Long-term use of IgA-depleted intravenous immunoglobulin in immunodeficient subjects with anti-IgA antibodies

Risk factors of partial IgA deficiency among low serum IgA patients: a retrospective observational study

Introduction

Partial IgA deficiency (pIgAD), including selective IgA deficiency, is one of the most common types of immunodeficiency. Early detection is crucial to prevent complications, such as recurrent infections and anaphylactic reactions to blood derivatives.

Material and methods

Useful screening methods have not yet been established. We conducted a single-center retrospective observational study, with low serum IgA patients to clarify the risk factors of pIgAD among patients with low serum levels of IgA. All patients with low serum IgA levels treated in our outpatient clinic from April 2010 to March 2016 were retrospectively reviewed using electronic medical records. We performed c² tests and Student’s t-tests for the univariate analysis, logistic regression analysis using the multiple imputation method for the multivariate analysis, and receiver operating characteristic (ROC) curve analysis.

Results

The univariate analysis showed statistically significant differences between the pIgAD group and the non-pIgAD group in age, gender, blood cell counts, serum protein levels, and renal function tests. The multivariate analysis revealed that female gender, a white blood cell counts lower than 10,000/µl, and a hemoglobin level of 10.0-15.0 g/dl are predictive factors of pIgAD.

Conclusions

After estimating any missing data using the multiple imputation method, age younger than 60 years old was also statistically significant. ROC curve analysis confirmed the validity of the model used in our multivariate analysis. When clinicians encounter low serum IgA patients who are female, of younger age, and have normal blood cell counts, and hemoglobin levels, they should suspect the existence of pIgAD.

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.

Pemphigus

Pemphigus is a group of IgG-mediated autoimmune diseases of stratified squamous epithelia, such as the skin and oral mucosa, in which acantholysis (the loss of cell adhesion) causes blisters and erosions. Pemphigus has three major subtypes: pemphigus vulgaris, pemphigus foliaceus and paraneoplastic pemphigus. IgG autoantibodies are characteristically raised against desmoglein 1 and desmoglein 3, which are cell-cell adhesion molecules found in desmosomes. The sites of blister formation can be physiologically explained by the anti-desmoglein autoantibody profile and tissue-specific expression pattern of desmoglein isoforms. The pathophysiological roles of T cells and B cells have been characterized in mouse models of pemphigus and patients, revealing insights into the mechanisms of autoimmunity. Diagnosis is based on clinical manifestations and confirmed with histological and immunochemical testing. The current first-line treatment is systemic corticosteroids and adjuvant therapies, including immunosuppressive agents, intravenous immunoglobulin and plasmapheresis. Rituximab, a monoclonal antibody against CD20⁺ B cells, is a promising therapeutic option that may soon become first-line therapy. Pemphigus is one of the best-characterized human autoimmune diseases and provides an ideal paradigm for both basic and clinical research, especially towards the development of antigen-specific immune suppression treatments for autoimmune diseases.

The long and winding road to IgA deficiency: causes and consequences

INTRODUCTION

The most common humoral immunodeficiency is IgA deficiency. One of the first papers addressing the cellular and molecular mechanisms underlying IgA deficiency indicated that immature IgA-positive B-lymphocytes are present in these patients. This suggests that the genetic background for IgA is still intact and that class switching can take place. At this moment, it cannot be ruled out that genetic as well as environmental factors are involved. Areas covered: A clinical presentation, the biological functions of IgA, and the management of IgA deficiency are reviewed. In some IgA deficient patients, a relationship with a loss-of-function mutation in the TACI (transmembrane activator and calcium-modulating cyclophilin ligand interaction) gene has been found. Many other genes also have been associated. Gut microbiota are an important environmental trigger for IgA synthesis. Expert commentary: Expression of IgA deficiency is due to both genetic and environmental factors and a role for gut microbiota cannot be excluded.

Anaphylaxis to IVIG

Anaphylactic reactions are a known complication in some IgA-deficient patients receiving blood or plasma transfusions. It is of particular interest that anaphylaxis has been observed in patients with common variable immunodeficiency (CVID) who are receiving intravenous gammaglobulin (IVIG), and in that, although these patients have an impaired response to common vaccines, they retain the ability to produce autoantibodies. In this study, we review IgA antibodies (both IgG- and IgE-mediated reactions) in patients with CVID and hypogammaglobulinemia, anaphylaxis in antibody immunodeficient patients receiving IVIG, and proposed mechanisms of desensitization and prevention of anaphylactic reactions in immunodeficient patients receiving IVIG. We summarize and assess the 23 case reports documented in the literature that have described anaphylactic reactions in immunodeficient patients receiving IVIG since 1962 until currently, and make a comparison of their immunoglobulin levels, IgG anti-IgA, IgE anti-IgA, concentration of IVIG, IgA content in IVIG, method used to detect antibodies, length of treatment, and any subsequent tolerated treatment documented.

