Elevated IgE and atopy in patients treated for early-onset ADA-SCID

Very high immunoglobulin E levels in children: when from pediatrician to immunologist?

BACKGROUND

Total serum immunoglobulin E (IgE) is increased in many situations such as allergic diseases, primary immunodeficiencies (PID), parasitosis, infections and malignancies. When IgE levels are >1000 kU/L PIDs are suspected by pediatricians. We tried to define some clinical and laboratory parameters to distinguish PID from the others.

METHODS

We evaluated 158 children between 1.7-17 years (mean: 6.6±3.4) for allergic diseases, PID, parasitosis and others. Total IgE, specific IgE, immunoglobulin levels and skin prick tests were performed to all patients. Parasite investigations, viral serological tests and detailed immunologic tests were analyzed in only patients who had suspected complaints. Hyper IgE syndrome (HIES) scoring sheet was filled out for all patients.

RESULTS

Among all patients, 114 were diagnosed as bronchial asthma, allergic rhino-conjunctivitis or atopic dermatitis. PID diagnosis was established in totally 32 patients. Immunological evaluations were normal in 126 patients. Eleven patients were accepted as parasitosis. Median HIES score was 18 (5-44 points).

CONCLUSIONS

Pediatricians may use HIES scoring sheet when they suspect a patient with PID. If the patient has very low points, they may follow the patient. If there are about 18-20 points, they should get an opinion from an immunologist for detailed immunologic tests.

Long-term and real-world safety and efficacy of retroviral gene therapy for adenosine deaminase deficiency

Adenosine deaminase (ADA) deficiency leads to severe combined immunodeficiency (SCID). Previous clinical trials showed that autologous CD34+ cell gene therapy (GT) following busulfan reduced-intensity conditioning is a promising therapeutic approach for ADA-SCID, but long-term data are warranted. Here we report an analysis on long-term safety and efficacy data of 43 patients with ADA-SCID who received retroviral ex vivo bone marrow-derived hematopoietic stem cell GT. Twenty-two individuals (median follow-up 15.4 years) were treated in the context of clinical development or named patient program. Nineteen patients were treated post-marketing authorization (median follow-up 3.2 years), and two additional patients received mobilized peripheral blood CD34+ cell GT. At data cutoff, all 43 patients were alive, with a median follow-up of 5.0 years (interquartile range 2.4-15.4) and 2 years intervention-free survival (no need for long-term enzyme replacement therapy or allogeneic hematopoietic stem cell transplantation) of 88% (95% confidence interval 78.7-98.4%). Most adverse events/reactions were related to disease background, busulfan conditioning or immune reconstitution; the safety profile of the real world experience was in line with premarketing cohort. One patient from the named patient program developed a T cell leukemia related to treatment 4.7 years after GT and is currently in remission. Long-term persistence of multilineage gene-corrected cells, metabolic detoxification, immune reconstitution and decreased infection rates were observed. Estimated mixed-effects models showed that higher dose of CD34+ cells infused and younger age at GT affected positively the plateau of CD3+ transduced cells, lymphocytes and CD4+ CD45RA+ naive T cells, whereas the cell dose positively influenced the final plateau of CD15+ transduced cells. These long-term data suggest that the risk-benefit of GT in ADA remains favorable and warrant for continuing long-term safety monitoring. Clinical trial registration: NCT00598481 , NCT03478670 .

Genetic/Environmental Contributions and Immune Dysregulation in Children with Atopic Dermatitis

Atopic dermatitis (AD) is one of the most common skin conditions in humans. AD affects up to 20% of children worldwide and results in morbidity for both patients and their caregivers. The basis of AD is an interplay between genetics and the environment characterized by immune dysregulation. A myriad of mutations that compromise the skin barrier and/or immune function have been linked to AD. Of these, filaggrin gene (FLG) mutations are the most evidenced. Many other mutations have been implicated in isolated studies that are often unreplicated, creating an archive of genes with potential but unconfirmed relevance to AD. Harnessing big data, polygenic risk scores (PRSs) and genome-wide association studies (GWAS) may provide a more practical strategy for identifying the genetic signatures of AD. Epigenetics may also play a role. Staphylococcus aureus is the most evidenced microbial contributor to AD. Cutaneous dysbiosis may result in over-colonization by pathogenic strains and aberrant skin immunity and inflammation. Aeroallergens, air pollution, and climate are other key environmental contributors to AD. The right climate and/or commensals may improve AD for some patients.

