Low Serum IgE Is a Sensitive and Specific Marker for Common Variable Immunodeficiency (CVID)

Selective immunoglobulin E deficiency and its association with autoimmune and autoinflammatory diseases

Background: Selective immunoglobulin E deficiency (sIgED) is a rare condition characterized by low serum IgE levels with normal levels of other immunoglobulin classes. The prevalence of sIgED varies considerably across populations, with a higher prevalence observed in clinical settings. Studies report sIgED prevalence that ranges up to 9.7% in patients attending rheumatology clinics, 8.1% in allergy/immunology clinics, and 2.6% in healthy blood donors. Its role in immune regulation and association with autoimmune and autoinflammatory disorders remains poorly understood. Objective: This study aimed to investigate the relationship between sIgED and immune-mediated diseases by hypothesizing that sIgED may predispose individuals to an increased prevalence of these conditions. Methods: This retrospective cohort study analyzed data from 3692 patients at a tertiary care center between November 2018 and December 2023. Patients with IgE levels ≤2.5 IU/mL and normal levels of other immunoglobulin classes were classified as having sIgED, whereas those with IgE levels >2.5 IU/mL served as controls. Autoimmune and autoinflammatory diseases were identified by using medical records and International Classification of Diseases codes. Statistical analyses were performed to compare the prevalence of these conditions between the groups. Results: The prevalence of autoimmune and autoinflammatory diseases was significantly higher in the sIgED group versus controls (25.2% versus 15.6%; p < 0.001). Conditions such as Hashimoto thyroiditis, vitiligo, familial Mediterranean fever, and Behçet disease were disproportionately observed in patients with sIgED. Demographic characteristics, including age and gender, were not significantly different between the groups (p = 0.171 and p = 0.257, respectively). Conclusion: The sIgED is associated with a higher prevalence of autoimmune and autoinflammatory diseases, which underscores its potential role in immune dysregulation. This finding highlights the need for further prospective, multicenter studies to validate these associations, elucidate underlying mechanisms, and explore potential clinical implications of IgE deficiency in immune-mediated pathologies.

Functional testing of humoral immunity in the Prevnar 20 era

Humoral immune disorders such as common variable immunodeficiency and specific antibody deficiency are prevalent in clinical practice and require accurate functional testing of humoral immunity for diagnosis and to guide treatment approach. Traditionally, the 23-valent pneumococcal polysaccharide vaccine (PPSV23) has been used to assess polysaccharide antibody responses by measuring pre- and post-vaccination pneumococcal titers. However, the recent introduction of pneumococcal conjugate vaccines (PCVs), such as PCV13, PCV15, and PCV20, into the childhood and adult vaccine schedules has significantly reduced the number of unique serotypes available for testing and in turn has complicated the evaluation process. We retrospectively analyzed serotype-specific antibody responses in patients aged 2 to 65 years who received PPSV23 at the University of Virginia Health System to compare diagnostic outcomes using all 23 serotypes vs the limited number of unique serotypes not included in previous PCVs-11 serotypes for PCV13 recipients and 4 for PCV20 recipients. Our findings reveal that although previous PCVs mean that there is a reduced number of serotypes available for interpretation, PPSV23 testing maintains diagnostic accuracy between 81% and 84%. Despite limitations, the use of PPSV23 remains a valuable tool for identifying patients with clinically significant humoral immune deficiencies. In the future, alternative diagnostic approaches such as Salmonella typhi polysaccharide vaccine response and opsonophagocytosis assays may become more frequently used as part of the evaluation of humoral immune disorders.

If and When to Consider Prophylactic Immunoglobulin Replacement Therapy in Secondary Hypogammaglobulinemia

Secondary hypogammaglobulinemia (SHG), or decreased IgG levels due to reduced production or increased loss caused by medications or underlying conditions, can be associated with increased infection risk. Although immunoglobulin replacement therapy (IgRT) is generally accepted as a strategy to help prevent recurrent bacterial infections in SHG, controversy exists as to whether it should be initiated to prevent the first occurrence of infection. This question has been raised particularly in the setting of anti-CD20 therapy, solid organ transplant, and B-cell malignancies and their treatments once IgG levels fall below 300 to 400 mg/dL. This article reviews the evidence for and against initiating IgRT in these settings, as well as associated considerations for evaluation and monitoring. Although it is relatively clear that infection risk increases with decreasing IgG levels, the exact contribution of SHG to overall infection risk and the protective benefit of IgRT in the absence of infections remain unclear. In the absence of clear consensus, shared decision-making is often needed to determine if and when to initiate IgRT.

Characteristics of patients with low serum IgE levels and selective IgE deficiency: Data from an immunodeficiency referral center

Low immunoglobulin E (IgE) levels are defined as values below 2.5 IU/mL. Selective IgE deficiency (sIgED) refers to reduced serum IgE levels in patients with normal IgA/G/M levels. We evaluated 677 patients with low IgE levels. Recurrent infections (78.8 %), a history of allergy (27.3 %), and autoimmune/inflammatory diseases (18.3 %) are common. The primary immunodeficiency disease (PID) (n = 483, 71.3 %) diagnoses include 313 (46.2 %) patients with antibody deficiency and 119 (17.6 %) with combined immunodeficiency. Genetic pathogenic variants were present in 154 out of 207 PID patients. Within sIgED group, 23 (19.8 %) had primary immunodeficiencies. We observed a high prevalence of autoimmune/inflammatory diseases, allergies, malignancies, and PID among patients with low IgE levels. Therefore, clinicians should be vigilant when evaluating patients with low IgE levels, as this finding may indicate an underlying systemic disease or PID.

Various clinical manifestations of 223 patients with IgE deficiency in a tertiary hospital in China: A cross-sectional study

High Immunoglobulin E(IgE) levels associated with hypersensitivity or parasitic infection were well established, but the clinical significance of ultra-low IgE was largely unknown. Previous studies indicated these patients have an elevated risk of cancer, but large-scale epidemiological studies on the prevalence and clinical manifestations of these ultra-low IgE patients are still lacking. A total of 62,997 patients who were admitted to the First Affiliated Hospital of Wenzhou Medical University and had IgE level tests from January 2010 to March 2020 were included. Patients with serum IgE levels < 2 IU/mL were defined to have ultra-low IgE. And the clinical characteristics of these patients were retrospectively analyzed based on electronic medical record system and follow-up. A total of 223 patients (223/62,997, 0.35%) had ultra-low IgE were documented in 62,997 patients who had IgE tests. Among the clinical manifestations of these 223 ultra-low IgE patients, infection ranked first (125/223, 56.05%), following allergic diseases (51/223, 22.87%), hematological disorders (37/223, 16.59%), tumor (27/223, 12.11%) and autoimmune diseases (23/223, 10.31%). To the best of our knowledge, we first reported that the prevalence and clinical characteristics of 223 ultra-low IgE patients in China. The most common comorbidities were infection, allergic diseases, hematological disorders, tumor and autoimmune diseases.