IgG anti-IgA antibodies in paediatric antibody-deficient patients receiving intravenous immunoglobulin

BACKGROUND

Immunoglobulin replacement therapy is an effective route of management for both infections and non-infectious complications in predominantly antibody deficiency (PAD). Trace levels of IgA (ranged from 0.4 to 2500 mg/ml), which exist in all immunoglobulin products, could lead to an increased susceptibility for adverse reactions in PAD patients. Furthermore, the exact mechanism which stimulates the anti-IgA antibody production in PAD is still unknown. The aim of this study was to evaluate IgG anti-IgA antibodies in PAD patients receiving intravenous immunoglobulin (IVIg) and its predisposing factors.

METHODS

Available patients with confirmed diagnosis of PAD, who underwent regular IVIg replacement therapy in our centre, were enrolled in the study. Control group included 24 healthy individuals as the negative control and eight symptomatic patients with IgA deficiency as the positive control groups. IgG anti-IgA antibodies level was measured by the ELISA method.

RESULTS

A significant difference was observed between Anti-IgA level of common variable immunodeficiency (CVID) and other PAD groups (p=0.02). Moreover, six CVID patients were seropositive for the IgG anti-IgA antibody, with higher susceptibility to the adverse reactions (p<0.001). IgG anti-IgA level has a negative relationship with serum IgA level (r=-0.06) and IVIg treatment duration (r=-0.006).

CONCLUSION

Our data suggested that there was a significant association between anti-IgA antibody presence and the adverse reactions, especially in CVID patients with higher susceptibility to produce this constitutional antibody.

Long-Term Treatment and Transfusion of Normal Blood Components Following Tolerance Induction in Patients with Anti-IgA Anaphylactic Reactions

BACKGROUND

In general, patients with significant anti-Ig-A do not tolerate intravenous (i.v.) administration of normal blood products. Here, we present our experiences in the induction of immune tolerance (IIT) and long-term treatment in a series of such patients affected in such a way. The question whether blood components from IgA-deficient donors are required will be discussed.

METHODS

Ten adult patients (4 females and 6 males; age ranging from 36 to 75 years) with anti-IgA were included in this study. All patients required long-term treatment with blood components. One patient had IgA deficiency and paroxysmal nocturnal hemoglobinuria (PNH), and all other patients had common variable immunodeficiency (CVID). The particle gel immunoassay was used for the detection of anti-IgA. Immune tolerance to IgA was induced by controlled subcutaneous (s.c.) and/or i.v. infusions of IgG preparations.

RESULTS

Prior to IIT, anti-IgA was detectable in plasma samples of all patients and significantly diminished or abolished by controlled s.c. and/or i.v. infusions of IgG. Multiple transfusions with normal blood components could be repeatedly performed with the patient suffering from PNH without any complications. As long as i.v. IgG (IVIgG) infusions were consequently administered as individually required (intervals 2-8 weeks), none of the patients developed reactions during observation (up to 10 years). However, interruption of treatment and re-exposure to IVIgG resulted in adverse reactions.

CONCLUSION

Patients with significant anti-IgA can be safely desensitized and tolerate long-term IgG substitutions independent of the IgA concentration of the used blood component.

Safety and tolerability of immune globulin intravenous (human), 10% solution in Japanese subjects with mild to moderate Alzheimer's disease

BACKGROUND

Immune globulin intravenous (IGIV), 10% is a donor-derived polyclonal human immunoglobulin G antibody mixture that has potent immune modulatory properties and contains conformation selective anti-amyloid antibodies. We evaluated the safety and tolerability of multiple doses of IGIV, 10% in Japanese patients with mild to moderate Alzheimer's disease.

METHODS

Among the 16 subjects, 12 subjects were assigned to the IGIV group and 4 subjects to the placebo group. Subjects received a total of six infusions of either IGIV at a dose of 0.2 or 0.4 g/kg, or placebo every 2 weeks.

RESULTS

A total of 33 treatment-emergent adverse events (TEAE) occurred in 14 subjects: 13 TEAE in five subjects in both the IGIV 0.2 and 0.4 g/kg groups, and 7 TEAE in four subjects in the placebo group. The most common TEAE in the IGIV subjects were nasopharyngitis, injection-site swelling, and erythema. All 26 TEAE in the IGIV group were considered to be mild. Only one mild TEAE (rash) was considered to be possibly related to the study drug. There were no significant differences in incidence of TEAE between the treatment groups. Four serious TEAE were reported, and all of these were considered to be unrelated to the study treatment. Other assessments related to safety revealed neither clinically significant abnormal values nor findings in the study.

CONCLUSION

IGIV is generally safe and well tolerated with multiple intravenous infusions at doses of 0.2 g/kg and 0.4 g/kg in Japanese patients with mild to moderate Alzheimer's disease.

Prospective, randomized comparison of OM-85 BV and a prophylactic antibiotic in children with recurrent infections and immunoglobulin A and/or G subclass deficiency

BACKGROUND

Patients with immunoglobulin (Ig)A and/or IgG subclass deficiency may be asymptomatic or may have recurrent, mainly respiratory infections.

OBJECTIVE

This study compared the clinical efficacy and tolerability of prophylactic therapy with either the oral immunomodulator bacterial extract OM-85 BV or benzathine penicillin G (BPG) in the prevention of recurrent infections in symptomatic patients.

