Update on the use of immunoglobulin in human disease: A review of evidence.

Human immunoglobulin preparations for intravenous or subcutaneous administration are the cornerstone of treatment in patients with primary immunodeficiency diseases affecting the humoral immune system. Intravenous preparations have a number of important uses in the treatment of other diseases in humans as well, some for which acceptable treatment alternatives do not exist. We provide an update of the evidence-based guideline on immunoglobulin therapy, last published in 2006. Given the potential risks and inherent scarcity of human immunoglobulin, careful consideration of its indications and administration is warranted.

Rare variants at 16p11.2 are associated with common variable immunodeficiency.

BACKGROUND: Common variable immunodeficiency (CVID) is characterized clinically by inadequate quantity and quality of serum immunoglobulins with increased susceptibility to infections, resulting in significant morbidity and mortality. Only a few genes have been uncovered, and the genetic background of CVID remains elusive to date for the majority of patients. OBJECTIVE: We sought to seek novel associations of genes and genetic variants with CVID. METHODS: We performed association analyses in a discovery cohort of 164 patients with CVID and 19,542 healthy control subjects genotyped on the Immuno BeadChip from Illumina platform; replication of findings was examined in an independent cohort of 135 patients with CVID and 2,066 healthy control subjects, followed by meta-analysis. RESULTS: We identified 11 single nucleotide polymorphisms (SNPs) at the 16p11.2 locus associated with CVID at a genome-wide significant level in the discovery cohort. The most significant SNP, rs929867 (P = 6.21 × 10(-9)), is in the gene fused-in-sarcoma (FUS), with 4 other SNPs mapping to integrin CD11b (ITGAM). Results were confirmed in our replication cohort. Conditional association analysis suggests a single association signal at the 16p11.2 locus. A strong trend of association was also seen for 38 SNPs (P < 5 × 10(-5)) in the MHC region, supporting that this is a genuine CVID locus. Interestingly, we found that 80% of patients with the rare ITGAM variants have reduced switched memory B-cell counts. CONCLUSION: We report a novel association of CVID with rare variants at the FUS/ITGAM (CD11b) locus on 16p11.2. The association signal is enriched for promoter/enhancer markers in the ITGAM gene. ITGAM encodes the integrin CD11b, a part of complement receptor 3, a novel candidate gene implicated here for the first time in the pathogenesis of CVID.

Psychrobacter immobilis septicemia in a boy with X-linked chronic granulomatous disease and fulminant hepatic failure.

A 16-year old boy with chronic granulomatous disease (CGD) developed Psychrobacter immobilis septicemia during a course of fulminant hepatic failure. The patient died despite aggressive management with antimicrobials and corticosteroids. While Psychrobacter immobilis rarely affects humans, it should be considered an organism that can cause sepsis in patients with CGD.

Use and interpretation of diagnostic vaccination in primary immunodeficiency: a working group report of the Basic and Clinical Immunology Interest Section of the American Academy of Allergy, Asthma & Immunology.

A major diagnostic intervention in the consideration of many patients suspected to have primary immunodeficiency diseases (PIDDs) is the application and interpretation of vaccination. Specifically, the antibody response to antigenic challenge with vaccines can provide substantive insight into the status of human immune function. There are numerous vaccines that are commonly used in healthy individuals, as well as others that are available for specialized applications. Both can potentially be used to facilitate consideration of PIDD. However, the application of vaccines and interpretation of antibody responses in this context are complex. These rely on consideration of numerous existing specific studies, interpolation of data from healthy populations, current diagnostic guidelines, and expert subspecialist practice. This document represents an attempt of a working group of the American Academy of Allergy, Asthma & Immunology to provide further guidance and synthesis in this use of vaccination for diagnostic purposes in consideration of PIDD, as well as to identify key areas for further research.

Local and national advocacy support.

Decisions by third-party payors that are restricting delivery of appropriate IgG treatment for primary immunodeficiency disease (PIDD) are summoning action from patients, physicians, and their organizations to ensure that high quality treatment remains accessible. Some of the strongest advocacy to date is from patient organizations, such as the Immune Deficiency Foundation (IDF), which strive to educate stakeholders on key issues that determine patient access to appropriate IgG treatment. These issues include the ability to choose the appropriate site of care based on a patient's experience and circumstance and greater awareness of product choice. Advocacy by physicians on these issues at the local level is needed, as are national efforts by organizations such as the American Academy of Allergy, Asthma & Immunology and their regional societies.