Quercetin counteracts monosodium glutamate to mitigate immunosuppression in the thymus and spleen via redox-guided cellular signaling

BACKGROUND

Chronic inflammation brought on by oxidative stress can result in several immunopathologies. Natural compounds with antioxidant characteristics, like quercetin, have shown effectiveness in reducing oxidative damage and regulating the immune response.

PURPOSE

The commonly used food additive monosodium glutamate (M) causes immunosuppression by disrupting redox equilibrium and inducing oxidative stress. The goal of this work is to examine the therapeutic potential of quercetin against immunotoxicity brought on by M, revealing the molecular route implicated in such immunopathology by targeting the thymus and spleen, to support the development of future anti-inflammatory and antioxidant therapies.

STUDY DESIGN AND METHODS

M-fed rats were employed as an immunotoxicity model and were supplemented with quercetin for four weeks. Hematological and biochemical parameters were measured; H&E staining, immunohistochemistry, flow cytometry, real-time quantitative PCR, and western blotting were performed.

RESULTS

Based on the findings, TLR4 was activated by M to cause oxidative stress-mediated inflammation, which was alleviated by the supplementation of quercetin by modulating redox homeostasis to neutralize free radicals and suppress the inflammatory response. To prevent M-induced inflammation, quercetin demonstrated anti-inflammatory functions by blocking NF-kB activation, lowering the production of pro-inflammatory cytokines, and increasing the release of anti-inflammatory cytokines. By normalizing lipid profiles and lowering the potential risk of immunological deficiency caused by M, quercetin also improves lipid metabolism. Additionally, it has shown potential for modifying insulin levels, suggesting a possible function in controlling M-induced alteration in glucose metabolism. The addition of quercetin to M enhanced the immune response by improving immunoglobulin levels and CD4/CD8 expression in the thymus and spleen. Additionally, quercetin inhibited apoptosis by controlling mitochondrial caspase-mediated cellular signaling, suggesting that it may be able to halt cell death in M-fed rats.

CONCLUSION

The results of this study first indicate that quercetin, via modulating redox-guided cellular signaling, has a promising role in reducing immune disturbances. This study illuminates the potential of quercetin as a safe, natural remedy for immunopathology caused by M, including thymic hypoplasia and/or splenomegaly, and paves the way for future anti-inflammatory and antioxidant supplements.

The Association Between Malignancy, Immunodeficiency, and Atopy in IgE-Deficient Patients

BACKGROUND

Studies show that IgE-deficient patients (IgE <2.5 kU/L) have a high prevalence of malignancy, but relevant clinical and laboratory characteristics associated with this susceptibility have never been well characterized.

OBJECTIVE

To evaluate if there is an association between a malignancy diagnosis and other immunological parameters (atopy or other immune abnormalities) in IgE-deficient patients.

METHODS

We retrospectively analyzed medical records of 408 IgE-deficient adults seen at our institution between 2005 and 2020.

RESULTS

A malignancy diagnosis was found in 23.5% (96 of 408) of IgE-deficient patients. Among those who had allergy skin testing performed for allergic rhinitis-like symptoms, the nonatopic IgE-deficient patients (negative environmental skin tests) were more likely to have a malignancy diagnosis than the atopic group (odds ratio [OR] = 4.36, 95% confidence interval [CI]: 1.11-17.13, P = .03). The IgE-deficient individuals with an additional non-common variable immunodeficiency (non-CVID) humoral abnormality (n = 75; with low IgG, IgA, or IgM without meeting criteria for CVID) were more likely to have a malignancy diagnosis than those with only a selective IgE deficiency (n = 134; with normal IgA, IgM, and IgG) (OR = 2.79, 95% CI: 1.37-5.68, P = .005). Among the IgE-deficient patients, certain less well-defined immune abnormalities such as IgM deficiency (OR = 2.46, 95% CI: 1.13-5.36, P = .02), IgG2 deficiency (OR = 10.14, 95% CI: 1.9-54.1, P = .007), and CD4 lymphopenia (OR = 7.81, 95% CI: 2.21-27.63, P = .001) were associated with higher malignancy odds than those without these abnormalities.

CONCLUSION

The odds of a malignancy diagnosis are not shared equally by all IgE-deficient patients. Prospective studies are needed to determine the utility of performing skin testing and measuring additional immunological parameters in assessing the long-term malignancy risk in IgE-deficient patients.

Elevated IgE Levels-An Allergy or an Underlying Inborn Error of Immunity in Children with Recurrent Infections?

Elevated immunoglobulin E (IgE) is a hallmark of allergic diseases. However, high IgE levels also occur in a number of other infectious and noninfectious diseases. In most cases, elevated IgE levels indicate allergy, eczema, or chronic skin infection. Very high IgE levels are not uncommon in patients with active eczema but more often indicate monogenic atopic disorder or inborn errors of immunity with an atopic phenotype. We conducted a retrospective study of 385 children with suspected immune deficiency referred to the clinic over a 9-year period. Measurement of IgE, IgG, IgA, IgM, and IgG subclasses in blood samples revealed that nearly one-third of the patients had elevated serum IgE levels. Most of the cases with elevated IgE were children with underlying atopy-mainly atopic dermatitis and, to a lesser extent, bronchial asthma-whereas 40.12% (37 children) had no atopy at all. In the most severe cases (with extremely elevated IgE or severe dermatitis), we confirmed genetic mutations for underlying immunodeficiency. Our results indicate that allergic phenotype should not be underestimated and that children with more severe allergic disease should be evaluated for an underlying inborn error of immunity. If inborn error of immunity (IEI) is suspected, a comprehensive immunologic evaluation is required. Genetic testing helps identify the specific genetic abnormality, which provides important insight into the immunopathogenesis of the disease and accurate determination of optimal therapy.

Impaired Response to Polysaccharide Vaccine in Selective IgE Deficiency

PURPOSE

Immunoglobulin E deficiency (IgED) (defined as IgE < 2 IU/mL) is enriched in patients with primary antibody deficiency (PAD). We hypothesized that selective IgED (sIgED) is a more sensitive predictor of the development of PAD than declining IgG, as IgE production typically requires two class switch recombination (CSR) events in contrast to IgG. Thus, the inability of patients with sIgED to mount an appropriate antibody response to a T-cell independent antigen or evidence of aberrant induction of ɛ germ line (ɛGL) or IgE heavy chain (IgEHC) transcripts in vitro would support the concept that sIgED is a biomarker for emerging PAD.

METHODS

We compared pre- and post-polysaccharide vaccination titers in healthy patients with sIgED without a history of recurrent infections or autoimmunity (n = 20) and in healthy controls (HCs) (n = 17). Subsequently, we assessed in vitro induction of εGL and IgEHC transcripts in patients with sIgED and HC (n = 6) in response to IL-4 + CD40L stimulation.

