Attending to warning signs of primary immunodeficiency diseases across the range of clinical practice

Current Issues in the Management of IgG Subclass Deficiencies in Adults With Chronic Respiratory Diseases

Primary immunodeficiency diseases (PIDs) are uncommon in adults; however, immunoglobulin G subclass deficiency (IGGSCD) is often found in a subset of adult patients with chronic respiratory diseases. As quantitative laboratory tests are used to diagnose IGGSCD, the clinical significance of IGGSCD remains controversial. However, respiratory infection is a common presenting feature of IGGSCD, and respiratory complications are responsible for subsequent morbidities, such as severe asthma, bronchiectasis, chronic obstructive airway diseases, and mortality. This review summarizes the current epidemiological data for PIDs, focusing on IGGSCD in the adult population. In addition, the investigation, treatment, and management strategies are detailed, including distinct issues faced by patients with chronic airway disease and their physicians in the proper diagnosis and treatment of IGGSCD.

Genetic screening in a Brazilian cohort with inborn errors of immunity

BACKGROUND

Inherited genetic defects in immune system-related genes can result in Inborn Errors of Immunity (IEI), also known as Primary Immunodeficiencies (PID). Diagnosis of IEI disorders is challenging due to overlapping clinical manifestations. Accurate identification of disease-causing germline variants is crucial for appropriate treatment, prognosis, and genetic counseling. However, genetic sequencing is challenging in low-income countries like Brazil. This study aimed to perform genetic screening on patients treated within Brazil's public Unified Health System to identify candidate genetic variants associated with the patient's phenotype.

METHODS

Thirteen singleton unrelated patients from three hospitals in Rio de Janeiro were enrolled in this study. Genomic DNA was extracted from the peripheral blood lymphocytes of each patient, and whole exome sequencing (WES) analyses were conducted using Illumina NextSeq. Germline genetic variants in IEI-related genes were prioritized using a computational framework considering their molecular consequence in coding regions; minor allele frequency ≤ 0.01; pathogenicity classification based on American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP) guidelines gathered from the VarSome clinical database; and IEI-related phenotype using the Franklin tool. The genes classification into IEI categories follows internationally recognized guidelines informed by the International Union of Immunological Societies Expert Committee. Additional methods for confirmation of the variant included Sanger sequencing, phasing analysis, and splice site prediction.

RESULTS

A total of 16 disease-causing variants in nine genes, encompassing six different IEI categories, were identified. X-Linked Agammaglobulinemia, caused by BTK variations, emerged as the most prevalent IEI disorder in the cohort. However, pathogenic and likely pathogenic variants were also reported in other known IEI-related genes, namely CD40LG, CARD11, WAS, CYBB, C6, and LRBA. Interestingly, two patients with suspected IEI exhibited pathogenic variants in non-IEI-related genes, ABCA12 and SLC25A13, potentially explaining their phenotypes.

CONCLUSIONS

Genetic screening through WES enabled the detection of potentially harmful variants associated with IEI disorders. These findings contribute to a better understanding of patients' clinical manifestations by elucidating the genetic basis underlying their phenotypes.

Initial manifestations in Patients with Inborn Errors of Immunity Based on Onset Age: a Study from a Nationwide Survey in Japan

PURPOSE

Patients with inborn errors of immunity (IEI) manifest various initial symptoms; however, those that are critical for the early diagnosis of IEI have not been identified. Also, the significance of the ten warning signs of primary immunodeficiency (PID) among infants has not been established. This study aimed to conduct a nationwide survey of IEI in Japan and investigated the initial manifestations based on onset age.

METHODS

Among 1298 patients, data regarding the initial manifestation were available from 505 patients. Patients with autoinflammatory diseases, complement deficiency, and phenocopies of IEI were excluded.

RESULTS

The ten warning signs were positive in 67.3% of the cases. The positivity rate was low (20.5%) in patients with immune dysregulation. Although the positivity rate was low (36.6%) in patients aged less than 3 months, they were highly positive for family history of IEI (26.8%). Infectious symptoms were the most commonly observed in all age groups and in all disease categories. Symptoms of "immune dysregulation" were present in approximately 15% of the patients. Regarding the anatomical category, almost all initial symptoms were "systemic" infections in patients with X-linked severe combined immunodeficiency. Moreover, "respiratory" symptoms were the most common in patients with IEI aged ≥ 1 year and accounted for more than 50% in all age groups in patients with common variable immunodeficiency.

CONCLUSION

These results highlight the significance of the 10 warning signs and may serve as clinical indicators for early diagnosis, considering the initial presentation of IEI.

The Middle East and North Africa Diagnosis and Management Guidelines for Inborn Errors of Immunity

Human inborn errors of immunity (IEI) are a group of 485 distinct genetic disorders affecting children and adults. Signs and symptoms of IEI are heterogeneous, and accurate diagnosis can be challenging and depends on the available human expertise and laboratory resources. The Middle East and North Africa (MENA) region has an increased prevalence of IEI because of the high rate of consanguinity with a predominance of autosomal recessive disorders. This area also exhibits more severe disease phenotypes compared with other regions, probably due to the delay in diagnosis. The MENA-IEI registry network has designed protocols and guidelines for the diagnosis and treatment of IEI, taking into consideration the variable regional expertise and resources. These guidelines are primarily meant to improve the care of patients within the region, but can also be followed in other regions with similar patient populations.

Diagnostic Testing Procedures and Challenges for Primary Immunodeficiencies

Primary immunodeficiencies are rare but are often on the differential diagnosis list when patients present with recurrent or atypical infections. Patients with primary immunodeficiencies can present with a variety of symptoms and can present providers with diagnostic challenges given this variability, and the severe implications of immunodeficiencies can sometimes lead providers to pursue broad workups that may not be necessary. However, there are certain symptom patterns providers can look out for and diagnostic steps that can be taken to triage these presentations. We have used the practice modeled in the "Five Fingers of the Immune Workup" to outline common laboratory tests for clinicians to order when they are concerned for immunodeficiencies while remembering that these diagnoses are often rare, and true concern for this pathology would warrant referral to a specialist. [Pediatr Ann. 2022;51(12):e480-e484.].

Serum immunoglobulin levels, complement components 3 and 4, HLA-B27 allele and spondyloarthropathy in patients with non-infectious anterior uveites

OBJECTIVE

To identify the relationship between serum immunoglobulin levels, complement components 3 and 4, the presence of the HLA-B27 allele and diagnosis of spondyloarthropathies in patients with non-infectious anterior uveitis.

MATERIALS AND METHODS

The participants were 197 patients with a non-infectious anterior uveitis. The concentrations of serum immunoglobulins, C3 and C4 proteins of the complement were determined by turbidimetry. The personal history of suspected immunodeficiency, ophthalmological complications, arthralgia, family history of spondyloarthropathies and the presence of the HLA-B27 allele were collected.

