IVIG-induced neutropenia is frequent in dermatological patients. A risk of secondary bacterial infections cannot be excluded.

Responsiveness to i.v. immunoglobulin therapy in patients with toxic epidermal necrolysis: A novel pharmaco-immunogenetic concept

Toxic epidermal necrolysis (TEN) represents a rare drug-induced autoimmune reaction with delayed-type hypersensitivity that initiates the process of developing massive keratinocyte apoptosis, dominantly in the dermoepidermal junction. Although the etiopathophysiology has not yet been fully elucidated, the binding of Fas ligand (FasL, CD95L) to the Fas receptor (CD95) was shown to play a key role in the induction of apoptosis in this syndrome. The knowledge of the role of immunoglobulin G (IgG) in inhibition of Fas-mediated apoptosis contributed to the introduction of i.v. Ig (IVIg) in the therapy of TEN patients. Despite great enthusiasm for this therapy at the end of the 1990s, subsequent studies in various populations and meta-analyses could not unequivocally confirm the efficacy of the IVIg-based treatment concept. Today, therefore, we are faced with the dilemmas of how to adjust therapy of TEN patients most effectively, which patients could benefit from IVIg therapy and what dose of the preparation should be administrated. The ground-breaking question is: do the host genetic profiles influence the responsiveness and side-effects of IVIg therapy in TEN patients? Based on recent pharmacological, immunological and genetic findings, we suggest that the variability of IVIg therapy outcomes in TEN patients may be related to functional variants in Fas, FasL and Fc-γ receptor genes. This novel concept could lead to improved quality of care for patients with TEN, facilitating personalized therapy to reduce mortality.

Acute massive pulmonary embolism treated by urgent pulmonary embolectomy: A case report

The management of acute massive pulmonary embolism presents a clinical challenge as currently there is no consensus for definitive treatment. Early decision-making regarding surgical intervention is essential when the risk of mortality is high.

Should we prevent thrombosis related to intravenous immunoglobulin infusions with systematic anticoagulant prophylaxis?

Intravenous immunoglobulins (IVIg) are commonly used for treatment of dysimmune diseases, but they are known to promote thrombotic events. The medical records of patients who received IVIg infusions to treat neuromuscular disorders were retrospectively studied during two periods: the on-demand period (May 2013-January 2015), when patients received anticoagulant prophylaxis based on personal thrombotic risk factors, and the systematic period (May 2015-January 2017), when patients received systematic anticoagulant prophylaxis. Of the 334 total patients included, 19/153 received anticoagulant prophylaxis in the on-demand period, and 181 were treated in the systematic period. In the on-demand period, thrombosis occurred in three patients (1.96%) as one central retinal artery occlusion, one pulmonary embolism, and one brachiocephalic vein thrombosis. In the systematic period, thrombosis occurred in two patients (1.1%), both as pulmonary embolisms. There was no statistical difference in thrombosis incidence between the periods (P=0.66). The only factor associated with thrombosis was splenectomy (20% versus 0.3% in patients without thrombosis, P=0.03). There were no adverse events due to thromboprophylaxis by low-molecular-weight heparin in either period. Systematic thromboprophylaxis did not significantly reduce the incidence of thrombosis versus thromboprophylaxis based on personal thrombotic risk.

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.