RESULTS

Thirty percent of patients with sIgED did not have a robust vaccine response compared to 0% of HCs (p = 0.017). Individuals with sIgED with an abnormal vaccine response demonstrated persistent germline mRNA expression in their B-cells at day 5, with lower levels of IgEHC, compared to both HCs and sIgED participants with a normal vaccine response.

CONCLUSION

Patients with sIgED are more likely to have abnormal antibody responses to a T cell-independent antigen and may have dysregulated CSR machinery. Following individuals with sIgED longitudinally may be beneficial in the early identification of PAD.

Allergic Diseases as a Clinical Phenotype Marker in Patients with Common Variable <bold>Immunodeficiency</bold>

INTRODUCTION

Patients with common variable immunodeficiency (CVID) have been shown to be more predisposed to develop allergic diseases because of mucosal immune defects and immune dysregulation. The aim of this study was to determine the prevalence, and clinical and laboratory characteristics of various allergic diseases in patients with CVID.

METHODS

The study included patients aged ≥18 years who were followed up for a diagnosis of CVID. Patients were separated into 5 groups according to the clinical phenotypic characteristics of lymphoproliferation, autoimmunity, gastrointestinal diseases, allergic diseases, and malignancy. Atopic dermatitis (AD), drug hypersensitivity reaction (DHR), allergic rhinitis (AR), and asthma were accepted as allergic diseases.

RESULTS

The most commonly seen clinical phenotypes were lymphoproliferation in 41 (48.8%) patients and allergic diseases in 31 (37%). AD was determined in 2 (2.4%) patient, DHR in 5 (6%), AR in 7 (8.3%), and asthma in 21 (25%). The delay in diagnosis of patients with allergic disease was determined to be shorter compared to those without allergic disease (p = 0.042). Serum total immunoglobulin E level, CD19+ B cell, switched memory B cell, and natural killer cell counts were determined to be higher in the CVID patients with allergic disease compared to those without (p = 0.007, p = 0.022, p = 0.023, p = 0.017, respectively).

CONCLUSION

Allergic diseases should be considered as a marker of clinical phenotype in CVID because of the clinical and immunological differences. Early diagnosis and treatment of allergic diseases in patients with CVID can improve quality of life.

The Very Low IgE Producer: Allergology, Genetics, Immunodeficiencies, and Oncology

Opposite to other immunoglobulin (Ig) classes and subclasses, there is no consensus on the definition of normal levels of serum total IgE. However, longitudinal studies on birth cohorts produced growth charts of total IgE levels in helminth-free and never atopic children and defining the normal ranges of total serum IgE concentration at the individual, rather than population, level. Accordingly, very 'low IgE producers' (i.e., children whose tIgE level belong to the lowest percentiles) became atopic while keeping their total IgE levels in a range considered 'normal' if compared to the general age-matched population but 'abnormally high' if projected on the tIgE growth chart against the trajectory of that child's own percentile levels. In 'low IgE producers', the IgE-specific activity, i.e., the ratio between allergen-specific and total IgE, is more important than the absolute specific IgE levels to confirm causality between allergen exposure and allergic symptoms. Patients with allergic rhinitis or peanut anaphylaxis but low or undetectable allergen-specific IgE levels must therefore be reconsidered considering their total IgE levels. Low IgE producers have been also associated with common variable immunodeficiency, lung diseases, and malignancies. A few epidemiological studies have shown a higher risk of malignancies in very low IgE producers, leading to a debated hypothesis proposing a novel, evolutionistic-relevant function for IgE antibodies for antitumor immune surveillance.

Efficacy of dupilumab for the treatment of severe skin disease in cytotoxic T lymphocyte antigen-4 insufficiency: A role of type 2 inflammation?

We report on the successful treatment of a severe, recalcitrant dermatitis caused by CTLA-4 insufficiency with dupilumab, raising the possibility of a role of type 2 immunity in clinical conditions associated with CTLA-4 insufficiency.

The prevalence of ultra-low total IgE level among Egyptian population: impact of age, sex, and socioeconomic class

Background

Immunoglobulin E (IgE) is the least prevalent antibody type; it plays a key role in host immunity against parasitic infections and allergic diseases. Association between IgE deficiency and higher malignancy rates has been suggested in many studies.

Objectives

The goal of our study was to determine the prevalence of ultra-low total IgE levels and their variations according to sex and age among the Egyptian population.

Methodology

This multicenter retrospective cross-sectional study included serum total IgE and CBC records of 1099 children and 993 adults recruited from private and public hospitals in Egypt between 2015 and 2021. Total IgE levels were classified into ultra-low, normal, high, and very high.

Results

Of all included subjects, 0.8% had ultra-low IgE levels and 74.4% had normal IgE levels. High and very high serum total IgE levels were 24.1% and 0.7%, respectively. IgE levels were significantly higher among adults than children 45 (16.5–113.25) IU/ml vs. 20 (10–75) IU/ml; p < 0.001and among private hospital’s patients than the public one (40 (15–98.4) IU/ml vs. 25 (10–98.4) IU/ml; p = 0.002. No significant difference between total IgE serum levels regarding gender (p = 0.825). Total IgE levels were higher among young adults, with a gradual decline among older patients and a peak among the 50 s and 60 s patients. Pearson correlation between IgE and absolute eosinophilic count showed positive correlation but did not reach significant level r = 0.04, p = 0.367.

Conclusion

Age and socioeconomic class have impacts on total IgE levels with a relatively low prevalence of ultra-low IgE among the Egyptian population.

Relationship between low serum immunoglobulin E levels and malignancies in 9/11 World Trade Center responders

BACKGROUND

Individuals with very low immunoglobulin E (IgE) levels have a high risk of developing malignancy. Previous studies have revealed that World Trade Center (WTC) responders exposed to carcinogens have an elevated risk of some cancers.

OBJECTIVE

To evaluate the association between low-serum IgE levels and cancer development in WTC-exposed responders.

METHODS

IgE levels were measured in 1851 WTC responders after September 11, 2001. This is the first pilot study in humans comparing the odds of developing cancer in this high-risk population, between the "low-IgE" (IgE in the lowest third percentile) vs "non-low-IgE" participants.

RESULTS

A significantly higher proportion of hematologic malignancies was found in low-IgE (4/55, 7.3%) compared with non-low-IgE (26/1796, 1.5%, P < .01) responders. The proportion of solid tumors were similar in both groups (5.5% vs 11.4%, P > .05). After adjustment for relevant confounders (race, sex, age at blood draw, WTC arrival time, smoking status), the low-IgE participants had 7.81 times greater odds (95% confidence interval, 1.77-29.35) of developing hematologic cancer when compared with non-low-IgE participants. The hematologic cancers found in this cohort were leukemia (n = 1), multiple myeloma (n = 1), and lymphoma (n = 2). No statistical significance was found when estimating the odds ratio for solid tumors in relation to IgE levels.