RESULTS

A family history of spondyloarthropathy, axial arthralgias, and ophthalmological complications were more frequent in HLA-B27 positive patients (P=.0005, P≤.0001, P≤.0001 respectively) and in patients with spondyloarthropathy diagnoses (P≤.0001, P≤.0001, P≤.0001 respectively). A personal history of recurrent sepsis, and gastrointestinal abnormalities was associated with the presence of the HLA-B27 allele (P≤.0001, P=.0240 respectively) and with the diagnosis of spondyloarthropathy (P=.0492, P=.0017 respectively). IgG decrease was observed (χ²=18.5, OR=5.03, 95% CI=2.32-10.89, P=.0001) and M (OR=7.13, 95% CI=1.40-36.4; P=.0128) in patients positive for the HLA-B27 allele and in patients with a diagnosis of SpA (P=.0364 and P=.0028 respectively). The decrease of C3 proteins (OR=4.82; CI 95%=1.35-17.11; P=.0328) and C4 (OR=9.09; CI 95%=2.13-38.88; P=.0074) were associated with a spondyloarthropathies diagnosis.

CONCLUSIONS

Patients with non-infectious anterior uveitis, positive for the HLA-B27 allele and diagnosed with spondyloarthropathies have alterations in serum immunoglobulin levels and complement components 3 and 4, which could contribute to the perpetuation and worse clinical course of this disease.

Cow's milk allergy non-responsive to amino acid-based formula? A successful transplanted patient with immune dysregulation, polyendocrinopathy, enteropathy, and X-linked syndrome

The wide variety of IPEX symptoms leads to diagnosis and treatment delay with fatal outcomes if left untreated before two first years of life. Cow's milk allergy non-responsive to amino acid-based formula must raise suspicion of this syndrome.

Identifying Safety Thresholds for Immunosuppressive Drugs: Applying Insights from Primary Antibody Deficiencies to Mitigate Adverse Events in Secondary Antibody Deficiencies Using Mathematical Modeling of Preclinical and Early Clinical Data

Immunosuppressive drugs can alleviate debilitating symptoms of autoimmune diseases, but, by the same token, excessive immune suppression can result in an increased risk of infection. Despite the dangers of a compromised immune system, clear definitions of what constitutes excessive suppression remain elusive. Here we review the most common infections associated with primary antibody deficiencies (PADs), such as agammaglobulinemia, common variable immunodeficiency (CVID), and IgA deficiency, as well as infections that are associated with drug-induced or secondary antibody immunodeficiencies (SADs). We identify a number of bacterial, viral, and fungal infections (e.g., Listeria monocytogenes, Staphylococcus sp., Salmonella spp., Escherichia coli, influenza, varicella zoster virus, and herpes simplex virus) associated with both PADs and SADs, and suggest that diagnostic criteria for PADs could be used as a first-line measure to identify potentially unsafe levels of immune suppression in SADs. Specifically, we suggest that, based on PAD diagnostic criteria, IgG levels should remain above 2-3 g/L, IgA levels should not fall below 0.07 g/L, and IgM levels should remain above 0.4 g/L to prevent immunosuppressive drugs from inducing mimicking PAD-like effects. We suggest that these criteria could be used in the early stages of drug development, and that pharmacokinetic and pharmacodynamic modeling could help guide patient selection to potentially improve drug safety. We illustrate the proposed approach using atacicept as an example and conclude with a discussion of the applicability of this approach for other drugs that may induce excessive immune suppression.

Acquired low immunoglobulin levels and risk of clinically relevant infection in adult patients with systemic lupus erythematosus: a cohort study

OBJECTIVE

Infection is a leading cause of death in the SLE population. Low immunoglobulin levels might be a potential risk for infection. We aimed to assess whether acquired low levels of any type of immunoglobulin increase the risk of clinically relevant infection in adult patients with SLE.

METHODS

We compared adult SLE patients who had acquired any low immunoglobulin levels (IgA, IgM or IgG) for 2 years with patients with normal or high levels with respect to clinically relevant infection (defined as infections requiring intravenous or oral antibiotics) in a prospective cohort study. Group balance was achieved using propensity score adjustment, matching and inverse probability weighting. Primary analysis was time to event using Cox-regression modelling adjusting for potential confounders. Sensitivity analyses were conducted to examine several exposure and outcome definitions.

RESULTS

Patients with hypogammaglobulinaemia had longer disease duration, more lupus nephritis history, higher proteinuria and more accumulated damage. Low IgA level was associated with increased risk of clinically relevant infection [hazard ratio (HR): 2.24, 95% CI: 1.61, 3.12] while low IgG (HR: 1.15, 95% CI: 0.84, 1.59) or low IgM (HR: 0.95, 95% CI: 0.73, 1.23) was not. Low immunoglobulin recovery in the first year was 2.5% (11), second year 8.2% (36), third year 10.1% (44) and fourth year 18.4% (80), and 60% (263) of acquired hypogammaglobulinaemia recovered over 4 years.

CONCLUSION

The majority of acquired hypogammaglobulinaemia in adult patients with SLE is transient. Only low acquired IgA was associated with increased risk of infection among adult patients with SLE. Whether immunoglobulin replacement provides additional protective effect requires further investigation.

Initial presenting manifestations in 16,486 patients with inborn errors of immunity include infections and noninfectious manifestations

BACKGROUND

Inborn errors of immunity (IEI) are rare diseases, which makes diagnosis a challenge. A better description of the initial presenting manifestations should improve awareness and avoid diagnostic delay. Although increased infection susceptibility is a well-known initial IEI manifestation, less is known about the frequency of other presenting manifestations.

OBJECTIVE

We sought to analyze age-related initial presenting manifestations of IEI including different IEI disease cohorts.

METHODS

We analyzed data on 16,486 patients of the European Society for Immunodeficiencies Registry. Patients with autoinflammatory diseases were excluded because of the limited number registered.

RESULTS

Overall, 68% of patients initially presented with infections only, 9% with immune dysregulation only, and 9% with a combination of both. Syndromic features were the presenting feature in 12%, 4% had laboratory abnormalities only, 1.5% were diagnosed because of family history only, and 0.8% presented with malignancy. Two-third of patients with IEI presented before the age of 6 years, but a quarter of patients developed initial symptoms only as adults. Immune dysregulation was most frequently recognized as an initial IEI manifestation between age 6 and 25 years, with male predominance until age 10 years, shifting to female predominance after age 40 years. Infections were most prevalent as a first manifestation in patients presenting after age 30 years.

CONCLUSIONS

An exclusive focus on infection-centered warning signs would have missed around 25% of patients with IEI who initially present with other manifestations.

Immunological deficiencies: more frequent than they seem to be

OBJECTIVE

A review article was carried out, addressing the clinical and epidemiological characteristics of immune system deficiencies, which are associated with or predispose to recurrent infectious processes, autoimmune diseases, auto inflammatory diseases, or neoplasms, and which are classified as inborn errors of immunity (IEI) and secondary immunodeficiencies (SID). Emphasis was placed on the classification of the main signs and symptoms for each organ and system, which will serve as warning signs, to guide the pediatrician in the investigation of the main IEI. In addition, the main secondary changes in the immune system triggered by infections (with emphasis on COVID-19), drugs, chronic diseases, metabolic and nutritional disorders were identified.