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

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

Engineering of Fc Multimers as a Protein Therapy for Autoimmune Disease

The success of Intravenous Immunoglobulin in treating autoimmune and inflammatory processes such as immune thrombocytopenia purpura and Kawasaki disease has led to renewed interest in developing recombinant molecules capable of recapitulating these therapeutic effects. The anti-inflammatory properties of IVIG are, in part, due to the Fc region of the IgG molecule, which interacts with activating or inhibitory Fcγ receptors (FcγRs), the neonatal Fc Receptor, non-canonical FcRs expressed by immune cells and complement proteins. In most cases, Fc interactions with these cognate receptors are dependent upon avidity—avidity which naturally occurs when polyclonal antibodies recognize unique antigens on a given target. The functional consequences of these avid interactions include antibody dependent cell-mediated cytotoxicity, antibody dependent cell phagocytosis, degranulation, direct killing, and/or complement activation—all of which are associated with long-term immunomodulatory effects. Many of these immunologic effects can be recapitulated using recombinant or non-recombinant approaches to induce Fc multimerization, affording the potential to develop a new class of therapeutics. In this review, we discuss the history of tolerance induction by immune complexes that has led to the therapeutic development of artificial Fc bearing immune aggregates and recombinant Fc multimers. The contribution of structure, aggregation and N-glycosylation to human IgG: FcγR interactions and the functional effect(s) of these interactions are reviewed. Understanding the mechanisms by which Fc multimers induce tolerance and attempts to engineer Fc multimers to target specific FcγRs and/or specific effector functions in autoimmune disorders is explored in detail.

Measurement of isoagglutinins in immunoglobulins for intravenous application by flow cytometry

Isoagglutinins present in intravenous immunoglobulin (IVIG) products have been linked to haemolysis. Therefore, accurately assessing isoagglutinin content in IVIG products is important. The standard European Pharmacopoeia (Ph.Eur.) direct assay is limited by low precision. Here, we describe the development of a fluorescence-activated cell sorting (FACS) method for assessing isoagglutinin levels. Serially diluted IVIG samples were incubated with red blood cells (RBCs), RBC-bound anti-A and anti-B antibodies were detected using a fluorescently-labelled antibody and the median fluorescence intensity of samples was assessed by FACS. Results were compared with the Ph.Eur. direct assay. The method was used to determine isoagglutinins in commercial products produced with and without isoagglutinin reduction steps. Assay precision, reported as the coefficient of variation, for the FACS method was 14% and 8% for anti-A and anti-B, respectively versus 33% and 20% with the Ph.Eur. direct assay. Application of the method on commercially available IVIGs revealed differences in isoagglutinin content between products produced with and without isoagglutinin reduction steps. This FACS assay allows for quantification of isoagglutinin concentrations in IVIGs with higher precision than the Ph.Eur. direct assay. Also the FACS assay confirms differences in isoagglutinin levels between IVIG products and the efficacy of isoagglutinin reduction measures.

Immune mediated pediatric encephalitis - need for comprehensive evaluation and consensus guidelines

Background

Autoimmune encephalitis is characterized by neuropsychiatric symptoms associated with brain inflammation. The differential is usually broad and Psychiatry often collaborates with Neurology in diagnostic clarification and symptom management. At least 40% of neuroencephalitis cases are of unknown etiology which adds to difficulties in making the right diagnosis and deciding on the appropriate treatment (Granerod et al., Lancet Infect Dis 10:835-44, 2010). The aim of this case series was to present four cases with complicated psychiatric symptomatology and isolated neurologic signs and symptoms, evaluated at a large tertiary medical center and treated for suspected autoimmune encephalitis, demonstrating the complexity of diagnosis and treatment.

Case presentation

Four diagnostically challenging and heterogeneous cases displayed clinical symptomatology suggestive of autoimmune encephalitis. All cases presented with neurologic and psychiatric symptoms, but had negative autoantibody panels, normal or inconclusive magnetic resonance imaging results and non-specific cerebrospinal fluid changes. All were challenged with immunosuppressive/immunomodulatory treatments with overall poor response rates.

Conclusions

There is a heterogeneous presentation of autoimmune encephalitis in pediatric populations. In the absence of positive findings on testing, individuals who do not meet proposed criteria for seronegative encephalitis may be misdiagnosed, and/or may not respond adequately to treatment. In those cases, comprehensive evaluation and stringent application of consensus guidelines is necessary.