CONCLUSION

WTC responders with low serum IgE levels had the highest odds of developing hematologic malignancies. This hypothesis-generating study suggests that low serum IgE levels might be associated with the development of specific malignancies in at-risk individuals exposed to carcinogens. Larger, multicenter studies with adequate follow-up of individuals with different IgE levels are needed to better evaluate this relationship.

Skin Manifestations in Patients with Selective Immunoglobulin E Deficiency

Selective immunoglobulin E deficiency (SIgED) is still an unrecognised primary immunodeficiency despite several observations supporting its existence. This study aimed to describe the skin manifestations associated with SIgED. We retrospectively assessed medical records of patients with SIgED, the diagnosis being based on serum IgE levels ≤2 Uk/L associated with normal serum levels of immunoglobulins G, M, and A. A total of 25 patients (24 female) with SIgED were included in the study. Eleven patients (44%) presented chronic spontaneous urticaria (CSU), five (20%) angioedema always associated with CSU, five erythema (20%), and six eczema (24%). Other, less frequent manifestations were lichen planus, anaphylactoid purpura, thrombocytopenic purpura, bullous pemphigoid, bullous pyoderma gangrenosum, and atypical skin lymphoproliferative infiltrate associated with reactive lymphadenopathy, chronic cholestasis, arthritis, and fibrosing mediastinitis. Fifteen patients (60%) had different types of associated autoimmune diseases, Hashimoto's thyroiditis being the most frequent (n = 5, 20%), followed by arthritis (n = 4, 16%), autoimmune hepatitis, neutropenia, vitiligo, and Sjögren's syndrome (n = 2, 8% each). Five malignancies were diagnosed in four patients (16%). An ultralow IgE serum level may be the only biomarker that reveals the presence of a dysregulated immune system in patients with a broad spectrum of skin manifestations.

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.

Risk Factors of Pneumonia in Primary Antibody Deficiency Patients Receiving Immunoglobulin Therapy: Data from the US Immunodeficiency Network (USIDNET)

BACKGROUND

Despite immunoglobulin replacement (IgRT) therapy, some patients with primary antibody deficiency (PAD) continue to develop respiratory infections. Recurrent and severe respiratory infections, particularly pneumonia, can lead to significant morbidity and mortality. Therefore, we sought to determine the risk factors of developing pneumonia in PAD patients, already receiving IgRT.

METHODS

We evaluated clinical and laboratory features of PAD patients enrolled in the US Immune Deficiency Network (USIDNET) registry by April 2017. Patients were included if they met the following criteria: (1) PAD diagnosis (common variable immunodeficiency (CVID), agammaglobulinemia, hypogammaglobinemia, and specific antibody deficiency (SAD) and (2) available data on infections before and after IgRT. Patients were excluded if they were not receiving IgRT, or if no pre/post infections data were available. Descriptive and multivariable logistic regression analyses were used to identify factors associated with pneumonia post-IgRT.

RESULTS

A total of 1232 patients met the inclusion criteria. Following IgRT, 218 patients (17.7%) were reported to have at least one pneumonia episode. Using multivariate logistic regression analysis, we found a statistically significant increased risk of pneumonia in patients with asthma (OR: 2.55, 95% CI (1.69-3.85), p < 0.001) bronchiectasis (OR: 3.94, 95% CI (2.29-6.80), p < 0.001), interstitial lung disease (ILD) (OR: 3.28, 95%CI (1.43-7.56), p < 0.005), splenomegaly (OR: 2.02, 95%CI (1.08-3.76), p < 0.027), allergies (OR: 2.44, 95% CI [1.44-4.13], p = 0.001), and patients who were not on immunosuppressives (OR: 1.61; 95%CI [1.06-2.46]; p = 0.027). For every 50 unit increase in IgA, the odds of reporting pneumonia post IgRT decreased (OR: 0.86, 95% CI [0.73-1.02], p = 0.062). Infectious organisms were reported in 35 of 218 patients who reported pneumonia after IgRT. Haemophilus influenzae was the most frequently reported (n = 11, 31.43%), followed by Streptococcus pneumoniae (n = 7, 20.00%).

CONCLUSION

Our findings suggest PAD patients with chronic and structural lung disease, splenomegaly, and allergies were associated with persistent pneumonia. However, our study is limited by the cross-sectional nature of the USIDNET database and limited longitudinal data. Further studies are warranted to identify susceptible causes and explore targeted solutions for prevention and associated morbidity and mortality.

CLINICAL IMPLICATIONS

Patients with primary antibody deficiency with structural lung disease, allergies, and splenomegaly are associated with persistent pneumonia post-IgRT.

Skin Testing Is Useful in Assessing Aeroallergen Sensitization in IgE Deficient Patients with Environmental Allergy-Like Symptoms

BACKGROUND

The value of aeroallergen skin testing is not known in IgE deficient individuals (IgE<2.5 kU/L).

OBJECTIVE

To investigate the utility of skin prick (SPT), intradermal skin testing (IDST) and measuring serum specific IgE (ssIgE) in IgE deficient patients presenting with environmental allergy-like symptoms.

METHODS

Individuals with IgE deficiency who had both SPT and IDST performed between 2010 to 2020 were matched (age and gender) to three different groups of non-IgE deficient patients with IgE≥2.5 kU/L (normal IgE [2.5 ≤ IgE<100], high IgE [100≤IgE<1000] and very high IgE levels [≥1000 kU/L]) who also had skin testing performed for evaluation of environmental allergy-like symptoms.

RESULTS

Among 34 IgE deficient patients who completed SPT and IDST, 52.9% (18/34) had at least one positive skin test (4 ± 3 positive tests/patient), compared with 91.2% in those with normal, 94.1% with high or 97.1% with very high IgE levels (p < 0.01). In contrast, only one of the IgE deficient patients had detectable ssIgE, while ssIgE levels were significantly higher in all other IgE subgroups. Allergic immunotherapy was prescribed for 22.2% of the IgE-deficient patients with positive skin tests, similar to those with normal (2/31, 6.5%, p = 0.21), high IgE (9/32, 28.1%, p = 0.25) and very high IgE levels (8/33, 23.5%, p = 0.07), with similar efficacy in their symptoms control.

CONCLUSION

Individuals with IgE deficiency may present with environmental allergy-like symptoms. A combination of SPT and IDST is useful for diagnosing aeroallergen sensitizations in these patients, indicating the presence of skin mast cell-bound IgE in some of these individuals, despite very low serum IgE levels. Further studies are needed to assess the exact significance of positive skin tests and the benefits of immunotherapy in this group.