Genome-wide association identifies diverse causes of common variable immunodeficiency.

BACKGROUND: Common variable immunodeficiency (CVID) is a heterogeneous immune defect characterized by hypogammaglobulinemia, failure of specific antibody production, susceptibility to infections, and an array of comorbidities. OBJECTIVE: To address the underlying immunopathogenesis of CVID and comorbidities, we conducted the first genome-wide association and gene copy number variation (CNV) study in patients with CVID. METHODS: Three hundred sixty-three patients with CVID from 4 study sites were genotyped with 610,000 single nucleotide polymorphisms (SNPs). Patients were divided into a discovery cohort of 179 cases in comparison with 1,917 control subjects and a replication cohort of 109 cases and 1,114 control subjects. RESULTS: Our analyses detected strong association with the MHC region and association with a disintegrin and metalloproteinase (ADAM) genes (P combined = 1.96 × 10(-7)) replicated in the independent cohort. CNV analysis defined 16 disease-associated deletions and duplications, including duplication of origin recognition complex 4L (ORC4L) that was unique to 15 cases (P = 8.66 × 10(-16)), as well as numerous unique rare intraexonic deletions and duplications suggesting multiple novel genetic causes of CVID. Furthermore, the 1,000 most significant SNPs were strongly predictive of the CVID phenotype by using a Support Vector Machine algorithm with positive and negative predictive values of 1.0 and 0.957, respectively. CONCLUSION: Our integrative genome-wide analysis of SNP genotypes and CNVs has uncovered multiple novel susceptibility loci for CVID, both common and rare, which is consistent with the highly heterogeneous nature of CVID. These results provide new mechanistic insights into immunopathogenesis based on these unique genetic variations and might allow for improved diagnosis of CVID based on accurate prediction of the CVID clinical phenotypes by using our Support Vector Machine model.

Efficacy, Safety and Tolerability of a New 10% Intravenous Immunoglobulin for the Treatment of Primary Immunodeficiencies.

We report here the results of a phase 3 study to assess the efficacy, safety, and tolerability of GC5107, a new 10% liquid intravenous immunoglobulin (IVIG) in preventing serious bacterial infections in patients with primary immunodeficiency (ClinicalTrials.gov: NCT02783482). Over a 12-month study period, 49 patients aged 3 to 70 years with a confirmed diagnosis of primary immunodeficiency received GC5107 at doses ranging from 319 to 881 mg/kg body weight every 21 or 28 days, according to their previous IVIG maintenance therapy. A total of 667 infusions of GC5107 were administered comprising a total of 45.86 patient-years of treatment. A single acute serious bacterial infection occurred during the study, resulting in an incidence of 0.02 events per patient-year (upper 99% one-sided confidence interval limit: 0.21), meeting the prespecified primary efficacy endpoint. The mean incidence of infections other than acute serious bacterial infections was 2.9 infections per patient-year. Efficacy was also demonstrated by the low mean annualized rate of hospitalizations due to infection (0.1 day) and the mean annualized duration of hospitalizations (0.1 day). The mean rate of intravenous and oral antibiotic use was 0.1 day and 13.2 days, respectively. There was a mean of 7.1 days of missed work, school, or daycare days. The proportion of infusions with temporally associated adverse events (TAAEs) occurring during or within 72 hours after GC5107 infusion was 0.24 (upper 95% one-sided confidence interval limit: 0.31), meeting the pre-specified primary safety endpoint. Overall, 149 of 667 infusions (22%) were associated with TAAEs. The most common TAAE was headache, reported by 49% of patients. More than 98% (731/743) of all adverse events that occurred throughout the 12-month study period were mild or moderate. More than 98% of infusions were completed without discontinuation, interruption or rate reduction. There were no treatment-emergent serious adverse events related to GC5107 or study discontinuations due to an adverse event. Overall, pharmacokinetic parameters for GC5107 were within the range of those reported in studies of other marketed IVIG products. Results of the present study demonstrate that GC5107 is an effective, safe and well-tolerated treatment for patients with primary immunodeficiency.

Diagnosis and management of Specific Antibody Deficiency.

Specific antibody deficiency is a primary immunodeficiency disease recognized by the International Union of Immunology Societies and defined by recurrent respiratory infections with normal immunoglobulins, but diminished antibody responses to polysaccharide antigens after vaccination with the 23 valent pneumococcal polysaccharide vaccine. Clinical immunologists struggle with diagnosis and treatment, because the definition of an adequate response to immunization remains controversial. Specific antibody deficiency is managed clinically with close follow-up and prompt treatment of infections, antibiotic prophylaxis, or immune globulin therapy. Treatment is individualized using clinical judgment and existing practice guidelines, which will likely evolve as more studies become available.