METHODS

In this 26-month, prospective, randomized study conducted at the Department of Pediatric Immunology, Ege University (Izmir, Turkey), children aged 1 to 12 years with recurrent infections and IgA and/or IgG subclass deficiency were enrolled. After an initial 12-month control period, patients were randomized to receive OM-85 BV or BPG. OM-85 BV (3.5-mg capsule) was given once daily for the first 10 days of each month for the first 3 months of the study. IM injections of BPG were given at a dose of 1.2 million units (for patients with body weight > 27 kg) or at a half-dose (for patients with body weight ≤27 kg) every 3 weeks for 12 months. In nonresponders (ie, those who continued to have recurrent infections at 12-month follow-up), IV immunoglobulin (IVIG) replacement therapy at 400 mg/kg body weight was given every 4 weeks for an additional 12 months. The results of IVIG therapy were assessed by the authors using clinical observation. Adverse effects and adverse drug reactions were documented by the authors for each vaccine, prophylactic therapy, and IVIG.

RESULTS

A total of 91 children (56 boys, 35 girls; mean [SD] age at the start of the control period, 46.4 [31.0] months) were enrolled. Of these, 44 were randomized to the OM-85 BV group and 47 to the BPG group. The year before prophylactic therapy, the mean (SD) number of reported infections was 10.7 (3.6) and the mean (SD) number of antibiotic courses was 9.7 (3.6) (OM-85 BV group: mean [SD] number of reported infections, 10.5 [3.3]; mean (SD) number of antibiotic courses, 9.3 [3.3]; BPG group: mean [SD] number of reported infections, 10.8 [3.9], mean (SD) number of antibiotic courses, 10.1 [3.9]). At 12 months, the number of infections and antibiotic courses decreased significantly in the entire study population, but the between-group difference was not significant. Five patients in each group (OM-85 BV group, 11.4%; BPG group, 10.6%) were considered nonresponders and received IVIG treatment. Compared with responders, nonresponders were significantly younger (mean [SD] age, 34.40 [21.70] months vs 52.65 [30.52] months; P = 0.036) and had lower serum IgG (P<0.001), IgG1 (P = 0.006), IgG2 (P = 0.003), IgG3 (P = 0.035), and IgM (P = 0.008) levels and antibody responses to tetanus toxoid and Haemophilus influenzae type b (Hib) vaccines (P = 0.036 and 0.013, respectively). At 12-month follow-up, a protective effect of the prophylactic IVIG therapy was seen, with a statistically significant reduction in the number of infections to 3.3 (2.4) and in the number of antibiotic courses to 2.7 (2.5) (both P = 0.005).

CONCLUSIONS

In this study population of children with recurrent infections and IgA and/or IgG subclass deficiency, prophylactic therapy with either OM-85 BV or an antibiotic significantly decreased the number of infections per year. In addition, nonresponders benefited from IVIG replacement therapy.

Nursing guidelines for administration of immunoglobulin replacement therapy

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

The effect of bovine colostrum on viral upper respiratory tract infections in children with immunoglobulin A deficiency

INTRODUCTION

Immunoglobulin A (IgA)-deficient patients predominantly suffer from respiratory and gastrointestinal infections since secretory IgA has important functions to protect mucosal surfaces.

OBJECTIVE

To evaluate the effect of bovine colostrum, rich in IgA, on the treatment of viral upper respiratory tract (URT) infections in IgA-deficient children.

METHODS

Thirty-one IgA-deficient children with viral URT infections were included in this double-blind, placebo-controlled study, and randomly oral bovine colostrum or placebo was given three times a day for 1 week. Samples of saliva IgA were collected before treatment, after the administration of the first dose, and after the last dose. Mothers of the children completed a daily questionnaire regarding the severity of the infection and any adverse effects.

RESULTS

The bovine colostrum group had a lower infection severity score than the placebo group after 1 week (respectively 0.81±0.83, 3.00±1.85; P=0.000), but there was no difference between the salivary IgA levels of the groups.

CONCLUSION

This is the first study to evaluate the effect of bovine colostrum in IgA-deficient children, and no adverse effects were observed. However, further studies are needed to confirm the efficacy and safety of bovine colostrum in IgA-deficient patients.

Toxicities of immunosuppressive treatment of autoimmune neurologic diseases

In parallel to our better understanding of the role of the immune system in neurologic diseases, there has been an increased availability in therapeutic options for autoimmune neurologic diseases such as multiple sclerosis, myasthenia gravis, polyneuropathies, central nervous system vasculitides and neurosarcoidosis. In many cases, the purported benefits of this class of therapy are anecdotal and not the result of good controlled clinical trials. Nonetheless, their potential efficacy is better known than their adverse event profile. A rationale therapeutic decision by the clinician will depend on a comprehensive understanding of the ratio between efficacy and toxicity. In this review, we outline the most commonly used immune suppressive medications in neurologic disease: cytotoxic chemotherapy, nucleoside analogues, calcineurin inhibitors, monoclonal antibodies and miscellaneous immune suppressants. A discussion of their mechanisms of action and related toxicity is highlighted, with the goal that the reader will be able to recognize the most commonly associated toxicities and identify strategies to prevent and manage problems that are expected to arise with their use.