SOURCES OF DATA

This review included articles published in the last five years and that were identified in the MEDLINE platform (PubMed).

SUMMARY OF FINDINGS

The recurrence of infectious processes, associated with the severity of the condition and/or unusual profile of the infectious agent, always related to the age range of symptom onset, are the most important findings for suspected diagnosis.

CONCLUSIONS

Considering this scenario, immunity disorders should be part of the investigation carried out by the general pediatrician, whether they are the innate errors of immunity (primary immunodeficiencies) or secondary immunodeficiencies, so that the diagnosis is attained as early as possible and therapeutic measures are implemented, reducing the morbidity and mortality of these patients.

Failure of immunological competence: when to suspect?

OBJECTIVES

To draw physicians' attention to the different warning signs of diseases of inborn errors of immunity.

DATA SOURCES

A non-systematic review of the literature was carried out in the PubMed, LILACS, and SciELO databases, in addition to consultation of reference textbooks.

SUMMARY OF THE FINDINGS

It is known that the lack of immunological competence observed in patients with inborn errors of immunity diseases causes particularly serious and/or recurrent infections. However, manifestations related to autoimmunity, inflammation, allergies, and malignancy can also occur. Aiming at the early identification of these patients, a list of warning signs for inborn errors of immunity was created, in which the need for intravenous antibiotics or prolonged antibiotics use to control infection, failure to thrive, and positive family history for this group of diseases are considered the most sensitive. Regarding non-infectious manifestations, early onset, difficulty in controlling with the usual treatments, atypical presentations or association with other warning signs are noteworthy, and investigation for inborn errors of immunity in these situations is recommended.

CONCLUSIONS

This article highlights the importance of considering this group of diseases even in the face of patients with non-infectious manifestations. Disclosure of inborn errors of immunity diseases, especially to non-specialists, is essential for early diagnosis and, consequently, for the reduction of these patients' morbidity and mortality.

PI Prob: A risk prediction and clinical guidance system for evaluating patients with recurrent infections

Background

Primary immunodeficiency diseases represent an expanding set of heterogeneous conditions which are difficult to recognize clinically. Diagnostic rates outside of the newborn period have not changed appreciably. This concern underscores a need for novel methods of disease detection.

Objective

We built a Bayesian network to provide real-time risk assessment about primary immunodeficiency and to facilitate prescriptive analytics for initiating the most appropriate diagnostic work up. Our goal is to improve diagnostic rates for primary immunodeficiency and shorten time to diagnosis. We aimed to use readily available health record data and a small training dataset to prove utility in diagnosing patients with relatively rare features.

Methods

We extracted data from the Texas Children’s Hospital electronic health record on a large population of primary immunodeficiency patients (n = 1762) and appropriately-matched set of controls (n = 1698). From the cohorts, clinically relevant prior probabilities were calculated enabling construction of a Bayesian network probabilistic model(PI Prob). Our model was constructed with clinical-immunology domain expertise, trained on a balanced cohort of 100 cases-controls and validated on an unseen balanced cohort of 150 cases-controls. Performance was measured by area under the receiver operator characteristic curve (AUROC). We also compared our network performance to classic machine learning model performance on the same dataset.

Results

PI Prob was accurate in classifying immunodeficiency patients from controls (AUROC = 0.945; p<0.0001) at a risk threshold of ≥6%. Additionally, the model was 89% accurate for categorizing validation cohort members into appropriate International Union of Immunological Societies diagnostic categories. Our network outperformed 3 other machine learning models and provides superior transparency with a prescriptive output element.

Conclusion

Artificial intelligence methods can classify risk for primary immunodeficiency and guide management. PI Prob enables accurate, objective decision making about risk and guides the user towards the appropriate diagnostic evaluation for patients with recurrent infections. Probabilistic models can be trained with small datasets underscoring their utility for rare disease detection given appropriate domain expertise for feature selection and network construction.

Primary Immun Deficiency in Patients with Non-Cystic Fibrosis Bronchiectasis and Its Relationship with Clinical Parameters

OBJECTIVE

Bronchiectasis is characterized by chronic respiratory infection. The role of immunodeficiency in this disease is poorly studied in relation to clinical indices. The primary aim of this study was to determine the frequency of these neglected altered immune status by evaluating immunoglobulins, lymphocyte subsets, complement levels, and neutrophil function, and to assess its relationship with clinical parameters in adult patients with non-cystic fibrosis bronchiectasis (NCFB).

MATERIAL AND METHODS

A total of 74 (30 men and 44 women with a mean age of 47±17 years) adult patients with stable NCFB were enrolled in this study. The bronchiectasis severity index (BSI) and FACED (F:FEV1, A: Age, C: Chronic colonization, E: Extension, D: Dyspnea) scores were assessed. Peripheral blood samples were collected for the detection of total IgG, IgA, IgM, IgE, and IgG subclasses and C3 and C4 levels. The counts of CD3, CD4, CD8, CD19, CD16/56 expressing peripheral blood lymphocytes and neutrophil oxidative function were evaluated.

RESULTS

In the study population, BSI and FACED severity index scores increased with longer duration of the disease (p=0.01 and p=0.040, respectively). Of the 74 patients, 27 (37%) showed humoral aberrations. The number of male patients were higher in this group (p=0.03). High serum total IgE levels were associated with high scores in BSI (moderate-severe group versus mild group, p=0.030). Patients with bronchiectasis demonstrated lower CD3+ T cell count, lower CD4+ T helper cell percentage, and lower CD4+ T cell count (p=0.031, p=0.030, p=0.029, respectively) than healthy subjects. A significant negative correlation was found between the percentage and count of CD16/56+ natural killer (NK) cells and the number of exacerbations within the past year (r=-0.230, p=0.049 and r=-0.264, p=0.023, respectively).

CONCLUSION

Humoral aberrations in adult patients with NCFB were found to be frequent. IgE levels were related to high scores for disease severity indices. Furthermore, patients with low percentage and counts of NK cells had higher rates of exacerbations. These results emphasize the importance of immune function assessment in adult patients with NCFB.

Diagnostic Approach to the Patients with Suspected Primary Immunodeficiency

BACKGROUND AND OBJECTIVE

Primary immunodeficiency diseases (PIDs) are a group of more than 350 disorders affecting distinct components of the innate and adaptive immune systems. In this review, the classic and advanced stepwise approach towards the diagnosis of PIDs are simplified and explained in detail.

RESULTS

Susceptibility to recurrent infections is the main hallmark of almost all PIDs. However, noninfectious complications attributable to immune dysregulation presenting with lymphoproliferative and/or autoimmune disorders are not uncommon. Moreover, PIDs could be associated with misleading presentations including allergic manifestations, enteropathies, and malignancies.