Immunoglobulin E response in health and disease beyond allergic disorders

Immunoglobulin E is the latest discovered of immunoglobulin family and has been long associated with anaphylaxis and worm expulsion. Immunoglobulin E, along with mast cells, basophils, and eosinophils, is also a hallmark of type 2 immunity which is dysregulated in numerous diseases such as asthma, rhinitis, atopic dermatitis, and eosinophilic esophagitis in addition to anaphylaxis as aforementioned. However, recent advances have shed light on IgE regulation and memory explaining the low level of free IgE, the scarcity of IgE plasma cells that are mainly short live and the absence of IgE memory B cells in homeostatic conditions. Furthermore, IgE was implicated in inflammatory conditions beyond allergic disorders where IgE-mediated facilitated antigen presentation can enhance cellular and humoral response against autoantigens in systemic lupus or chronic urticaria leading to more severe disease and even against neoantigen facilitating tumor cell lysis. At last, IgE was unexpectedly associated with allograft rejection or atheromatous cardiovascular diseases where precise mechanisms remain to be deciphered. The purpose of this review is to summarize these recent advances in IgE regulation, biology, and physiopathology beyond allergic diseases opening whole new fields of IgE biology to explore.

Serum Allergen-Specific IgE among Pediatric Patients with Primary Immunodeficiency

Background: Allergy is a clinical condition that reflects a deviated function of the immune system. The purpose of this study was to evaluate serum allergen-specific IgE (sIgE) along with clinical manifestations of allergy in patients with diagnosed primary immunodeficiency (PID). Methods: 72 patients, aged 1−17 years, diagnosed with PID and hospitalized between July 2020 and February 2021 were included in the study. Blood samples were obtained by venipuncture. sIgE (30 allergens), blood eosinophil count, as well as total IgE and IgG were measured and assessed in relation to a detailed medical examination. Results: Serum sIgE was detected in the blood of 50% of the patients in the study group, which significantly correlated (p < 0.0001) with clinical symptoms of allergy. During the period of the study, 61.1% of the patients showed symptoms of allergy, with 77.27% of them having tested positive for sIgE. The total IgE level was elevated in 18.06% of the patients and correlated with clinical symptoms of allergy (p = 0.004). An elevated total IgE level was not observed in children receiving immunoglobulin replacement therapy. Conclusion: The study showed that serum sIgE and total IgE together might be a plausible diagnostic tool for PID patients. However, for patients receiving immunoglobulin replacement therapy, the assessment of total IgE is not useful.

Immune Dysregulation in Pediatric Common Variable Immunodeficiency: Implications for the Diagnostic Approach

Infections and infectious complications are hallmarks of common variable immunodeficiency (CVID) and the leading cause of morbidity and mortality in affected patients at any age. However, the pediatric CVID is no longer perceived as a primary immunodeficiency associated solely with infectious manifestations; autoimmune, allergic, lymphoproliferative, and malignant disorders and organ-specific immunopathology also characterize the spectrum of non-infectious complications. In this study, we sought to determine the role of immune dysregulation and frequency of non-infectious sequelae in children affected with CVID. We also aimed at providing an insight into the pathogenesis of non-infectious complications and at delineating the diagnostic approach to pediatric CVID with immune dysregulation. An in-depth retrospective analysis of clinical manifestations and their correlations with selected immune parameters was performed in a group of 39 CVID children, followed by our pediatric immunology department. Whereas recurrent sinopulmonary infections were present in all (100%) of the children studied, an unexpectedly high rate of non-infectious disorders and immune dysregulation phenotypes were observed in as many as 32 (82.05%) patients, compared with infection-only phenotypes limited to 7 (17.95%) male patients. The most common inflammatory comorbidity was asthma, diagnosed in 21 (53.85%) patients. The second most frequent immune dysregulation group was autoimmune disorders, present in 18 (46.15%) of the children studied with a high rate of autoimmune thyroiditis in as many as 10 (25.64%) of the CVID-affected children. Lymphoproliferation was seen in 14 children (35.90%), and, among them, lymphadenopathy occurred in nine (23.08%) cases and granulomatous lymphocytic interstitial lung disease in seven (17.95%) cases. Finally, malignancies occurred in two female patients (5.13%), papillary thyroid cancer in the first one and T-cell lymphoblastic leukemia in the other one. The most prominent abnormalities in the B- and T-cell compartment contributing to complex immune deficiency and immune dysregulation phenotypes were seen in the autoimmunity group, showing significant reductions in the switched memory B cell, naive T helper cell, and regulatory T-cell subsets. Herein, we document the previously unreported high rate of immune dysregulation in pediatric CVID as a clinical and diagnostic challenge with the variability of defects in the humoral and cellular immune responses.

Immune Dysregulation in Patients With Chromosome 18q Deletions-Searching for Putative Loci for Autoimmunity and Immunodeficiency

Introduction

Autoimmune disorders, IgA deficiency, and allergies seem to be common among individuals with 18q deletion syndrome [OMIM 601808]. We aimed to determine the prevalence, mechanism, and genetic background of autoimmunity, immune deficiency, and allergy in a cohort of patients with 18q deletions.

Material and Methods

Medical registries and social media were used to recruit the patients. Microarray oligonucleotide comparative genomic hybridization (aCGH) (Agilent, Santa Clara, CA, USA) was performed in all patients to identify size and location of chromosome 18 deletion. Clinical evaluation and medical record collection were performed in each of the study participants. The history of autoimmune disorders, severe and/or recurrent infections, and symptoms of allergy were noted. Total immunoglobulin IgG, IgA, IgM, IgE, and IgG1-4 serum levels were measured using nephelometry and ELISA methods. Lymphocyte T subset phenotyping was performed in 24 subjects from 18q del cohort. To predict the most promising candidate genes, we used the ENDEAVOUR-a free web resource for gene prioritization.

Results

18q deletion was confirmed by means of array CGH analysis in 27 individuals, 15 (55.6%) females and 12 males, referred to the project by specialists in medical genetics, diabetology, or pediatric endocrinology between May 2015 and December 2019. The mean age at examination was 11.8 years (min-max: 4.0-33.5). Autoimmune disorders were present in 14/27 (51.8%) of the cohort. In eight of patients, symptoms of immune deficiency coexisted with autoimmunity. Allergy was reported in nine of 27 (33.4%) patients. Over 89% of patients presented with at list one type of immunoglobulin (IgA, IgM, IgG, IgE, and IgG1-4) deficiency and eight of 25 (32%) had abnormalities in at least two major immunoglobulin (IgG, IgA, IgM) measurements (CVID-like phenotype). Patients with 18q del exhibited a significantly decreased CD4, Treg FOXP3+, TregFOXP3+Helios+, and TemCD4 cell numbers in comparison with the control groups of 24 T1DM patients and 28 healthy controls.

Conclusions

Patients with 18q deletions frequently suffer from autoimmune disorders, recurrent infections, and allergy due to immune dysregulation presenting with variable antibody deficiencies and T-regulatory cell deficiency (CD4+CD25+CD127lowFOXP3+). The spectrum of speculations regarding which gene might be responsible for such phenotype ranges from single gene haploinsufficiency to deletion of a cluster of immunogenes located distally to 18q21.