[Intravenous immunoglobulin-induced thrombocytopenia in patient with chronic inflammatory demyelinating polyneuropathy]

A 69-year-old man was admitted to our hospital because of dysesthesia in right palm and left upper limb, gait disturbance, and muscle weakness in both lower limbs. At the same time of neurological impairment appeared, he developed pemphigoid. Lumber MRI showed swelling of cauda equina nerve root. We diagnosed as chronic inflammatory demyelinating polyneuropathy based on an electrophysiological examination, and 2 courses of intravenous immunoglobulin therapy (IVIG) were initiated. After the treatments, symptoms improved immediately. However, thrombocytopenia was seen after each treatment which began on the second day of treatment start, reaching the lowest point from about 10 to 14 days, and improved naturally from 10 to 15 days after the end of IVIG. Difficulty in hemostasis was seen during dialysis due to thrombocytopenia. As a cause of thrombocytopenia, formation of IgG-platelet complexes could be considered, and the presence of multiple inflammatory diseases which activated Fcγ receptors play key roles could be a risk for IVIG related thrombocytopenia.

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.

Complications of Immunoglobulin Therapy and Implications for Treatment of Inflammatory Neuropathy: A Review

BACKGROUND

Intravenous Immunoglobulin (IVIg) forms a cornerstone of effective treatment for acute and chronic inflammatory neuropathies, with a class I evidence base in Guillain-Barré Syndrome (GBS), Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) and multifocal motor neuropathy (MMN). It is generally considered to be a safe therapy however there are several recognised complications which are reviewed in this article.

DISCUSSION AND CONCLUSION

Most adverse events are immediate and mild such as headache, fever and nausea although more serious immediate reactions such as anaphylaxis may rarely occur. Delayed complications are rare but may be serious, including thromboembolic events and acute kidney injury, and these and associated risk factors are also discussed. We emphasise the importance of safe IVIg administration and highlight practical measures to minimise complications of this therapy.

Efgartigimod improves muscle weakness in a mouse model for muscle-specific kinase myasthenia gravis

Myasthenia gravis is hallmarked by fatigable muscle weakness resulting from neuromuscular synapse dysfunction caused by IgG autoantibodies. The variant with muscle-specific kinase (MuSK) autoantibodies is characterized by prominent cranial and bulbar weakness and a high frequency of respiratory crises. The majority of MuSK MG patients requires long-term immunosuppressive treatment, but the result of these treatments is considered less satisfactory than in MG with acetylcholine receptor antibodies. Emergency treatments are more frequently needed, and many patients develop permanent facial weakness and nasal speech. Therefore, new treatment options would be welcome. The neonatal Fc receptor protects IgG from lysosomal breakdown, thus prolonging IgG serum half-life. Neonatal Fc receptor antagonism lowers serum IgG levels and thus may act therapeutically in autoantibody-mediated disorders. In MuSK MG, IgG4 anti-MuSK titres closely correlate with disease severity. We therefore tested efgartigimod (ARGX-113), a new neonatal Fc receptor blocker, in a mouse model for MuSK myasthenia gravis. This model involves 11 daily injections of purified IgG4 from MuSK myasthenia gravis patients, resulting in overt myasthenic muscle weakness and, consequently, body weight loss. Daily treatment with 0.5 mg efgartigimod, starting at the fifth passive transfer day, reduced the human IgG4 titres about 8-fold, despite continued daily injection. In muscle strength and fatigability tests, efgartigimod-treated myasthenic mice outperformed control myasthenic mice. Electromyography in calf muscles at endpoint demonstrated less myasthenic decrement of compound muscle action potentials in efgartigimod-treated mice. These substantial in vivo improvements of efgartigimod-treated MuSK MG mice following a limited drug exposure period were paralleled by a tendency of recovery at neuromuscular synaptic level (in various muscles), as demonstrated by ex vivo functional studies. These synaptic improvements may well become more explicit upon longer drug exposure. In conclusion, our study shows that efgartigimod has clear therapeutic potential in MuSK myasthenia gravis and forms an exciting candidate drug for many autoantibody-mediated neurological and other disorders.

A serious thrombotic event in a patient with immune thrombocytopenia requiring intravenous immunoglobulin: a case report

BACKGROUND

Immune thrombocytopenia is an acquired autoimmune disease. Recently, there has been evidence of thrombotic risk in patients with immune thrombocytopenia, but the mechanism is still inconclusive. Intravenous immunoglobulin infusion therapy is considered an efficient treatment; however, it still is associated with adverse events of fever, chills, and hypotension, as well as serious complications such as thrombosis. We report a case a patient with relapsed immune thrombocytopenia who developed ischemic stroke after an intravenous immunoglobulin infusion.