CONCLUSION

Timely diagnosis is the most essential element in improving outcome and reducing the morbidity and mortality in PIDs. This wouldn't be possible unless the physicians keep the diagnosis of PID in mind and be sufficiently aware of the approach to these patients.

PHYSICIAN CHARACTERISTICS THAT INFLUENCE PATIENT PARTICIPATION IN THE TREATMENT OF PRIMARY IMMUNODEFICIENCY

OBJECTIVE

Shared decision making (SDM) is recommended to improve healthcare quality. Physicians who use a rational decision-making style and patient-centric approach are more likely to incorporate SDM into clinical practice. This paper explores how certain physician characteristics such as gender, age, race, experience, and specialty explain patient participation.

METHODS

A multi-group structural equation model tested the relationship between physician decision-making styles, patient-centered care, physician characteristics, and patient participation in clinical treatment decisions. A survey was completed by 330 physicians who treat primary immunodeficiency. Sample group responses were compared between groups across specialty, age, race, experience, or gender.

RESULTS

A patient-centric approach was the main factor that encouraged SDM independent of physician decision-making style with both treatment protocols and product choices. The positive effect of patient-centrism is stronger for immunologists, more experienced physicians, or male physicians. A rational decision-making style increases participation for non-immunologists, older physicians, white physicians, less-experienced physicians and female physicians.

CONCLUSION

A patient-centric approach, rational decision-making and certain physician characteristics help explain patient participation in clinical decisions. Practice Implications Future SDM research and policy initiatives should focus on physician adoption of patient-centric approaches to chronic care diseases and the potential bias associated with physician characteristics and decision-making style.

Serum Immunoglobulin Levels, Complement Components 3 and 4, HLA-B27 Allele and Spondyloarthropathy in Patients with Non-Infectious Anterior Uveites

OBJECTIVE

To identify the relationship between serum immunoglobulin levels, complement components 3 and 4, the presence of the HLA-B27 allele and diagnosis of spondyloarthropathies in patients with non-infectious anterior uveitis.

MATERIALS AND METHODS

The participants were 197 patients with a non-infectious anterior uveitis. The concentrations of serum immunoglobulins, and C3 and C4 proteins of the complement were determined by turbidimetry. The personal history of suspected immunodeficiency, ophthalmological complications, arthralgia, family history of spondyloarthropathies and the presence of the HLA-B27 allele were collected.

RESULTS

A family history of spondyloarthropathy, axial arthralgias, and ophthalmological complications were more frequent in HLA-B27 positive patients (P=.0005, P≤.0001, and P≤.0001, respectively) and in patients with spondyloarthropathy diagnoses (P≤.0001, P≤.0001, and P≤.0001, respectively). A personal history of recurrent sepsis, and gastrointestinal abnormalities was associated with the presence of the HLA-B27 allele (P≤.0001, and P=.0240, respectively) and with the diagnosis of spondyloarthropathy (P=.0492, and P=.0017, respectively). IgG decrease was observed (χ2=18.5, OR 5.03, 95% CI 2.32-10.89; P=.0001) and IgM (OR 7.13, 95% CI 1.40-36.4; P=.0128) in patients positive for the HLA-B27 allele and in patients with a diagnosis of spondyloarthropathies (P=.0364 and P=.0028, respectively). The decrease of C3 proteins (OR 4.82; CI 95% 1.35-17.11; P=.0328) and C4 (OR 9.09; CI 95% 2.13-38.88; P=.0074) were associated with a spondyloarthropathies diagnosis.

CONCLUSIONS

Patients with non-infectious anterior uveitis, positive for the HLA-B27 allele and diagnosed with spondyloarthropathies have alterations in serum immunoglobulin levels and complement components 3 and 4, which could contribute to the perpetuation and worse clinical course of this disease.

Late diagnosis of chronic granulomatous disease

Modern era advancements in medical care, with improved treatment of infections, can result in delayed diagnosis of congenital immunodeficiencies. In this study we present a retrospective cohort of 16 patients diagnosed with Chronic Granulomatous Disease (CGD) at adulthood. Some of the patients had a milder clinical phenotype, but others had a classic phenotype with severe infectious and inflammatory complications reflecting a profoundly impaired neutrophil function. It is therefore of great importance to investigate the individual journey of each patient through different misdiagnoses and the threads which led to the correct diagnosis. Currently the recommended definitive treatment for CGD is hematopoietic stem cell transplantation (HSCT). Although survival of our patients to adulthood might argue against the need for early HSCT during infancy, we claim that the opposite is correct, as most of them grew to be severely ill and diagnosed at a stage when HSCT is debatable with potentially an unfavorable outcome. This cohort stresses the need to increase awareness of this severe congenital immunodeficiency among clinicians of different specialties who might be treating undiagnosed adult patients with CGD.

European Society for Immunodeficiencies (ESID) and European Reference Network on Rare Primary Immunodeficiency, Autoinflammatory and Autoimmune Diseases (ERN RITA) Complement Guideline: Deficiencies, Diagnosis, and Management

This guideline aims to describe the complement system and the functions of the constituent pathways, with particular focus on primary immunodeficiencies (PIDs) and their diagnosis and management. The complement system is a crucial part of the innate immune system, with multiple membrane-bound and soluble components. There are three distinct enzymatic cascade pathways within the complement system, the classical, alternative and lectin pathways, which converge with the cleavage of central C3. Complement deficiencies account for ~5% of PIDs. The clinical consequences of inherited defects in the complement system are protean and include increased susceptibility to infection, autoimmune diseases (e.g., systemic lupus erythematosus), age-related macular degeneration, renal disorders (e.g., atypical hemolytic uremic syndrome) and angioedema. Modern complement analysis allows an in-depth insight into the functional and molecular basis of nearly all complement deficiencies. However, therapeutic options remain relatively limited for the majority of complement deficiencies with the exception of hereditary angioedema and inhibition of an overactivated complement system in regulation defects. Current management strategies for complement disorders associated with infection include education, family testing, vaccinations, antibiotics and emergency planning.

Primary Immunodeficiency in the NICU

Primary immunodeficiency disorders (PIDs) are genetic diseases that lead to increased susceptibility to infection. Hundreds of PIDs have now been described, but a select subset commonly presents in the neonatal period. Neonates, especially premature newborns, have relative immune immaturity that makes it challenging to differentiate PIDs from intrinsic immaturity. Nonetheless, early identification and appropriate management of PIDs are critical, and the neonatal clinician should be familiar with a range of PIDs and their presentations. The neonatal clinician should also be aware of the importance of consulting with an immunologist when a PID is suspected. The role of newborn screening for severe combined immunodeficiency, as well as the initial steps of laboratory evaluation for a PID should be familiar to those caring for neonates. Finally, it is important for providers to be familiar with the initial management steps that can be taken to reduce the risk of infection in affected patients.

Shared decision making: Does a physician's decision-making style affect patient participation in treatment choices for primary immunodeficiency?