A Critical Review on the Standardization and Quality Assessment of Nonfunctional Laboratory Tests Frequently Used to Identify Inborn Errors of Immunity

Inborn errors of immunity (IEI), which were previously termed primary immunodeficiency diseases, represent a large and growing heterogeneous group of diseases that are mostly monogenic. In addition to increased susceptibility to infections, other clinical phenotypes have recently been associated with IEI, such as autoimmune disorders, severe allergies, autoinflammatory disorders, benign lymphoproliferative diseases, and malignant manifestations. The IUIS 2019 classification comprises 430 distinct defects that, although rare individually, represent a group affecting a significant number of patients, with an overall prevalence of 1:1,200-2,000 in the general population. Early IEI diagnosis is critical for appropriate therapy and genetic counseling, however, this process is deeply dependent on accurate laboratory tests. Despite the striking importance of laboratory data for clinical immunologists, several IEI-relevant immunoassays still lack standardization, including standardized protocols, reference materials, and external quality assessment programs. Moreover, well-established reference values mostly remain to be determined, especially for early ages, when the most severe conditions manifest and diagnosis is critical for patient survival. In this article, we intend to approach the issue of standardization and quality control of the nonfunctional diagnostic tests used for IEI, focusing on those frequently utilized in clinical practice. Herein, we will focus on discussing the issues of nonfunctional immunoassays (flow cytometry, enzyme-linked immunosorbent assays, and turbidimetry/nephelometry, among others), as defined by the pure quantification of proteins or cell subsets without cell activation or cell culture-based methods.

Spectrum of Disease Manifestations in Patients with Selective Immunoglobulin E Deficiency

BACKGROUND

Selective IgE deficiency (SIgED) has been previously evaluated in selected patients from allergy units. This study investigates the effects of SIgED on the entire population in a hospital setting and sought to delineate in detail the clinical aspects of SIgED.

METHODS

A retrospective study of the data obtained from electronic medical records of 52 adult patients (56% female) with a mean age of 43 years and IgE levels of <2.0 kU/L with normal immunoglobulin (Ig) IgG, IgA, and IgM levels, seen at our hospital, without selection bias, from 2010 to 2019.

RESULTS

Recurrent upper respiratory infections were recorded in 18 (34.6%) patients, pneumonia was recorded in 16 (30.7%) patients, bronchiectasis was recorded in 16 (30.7%) patients, and asthma was recorded in 10 (19.2%) patients. Eighteen patients (34.6%) suffered autoimmune clinical manifestations either isolated (19%) or combining two or more diseases (15%), Hashimoto's thyroiditis being the most frequent (19%), which was followed by arthritis (10%) and thrombocytopenia and/or neutropenia (5.7%). Other less frequent associations were Graves' disease, primary sclerosing cholangitis, Sjögren's syndrome, and autoimmune hepatitis. Eczematous dermatitis (15.3%), chronic spontaneous urticaria (17.3%), and symptoms of enteropathy (21%) were also highly prevalent. Thirty percent of patients developed malignancies, with non-Hodgkin lymphomas (13.4%) being the most prevalent.

CONCLUSIONS

The clinical manifestations of SIgED encompass a variety of infectious, non-infectious complications, and malignancy. Since it cannot be ruled out that some type of selection bias occurred in the routine assessment of IgE serum Ievels, prospective studies are required to better characterize SIgED and to determine whether it should be added to the list of antibody deficiencies.

Is There a Clinical Significance of Very Low Serum Immunoglobulin E Level?

PURPOSE

High serum immunoglobulin (Ig) E levels are associated with allergies, parasitic infections, and some immune deficiencies; however, the potential effects and clinical implications of low IgE levels on the human immune system are not well-known. This study aims to determine the disorders accompanying very low IgE levels in children and adults.

METHODS

The patients whose IgE levels were determined between January 2015 and September 2020 were analyzed, and the patients with an IgE level < 2 IU/mL were included in this study. Demographic data, immunoglobulin levels, autoantibody results, and the diagnoses of the patients were noted from the electronic recording system of the hospital.

RESULT

The IgE levels were measured in 34,809 patients (21,875 children, 12,934 adults), and 130 patients had IgE levels < 2 IU/mL. Fifty-seven patients were children (0.26%); 73 were adults (0.56%). There was a malignant disease in 34 (9 of them children) (26%), autoimmune diseases in 20 (3 of them children) (15.4%), and immunodeficiency in 17 (14 of them children) (13.1%) of the patients. The most common reasons were other diseases, immunodeficiency and malignancy in children, and malignancy, autoimmune disorders, and other diseases in the adults, in rank order. The IgE level did not show any correlation with the levels of other immunoglobulins.

CONCLUSION

Although rare, a low IgE level has been shown to accompany malignancies, autoimmune disorders, and immune deficiencies. Patients with very low IgE levels should be carefully monitored for systemic disorders.

Lower IgA Levels in Chronic Spontaneous Urticaria Are Associated With Lower IgE Levels and Autoimmunity

Background

The pathogenesis of chronic spontaneous urticaria (CSU) is still insufficiently understood. Recent findings suggest that immunoglobulins, in particular IgE but also IgA, play a role in the development of CSU.

Objective

Our aim was to assess differences in clinical and laboratory markers between CSU patients with and without lower levels of serum IgA and IgE.

Methods

We analyzed the data of 606 patients with CSU by dividing them into four groups based on their IgA and IgE levels. The groups were compared for their spectrum of symptoms, disease activity, concomitant autoimmunity and routine laboratory markers. Autoreactivity was assessed by basophil activation test (BAT). Moreover, IgE-anti-thyroid peroxidase (TPO) was measured.

Results

Of the patients with lower IgE levels, 66.5% also had lower IgA levels (r=0.316, p<0.001). Patients with lower IgA and lower IgE levels showed a higher prevalence of recurrent angioedema (p=0.03, p=0.04) and concomitant autoimmunity (p=0.006, p<0.001). Autoreactivity was also found more frequently in patients with lower IgA and lower IgE levels (p=0.003, p<0.001). Reduced basophil counts were linked to both, lower IgA and lower IgE levels (p<0.001), whereas low eosinophil counts were primarily present in patients with lower IgE levels (p=0.04, p<0.001). Patients with elevated IgE-anti-TPO levels had lower IgA (p=0.007) and IgE levels (p=0.001).

Conclusion

Lower IgA levels in CSU are linked to lower IgE levels and features of autoimmune urticaria. Our findings encourage to screen CSU patients for serum IgA and IgE levels and to further assess their role as disease biomarkers.

Increased Malignancy Rate in Children With IgE Deficiency: A Single-center Experience

BACKGROUND

Immunoglobulin (Ig) E-deficient adults (IgE<2.5 kU/L) have increased susceptibility for developing malignancy. We evaluated the association between IgE deficiency and cancer diagnosis in children (age younger than 18 y), compared with those non-IgE-deficient (IgE≥2.5 kU/L).