CASE PRESENTATION

A 49-year-old Thai woman with relapsed/refractory immune thrombocytopenia came to our hospital with a large hematoma at the right buttock, and her platelet was decreased to 3 × 10⁹/L. She was admitted to our hospital for intravenous immunoglobulin administration. One hour after completion of intravenous immunoglobulin infusion, the patient's sister complained that the patient was unconscious and could not move both legs and arms. Emergency computed tomography of the brain showed no abnormal findings, such as brain edema, intracranial hemorrhage, or infarction. One day later, repeat computed tomography of the brain displayed extensive acute ischemic changes and loss of gray-white differentiation of bilateral cerebral hemispheres.

CONCLUSIONS

We performed an extensive literature review to determine the possible causes of serious thrombotic events in immune thrombocytopenia between the predictive factors of the disease and intravenous immunoglobulin. Although intravenous immunoglobulin is an effective treatment, thrombotic complications can occur. We emphasize that in patients with atherosclerosis risk factors or thrombophilia, the appropriateness of administering an intravenous immunoglobulin infusion should be carefully evaluated.

A recombinant human IgG1 Fc multimer designed to mimic the active fraction of IVIG in autoimmunity

The antiinflammatory effects of i.v. Ig (IVIG) in the treatment of autoimmune disease are due, in part, to the Fc fragments of Ig aggregates. In order to capitalize on the known antiinflammatory and tolerogenic properties of Ig Fc aggregates, we created a recombinant human IgG1 Fc multimer, GL-2045. In vitro, GL-2045 demonstrated high-avidity binding to Fc receptors, blocked the binding of circulating immune complexes from patients with rheumatoid arthritis to human Fcγ receptors (FcγRs), and inhibited antibody-mediated phagocytosis at log order-lower concentrations than IVIG. In vivo, administration of GL-2045 conferred partial protection against antibody-mediated platelet loss in a murine immune thrombocytopenic purpura (ITP) model. GL-2045 also suppressed disease activity in a therapeutic model of murine collagen-induced arthritis (CIA), which was associated with reduced circulating levels of IL-6. Furthermore, GL-2045 administration to nonhuman primates (NHPs) transiently increased systemic levels of the antiinflammatory cytokines IL-10 and IL-1RA, reduced the proinflammatory cytokine IL-8, and decreased surface expression of CD14 and HLA-DR on monocytes. These findings demonstrate the immunomodulatory properties of GL-2045 and suggest that it has potential as a treatment for autoimmune and inflammatory diseases, as a recombinant alternative to IVIG.

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.

A Pilot Study to Assess Safety and Feasibility of Intrathecal Immunoglobulin for the Treatment of Adults with Tetanus

Tetanus remains a significant burden in many low- and middle-income countries. The tetanus toxin acts within the central nervous system and intrathecal antitoxin administration may be beneficial, but there are safety concerns, especially in resource-limited settings. We performed a pilot study to assess the safety and feasibility of intrathecal human tetanus immunoglobulin in five adults with tetanus before the conduct of a large randomized controlled trial. Intrathecal injection via lumbar puncture was given to all patients within a median 140 (range 100–165) minutes of intensive care unit (ICU) admission. There were no serious adverse effects associated with the procedure although three patients had probably related minor adverse events which resolved spontaneously. Median ICU length of stay was 14 (range 5–17) days. Two patients required mechanical ventilation and one developed a deep vein thrombosis. Within 240 days of hospital discharge, no patients died and all patients returned to work.

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.