The role of anti-IgA antibodies in causing adverse reactions to gamma globulin infusion in immunodeficient patients: a comprehensive review of the literature

Anaphylactic reactions to immunoglobulin infusions in immunodeficient patients with undetectable IgA have been attributed in several reports to IgG or IgE anti-IgA antibodies. However, other reports have not supported an association between such antibodies and the development of severe reactions. We have reviewed the articles reporting reactions to immunoglobulin products in IgA-deficient patients, as well as those describing the presence of such antibodies in the absence of reactions to infusions. A variety of factors might influence the association of adverse reactions with anti-IgA antibodies, including the serum concentration and isotype (IgG or IgE) of the anti-IgA antibody, its specificity (class or subclass specific), the method of measurement, and the IgA content of the gamma globulin infusion and its route of administration. The role of anti-IgA antibodies in causing anaphylaxis in IgA-deficient patients receiving gamma globulin therapy is still controversial. Larger (multicenter) studies are needed to further evaluate this association.

Relevant criteria for selecting an intravenous immunoglobulin preparation for clinical use

Over the past several decades, the use of intravenous human normal immunoglobulin (IVIg) products in a diverse range of immunodeficiency, inflammatory and infectious disorders has increased significantly. Newer manufacturing processes have increased the yield of intact IVIg molecules and have also improved the tolerability and safety of these products, including reducing the transmission risk of blood-borne diseases. While there are no appreciable differences between the numerous commercially available IVIg products in terms of efficacy, different manufacturing processes and the final composition of IVIg products have resulted in different safety and tolerability profiles. The tolerability profile of different IVIg products may be idiosyncratic for individual patients and may not be predictable, based on product characteristics. Consequently, patients receiving an IVIg product should be carefully monitored at initial exposure, and switching of products should be avoided. To achieve the best outcomes in patients requiring IVIg therapy, treatment should be tailored to the patient's needs. The risk/benefit profile of an IVIg in relation to patient risk factors and the underlying immune deficiency, or autoimmune or inflammatory disorder should be considered when deciding on the most appropriate therapy.

Common variable immunodeficiency: an update on therapeutic approaches

Common variable immunodeficiency (CVID) is not a homogeneous disease, as has become clear from recent scientific studies. This makes the interpretation of studies of clinical therapeutics difficult to assess and raises questions about historical case reports. The evidence for the optimum use of replacement immunoglobulin in CVID is reviewed. This therapy represents the current gold standard, despite attempts to use other immunostimulatory compounds. Questions of product properties, product selection, adverse events and infectious risks are addressed. Products are not interchangeable and have different physicochemical characteristics. Despite intravenous immunoglobulin being in use for 20 years, there are still unanswered questions over dose and target trough IgG levels, particularly with respect to patients with established lung disease. The management of organ-based complications of CVID is discussed. This includes the treatment of unusual infections such as mycoplasmas and enteroviruses, which are specific to antibody deficiency. The diagnosis and treatment of the granulomatous disease of CVID is discussed. The role of surgery, including lung transplantation, in the management of CVID complications is reviewed. There are few available data on optimum strategies for antibiotic usage for bacterial infective complications and it is clear that present regimens, at least in severe recurrent sinus disease, are not consistently effective. Better clinical trials are required to identify appropriate regimens and validate or disprove widely held assumptions about therapy in CVID. Despite advances in diagnosis and management, there is abundant evidence in the UK that patients do not yet receive rapid diagnosis and optimum therapy, even within the limited published data currently available. This leads to considerable avoidable morbidity and mortality.

Selective IgA deficiency

Introduction

Immunoglobulin A (IgA) deficiency is the most common primary immunodeficiency defined as decreased serum level of IgA in the presence of normal levels of other immunoglobulin isotypes. Most individuals with IgA deficiency are asymptomatic and identified coincidentally. However, some patients may present with recurrent infections of the respiratory and gastrointestinal tracts, allergic disorders, and autoimmune manifestations.

IgA and Its Functions

Although IgA is the most abundant antibody isotype produced in the body, its functions are not clearly understood. Subclass IgA1 in monomeric form is mainly found in the blood circulation, whereas subclass IgA2 in dimeric form is the dominant immunoglobulin in mucosal secretions. Secretory IgA appears to have prime importance in immune exclusion of pathogenic microorganisms and maintenance of intestinal homeostasis. Despite this critical role, there may be some compensatory mechanisms that would prevent disease manifestations in some IgA-deficient individuals.

Pathogenesis

In IgA deficiency, a maturation defect in B cells to produce IgA is commonly observed. Alterations in transmembrane activator and calcium modulator and cyclophilin ligand interactor gene appear to act as disease-modifying mutations in both IgA deficiency and common variable immunodeficiency, two diseases which probably lie in the same spectrum. Certain major histocompatibility complex haplotypes have been associated with susceptibility to IgA deficiency.

Conclusion

The genetic basis of IgA deficiency remains to be clarified. Better understanding of the production and function of IgA is essential in elucidating the disease mechanism in IgA deficiency.