Overall health care spending in the United States is equivalent to more than 15% of GDP, yet outcomes rank below the top 25 in most quality categories when compared with other Organization for Economic Cooperation and Development (OECD) countries. The majority of spending is consumed by small patient populations with chronic diseases. Experts believe increased patient-physician shared decision making (SDM) should result in better overall longitudinal care but understanding the physician's role in facilitating SDM is limited. Structural equation modelling was applied to results of a 2016 questionnaire-based survey of 330 US physicians who treat approximately 55% of primary immune deficiency requiring immune globulin therapy; it tested the relationship between slow/rational vs fast/intuitive decision-making styles and SDM as mediated by patient-centric care and moderated by physician's trust in the patient. The results showed a statistically significant relationship between slow/rational decision making and SDM. The results also suggest differences related to age, gender, education, and race but no differences related to trust.

Diagnosis of primary immunodeficiency diseases in the developing world: the need for education and networking with the developed world

PURPOSE OF REVIEW

Even with the evident improvement in knowledge about clinical and molecular aspects and the technology used to diagnose primary immunodeficiency diseases (PIDs), there is still a significant delay in recognition of these diseases in the developing world, specifically in Latin America. In this review, the goal is to outline the challenges that need to overcome for the diagnosis of PIDs and the optimization of resources available based on our experience.

RECENT FINDINGS

We describe the advances achieved in the past decade in Latin America in terms of recognition of PIDs, as well as the need for improvement. We outline the need for continued medical education, the lack of resources for laboratory testing, and how genetic testing through next-generation sequencing (that is becoming a day-to-day tool) can be achieved in the developing world.

SUMMARY

We aim to gather information about the limitations and challenges for the diagnosis of PIDs in a low-resource environment and the opportunities to benefit from the available advanced tools for diagnosis.

The influence of clinical features mimicking primary immunodeficiency diseases (mPID) on children with Langerhans cell histiocytosis (LCH) - Four with mPID among 39 LCH children from one referral center during 18-year period

BACKGROUND

Recurrent or refractory infections can be a warning sign of primary immunodeficiency diseases (PID). Such mimicking PID (mPID) can occur in patients with Langerhans cell histiocytosis (LCH). Because some cases with refractory molluscum contagiosum-like lesions and persistent otorrhea are finally diagnosed with LCH, we wondered whether such mPID can occur in LCH children and affect on their prognosis.

METHODS

We retrospectively reviewed all children with LCH at our institute from 2001 to 2018. A complete medical review of sex, age, symptoms, treatment course, and outcome comparison was performed.

RESULTS

Of 39 enrolled LCH patients, three had persistent otorrhea and one had refractory molluscum contagiosum-like lesions despite aggressive antibiotic therapy. These four cases with mPID had significantly higher rates of multi-system involvement, recurrence and 5-month more lag time, but no risk organ (liver, spleen and bone marrow) involvement compared to those without mPID, although bone and skin were the most involved in both groups. Overall, the lag-time in multi-system was longer than that in single-system involvement (median 2.5 vs. 1.0 months; p = 0.003). The diagnosis-age of risk organ involvement was younger than those without (median 8 vs. 43 months; p = 0.004). There were no significant differences in diagnosis-age, single/multi-system and risk organ involvement between remission and recurrence groups. All were alive excluding four who were lost to follow-up.

CONCLUSIONS

The LCH children with mPID had greater lag time, multi-system involvement, recurrence and more refractory treatment including transplantation despite the ratio of bone and skin lesions equal to those without mPID.

Gene- and Disease-Based Expansion of the Knowledge on Inborn Errors of Immunity

The recent report of the International Union of Immunological Societies (IUIS) has provided the categorized list of 354 inborn errors of immunity. We performed a systematic analysis of genes and diseases from the IUIS report with the use of the OMIM, ORPHANET, and HPO resources. To measure phenotypic similarity we applied the Jaccard/Tanimoto (J/T) coefficient for HPO terms and top-level categories. Low J/T coefficients for HPO terms for OMIM or ORPHANET disease pairs associated with the same genes indicated high pleiotropy of these genes. Gene ORGANizer enrichment analysis demonstrated that gene sets related to HPO top-level categories were most often enriched in immune, lymphatic, and corresponding body systems (for example, genes from the category "Cardiovascular" were enriched in cardiovascular system). We presented available data on frequent and very frequent clinical signs and symptoms in inborn errors of immunity. With the use of DisGeNET, we generated the list of 25 IUIS/OMIM diseases with two or more relatively high score gene-disease associations, found for unrelated genes and/or for clusters of genes coding for interacting proteins. Our study showed the enrichment of gene sets related to several IUIS categories with neoplastic and autoimmune diseases from the GWAS Catalog and reported individual genes with phenotypic overlap between inborn errors of immunity and GWAS diseases/traits. We concluded that genetic background may play a role in phenotypic diversity of inborn errors of immunity.

Primary Immunodeficiency and the Gut

This article presents the most common gastrointestinal, hepatic, and pancreatic manifestations of the primary immunodeficiency diseases, including the appropriate laboratory testing, endoscopic evaluation, and recommendations for further management.

Managing costs in primary immunodeficiency: minimal immunophenotyping and three national references

Our aim was to evaluate the cost-effectiveness of a minimal lymphocyte subset quantification (LSQ) by flow cytometry as the first screening in children with clinically suspected primary immunodeficiency (PID). Two hundred sixty-eight Brazilian patients (0-21 years old) were studied. They were divided by clinical and phenotypical features into those fulfilling criteria for PID (PID phenotype) according to the 2017 International Union of Immunological Societies (IUIS) classification and those not fulfilling these criteria (non-PID phenotype). We evaluated how many patients had values below the 10th percentile for five lymphocyte subsets in peripheral blood, (suggestive of PID) according to reference values for Brazil, Italy and USA. Three lymphocyte subsets (T CD3/CD4, B CD19 and NK CD16/CD56) had p-value < 0.05 and Odds Ratio (OR) indicating a risk at least two times higher for the diagnosis of a PID phenotype. The application of Kappa coefficient (k) on Brazilian vs Italian and Brazilian vs US data sets resulted in k compatible with strong or excellent level of agreement between the three classification systems. The authors conclude that a number of CD3⁺ /CD4⁺ , CD19⁺ and CD16⁺ /CD56⁺ (NK) cells in peripheral blood <10th percentile represented a significant risk for the diagnosis of PID in this cohort. Natural killer (NK) deficiency is quite rare and has a very specific clinical profile. So, the analysis of these cells could be requested only in some cases, saving even more costs. The minimal immunophenotyping, with quantification of T CD4⁺ , CD19⁺ and in some cases CD16⁺ /CD56⁺ cells, may be a useful tool for the first screening of PID, saving costs, especially in developing countries.