Autoimmune haemolytic anaemia in a patient with advanced lung adenocarcinoma and chronic lymphocytic leukaemia receiving nivolumab and intravenous immunoglobulin

We describe a rare case of severe autoimmune haemolytic anaemia (AIHA) in the setting of underlying chronic lymphocytic leukaemia receiving intravenous immunoglobulin, history of warm IgG autoantibody and treatment with nivolumab for advanced non-small cell lung cancer. In this report, we describe AIHA as a potential serious immune-related adverse event from immune checkpoint inhibitors, discuss other potential contributing factors and review previously described cases of AIHA in patients receiving programmed death 1 (PD-1) inhibitors. In the era of immunotherapy, we hope to add literature to raise awareness of potential immune-related sequelae such as AIHA. We aim to highlight the importance of close monitoring for prompt identification and management of potentially fatal AIHA and immune-related adverse events of PD-1 inhibitors by holding immunotherapy and treating with high-dose steroids, particularly in subgroups which may be at increased risk.

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.

Essentials of the Production of Safe and Efficacious State-of-the-Art Polyclonal IgG Concentrates

Severe noninfectious adverse events (AEs) and transmission of pathogens by plasma-derived protein concentrates from the very beginning of their clinical use were threats for recipients (see Chap. 10.1007/978-3-319-68038-5_11 for additional information). “Standard IgG” preparations were the first available for clinical use. They were produced by the cold-ethanol fractionation methods and did not make an exception. Noninfectious severe AEs occurred while infectious AEs were rarely reported. Indeed, prior to the introduction of mass screening for infection markers of plasma donations, inadvertent transmission of HIV to recipients of factor VIII and factor IX concentrates did occur, while IgG concentrates obtained from the same plasma pool did rarely transmit HIV (Morgenthaler 2001). Rare transmissions were restricted to products not exposed to low pH. The very few incidences of HIV and some incidences of HCV transmission by IgG concentrates in the early 1990s together with many cases of coagulation factor concentrates transmitted viral disease clearly demonstrated the need to establish standardized measures to render plasma products pathogen safe. In the second half of the 1990s, authorities shifted regulatory emphasis from a scientific review of the processes to a focus on compliance to current good manufacturing practice (cGMP). The focus on cGMP compliance was applied to all aspects of plasma fractionation and the clinical use of plasma products. Court injunctions and warning letters were the consequences of this paradigm shift by authorities. This in turn resulted in a paradigm shift how the modern plasma industry operates (Steinhardt 1998).

II Brazilian Consensus on the use of human immunoglobulin in patients with primary immunodeficiencies

In the last few years, new primary immunodeficiencies and genetic defects have been described. Recently, immunoglobulin products with improved compositions and for subcutaneous use have become available in Brazil. In order to guide physicians on the use of human immunoglobulin to treat primary immunodeficiencies, based on a narrative literature review and their professional experience, the members of the Primary Immunodeficiency Group of the Brazilian Society of Allergy and Immunology prepared an updated document of the 1^st Brazilian Consensus, published in 2010. The document presents new knowledge about the indications and efficacy of immunoglobulin therapy in primary immunodeficiencies, relevant production-related aspects, mode of use (routes of administration, pharmacokinetics, doses and intervals), adverse events (major, prevention, treatment and reporting), patient monitoring, presentations available and how to have access to this therapeutic resource in Brazil.

Intravenous immunoglobulin-induced acute thrombocytopenia

BACKGROUND

Intravenous immunoglobulin (IVIG) has known efficacy in various hematologic conditions, including immune thrombocytopenic purpura.

STUDY DESIGN AND METHODS

We present the clinical course of a patient with splenic marginal zone lymphoma, who developed acute thrombocytopenia on three consecutive episodes, with nadir counts of 27 × 10⁹ , 50 × 10⁹ , and 9 × 10⁹ /L, upon administration of Intratect IVIG for hypogammaglobulinemia. An immunofluorescence test applying flow cytometry and monoclonal antibody immobilization of platelet antigens (MAIPA) assay were used to evaluate the reaction between IgG present in the IVIG preparations and the patient's or healthy donors' platelets (PLTs).

RESULTS

A strong direct binding reaction was observed between the patient's PLTs and Intratect IgG using both methods. A similar reaction failed to materialize with controls. Binding was not antigen specific according to MAIPA.

CONCLUSIONS

This is the first reported case of thrombocytopenia as a possible adverse effect of IVIG.