Immunoglobulin use in immune deficiency and autoimmune disease states.

Although immunoglobulin (Ig) has been available since the 1950s for replacement therapy in primary immune deficiency, many other effective uses of this class of biologics have been investigated and evolved over recent decades. Ig administration has become common practice in the treatment of the immunocompromised patient and has recently expanded into the treatment of those patients with an inflammatory disease and autoimmune neuropathies per established clinical guidelines. As research into the genetic basis of disease advances, clinicians should better assess complex data surrounding safe and effective uses of Ig to treat patients who present with B-cell and T-cell deficiencies, along with those harboring gene deletions or genetic anomalies who may potentially benefit from Ig therapy. Evidence-based clinical indications for the use of Ig include idiopathic thrombocytopenic purpura, B-cell chronic lymphocytic leukemia, Kawasaki disease, chronic idiopathic demyelinating polyneuropathy, multifocal motor neuropathy, bone marrow transplantation, and pediatric HIV infection, among others, and have evolved over time. Ig is also often tried in refractory cases that might benefit from its anti-inflammatory effects or empirically in off-label situations. Due to its anti-inflammatory effects, high-dose Ig has been used for numerous off-label indications with varying levels of effectiveness and evidence to support its use. A review of all autoimmune conditions for which Ig has been used is beyond the scope of this article and newer treatments are available for many of these disorders. Here the focus will be on selected conditions in which Ig has clear benefit. Because there is a limited supply of Ig and a need for further research into optimal use, it is important for healthcare professionals to better understand current and developing indications and data/levels of evidence to support Ig therapy as its role continues to evolve.

Genetic engineering of T cells for adoptive immunotherapy.

To be effective for the treatment of cancer and infectious diseases, T cell adoptive immunotherapy requires large numbers of cells with abundant proliferative reserves and intact effector functions. We are achieving these goals using a gene therapy strategy wherein the desired characteristics are introduced into a starting cell population, primarily by high efficiency lentiviral vector-mediated transduction. Modified cells are then expanded using ex vivo expansion protocols designed to minimally alter the desired cellular phenotype. In this article, we focus on strategies to (1) dissect the signals controlling T cell proliferation; (2) render CD4 T cells resistant to HIV-1 infection; and (3) redirect CD8 T cell antigen specificity.

Fiscal implications of newborn screening in the diagnosis of severe combined immunodeficiency.

In the United States, newborn screening (NBS) is currently recommended for identification of 31 debilitating and potentially fatal conditions. However, individual states determine which of the recommended conditions are screened. The addition of severe combined immunodeficiency (SCID) screening to the recommended NBS panel has been fully instituted by 18 states, with another 11 states piloting programs or planning to begin screening in 2014. Untreated, SCID is uniformly fatal by 2 years of age. Hematopoietic stem cell transplantation usually is curative, but the success rate depends on the age at which the procedure is performed. Short-term implementation costs may be a barrier to adding SCID to states' NBS panels. A retrospective economic analysis was performed to determine the cost-effectiveness of NBS for early (<3.5 months) versus late (≥3.5 months) treatment of children with SCID at 3 centers over 5 years. The mean total charges at these centers for late treatment were 4 times greater than early treatment ($1.43 million vs $365,785, respectively). Mean charges for intensive care treatments were >5 times higher ($350,252 vs $66,379), and operating room-anesthesia charges were approximately 4 times higher ($57,105 vs $15,885). The cost-effectiveness of early treatment for SCID provides a strong economic rationale for the addition of SCID screening to NBS programs of other states.

Issues in solid-organ transplantation in children: translational research from bench to bedside.

In this review, we identify important challenges facing physicians responsible for renal and cardiac transplantation in children based on a review of the contemporary medical literature. Regarding pediatric renal transplantation, we discuss the challenge of antibody-mediated rejection, focusing on both acute and chronic antibody-mediated rejection. We review new diagnostic approaches to antibody-mediated rejection, such as panel-reactive antibodies, donor-specific cross-matching, antibody assays, risk assessment and diagnosis of antibody-mediated rejection, the pathology of antibody-mediated rejection, the issue of ABO incompatibility in renal transplantation, new therapies for antibody-mediated rejection, inhibiting of residual antibodies, the suppression or depletion of B-cells, genetic approaches to treating acute antibody-mediated rejection, and identifying future translational research directions in kidney transplantation in children. Regarding pediatric cardiac transplantation, we discuss the mechanisms of cardiac transplant rejection, including the role of endomyocardial biopsy in detecting graft rejection and the role of biomarkers in detecting cardiac graft rejection, including biomarkers of inflammation, cardiomyocyte injury, or stress. We review cardiac allograft vasculopathy. We also address the role of genetic analyses, including genome-wide association studies, gene expression profiling using entities such as AlloMap®, and adenosine triphosphate release as a measure of immune function using the Cylex® ImmuKnow™ cell function assay. Finally, we identify future translational research directions in heart transplantation in children.