Inborn Errors of Immunity Associated with Elevated IgE

OBJECTIVE

To review the characteristic clinical and laboratory features of inborn errors of immunity that are associated with elevated IgE levels DATA SOURCE: Primary peer-reviewed literature.

STUDY SELECTION

Original research articles reviewed include interventional studies, retrospective studies, case-control studies, cohort studies and review articles related to the subject matter.

RESULTS

An extensive literature review was completed to allow for comprehensive evaluation of several monogenic inborn errors of immunity. This review includes a description of the classic clinical features, common infections, characteristic laboratory findings, specific diagnostic methods (when applicable), and genetic basis of disease of each syndrome. A comprehensive flow diagram was created to assist them in the diagnosis and evaluation of patients with elevated IgE levels who may require evaluation for an IEI.

CONCLUSION

IEI should be considered in patients with elevated IgE levels, especially if they have recurrent infections, eczematous dermatitis, malignancy, lymphoproliferation, autoimmunity, and/or connective tissue abnormalities.

Diagnostic Challenges in Patients with Inborn Errors of Immunity with Different Manifestations of Immune Dysregulation

Inborn errors of immunity (IEI), formerly known as primary immunodeficiency disorders (PIDs), are inherited disorders caused by damaging germline variants in single genes, which result in increased susceptibility to infections and in allergic, autoimmune, autoinflammatory, nonmalignant lymphoproliferative, and neoplastic conditions. Along with well-known warning signs of PID, attention should be paid to signs of immune dysregulation, which seem to be equally important to susceptibility to infection in defining IEI. The modern diagnostics of IEI offer a variety of approaches but with some problems. The aim of this review is to discuss the diagnostic challenges in IEI patients in the context of an immune dysregulation background.

Atopy as Immune Dysregulation: Offender Genes and Targets

Allergic diseases are a heterogeneous group of disorders resulting from exaggerated type 2 inflammation. Although typically viewed as polygenic multifactorial disorders caused by the interaction of several genes with the environment, we have come to appreciate that allergic diseases can also be caused by monogenic variants affecting the immune system and the skin epithelial barrier. Through a myriad of genetic association studies and high-throughput sequencing tools, many monogenic and polygenic culprits of allergic diseases have been described. Identifying the genetic causes of atopy has shaped our understanding of how these conditions occur and how they may be treated and even prevented. Precision diagnostic tools and therapies that address the specific molecular pathways implicated in allergic inflammation provide exciting opportunities to improve our care for patients across the field of allergy and immunology. Here, we highlight offender genes implicated in polygenic and monogenic allergic diseases and list targeted therapeutic approaches that address these disrupted pathways.

Allergic manifestations of inborn errors of immunity and their impact on the diagnosis: A worldwide study

Background

Allergies have long been observed in Inborn Errors of Immunity (IEI) and might even be the first presentation resulting in delayed diagnosis or misdiagnosis in some cases. However, data on the prevalence of allergic diseases among IEI patients are limited and contradictory.

Objective

To provide a worldwide view of allergic diseases, across a broad spectrum of IEI, and their impact on the timely diagnosis of IEI.

Methods

This is a worldwide study, conceived by the World Allergy Organization (WAO) Inborn Errors of Immunity Committee. A questionnaire was developed and pilot-tested and was sent via email to collect data from 61 immunology centers known to treat pediatric and/or adult IEI patients in 41 countries. In addition, a query was submitted to The United States Immunodeficiency Network (USIDNET) at its website.

Results

Thirty centers in 23 countries caring for a total 8450 IEI patients responded. The USIDNET dataset included 2332 patients. Data from responders showed that a median (IQR) of 16.3% (10–28.8%) of patients experienced allergic diseases during the course of their IEI as follows: 3.6% (1.3–11.3%) had bronchial asthma, 3.6% (1.9–9.1%) atopic dermatitis, 3.0% (1.0–7.8%) allergic rhinitis, and 1.3% (0.5–3.3%) food allergy. As per the USIDNET data, the frequency of allergy among IEI patients was 68.8% (bronchial asthma in 46.9%). The percentage of IEI patients who presented initially with allergic disorders was 8% (5–25%) and diagnosis delay was reported in 7.5% (0.9–20.6%). Predominantly antibody deficiencies had the highest frequency of allergic disease followed by combined immunodeficiency with a frequency of 40.3% (19.2–62.5%) and 20.0% (10–32%) respectively. As per the data of centers, anaphylaxis occurred in 25/8450 patients (0.3%) whereas per USIDNET dataset, it occurred in 249/2332 (10.6%); drugs and food allergy were the main causes in both datasets.