Effect of intravenous immunoglobulin administration on erythrocyte and leucocyte parameters

BACKGROUND

Intravenous immunoglobulins (IVIG) are an attractive therapeutic tool for therapy of toxic epidermal necrolysis and severe forms of certain autoimmune diseases, including dermatomyositis, autoimmune blistering diseases, systemic vasculitis and lupus erythematodes.

OBJECTIVES

Prompted by a case of IVIG-associated haemolytic anaemia, the effects of IVIG administrations on haematological parameters in patients with dermatological conditions were investigated.

METHODS

Erythrocyte and leucocyte parameters were retrospectively analysed in 16 patients who had received IVIG at doses from 1 to 3 g/kg bodyweight (n = 35 cycles). The influence of IVIG on leucocyte survival was determined in vitro.

RESULTS

Decreased absolute erythrocyte numbers, haemoglobin and haematocrit levels and a case of haemolytic anaemia were linked to transfusion of high-, but not low-dose IVIG. In contrast, leucopenia post-IVIG occurred in the vast majority of the recipients, unrelated to the administered IVIG amounts. In vitro investigations revealed a dose-dependent impairment of cell survival by IVIG in the neutrophil and monocyte, but not in the lymphocyte subpopulations. In several IVIG preparations, substantial amounts of blood group anti-A/anti-B antibodies were detected which could have accounted for the observed changes in the haematological parameters in our study cohort.

CONCLUSIONS

IVIG products should be administered strictly according to indications. Commercially available IVIG products can contain blood group-specific antibodies that may induce haemolysis in some recipients. Monitoring of blood counts during applied IVIG therapy, especially when high doses are administered, is recommended.

Hemolysis related to intravenous immunoglobulins is dependent on the presence of anti-blood group A and B antibodies and individual susceptibility

BACKGROUND

Patients treated with intravenous immunoglobulins (IVIG) rarely experience symptomatic hemolysis. Although anti-A and anti-B isoagglutinins from the product are involved in most cases, the actual mechanisms triggering hemolysis are unclear.

STUDY DESIGN AND METHODS

A prospective, open-label, multicenter, single-arm clinical trial in 57 patients with immune thrombocytopenia treated with IVIG (Privigen, CSL Behring) was conducted.

RESULTS

Twenty-one patients received one infusion (1 g/kg) and 36 received two infusions (2 × 1 g/kg) of IVIG. After a study duration of more than 2 years, no cases of clinically significant hemolysis as defined in the protocol were identified. Data of patients with mild hematologic and biochemical changes were analyzed in more detail. Twelve cases (10/23 patients with blood group A1 and 2/11 patients with blood group B, all having received 2 g/kg IVIG) were adjudicated as mild hemolysis (median hemoglobin [Hb] decrease, -3.0 g/dL); Hb decreases were transient, with partial or full recovery achieved by last visit. Eighteen patients (31.6%), all with non-O blood group, of whom 16 (88.9%) received 2 g/kg IVIG, fulfilled post hoc criteria for hemolytic laboratory reactions. Red blood cell (RBC) eluates of all direct antiglobulin test-positive samples were negative for non-ABO blood group antibodies. Blood groups A and B antigen density on RBCs appeared to be a risk factor for hemolytic laboratory reactions. Platelet response to treatment was observed in 42 patients (74%); eight of 12 patients with complete response had blood group A1.

CONCLUSION

Isoagglutinins are involved in clinically nonsignificant hemolysis after treatment with IVIG, but individual susceptibility varies greatly.

The potential of intravenous immunoglobulins for cancer therapy: a road that is worth taking?

Much has been learned recently about the role of immunoglobulins as effector molecules of the adaptive immunity and as active elements in the maintenance of immune homeostasis. The increasing number of pathologies where intravenous immunoglobulins (IVIg) display a beneficial action illustrates their therapeutic relevance. Considering recent findings on the ability of IVIg to modulate macrophage polarization, herein we review evidences on the antitumoral activity of IVIg. Fragmentary and nonconclusive, available evidences are just suggestive of the potential of IVIg in antitumoral therapy, but encourage for the generation of additional evidences through well-designed clinical trials, and for additional studies to address the molecular effects of IVIg as a means to avoid the extrapolation of data gathered from animal models.