Co-appearance of OPV and BCG vaccine-derived complications in two infants with severe combined immunodeficiency

Infants with severe combined immunodeficiency (SCID) are at risk of developing severe life-threatening infections if they are inadvertently given attenuated live vaccines. Concomitant appearance of two live vaccine-associated complications in one person is rarely reported. In this study, we present two SCID infants, who received BCG and oral polio vaccines according to their local immunization schedule early in life, before the diagnosis of immunodeficiency was made. Their clinical presentation, extensive immunological workup, genetic tests, and clinical disease course are presented. Both patients developed localized and disseminated infections originating from the BCG vaccine (BCGitis and BCGiosis, respectively) and in addition suffered from diarrhea and chronic fecal secretion of vaccine-derived poliovirus. Alarmingly, in case 2, the poliovirus was a type 2 vaccine-derived poliovirus in which both neurovirulence attenuation sites reverted to the neurovirulent genotype. These cases highlight the importance of early recognition of SCID by neonatal screening or thorough family anamnesis, and the need to further defer the timing of administration of attenuated live vaccines.

Primary and Secondary Immunodeficiency Diseases in Oncohaematology: Warning Signs, Diagnosis, and Management

Background: Immunodeficiencies (ID), in particular primary immunodeficiencies (PID), are often associated with haematological manifestations, such as peripheral cytopenias or lymphoproliferative syndromes. Early diagnosis and management have significant prognostic implications. Secondary immunodeficiencies (SID) may also be induced by oncohaematological diseases and their treatments. Haematologists and oncologists must therefore be aware of the association between blood disorders and cancer and ID, and be prepared to offer their patients appropriate treatment without delay. Our aim was to define the warning signs of primary and secondary IDs in paediatric and adult patients with oncohaematological manifestations. Methods: A multidisciplinary group of six experts (2 haematologists, 2 immunologists, and 2 paediatricians specializing in ID) conducted a literature review and prepared a document based on agreements reached an in-person meeting. An external group of 44 IDs specialists from all over Spain assessed the document and were consulted regarding their level of agreement. Results: This document identifies the haematological and extra-haematological diseases that should prompt a suspicion of PIDs in adults and children, in both primary care and haematology and oncology departments. Cytopenia and certain lymphoproliferative disorders are key diagnostic pointers. The diagnosis must be based on a detailed clinical history, physical exploration, complete blood count and standard laboratory tests. The immunological and haematological tests included in the diagnostic process will depend on the care level. Patients who are candidates for immunoglobulin replacement therapy must be carefully selected, and treatment should be offered as soon as possible to avoid the development of complications. Finally, this document recommends procedures for monitoring these patients. Conclusions: This document combines scientific evidence with the opinion of a broad panel of experts, and emphasizes the importance of an early diagnosis and treatment to avoid complications. The resulting document is a useful tool for primary care physicians and specialists who see both adult and paediatric patients with oncohaematological diseases.

X-linked agammaglobulinemia (XLA):Phenotype, diagnosis, and therapeutic challenges around the world

Background

X-linked agammaglobulinemia is an inherited immunodeficiency recognized since 1952. In spite of seven decades of experience, there is still a limited understanding of regional differences in presentation and complications. This study was designed by the Primary Immunodeficiencies Committee of the World Allergy Organization to better understand regional needs, challenges and unique patient features.

Methods

A survey instrument was designed by the Primary Immunodeficiencies Committee of the World Allergy Organization to collect both structured and semi-structured data on X-linked agammaglobulinemia. The survey was sent to 54 centers around the world chosen on the basis of World Allergy Organization participation and/or registration in the European Society for Immunodeficiencies. There were 40 centers that responded, comprising 32 countries.

Results

This study reports on 783 patients from 40 centers around the world. Problems with diagnosis are highlighted by the reported delays in diagnosis>24 months in 34% of patients and the lack of genetic studies in 39% of centers Two infections exhibited regional variation. Vaccine-associated paralytic poliomyelitis was seen only in countries with live polio vaccination and two centers reported mycobacteria. High rates of morbidity were reported. Acute and chronic lung diseases accounted for 41% of the deaths. Unusual complications such as inflammatory bowel disease and large granular lymphocyte disease, among others were specifically enumerated, and while individually uncommon, they were collectively seen in 20.3% of patients. These data suggest that a broad range of both inflammatory, infectious, and autoimmune conditions can occur in patients. The breadth of complications and lack of data on management subsequently appeared as a significant challenge reported by centers. Survival above 20 years of age was lowest in Africa (22%) and reached above 70% in Australia, Europe and the Americas. Centers were asked to report their challenges and responses (n = 116) emphasized the difficulties in access to immunoglobulin products (16%) and reflected the ongoing need for education of both patients and referring physicians.

Conclusions

This is the largest study of patients with X-linked agammaglobulinemia and emphasizes the continued morbidity and mortality of XLA despite progress in diagnosis and treatment. It presents a world view of the successes and challenges for patients and physicians alike. A pivotal finding is the need for education of physicians regarding typical symptoms suggesting a possible diagnosis of X-linked agammaglobulinemia and sharing of best practices for the less common complications.

The European Society for Immunodeficiencies (ESID) Registry Working Definitions for the Clinical Diagnosis of Inborn Errors of Immunity

Patient registries are instrumental for clinical research in rare diseases. They help to achieve a sufficient sample size for epidemiological and clinical research and to assess the feasibility of clinical trials. The European Society for Immunodeficiencies (ESID) registry currently comprises information on more than 25,000 patients with inborn errors of immunity (IEI). The prerequisite of a patient to be included into the ESID registry is an IEI either defined by a defect in a gene included in the disease classification of the international union of immunological societies, or verified by applying clinical criteria. Because a relevant number of patients, including those with common variable immunodeficiency (CVID), representing the largest group of patients in the registry, remain without a genetic diagnosis, consensus on classification of these patients is mandatory. Here, we present clinical criteria for a large number of IEI that were designed in expert panels with an external review. They were implemented for novel entries and verification of existing data sets from 2014, yielding a substantial refinement. For instance, 8% of adults and 27% of children with CVID (176 of 1704 patients) were reclassified to 22 different immunodeficiencies, illustrating progress in genetics, but also the previous lack of standardized disease definitions. Importantly, apart from registry purposes, the clinical criteria are also helpful to support treatment decisions in the absence of a genetic diagnosis or in patients with variants of unknown significance.

Primary immunodeficiency diseases in lung disease: warning signs, diagnosis and management

Background

Pulmonary complications are common in primary immunodeficiency diseases (PID) and contribute to morbidity and mortality in these patients. However, their varied presentation and a general lack of awareness of PID in this setting make early diagnosis and treatment difficult. The aim of this study was to define the warning signs of PID in patients with respiratory manifestations, the necessary diagnostic tests, and the therapeutic management of both children and adults.

Methods

A review of the literature was performed, and 43 PID interdisciplinary specialists were consulted.

Results

This document identifies the pulmonary and extrapulmonary manifestations that should prompt a suspicion of PID, the immunological and respiratory tests that should be included in the diagnostic process according to the level of care, recommendations regarding the use of immunoglobulin replacement therapy according to the specific immunodeficiency, and the minimum recommended immunological and pulmonary monitoring in these patients.