Conclusions

This multinational study brings to focus the relation between allergic diseases and IEI. Major allergies do occur in IEI patients but were less frequent than the general population. Initial presentation with allergy could adversely affect the timely diagnosis of IEI. There is a need for policies to raise awareness and educate primary care and other referring specialties on the association of allergic diseases with IEI. This study provides a network among centers for future prospective studies in the field.

Eosinophilia Associated With Immune Deficiency

The differential diagnosis of eosinophilia is broad and includes infections, malignancies, and atopy as well as inborn errors of immunity (IEI). Certain types of IEIs are known to be associated with elevated numbers of eosinophils and frequently elevated serum IgE, whereas for others the degree and frequency of eosinophilia are less established. The molecular defects underlying IEI are heterogeneous and affect different pathways, which highlights the complex regulations of this cell population within the immune system. In this review, we list and discuss clinical manifestations and therapies of immune deficiency or immune dysregulation disorders associated with peripheral blood or tissue eosinophilia with or without raised IgE levels. We present illustrative case vignettes for the most common entities and propose a diagnostic algorithm aiming to help physicians systematically to evaluate patients with eosinophilia and suspicion of an underlying IEI.

Inborn errors of immunity with atopic phenotypes: A practical guide for allergists

Inborn errors of immunity (IEI) are a heterogeneous group of disorders, mainly resulting from mutations in genes associated with immunoregulation and immune host defense. These disorders are characterized by different combinations of recurrent infections, autoimmunity, inflammatory manifestations, lymphoproliferation, and malignancy. Interestingly, it has been increasingly observed that common allergic symptoms also can represent the expression of an underlying immunodeficiency and/or immune dysregulation.

Very high IgE levels, peripheral or organ-specific hypereosinophilia, usually combined with a variety of atopic symptoms, may sometimes be the epiphenomenon of a monogenic disease. Therefore, allergists should be aware that severe and/or therapy-resistant atopic disorders might be the main clinical phenotype of some IEI. This could pave the way to target therapies, leading to better quality of life and improved survival in affected patients.

Pulmonary Manifestations of Endocrine and Metabolic Diseases in Children

Advances in technology, methodology, and deep phenotyping are increasingly driving the understanding of the pathologic basis of disease. Improvements in patient identification and treatment are impacting survival. This is true in endocrinology and inborn errors of metabolism, where disease-modifying therapies are developing. Inherent to this evolution is the increasing awareness of the respiratory manifestations of these rare diseases. This review updates clinicians, stratifying diseases spirometerically; pulmonary hypertension and diseases with a predisposition to recurrent pulmonary infection are discussed. This division is artificial; many diseases have multiple pathologic effects on respiration. This review does not cover the impact of obesity.

Primary Atopic Disorders

Primary atopic disorders describes a series of monogenic diseases that have allergy- or atopic effector–related symptoms as a substantial feature. The underlying pathogenic genetic lesions help illustrate fundamental pathways in atopy, opening up diagnostic and therapeutic options for further study in those patients, but ultimately for common allergic diseases as well. Key pathways affected in these disorders include T cell receptor and B cell receptor signaling, cytokine signaling, skin barrier function, and mast cell function, as well as pathways that have not yet been elucidated. While comorbidities such as classically syndromic presentation or immune deficiency are often present, in some cases allergy alone is the presenting symptom, suggesting that commonly encountered allergic diseases exist on a spectrum of monogenic and complex genetic etiologies that are impacted by environmental risk factors.

The overlap between allergy and immunodeficiency

PURPOSE OF REVIEW

The mechanisms underlying the overlap of, and relationship between, atopy and immunodeficiency are just beginning to be recognized, through the identification of novel genetic conditions and the reexamination of well known primary immunodeficiencies. The present review seeks both to frame the topic and to highlight the most recent literature combining allergy in the context of immunodeficiency.