Efficient clinical scale gene modification via zinc finger nuclease-targeted disruption of the HIV co-receptor CCR5.

Since HIV requires CD4 and a co-receptor, most commonly C-C chemokine receptor 5 (CCR5), for cellular entry, targeting CCR5 expression is an attractive approach for therapy of HIV infection. Treatment of CD4(+) T cells with zinc-finger protein nucleases (ZFNs) specifically disrupting chemokine receptor CCR5 coding sequences induces resistance to HIV infection in vitro and in vivo. A chimeric Ad5/F35 adenoviral vector encoding CCR5-ZFNs permitted efficient delivery and transient expression following anti-CD3/anti-CD28 costimulation of T lymphocytes. We present data showing CD3/CD28 costimulation substantially improved transduction efficiency over reported methods for Ad5/F35 transduction of T lymphocytes. Modifications to the laboratory scale process, incorporating clinically compatible reagents and methods, resulted in a robust ex vivo manufacturing process capable of generating >10(10) CCR5 gene-edited CD4+ T cells from healthy and HIV+ donors. CD4+ T-cell phenotype, cytokine production, and repertoire were comparable between ZFN-modified and control cells. Following consultation with regulatory authorities, we conducted in vivo toxicity studies that showed no detectable ZFN-specific toxicity or T-cell transformation. Based on these findings, we initiated a clinical trial testing the safety and feasibility of CCR5 gene-edited CD4+ T-cell transfer in study subjects with HIV-1 infection.

Agammaglobulinemia and absent B lineage cells in a patient lacking the p85α subunit of PI3K.

Whole exome sequencing was used to determine the causative gene in patients with B cell defects of unknown etiology. A homozygous premature stop codon in exon 6 of PIK3R1 was identified in a young woman with colitis and absent B cells. The mutation results in the absence of p85α but normal expression of the p50α and p55α regulatory subunits of PI3K. Bone marrow aspirates from the patient showed <0.1% CD19(+) B cells with normal percentages of TdT(+)VpreB(+)CD19(-) B cell precursors. This developmental block is earlier than that seen in patients with defects in the B cell receptor signaling pathway or in a strain of engineered mice with a similar defect in p85α. The number and function of the patient's T cells were normal. However, Western blot showed markedly decreased p110δ, as well as absent p85α, in patient T cells, neutrophils, and dendritic cells. The patient had normal growth and development and normal fasting glucose and insulin. Mice with p85α deficiency have insulin hypersensitivity, defective platelet function, and abnormal mast cell development. In contrast, the absence of p85α in the patient results in an early and severe defect in B cell development but minimal findings in other organ systems.

Genetic determinants in HIV-1 Gag and Env V3 are related to viral response to combination antiretroviral therapy with a protease inhibitor.

OBJECTIVE: To identify novel viral determinants in HIV-1 protease, Gag, and envelope V3 that relate to outcomes to initial protease inhibitor-based antiretroviral therapy. DESIGN: A longitudinal cohort study of protease inhibitor-naive, HIV-infected individuals was designed to identify genetic variables in viral Gag and envelope sequences associated with response to antiretroviral therapy. METHODS: Genetic and statistical models, including amino acid profiles, phylogenetic analyses, receiver operating characteristic analyses, and covariation analyses, were used to evaluate viral sequences and clinical variables from individuals who developed immune reconstitution with or without suppression of viral replication. RESULTS: Pretherapy chemokine (C-X-C motif) receptor 4-using V3 regions had significant associations with viral failure (P = 0.04). Amino acid residues in protease covaried with Gag residues, particularly in p7(NC), independent of cleavage sites. Pretherapy V3 charge combined with p6(Pol) and p2/p7(NC) cleavage site genotypes produced the best three-variable model to predict viral suppression in 88% of individuals. Combinations of baseline CD4 cell percentage with genetic determinants in Gag-protease predicted viral fitness in 100% of individuals who failed to suppress viral replication. CONCLUSION: Baseline genetic determinants in Gag p6(Pol) and p2/p7(NC), as well as envelope, provide novel combinations of biomarkers for predicting emergence of viral resistance to initial therapy regimens.