Common variable immunodeficiency: etiological and treatment issues

One of the great advances in clinical medicine was the recognition of the pleomorphism of the immune response and the multiple afferent and efferent limbs of antigen processing and responsiveness. A significant contribution to this understanding was derived from studies of human immunodeficiency states, including both inherited and acquired syndromes. Amongst these syndromes, one of the most common, and least understood, is common variable immune deficiency (CVID). CVID is a syndrome that leads to a reduction in serum immunoglobulins and complications including recurrent infections. Management includes immunoglobulin replacement therapy; however, patients with CVID are at risk for complications of exogenous immunoglobulin administration as well as CVID-associated diseases such as autoimmune processes and malignancies. To assess the current state of knowledge in the field, we performed a literature review of a total of 753 publications covering the period of 1968 until 2008. From this list, 189 publications were selected for discussion. In this review, we demonstrate that while the molecular basis of CVID in many cases remains incompletely understood, significant strides have been made and it is now clear that there is involvement of several pathways of immune activation, with contributions from both T and B cells. Furthermore, despite the current gaps in our knowledge of the molecular pathogenesis of the syndrome, there have been dramatic advances in management that have led to improved survival and significantly reduced morbidity in affected patients.

Antibody-mediated rejection: treatment alternatives and outcomes

Over the past 10 years, thanks to the development of sensitive methods of antibody detection and markers of antibody injury such as C4d staining, the role of anti-human leukocyte antigen (HLA) and non-HLA alloantibodies as effectors of acute and chronic immune allograft injury has been revisited. Antibody-mediated rejection (AMR) defines all allograft rejection caused by antibodies directed against donor-specific HLA molecules, blood group antigen (ABO)-isoagglutinins, or endothelial cell antigens. Antibody-mediated rejection can be a recalcitrant process, resistant to therapy and carries an ominous prognosis to the graft. In concordance with these views, treatment protocols for AMR use permutations of a multiple-prong approach that include (1) the suppression of the T-cell dependent antibody response, (2) the removal of donor reactive antibody, (3) the blockade of the residual alloantibody, and (4) the depletion of naive and memory B-cells. Although all published protocols report a variable rate of success, a major weakness of all current protocols is the lack of effective anti-plasma cell agents. In comparison to acute AMR, the treatment for chronic AMR (CAMR) is not well characterized. Although in acute AMR large titers of pre-existent alloantibodies result in massive activation of the complement system and lytic injury of the graft endothelium, thereby requiring aggressive and fast removal of the offending agents, in CAMR, complement activation results in sublytic endothelial cell injury and activation. Although this type of injury results in chronic graft failure, its slow progression likely renders it amenable of suppression by heightening of maintenance immunosuppression and anti-idiotypic blockade of the circulating alloantibody without the need of plasma exchange. In this review, we will discuss the rationale behind the design of treatment protocols for acute AMR and CAMR as well as their reported results and complications.

History of immunoglobulin replacement

The provision of antibodies to prevent and treat infection began with the application of "curative serum" in the first years of the last century. After the process of large-scale plasma fractionation was developed in the 1940s, the general use of immunoglobulin expanded. Intravenous immunoglobulin products became available in the 1970s, and their only use for the provision of antibodies governed the opinion of experts over the next decade. Modulation of inflammation and immunosuppression were introduced in treatment of inflammatory and autoimmune diseases and became accepted indications. The history of adverse events of treatment and their management are outlined in this article. Consensus indications and evidence-based off-label uses are discussed.

Immunoglobulin replacement therapy in children

The benefit of immunoglobulin (IG) replacement in primary antibody deficiencies is unquestionable. Many of these congenital disorders present early in life and this therapy is often first implemented in the young. This article focuses on the indications of IG replacement in children, with an emphasis on the specific diagnostic problems encountered in this population. Also presented is an overview of the practical aspects of IG administration in the pediatric setting, including the recognition and management of adverse reactions. Finally, the advent of subcutaneous IG, a therapeutic IG modality with the potential to have a great impact on the quality of life of children with antibody deficiencies and their families, is discussed.

Immune tolerance induction in patients with IgA anaphylactoid reactions following long-term intravenous IgG treatment

To date, there is very little information regarding the pathomechanism of IgA anaphylactoid reactions and the management of affected patients. Five adult patients with common variable immunodeficiency (CVID) and a history of anaphylactic reactions due to the administration of immunoglobulin preparations were studied. The activity of anti-IgA was determined by the gel agglutination technique using IgA-coated beads. Antibodies to IgA were detected in the serum of all five patients. Initially, IgA 'depleted' intravenous (i.v.) IgG preparations were infused carefully into the patients until the activity of anti-IgA was decreased significantly or became undetectable. Subsequently, unselected i.v. IgG preparations were infused, and the activity of anti-IgA was abolished in all cases. Intravenous IgG long-term administration results in tolerance induction in patients with IgA anaphylactoid reactions. This tolerance appears to be related to antibody blockage in the circulation and an inhibition of antibody production. Most importantly, IgA appears to play an important role in the treatment of CVID. Patients with IgA anaphylactoid reactions can be treated safely with IgA containing i.v. IgG preparations following tolerance induction.