RECENT FINDINGS

The true prevalence of atopic disorders in the setting of primary immunodeficiency as a whole is difficult to pinpoint, however there have been recent attempts to measure prevalence. Individual immunodeficiency disorders have been more carefully dissected for atopic disease and the mechanisms underlying the atopic phenotypic, whereas several newly described immune deficiencies because of single gene mutations are highly associated with atopic phenotypes. Finally, a number of novel genetic conditions with atopy being the primary feature, even in the absence of overt immune deficiency, have been described, providing instrumental clues into the diagnostic dilemmas these syndromes create.

SUMMARY

Defining and examining diseases with primary features of atopy and infection allow for a better understanding of the interplay between the two in rare disease, and hopefully sheds light on fundamental pathways involved in atopy and host defense in the general population.

Hyper-IgE in the allergy clinic--when is it primary immunodeficiency?

The 2017 International Union of Immunological Societies (IUIS) classification recognizes 3 hyper-IgE syndromes (HIES), including the prototypic Job's syndrome (autosomal dominant STAT3-loss of function) and autosomal recessive PGM3 and SPINK5 syndromes. Early diagnosis of PID can direct life-saving or transformational interventions; however, it remains challenging owing to the rarity of these conditions. This can result in diagnostic delay and worsen prognosis. Within increasing access to "clinical-exome" testing, clinicians need to be aware of the implication and rationale for genetic testing, including the benefits and limitations of current therapies. Extreme elevation of serum IgE has been associated with a growing number of PID syndromes including the novel CARD11 and ZNF341 deficiencies. Variable elevations in IgE are associated with defects in innate, humoral, cellular and combined immunodeficiency syndromes. Barrier compromise can closely phenocopy these conditions. The aim of this article was to update readers on recent developments at this important interface between allergy and immunodeficiency, highlighting key clinical scenarios which should draw attention to possible immunodeficiency associated with extreme elevation of IgE, and outline initial laboratory assessment and management.

Primary atopic disorders

Important insights from monogenic disorders into the immunopathogenesis of allergic diseases and reactions are discussed.

Monogenic disorders have provided fundamental insights into human immunity and the pathogenesis of allergic diseases. The pathways identified as critical in the development of atopy range from focal defects in immune cells and epithelial barrier function to global changes in metabolism. A major goal of studying heritable single-gene disorders that lead to severe clinical allergic diseases is to identify fundamental pathways leading to hypersensitivity that can be targeted to provide novel therapeutic strategies for patients with allergic diseases, syndromic and nonsyndromic alike. Here, we review known single-gene disorders leading to severe allergic phenotypes in humans, discuss how the revealed pathways fit within our current understanding of the atopic diathesis, and propose how some pathways might be targeted for therapeutic benefit.

Gene Therapy for Adenosine Deaminase Deficiency: A Comprehensive Evaluation of Short- and Medium-Term Safety

Loss of adenosine deaminase activity leads to severe combined immunodeficiency (ADA-SCID); production and function of T, B, and natural killer (NK) cells are impaired. Gene therapy (GT) with an autologous CD34⁺-enriched cell fraction that contains CD34⁺ cells transduced with a retroviral vector encoding the human ADA cDNA sequence leads to immune reconstitution in most patients. Here, we report short- and medium-term safety analyses from 18 patients enrolled as part of single-arm, open-label studies or compassionate use programs. Survival was 100% with a median of 6.9 years follow-up (range, 2.3 to 13.4 years). Adverse events were mostly grade 1 or grade 2 and were reported by all 18 patients following GT. Thirty-nine serious adverse events (SAEs) were reported by 15 of 18 patients; no SAEs were considered related to GT. The most common adverse events reported post-GT include upper respiratory tract infection, gastroenteritis, rhinitis, bronchitis, oral candidiasis, cough, neutropenia, diarrhea, and pyrexia. Incidence rates for all of these events were highest during pre-treatment, treatment, and/or 3-month follow-up and then declined over medium-term follow-up. GT did not impact the incidence of neurologic/hearing impairments. No event indicative of leukemic transformation was reported.