MATERIALS AND METHODS

Information about malignancy diagnosis were compared between 4 cohorts of children who had IgE levels measured at our institution: IgE-deficient (IgE<2.5 kU/L), normal IgE (2.5

RESULTS

Overall, 94/4586 (2%) children had IgE deficiency. A significantly higher malignancy rate was found in IgE-deficient children (3/94, 3.2%) compared with non-IgE-deficient cohort (13/4492, 0.3%, P<0.0001). Analysis of the groups with different IgE levels revealed a significantly higher rate of cancer in IgE-deficient children (3.2%) compared with those with normal (0.5%; odds ratio [OR]=7.84; 95% confidence interval [CI]: 1.94-31.61, P=0.004), high (0.2%; OR=25.80; 95% CI: 4.94-134.54, P=0.002), and very high IgE levels (0.2%; OR=42.17; 95% CI: 3.84-463.02, P<0.0001). All 3 IgE-deficient children had lymphoma. Malignancies in the other groups included lymphoma, leukemia, brain, liver, ovarian cancers.

CONCLUSIONS

Malignancy rate was higher in IgE-deficient children compared with those with normal, high, or very high IgE levels, supporting the hypothesis that IgE deficiency may be a marker for malignancy susceptibility in children. Larger, prospective studies are necessary to further evaluate this association.

Collapse

Key Words Collapse

MESH Headings

• Child
• Child, Preschool
• Female
• Humans
• Immunoglobulin E/blood
• Immunoglobulin E/deficiency
• Male
• Neoplasms/blood
• Neoplasms/diagnosis
• Neoplasms/etiology
• Odds Ratio
• Prospective Studies
• Risk Factors

Collapse

Grants Collapse

Affiliation(s)

Denisa Ferastraoaru Department of Internal Medicine/Allergy-Immunology, Albert Einstein College of Medicine/Montefiore Medical Center
Deborah Schwartz Albert Einstein College of Medicine, Bronx, NY
David Rosenstreich Department of Internal Medicine/Allergy-Immunology, Albert Einstein College of Medicine/Montefiore Medical Center

Collapse

Collaborators Collapse

The other side of the coin: IgE deficiency, a susceptibility factor for malignancy occurrence

Since the discovery of IgE, almost all attention was given to conditions with elevated specific or total IgE levels such as atopy, type I hypersensitivity reactions, or parasitic infestations. Recent prospective and retrospective studies show that having very low IgE levels, such as those seen in IgE deficiency (IgE<2.5 kU/L), is not without clinical consequences. Patients with ultra-low IgE levels have an elevated risk of cancer of any type. These results are in agreement with murine models research which demonstrated that grafted tumors grow faster and bigger on an IgE knockout background. The novel finding that IgE deficiency is a susceptibility factor for cancer, fits very well with the AllergoOncology concept. The reports on a beneficial, cytotoxic function of IgE, in cooperation with its high (FcεRI) and low (FcεRII, CD23) affinity IgE receptors resulting in tumor cell phagocytosis, propose a role of IgE in cancer surveillance. It appears that not only deficiency of serum IgE, but also lack of tissue-bound IgE is important in malignancy susceptibility in these patients. As such, IgE deficient individuals with absent serum and cell-bound IgE as suggested by negative type I hypersensitivity skin tests, are at the highest risk for a malignancy diagnosis. In contrast, IgE deficient individuals with cell-bound IgE depicted through positive type I hypersensitivity skin tests, have lower rates of malignancy diagnosis. The present report discusses the evidence and potential role of ultra-low IgE as a novel biomarker for cancer susceptibility.

Allergic-like disorders and asthma in patients with common variable immunodeficiency: a multi-center experience

OBJECTIVE

Common variable immune deficiency (CVID) encompasses a variety of diseases characterized by disturbed immunoglobulin (Ig) production and various immune dysregulations. Scarce data are available regarding relationships between CVID and allergic diseases. Here we examined possible associations between allergies and CVID.

METHODS

For this multicenter study, we prospectively enrolled 79 adult CVID patients (≥18 years) who were diagnosed and treated between 2002-2017 at the Hadassah-Hebrew University and Shaare Zedek Medical Centers, Jerusalem, Israel. These patients were examined for allergic manifestations. Patient evaluation comprised medical history, physical examination, skin allergen testing, complete blood count, serum immunoglobulins, IgE levels, and pulmonary function tests.

RESULTS

After implementing exclusion criteria, 29 patients were included in the final analysis. Allergic-like disorders were diagnosed in 65% of CVID patients with non-elevated serum IgE levels. Moreover, allergic CVID patients exhibited a higher prevalence of bronchiectasis on chest CT. Autoimmunity was diagnosed in 41.3% of CVID subjects. The type I allergy detected in our study was non-IgE mediated.

CONCLUSIONS

Timely diagnosis and stratification of allergy in CVID patients is expected to improve their outcome and quality of life, as well as promote appropriate treatment and better management of pulmonary exacerbations.

Prevalence and the impact of hypogammaglobulinemia in newly diagnosed chronic lymphocytic lymphoma patients

Objective

To examine the prevalence of hypogammaglobulinemia in chronic lymphocytic lymphoma (CLL) patients and to test the hypothesis that patients with hypogammaglobulinemia have a distinct clinical profile and outcome.

Methods

Immunoglobulin levels (IgA, IgG, IgM, IgE) were measured in newly diagnosed, treatment naïve banked samples of 150 patients with CLL followed prospectively for outcomes. Cox regression models were used to assess the effects of clinical variables on overall survival (OS).

Results

The median age of the selected CLL cohort was 64 years with a male predominance; 96.2% of the patients were white. Fifty-nine deaths occurred during a median follow up of 6.8 years. Hypogammaglobulinemia in CLL was common in our cohort with 88 (58.7%, 95% CI: 50.4-66.6%) patients having a measurable isotype deficiency. The most common Ig deficiency was IgM (44.0%). IgA deficiency or low IgE was associated with higher Rai stages as well as with higher white blood cell counts at presentation. Any immunoglobulin deficiency was not associated with overall survival.

Conclusion

A significant proportion of treatment-naïve CLL patients had underlying Ig deficiencies - both in isolation and in isotype combinations. Although a deficiency of IgA or IgE was associated with more severe disease at presentation, the impact of this association was mild.

AllergoOncology: ultra-low IgE, a potential novel biomarker in cancer-a Position Paper of the European Academy of Allergy and Clinical Immunology (EAACI)

Elevated serum IgE levels are associated with allergic disorders, parasitosis and specific immunologic abnormalities. In addition, epidemiological and mechanistic evidence indicates an association between IgE-mediated immune surveillance and protection from tumour growth. Intriguingly, recent studies reveal a correlation between IgE deficiency and increased malignancy risk. This is the first review discussing IgE levels and links to pathological conditions, with special focus on the potential clinical significance of ultra-low serum IgE levels and risk of malignancy. In this Position Paper we discuss: (a) the utility of measuring total IgE levels in the management of allergies, parasitosis, and immunodeficiencies, (b) factors that may influence serum IgE levels, (c) IgE as a marker of different disorders, and d) the relationship between ultra-low IgE levels and malignancy susceptibility. While elevated serum IgE is generally associated with allergic/atopic conditions, very low or absent IgE may hamper anti-tumour surveillance, indicating the importance of a balanced IgE-mediated immune function. Ultra-low IgE may prove to be an unexpected biomarker for cancer risk. Nevertheless, given the early stage of investigations conducted mostly in patients with diseases that influence IgE levels, in-depth mechanistic studies and stratification of malignancy risk based on associated demographic, immunological and clinical co-factors are warranted.