A 10% ready-to-use intravenous human immunoglobulin offers potential economic advantages over a lyophilized product in the treatment of primary immunodeficiency

Intravenous immunoglobulin (IVIg) replacement therapy is the standard of care for patients with primary humoral immunodeficiencies. This study evaluated differences in infusion time between a 10% IVIg ready-to-use solution and a 6% IVIg lyophilized product and addressed potential cost implications. After receiving in-hospital treatment with 6% IVIg lyophilized solution for at least 6 months, 14 patients with humoral immunodeficiency without anti-IgA antibodies received five successive infusions with 10% IVIg ready-to-use solution. Data on infusion times were collected during the last two infusions of each IVIg product when maximum infusion rates had been reached. The median infusion time was reduced from 104.4 min with the 6% IVIg lyophilized solution to 51.0 min with the 10% IVIg ready-to-use solution (51% reduction), with corresponding median maximum infusion rates of 4.1 ml/kg/h and 5.9 ml/kg/h, respectively. Median gammaglobulin (IgG) trough levels were 7.1 g/l for the 6% IVIg lyophilized solution and 7.9 g/l for the 10% IVIg ready-to-use solution. Fewer adverse events were observed after infusing with 10% IVIg ready-to-use solution compared with 6% IVIg lyophilized preparation. We conclude that the 10% IVIg ready-to-use solution was well tolerated by most patients and reduced the median infusion time by 51% compared with a 6% lyophilized preparation of IVIg. The reduced bed occupancy and nursing time associated with a reduced infusion time, together with the elimination of a reconstitution step, were estimated to provide a cost-saving of 59.42 euros per patient per infusion. Thus, this product has the potential to reduce overall costs of IVIg treatment. Reduced infusion time is also likely to improve patients' quality of life.

Immunoglobulin treatment for primary antibody deficiencies: advantages of the subcutaneous route

Adults and children with primary antibody deficiencies are prone to bacterial infections affecting the respiratory tract and gastrointestinal canal. To prevent or alleviate infections, replacement therapy with IgG is needed, usually on a lifelong basis. The IgG can be administered intramuscularly, intravenously, or subcutaneously. Subcutaneous IgG (SCIG) therapy, using small portable pumps for once-per-week self infusions, has shown many advantages compared with the two other routes of administration. This review highlights findings from international studies and demonstrates that: (i) SCIG therapy is safe, with very few adverse effects; (ii) the therapy can be used for patients with previous adverse effects to intravenous administration of IgG; (iii) the therapy leads to high serum IgG levels and good protection against infections; (iv) the therapy facilitates home therapy, as the infusion technique is easy for children, adults and elderly people to learn and there is no need for venous access; (v) SCIG home therapy leads to significantly improved life situations for the patients; (vi) the SCIG home therapy regimen in particular reduces the costs of treatment.

Anti-IgA antibodies in common variable immunodeficiency (CVID): diagnostic workup and therapeutic strategy

Common Variable Immunodeficiency (CVID) patients who are seropositive for anti-IgA antibodies have a predisposition for anaphylactoid reactions to intravenous immunoglobulin replacement therapy (IVIG). Among 88 CVID patients, we identified eight with IgG anti-IgA antibodies (9%). All eight completely lacked IgA (<0.0009 g/l). Five of them had a history of anaphylactoid reactions to IVIG. However, four of these five patients tolerated subcutaneous immunoglobulin replacement therapy (SCIG). To identify predisposing factors for anti-IgA antibodies and related anaphylactoid reactions, we analyzed the clinical and immunological phenotype of affected patients. All eight IgG anti-IgA-positive patients lacked IgA(+) B cells in peripheral blood. Moreover, CVID patients with retained class-switched CD27(pos) IgM(neg) IgD(neg) memory B cells (Freiburg classification group II) and total IgA deficiency seem to have an increased risk for developing anti-IgA antibodies. In seven of the eight patients, lymphoproliferation was observed (most prominently nodular lymphatic hyperplasia), two had granulomatous disease, and two showed autoimmune phenomena.

A new strategy for the prevention of IgA anaphylactic transfusion reactions

BACKGROUND

Management of patients with clinically significant anti-IgA is difficult and unsatisfactory in many aspects.

PATIENTS AND METHOD

A 40-year-old man with common variable immunodeficiency had a previous history of anaphylaxis after an intramuscular immunoglobulin administration. His serum contained anti-IgA, and he required immunoglobulins for recurrent infections.

RESULTS

The administration of intravenous immunoglobulins (IVIgG) containing less than 0.1 mg per mL IgA led to an anaphylactic reaction after the transfusion of only 2 to 3 mL. The same IVIgG charge was subsequently pretreated with freshly separated autologous plasma and given to the patient on three consecutive days without any reaction (1.25, 10, and 10 g each in 400 mL plasma). Anti-IgA activity did not increase, and the patient was treated again without complications.

DISCUSSION

Ex vivo pretreatment of IVIgG preparations with autologous plasma appears to be safe and useful in the management of patients with clinically significant anti-IgA. To achieve a significant IgA blockage, the preparation to be used should not contain large amounts of IgA.