Eosinophilia Associated with Disorders of Immune Deficiency or Immune Dysregulation

Increased serum eosinophil levels have been associated with multiple disorders of immune deficiency or immune dysregulation. Although primary immunodeficiency diseases are rare, it is important to consider these in the differential diagnosis of patients with eosinophilia. In this review, the clinical features, laboratory findings, diagnosis, and genetic basis of disease of several disorders of immune deficiency or dysregulation are discussed. The article includes autosomal dominant hyper IgE syndrome, DOCK8 deficiency, phosphoglucomutase 3 deficiency, ADA-SCID, Omenn syndrome, Wiskott-Aldrich syndrome, Loeys-Dietz syndrome, autoimmune lymphoproliferative syndrome, immunodysregulation, polyendocrinopathy, enteropathy, X-linked syndrome, Comel-Netherton syndrome, and severe dermatitis, multiple allergies, and metabolic wasting syndrome.

Patterns of Allergic Sensitization in High IgE Syndromes

Dramatic elevations in the serum IgE level are seen both in polygenic allergic diseases such as atopic dermatitis and food allergy, and in a growing list of monogenic primary immune deficiencies (PIDs). Although the IgE produced in patients with PID has generally been considered to be driven by dysregulated IL-4 production and thus lack antigen specificity, in fact allergen-specific IgE can be detected by skin and serum testing in many of these patients. However, perhaps not surprisingly given the distinct immunologic pathways involved, the patterns of allergic disease and atopic sensitization vary widely between syndromes, leading to strikingly different clinical phenotypes.

Genetics of allergy and allergic sensitization: common variants, rare mutations

Our understanding of the specific genetic lesions in allergy has improved in recent years due to identification of common risk variants from genome-wide association studies (GWAS) and studies of rare, monogenic diseases. Large-scale GWAS have identified novel susceptibility loci and provided information about shared genetics between allergy, related phenotypes and autoimmunity. Studies of monogenic diseases have elucidated critical cellular pathways and protein functions responsible for allergy. These complementary approaches imply genetic mechanisms involved in Th2 immunity, T-cell differentiation, TGFβ signaling, regulatory T-cell function and skin/mucosal function as well as yet unknown mechanisms associated with newly identified genes. Future studies, in combination with data on gene expression and epigenetics, are expected to increase our understanding of the pathogenesis of allergy.

Spectrum of mutations in a cohort of UK patients with ADA deficient SCID: Segregation of genotypes with specific ethnicities

Severe combined immunodeficiency (SCID) arises from a number of different genetic defects, one of the most common being mutations in the gene encoding adenosine deaminase (ADA). In the UK, ADA deficient SCID compromises approximately 20% of all known cases of SCID. We carried out a retrospective analysis of the ADA gene in 46 known ADA deficient SCID patients on whom DNA had been stored. Here, we report a high frequency of two previously reported mutations and provide a link between the mutations and patient ethnicity within our patient cohort. We also report on 9 novel mutations that have been previously unreported.

Advances in basic and clinical immunology in 2013

A significant number of contributions to our understanding of primary immunodeficiencies (PIDs) in pathogenesis, diagnosis, and treatment were published in the Journal in 2013. For example, deficiency of mast cell degranulation caused by signal transducer and activator of transcription 3 deficiency was demonstrated to contribute to the difference in the frequency of severe allergic reactions in patients with autosomal dominant hyper-IgE syndrome compared with that seen in atopic subjects with similar high IgE serum levels. High levels of nonglycosylated IgA were found in patients with Wiskott-Aldrich syndrome, and these abnormal antibodies might contribute to the nephropathy seen in these patients. New described genes causing immunodeficiency included caspase recruitment domain 11 (CARD11), mucosa-associated lymphoid tissue 1 (MALT1) for combined immunodeficiencies, and tetratricopeptide repeat domain 7A (TTC7A) for mutations associated with multiple atresia with combined immunodeficiency. Other observations expand the spectrum of clinical presentation of specific gene defects (eg, adult-onset idiopathic T-cell lymphopenia and early-onset autoimmunity might be due to hypomorphic mutations of the recombination-activating genes). Newborn screening in California established the incidence of severe combined immunodeficiency at 1 in 66,250 live births. The use of hematopoietic stem cell transplantation for PIDs was reviewed, with recommendations to give priority to research oriented to establish the best regimens to improve the safety and efficacy of bone marrow transplantation. These represent only a fraction of significant research done in patients with PIDs that has accelerated the quality of care of these patients. Genetic analysis of patients has demonstrated multiple phenotypic expressions of immune deficiency in patients with nearly identical genotypes, suggesting that additional genetic factors, possibly gene dosage, or environmental factors are responsible for this diversity.