Reduction of Isoagglutinin in Intravenous Immunoglobulin (IVIG) Using Blood Group A- and B-Specific Immunoaffinity Chromatography: Industry-Scale Assessment

BACKGROUND

Hemolysis, a rare but potentially serious complication of intravenous immunoglobulin (IVIG) therapy, is associated with the presence of antibodies to blood groups A and B (isoagglutinins) in the IVIG product. An immunoaffinity chromatography (IAC) step in the production process could decrease isoagglutinin levels in IVIG.

OBJECTIVES

Our objectives were to compare isoagglutinin levels in a large number of IVIG (Privigen^®) batches produced with or without IAC and to assess the feasibility of the production process with an IAC step on an industrial scale.

METHODS

The IAC column comprised a blend of anti-A and anti-B resins formed by coupling synthetic blood group antigens (A/B-trisaccharides) to a base bead matrix, and was introduced towards the end of the industrial-scale IVIG manufacturing process. Isoagglutinin levels in IVIG were determined by anti-A and anti-B hemagglutinin direct and indirect methods according to the European Pharmacopoeia (Ph. Eur.) and an isoagglutinin flow cytometry assay. IVIG product quality was assessed with respect to the retention of immunoglobulin G (IgG) subclasses, specific antibodies, and removal of IgM using standardized procedures.

RESULTS

The IAC step reduced isoagglutinins in IVIG by two to three titer steps compared with lots produced without IAC. The median anti-A and anti-B titers with IAC were 1:8 and 1:4, respectively, when measured by the Ph. Eur. direct method, and 1:2 and <1, respectively, when measured by the Ph. Eur. indirect method. The isoagglutinin flow cytometry assay showed an 87-90 % reduction in isoagglutinins in post-IAC versus pre-IAC fractions. IAC alone reduced anti-A and anti-B of the IgMs isotype by 92.5-97.8 % and 95.4-99.2 %, respectively. Other product quality characteristics were similar with and without IAC.

CONCLUSIONS

IAC is an effective method for reducing isoagglutinin levels in IVIG, and it is feasible on an industrial scale.

Risk and safety requirements for diagnostic and therapeutic procedures in allergology: World Allergy Organization Statement

One of the major concerns in the practice of allergy is related to the safety of procedures for the diagnosis and treatment of allergic disease. Management (diagnosis and treatment) of hypersensitivity disorders involves often intentional exposure to potentially allergenic substances (during skin testing), deliberate induction in the office of allergic symptoms to offending compounds (provocation tests) or intentional application of potentially dangerous substances (allergy vaccine) to sensitized patients. These situations may be associated with a significant risk of unwanted, excessive or even dangerous reactions, which in many instances cannot be completely avoided. However, adverse reactions can be minimized or even avoided if a physician is fully aware of potential risk and is prepared to appropriately handle the situation. Information on the risk of diagnostic and therapeutic procedures in allergic diseases has been accumulated in the medical literature for decades; however, except for allergen specific immunotherapy, it has never been presented in a systematic fashion. Up to now no single document addressed the risk of the most commonly used medical procedures in the allergy office nor attempted to present general requirements necessary to assure the safety of these procedures. Following review of available literature a group of allergy experts within the World Allergy Organization (WAO), representing various continents and areas of allergy expertise, presents this report on risk associated with diagnostic and therapeutic procedures in allergology and proposes a consensus on safety requirements for performing procedures in allergy offices. Optimal safety measures including appropriate location, type and required time of supervision, availability of safety equipment, access to specialized emergency services, etc. for various procedures have been recommended. This document should be useful for allergists with already established practices and experience as well as to other specialists taking care of patients with allergies.