CONCLUSION

The strategy described here appears to be safe and may help prevent anaphylaxis in many instances.

Adverse reactions of prophylactic intravenous immunoglobulin infusions in Iranian patients with primary immunodeficiency

BACKGROUND

Although long-term intravenous immunoglobulin infusion is an effective treatment for children with antibody deficiencies, it can be complicated by systemic adverse reactions.

OBJECTIVE

To evaluate the adverse reactions of intravenous immunoglobulin therapy in patients with primary immunodeficiency.

METHODS

Seventy-one immunodeficient patients receiving intravenous immunoglobulin were evaluated during a 7-year period (1995-2002) at Children's Medical Center in Tehran, Iran. Immunological diagnoses were as follows: common variable immunodeficiency (31 patients), X-linked agammaglobulinemia (25 patients), IgG subclass deficiency (5 patients), hyper-IgM syndrome (2 patients), and ataxia-telangiectasia (8 patients).

RESULTS

One hundred fifty-two cases (12.35%) of adverse reactions occurred following 1,231 infusions in 35 patients. The most frequent immediate adverse reactions were mild reactions (131 infusions), including chills, fever, flushing, muscle pains, nausea, headache, and anxiety. Moderate reactions, such as vomiting, chest pain, and wheezing, occurred in 19 infusions. Two patients experienced severe adverse reactions. The highest proportion (23.06%) of reaction to injection was in patients with common variable immunodeficiency.

CONCLUSIONS

Intravenous immunoglobulin is a well tolerated medical agent for patients with antibody deficiency. However, to prevent occurrence of immediate adverse reactions during infusion in these patients, physicians should perform a detailed history and proper physical examination and check the titer of anti-IgA.

Common variable immunodeficiency

We describe a patient with common variable immunodeficiency who three times presented an anaphylactic reaction after intravenous immunoglobulin administration. These reactions were attributed to the total absence of IgG 2, 3 and 4.

[Intravenous immunoglobulin (Endobulin) clinical tolerance: prospective therapeutic follow-up of 142 adults and children]

PURPOSE

Prospective report of Endobulin clinical tolerance experience for 19 months over a large number of patients.

METHOD

Collect diagnosis, age, gender, weight, dose regimen, infusion duration, and clinical tolerance of Endobulin. Treatment with this product was the only inclusion criteria in this follow-up.

RESULTS

A hundred and forty-two patients, 85 children and 57 adults, mean age 23 (1-85 years) received 70 substitutive treatments for primary immunodeficiency, 36 substitutive treatments for secondary immunodeficiency and 36 immunomodulatory treatments. A thousand six hundred and sixty Endobulin infusions that led to 14, 061.5 g, from 52 different batches. Tolerance was judged as good for 135 patients even though side effects occurred in 2 of them. Thus, 133 out of 142 patients, that is 93.7% did not present any side effect and their tolerance to Endobulin infusions was defined as good. Tolerance was bad for 7 patients because of side effects occurrence. For a mean number of 11.7 infusions per patient (1-31), the 9 side effects observed led to a rate of 0.54% of collected infusions and 6.3% of patients included.

CONCLUSION

This therapeutic follow-up of 142 patients confirms Endobulin clinical tolerance judged as good in 93.7% of patients (133/142) with a very low rate of side effects of 0.54% of infusions (9 side effects for 1660 infusions) for a mean number of 11.7 infusions per patient for an average of 10.9 months follow-up.

IgG anti-IgA subclasses in common variable immunodeficiency and association with severe adverse reactions to intravenous immunoglobulin therapy

The current therapy for common variable immunodeficiency is based on the administration of intravenous immunoglobulin preparations which may cause severe adverse reactions. Some reports have associated these reactions with IgG anti-IgA antibodies, although this is not yet clear. We analyzed 20 sera from common variable immunodeficiency patients by an enzyme immunoassay to detect IgG anti-IgA and determine its subclass profile. Five patients presented high levels of these antibodies, all of them had IgG1, two had IgG2 and IgG4 and one had IgG3. Three of these five patients were receiving non IgA depleted intravenous immunoglobulin and had no severe adverse reactions. One patient had persisted with similar high levels of IgG anti-IgA during three years. Therefore, the IgG anti-IgA antibodies, regardless to their subclass profile in the common variable immunodeficiency patients sera do not seem to be associated with severe adverse reactions to intravenous immunoglobulins.