Issues in solid-organ transplantation in children: translational research from bench to bedside

In this review, we identify important challenges facing physicians responsible for renal and cardiac transplantation in children based on a review of the contemporary medical literature. Regarding pediatric renal transplantation, we discuss the challenge of antibody-mediated rejection, focusing on both acute and chronic antibody-mediated rejection. We review new diagnostic approaches to antibody-mediated rejection, such as panel-reactive antibodies, donor-specific cross-matching, antibody assays, risk assessment and diagnosis of antibody-mediated rejection, the pathology of antibody-mediated rejection, the issue of ABO incompatibility in renal transplantation, new therapies for antibody-mediated rejection, inhibiting of residual antibodies, the suppression or depletion of B-cells, genetic approaches to treating acute antibody-mediated rejection, and identifying future translational research directions in kidney transplantation in children. Regarding pediatric cardiac transplantation, we discuss the mechanisms of cardiac transplant rejection, including the role of endomyocardial biopsy in detecting graft rejection and the role of biomarkers in detecting cardiac graft rejection, including biomarkers of inflammation, cardiomyocyte injury, or stress. We review cardiac allograft vasculopathy. We also address the role of genetic analyses, including genome-wide association studies, gene expression profiling using entities such as AlloMap®, and adenosine triphosphate release as a measure of immune function using the Cylex® ImmuKnow™ cell function assay. Finally, we identify future translational research directions in heart transplantation in children.

Establishment of HIV-1 resistance in CD4+ T cells by genome editing using zinc-finger nucleases.

Homozygosity for the naturally occurring Delta32 deletion in the HIV co-receptor CCR5 confers resistance to HIV-1 infection. We generated an HIV-resistant genotype de novo using engineered zinc-finger nucleases (ZFNs) to disrupt endogenous CCR5. Transient expression of CCR5 ZFNs permanently and specifically disrupted approximately 50% of CCR5 alleles in a pool of primary human CD4(+) T cells. Genetic disruption of CCR5 provided robust, stable and heritable protection against HIV-1 infection in vitro and in vivo in a NOG model of HIV infection. HIV-1-infected mice engrafted with ZFN-modified CD4(+) T cells had lower viral loads and higher CD4(+) T-cell counts than mice engrafted with wild-type CD4(+) T cells, consistent with the potential to reconstitute immune function in individuals with HIV/AIDS by maintenance of an HIV-resistant CD4(+) T-cell population. Thus adoptive transfer of ex vivo expanded CCR5 ZFN-modified autologous CD4(+) T cells in HIV patients is an attractive approach for the treatment of HIV-1 infection.

Hypogammaglobulinemia in a pediatric tertiary care setting.

Hypogammaglobulinemia has been described as a secondary consequence of many disorders. It is also the seminal finding in many primary immune deficiencies. There are few studies examining the global etiologies of hypogammaglobulinemia. This study undertook a database discovery of all cases of laboratory-defined hypogammaglobulinemia identified in a large tertiary care pediatric hospital setting between August of 1990 until June of 2006. Eight thousand three hundred and four IgG levels were sent during that time frame. One thousand two hundred and ninety-five specimens from 680 individual patients exhibited hypogammaglobulinemia and these patients represent the study population. The majority of cases in whom an identifiable cause was found had pre-existing conditions and the IgG level was sent as part of a monitoring process. Of the 366 patients who had an IgG level obtained for diagnostic purposes, nearly half were found to have an immune deficiency. One hundred and seventy-two patients with an immune deficiency were identified. Seven percent of these had severe combined immune deficiency. Seventy-four percent of the immune deficient patients identified required active intervention with IVIG, bone marrow transplantation or other management (not including prophylactic antibiotics). Evaluating all patients with IgG levels less than half of the lower limit for age revealed 122 patients of whom 33% had a primary immune deficiency. This study provides a framework for considering causes of hypogammaglobulinemia. At the study institution, hypogammaglobulinemia was found most often as a secondary immune deficiency due to chemotherapy or from complex cardiac anomalies. The magnitude of the secondary hypogammaglobulinemia in a tertiary care setting requires public health consideration as these patients have an unknown risk of infection and an unknown risk of prolonged viral shedding; issues which could be important in epidemic settings.