Conclusions

This document is the first to combine scientific evidence with the opinion of a broad panel of experts specializing in the treatment of patients with immunodeficiencies. It aims to provide a useful tool for all practitioners who are regularly involved in the management of these patients.

Clinical Manifestation of Hyper IgE Syndrome Including Otitis Media

PURPOSE OF REVIEW

The hyper IgE syndromes (HIES) comprise a group of rare primary immunodeficiency disorders (PIDDs), which are characterized by extremely high serum IgE levels, eczema, recurrent skin and pulmonary infections. Both autosomal dominant (AD) HIES due to STAT3 mutations and autosomal recessive (AR) HIES due to PGM3, SPINK5, DOCK8 and TKY2 mutations have been reported. Here, we aim to summarize and compare the major clinical manifestations of different subtypes of HIES. We will also discuss otitis media, which usually do not get enough attention in HIES. Update and familiarity with these clinical features will help to make a better diagnose, assessment and treatment of HIES.

RECENT FINDINGS

Although hyper serum IgE levels have been identified in PGM3 deficiency and Comel-Netherton syndrome, PGM3 and SPINK5 genes were not included in the list of genetic etiologies of AR-HIES by the Expert Committee of the International Union of Immunological Societies until 2015. The identification of these HIES-causing genes greatly promoted the pathogenic mechanism studies of HIES. Also, in recent years, more clinical manifestations, which were often not of concern in HIES patients, have been shown to be highly related to HIES. For example, a significantly high frequency of vascular and gastrointestinal abnormities has been reported in STAT3-deficient AD-HIES patients. These new findings might help to provide new clues to the functional study of these HIES-related genes. This review summarizes and compares the major clinical manifestations of different subtypes of HIES, and we suggest that the incidence and severity of otitis media should not be underestimated in HIES patients.

Primary Immune Deficiencies in the Adult: A Previously Underrecognized Common Condition

The large majority of classified primary immune deficiency (PID) diseases present in childhood. Yet, most patients with PID are adults, with a large proportion experiencing onset of symptoms beyond their childhood years. Most of these are diagnosed predominantly with antibody defects, but cellular and other disorders are increasingly being identified in older patients as well. Moreover, advances in clinical immunology are allowing pediatric patients, even those with severe disease, to reach adulthood. Because of differences in the physiology and pathophysiology of children and adults, the presentation, diagnosis, and management of a complex chronic disease could differ significantly between these patient populations and therefore require modifications in approach.

An ABC of the Warning Signs of Hereditary Angioedema

Hereditary angioedema (HAE) with C1 inhibitor deficiency is a genetic disorder that clinically manifests with attacks of angioedema in the subcutaneous and submucosal tissues, mainly in the extremities, abdomen, and upper airway. During attacks, vascular permeability is increased due to increased bradykinin (BK). This means that special therapies are needed for attacks that do not respond to traditional antiallergic therapies involving antihistamines, corticosteroids, and epinephrine. The recurring attacks may disable patients and lead to frequent visits to emergency rooms where misdiagnoses are common. HAE attacks may be fatal when upper-airway edema occurs, if proper treatment with a C1 inhibitor concentrate or BK receptor antagonist is not administered or an emergency tracheostomy is not performed. We propose a mnemonic method for the warning signs of HAE for the use as a diagnostic tool, i.e., the so-called "ABC" of the warning signs of HAE. The letters represent the following: A = Angioedema, B = Bradykinin, C = C1 inhibitor, D = Distress factors, E = Epinephrine nonresponsive, F = Family history, and G = Glottis/Gastrointestinal edema. To avoid fatalities, medical staff and patients, including family members, must be aware of HAE. An alphabetical mnemonic method has been developed and we hope it may benefit patients.

Recurrent and Sustained Viral Infections in Primary Immunodeficiencies

Viral infections are commonplace and often innocuous. Nevertheless, within the population of patients with primary immunodeficiencies (PIDDs), viral infections can be the feature that drives a diagnostic evaluation or can be the most significant morbidity for the patient. This review is focused on the viral complications of PIDDs. It will focus on respiratory viruses, the most common type of viral infection in the general population. Children and adults with an increased frequency or severity of respiratory viral infections are often referred for an immunologic evaluation. The classic teaching is to investigate humoral function in people with recurrent sinopulmonary infections, but this is often interpreted to mean recurrent bacterial infections. Recurrent or very severe viral infections may also be a harbinger of a primary immunodeficiency as well. This review will also cover persistent cutaneous viral infections, systemic infections, central nervous system infections, and gastrointestinal infections. In each case, the specific viral infections may drive a diagnostic evaluation that is specific for that type of virus. This review also discusses the management of these infections, which can become problematic in patients with PIDDs.

Immunity Enhancement in Immunocompromised Gastrointestinal Cancer Patients with Allogeneic Umbilical Cord Blood Mononuclear Cell Transfusion

Objectives. In order to enhance the immunity of cancer patients to prevent relapse or to prolong survival time, umbilical cord blood mononuclear cells (UCMCs) were transplanted to cancer patients. Patients and Methods. UCMCs were transfused to 63 immunocompromised gastrointestinal cancer patients with nonmyeloablative (NMA) conditioning regimen. Results. The clinical study showed that the number of both T and B cells increased much more rapidly after transfusion of UCMCs than that of the control group without transplantation (p < 0.01). Proinflammation cytokines IFNγ and TNFα in serum increased to or above the normal range in 80.9% of patients at 12 weeks after UCMC transfusion. However, they recovered to the normal range in 21.7% of patients at the same time point in the control group only. In addition, the clinical investigation also showed that the transfusion of UCMC increased stable disease (SD) and reduced progressive disease (PD) significantly (p < 0.01); however, it did not have significant effects on complete response (CR), partial response (PR), or mortality rates compared with the control group (p > 0.05). Conclusions. UCMCs have powerful repairing effects on damaged cells and tissues and may reconstruct the impaired immunity. Transfusion of UCMCs could reconstruct the immunity of cancer patients with immunosuppression.