Induction of unresponsiveness against IgA in IgA-deficient patients on subcutaneous immunoglobulin infusion therapy

Patients with IgA deficiency often demonstrate circulating antibodies against IgA, which have been suggested to be associated with transfusion reactions. Sera from three patients with common variable immunodeficiency (CVID) and one with a selective IgA deficiency with anti-IgA antibodies receiving subcutaneous gammaglobulin replacement therapy were analysed for serum levels of IgG, IgA and anti-IgA before and during a treatment period of 4-7 years. Treatment with gammaglobulin preparations containing significant amounts of IgA (< 5 mg/ml) resulted in a decrease or disappearance of the anti-IgA antibodies. Analysis of serum fractions, however, revealed anti-IgA activity in the complex-containing fractions. In vitro experiments gave similar results with a shift of anti-IgA activity from the monomeric to the complex-containing fractions (that could not be detected in whole serum). When the patients were subsequently switched to treatment with a preparation containing less IgA (< 80 microg/ml) or made an interruption in the treatment schedule, the anti-IgA antibodies reappeared. Importantly, however, one of the patients lost his anti-IgA activity during a 3-month period on the preparation containing the higher IgA levels, and these antibodies did not reappear after switching to the low IgA-containing preparation. After 5 years on this preparation, anti-IgA can still not be detected, suggesting induction of unresponsiveness.

Transfusion management of an IgA deficient patient with anti-IgA and incidental correction of IgA deficiency after allogeneic bone marrow transplantation

A patient with multiple myeloma was noted to have an IgA deficiency during investigation of a possible transfusion reaction due to IgA deficiency and anti-IgA. Because of the patient's age, otherwise good health, and early stage of disease, he was enrolled in a research treatment protocol that involved an allogeneic bone marrow transplant (BMT). The BMT successfully put the patient in complete remission from his multiple myeloma and corrected his IgA deficiency. Class-specific IgG anti-IgA antibody that had been identified prior to BMT was no longer detectable in his plasma. Anaphylactic transfusion reactions were successfully avoided by using a combination of IgA-deficient and washed blood components including the marrow graft, and IgA-reduced intravenous immunoglobulin.

Characterisation of a chromatographically produced anti-D immunoglobulin product

A chromatographic fractionation method has been developed for the production of a liquid-stable anti-D immunoglobulin product for intravenous and intramuscular use. An immunoglobulin fraction, highly enriched with anti-D immunoglobulins, was isolated by cation-exchange column chromatography and further polished, first by anion-exchange chromatography, followed by an aluminium hydroxide gel treatment. The process includes two specific steps for virus inactivation and removal, namely S/D treatment and nanofiltration. The overall anti-D process yield is about 56%. The final product is stabilised with human albumin and glycine and placed in ready-to-use syringes. The anti-D product was shown to be stable in liquid state for at least 30 months at 4 degrees C.

Posttranscriptional regulation of T-cell IL-2 production by human pooled immunoglobin

We evaluated the mechanism by which human pooled gamma-globulin for intravenous use (hIVIG) inhibits interleukin-2 (IL-2) production by human T cells. hIVIG reduced by 70-95% the amount of IL-2 in culture supernatants from mitogen-stimulated peripheral blood T cells or Jurkat cells. This reduction was not apparent at the transcriptional level: hIVIG had no effect on the levels of IL-2 mRNA or on the accumulation of firefly luciferase when its gene was linked to the IL-2 promoters. In contrast, hIVIG inhibited IL-2 protein synthesis, and the intracellular IL-2 was not restored by monensin. Our results indicate that the inhibition of IL-2 production by hIVIG occurred post-transcriptionally, and also suggest that secretion was unaffected, and that this effect of hIVIG was specific for IL-2 (and possibly other related cytokines). The data identify a previously uncharacterized regulatory mechanism of IL-2 production and predict that this immunomodulatory effect of hIVIG may be significant for its therapeutic actions in immune-mediated diseases.

IgA deficiency and SLE: prevalence in a clinic population and a review of the literature

An association between systemic lupus erythematosus (SLE) and immunoglobulin A (IgA) deficiency has been reported previously and may have therapeutic consequences for patients who require treatment with intravenous immunoglobulin. We report the prevalence of IgA deficiency in a clinic population of 96 patients with SLE. Five patients were found to be consistently IgA deficient. These patients were more likely to be West Indian, to have anti-Sm and anti-La antibodies and to have a speckled pattern of antinuclear antibody. There were no significant differences in clinical features between IgA deficient and other SLE patients, nor in SLE-related HLA alleles. We thus confirm the increased prevalence of IgA deficiency in patients with SLE. A review of the literature is presented and we speculate on the nature of the link between IgA deficiency and SLE.

Gammagard and reported hepatitis C virus episodes

Since first licensed in the United States in 1986, Gammagard, an intravenous immunoglobulin produced by the Hyland Division of Baxter Healthcare Corporation, had been considered an effective and safe form of immunoglobulin. Its safety had been proved in patients with immunoglobulin A (IgA) deficiency, including those with the complication of anti-IgA antibodies. However, in early 1994, there were reported episodes of hepatitis C virus transmission associated with administration of Gammagard manufactured during April 1993 and thereafter. The investigations into the mechanisms to account for these events, including the manufacturing processes, are reviewed. The results of studies and analyses by both Baxter and the US Food and Drug Administration, including first- and second-generation enzyme-linked immunosorbent assays, polymerase chain reaction analyses, and the solvent-detergent viral-inactivation manufacturing step, are discussed. Evaluations of donor histories identified a group of donors who contributed to three target lots of the agent and who were subsequently excluded from donor pools. The classification scheme and criteria for all patient reports of hepatitis associated with administration of Gammagard, as well as the classification of all hepatitis C virus episodes, are presented.