Variable immunodeficiency study: Evaluation of two European cohorts within a variety of clinical phenotypes

INTRODUCTION

Given the wide heterogeneity of common variable immunodeficiency (CVID), several groups have proposed clinical and immunological classifications to better define follow-up and prognostic algorithms. The present study aims to validate recent clinical and laboratory algorithms, based on different combinations of CVID biomarkers, to provide more personalized treatment and follow-up strategies.

METHODS

We analysed clinical and immunological features of 80 patients with suspected or diagnosed CVID, in two reference centres of Portugal and Spain. Clinical manifestations were categorized into clinical phenotyping proposed by Chapel et al. [1] that included cytopenia; polyclonal lymphocytic infiltration; unexplained enteropathy; and no disease-related complications.

RESULTS

76% of patients in our cohort entered one of the four categories of clinical phenotyping, without overlap (cytopenia; polyclonal lymphocytic infiltration; unexplained enteropathy; and no disease-related complications). The most prominent phenotype was "cytopenia" (40%) followed by "polyclonal lymphocytic infiltration" (19%). The remaining 24% patients of our cohort had overlap of 2 clinical phenotypes (cytopenia and unexplained enteropathy mainly). A delay of CVID diagnosis in more than 6 years presented 3.7-fold higher risk of developing lymphoproliferation and/or malignancy (p < 0.05), and was associated with increased CD8⁺CD45RO ⁺ T-lymphocytes (p < 0.05). An association between decreased switched-memory B cells with lymphoproliferation and malignancy was observed (p < 0.03 and p < 0.05, respectively). CD4 ⁺ T-lymphocytopenia correlated with autoimmune phenotype, with 30% prevalence (p < 0.05). HLA-DR7 expression was related to CVID onset in early life in our patients (13 vs 25 years), and DQ2.5 or DQ2.2 with unexplained enteropathy (p < 0.05).

CONCLUSIONS

The phenotypic and genetic study is crucial for an adequate clinical orientation of CVID patients. In these two independent cohorts of patients, classification based in clinical and laboratory algorithms, provides more personalized treatment and follow-up strategies.

The Importance of Primary Immune Deficiency Registries: The United States Immunodeficiency Network Registry

The importance of registries is vital for almost every human disease but crucial for rare disorders, where the centralized collection, organization, and quality check of data create a platform from where multiple analyses and scientific advances are possible. In this article, the authors review the creation of the United States Immunodeficiency Network registry, its role, and the numerous scientific achievements generated from the collective effort of many.

Birds of a feather: Common variable immune deficiencies

OBJECTIVE

To update the reader on recently proposed common variable immune deficiency (CVID) diagnostic criteria, newly uncovered CVID pathobiology, freshly identified CVID-related genes, and novel CVID therapies.

DATA SOURCES

PubMed Central.

STUDY SELECTIONS

We selected 60 clinical and translational research articles that have shaped CVID diagnostic criteria, introduced personalized therapies, and advanced our understanding of CVID biology and genetics. We have incorporated recent articles and older published work that are foundational to the modern understanding of this protean disease.

RESULTS

CVID has proven to be a heterogenous group of antibody deficiency diseases driven by defects in diverse biologic processes, including B-cell development, activation, tolerance, class-switch recombination, somatic hypermutation, and lymphoproliferation. Recent genetic advances have enabled identification of several CVID-related gene defects that may contribute to patients' infectious and noninfectious symptoms.

CONCLUSION

Improved understanding of the aberrant biologic processes that drive CVID and the disease's genetic basis may be useful in directing therapeutic decisions, especially in cases complicated by autoimmune, lymphoproliferative, and inflammatory features.

Mild Hypogammaglobulinemia Can Be a Serious Condition

Background: Most patients with primary antibody deficiency (PAD) suffer from less well-described and understood forms of hypogammaglobulinemia (unclassified primary antibody deficiency, unPAD). Because of the moderately decreased immunoglobulin levels compared to CVID, unPAD is generally considered to be clinically mild and not very relevant.

Objective: To describe our cohort of—mainly—unPAD patients, and to analyze whether subgroups can be identified.

Methods: Data were prospectively collected (February-2012 to June-2016) as part of a standardized, 1-day Care Pathway for suspected primary immunodeficiency. The TNO-AZL Questionnaire for Health-Related Quality of Life (HRQoL) was part of the pre-first-visit intake procedure.

Results: Three hundred and twenty patients were referred to the Care Pathway. Data from 23/27 children and 99/113 adults who were diagnosed with PAD and gave informed consent were available for analysis. 89/99 adults had unPAD, the majority (74%) were female and 44% already showed bronchiectasis. HRQoL was significantly decreased in all domains, meaning that a lot of unPAD patients had to cope simultaneously with pain, negative feelings and impairments in cognition, home management tasks, sleep, social interaction, and work. The most prominently impaired HRQoL domain was vitality, indicating these patients feel extremely tired and worn out.

Conclusion: These results highlight the need for more attention to the potential patient burden of unPADs. A larger cohort is needed to increase our understanding of unPADs and to analyze whether distinct subgroups can be identified. For now, it is important for the clinician to acknowledge the existence of unPAD and be aware of its potential consequences, in order to timely and appropriately manage its effects and complications.

Chronic Rhinosinusitis in Children: Pathophysiology, Evaluation, and Medical Management

PURPOSE OF REVIEW

Pediatric chronic rhinosinusitis (CRS) is a common disorder that carries significant morbidity. The diagnosis requires sinus symptoms that persist despite standard medical therapy greater than 3 months. Viral infections, allergies, and anatomic differences in children lead to chronic obstruction of the osteomeatal complex.

RECENT FINDINGS

Chronic rhinosinusitis as a diagnosis is a conglomeration of multiple phenotypes and endotypes. As such, the diagnosis and management are complex. New survey studies provide some consensus on prevalence and management of this disease in children. In this review, we highlight the differential diagnosis of pediatric CRS, including non-eosinophilic/infectious variants, eosinophilic variants with and without nasal polyps, allergic fungal sinusitis, aspirin-exacerbated respiratory disease, primary immunodeficiency, and disorders of mucociliary clearance. Further, we detail treatment options that should be considered. Finally, we feature emerging potential treatment options of CRS, including anti-immunoglobulin E, interleukin-5, and interleukin-4 receptor alpha subunit.