Immunoglobulin-induced hemolysis, splenomegaly and inflammation in patients with antibody deficiencies

IgG replacement for primary antibody deficiencies is a safe treatment administered to prevent recurrent infections and reduce mortality. Recently, several reports described acute hemolytic episodes following IgG administration due to a passive transfer of blood group alloantibodies, including anti-A, anti-B, as well as anti-Rh antibodies. Here, we reviewed and discussed the consequences of passively transferred RBCs antibodies. The chronic passive transfer of alloantibodies might also cause a subclinical condition due to a compensated extravascular chronic hemolysis with poorly understood consequences. This phenomenon might possibly represent an unrecognized cause of splenomegaly and might contribute to inflammation in patients with primary antibody deficiencies.

Human immune globulin infusion in the management of multifocal motor neuropathy

Multifocal motor neuropathy (MMN) is a debilitating and rare disease causing profound weakness with minimal to no sensory symptoms. Conduction block is frequently seen on electrodiagnostic testing. An immune-mediated pathology is suspected though the exact underlying pathophysiology has yet to be elucidated. The presence of anti-GM1 ganglioside IgM antibodies coupled with favorable response to intravenous and subcutaneous immunoglobulins supports a complement-mediated mechanism which leads to destruction of nerve tissue with probable predilection to the nodes of Ranvier. High-dose immunoglobulin currently is the only treatment with proven efficacy for MMN patients. Unfortunately, many patients experience decreased responsiveness to immunoglobulins over time, requiring higher and more frequent dosing. In this review, we will focus on the pharmacology, efficacy, safety, and tolerability of intravenous and subcutaneous immune globulin infusion for treatment of MMN.

Management of adverse events in the treatment of patients with immunoglobulin therapy: A review of evidence

Immunoglobulin (IG) therapy is actually used for a broad range of diseases including primary and secondary immunodeficiency disorders, and autoimmune diseases. This therapy is available for intravenous (IV) and subcutaneous (SC) administration. The efficacy of the IG therapy has been demonstrated in numerous studies and across different diseases. Generally, IG infusions are well tolerated; however some well-known adverse reactions, ranging from mild to severe, are associated with the therapy. The most common adverse reactions including headache, nausea, myalgia, fever, chills, chest discomfort, skin and anaphylactic reactions, could arise immediately during or after the infusion. Delayed events could be more severe and include migraine headaches, aseptic meningitis, haemolysis renal impairment and thrombotic events. This paper reviews all the potential adverse events related to IG therapy and establishes a comprehensive guideline for the management of these events. Moreover it resumes the opinions and clinical experience of expert endorsers on the utilization of the treatment. Published data were classified into levels of evidence and the strength of the recommendation was given for each intervention according to the GRADE system.

Acute pulmonary embolism caused by highly aggregated intravenous immunoglobulin

BACKGROUND AND OBJECTIVES

Six patients died and one patient survived following infusion of a specific lot of intravenous immunoglobulin (IVIG) within half an hour in May 2008. This study elucidated the underlying pathogenesis.

MATERIALS AND METHODS

A variety of protein fractionation and identification approaches were employed to determine the abnormal components in IVIG products obtained from the hospital where the patients were treated. Animal studies using mice and monkeys were conducted to elucidate the pathophysiological mechanisms. In animal experiments, the effect and distribution of immunoglobulin was investigated using HE staining and immunohistochemistry (IHC) separately, while platelets and fibrinogen depletion were utilized to determine a possible link between thromboembolism formation in animals and the lethal effect of the IVIG. The size and distribution of the protein aggregates were determined with Coulter Counter Multisizer-3 after the dilution of the IVIG with plasma, and the lethal effect of the protein aggregates was simulated with artificial microparticles.

RESULTS

The IVIG retrieved from the hospital was found to have striking similarities to the heat-treated IVIG in terms of protein aggregation profiles and lethal effects. Post-mortem examination indicated that immunoglobulin aggregates were mainly found in the lung of the animals, while depletion of platelets and fibrinogen from the IVIG preparations failed to prevent the death of the animals. Similar amount of artificial microparticles caused animal death in similar fashion.

CONCLUSIONS

Our findings indicate that the retrieved IVIG exerted its lethal effects by blocking the pulmonary circulation without markedly altering the coagulation cascade or immunological events.