Microbial Disease Spectrum Linked to a Novel IL-12Rβ1 N-Terminal Signal Peptide Stop-Gain Homozygous Mutation with Paradoxical Receptor Cell-Surface Expression

Patients with Mendelian Susceptibility to Mycobacterial Diseases (MSMD) exhibit variable vulnerability to infections by mycobacteria and other intramacrophagic bacteria (e.g., Salmonella and Klebsiella) and fungi (e.g., Histoplasma, Candida, Paracoccidioides, Coccidioides, and Cryptococcus). The hallmark of MSMD is the inherited impaired production of interferon gamma (IFN-γ) or the lack of response to it. Mutations in the interleukin (IL)-12 receptor subunit beta 1 (IL12RB1) gene accounts for 38% of cases of MSMD. Most IL12RB1 pathogenic allele mutations, including ten known stop-gain variants, cause IL-12Rβ1 complete deficiency (immunodeficiency-30, IMD30) by knocking out receptor cell-surface expression. IL12RB1 loss-of-function genotypes impair both IL-12 and IL-23 responses. Here, we assess the health effects of a rare, novel IL12RB1 stop-gain homozygous genotype with paradoxical IL-12Rβ1 cell-surface expression. We appraise four MSMD children from three unrelated Brazilian kindreds by clinical consultation, medical records, and genetic and immunologic studies. The clinical spectrum narrowed down to Bacillus Calmette-Guerin (BCG) vaccine-related suppurative adenitis in all patients with one death, and recrudescence in two, histoplasmosis, and recurrence in one patient, extraintestinal salmonellosis in one child, and cutaneous vasculitis in another. In three patients, we established the homozygous Trp7Ter predicted loss-of-function inherited genotype and inferred it from the heterozygote parents of the fourth case. The Trp7Ter mutation maps to the predicted IL-12Rβ1 N-terminal signal peptide sequence. BCG- or phytohemagglutinin-blasts from the three patients have reduced cell-surface expression of IL-12Rβ1 with impaired production of IFN-γ and IL-17A. Screening of 227 unrelated healthy subjects from the same geographic region revealed one heterozygous genotype (allele frequency 0.0022) vs. one in over 841,883 public genome/exomes. We also show that the carriers bear European ancestry-informative alleles and share the extended CACCAGTCCGG IL12RB1 haplotype that occurs worldwide with a frequency of 8.4%. We conclude that the novel IL12RB1 N-terminal signal peptide stop-gain loss-of-function homozygous genotype confers IL-12Rβ1 deficiency with varying severity and early-onset age through diminished cell-surface expression of an impaired IL-12Rβ1 polypeptide. We firmly recommend attending to warning signs of IMD30 in children who are HIV-1 negative with a history of adverse effects to the BCG vaccine and presenting with recurrent Histoplasma spp. and extraintestinal Salmonella spp. infections.

Exome sequencing identifies a novel TTC37 mutation in the first reported case of Trichohepatoenteric syndrome (THE-S) in South Africa

Background

Trichohepatoenteric syndrome (THE-S) or phenotypic diarrhoea of infancy is a rare autosomal recessive disorder characterised by severe infantile diarrhoea, facial dysmorphism, immunodeficiency and woolly hair. It was first described in 1982 in two infants with intractable diarrhoea, liver cirrhosis and abnormal hair structure on microscopy. We report on two siblings from a consanguineous family of Somali descent who, despite extensive clinical investigation, remained undiagnosed until their demise. The index patient died of fulminant cytomegalovirus pneumonitis at 3 months of age.

Methods

Whole exome sequencing (WES) was performed on a premortem DNA sample from the index case. Variants in a homozygous recessive state or compound heterozygous state were prioritized as potential candidate variants using TAPER™. Sanger sequencing was done to genotype the parents, unaffected sibling and a deceased sibling for the variant of interest.

Results

Exome sequencing identified a novel homozygous mutation (c.4507C > T, rs200067423) in TTC37 which was confirmed by Sanger sequencing in the index case. The identification of this mutation led to the diagnosis of THE-S in the proband and the same homozygous variant was confirmed in a male sibling who died 4 years earlier with severe chronic diarrhoea of infancy. The unaffected parents and sister were heterozygous for the identified variant.

Conclusions

WES permitted definitive genetic diagnosis despite an atypical presentation in the index case and suggests that severe infection, likely secondary to immunodeficiency, may be a presenting feature. In addition definitive molecular diagnosis allows for genetic counseling and future prenatal diagnosis, and demonstrates the value of WES for post-mortem diagnosis of disorders with a non-specific clinical presentation in which a Mendelian cause is suspected.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-017-0388-5) contains supplementary material, which is available to authorized users.

Immunoglobulin G Subclass Deficiencies in Adult Patients with Chronic Airway Diseases

Immunoglobulin G subclass deficiency (IgGSCD) is a relatively common primary immunodeficiency disease (PI) in adults. The biological significance of IgGSCD in patients with chronic airway diseases is controversial. We conducted a retrospective study to characterize the clinical features of IgGSCD in this population. This study examined the medical charts from 59 adult patients with IgGSCD who had bronchial asthma or chronic obstructive pulmonary disease (COPD) from January 2007 to December 2012. Subjects were classified according to the 10 warning signs developed by the Jeffrey Modell Foundation (JMF) and divided into two patient groups: group I (n = 17) met ≥ two JMF criteria, whereas group II (n = 42) met none. IgG3 deficiency was the most common subclass deficiency (88.1%), followed by IgG4 (15.3%). The most common infectious complication was pneumonia, followed by recurrent bronchitis, and rhinosinusitis. The numbers of infections, hospitalizations, and exacerbations of asthma or COPD per year were significantly higher in group I than in group II (P < 0.001, P = 0.012, and P < 0.001, respectively). The follow-up mean forced expiratory volume (FEV1) level in group I was significantly lower than it was at baseline despite treatment of asthma or COPD (P = 0.036). In conclusion, IgGSCD is an important PI in the subset of patients with chronic airway diseases who had recurrent upper and lower respiratory infections as they presented with exacerbation-prone phenotypes, decline in lung function, and subsequently poor prognosis.

[Pulmonary manifestations in adult patients with a defect in humoral immunity]

Primary immunodeficiencies (PIDs) are a group of congenital diseases of the immune system, which numbers more than 230 nosological entities associated with lost, decreased, or wrong function of its one or several components. Due to the common misconception that these are extremely rare diseases that occur only in children and lead to their death at an early age, PIDs are frequently ruled out by physicians of related specialties from the range of differential diagnosis. The most common forms of PIDs, such as humoral immunity defects, common variable immune deficiency, X-linked agammaglobulinemia, selective IgA deficiency, etc., are milder than other forms of PID, enabling patients to attain their adult age, and may even manifest in adulthood. Bronchopulmonary involvements are the most common manifestations of the disease in patients with a defect in humoral immunity. Thus, a therapist and a pulmonologist are mostly the first doctors who begin to treat these patients and play a key role in their fate, since only timely diagnosis and initiation of adequate therapy can preserve not only the patient's life, but also its quality, avoiding irreversible complications. Chest computed tomography changes play a large role in diagnosis. These are not specific for PID; however, there are a number of characteristic signs that permit this diagnosis to be presumed.

Primary immunodeficiencies associated with eosinophilia

Background

Eosinophilia is not an uncommon clinical finding. However, diagnosis of its cause can be a dilemma once common culprits, namely infection, allergy and reactive causes are excluded. Primary immunodeficiency disorders (PID) are among known differentials of eosinophilia. However, the list of PIDs typically reported with eosinophilia is small and the literature lacks an inclusive list of PIDs which have been reported with eosinophilia. This motivated us to review the literature for all PIDs which have been described to have elevated eosinophils as this may contribute to an earlier diagnosis of PID and further the understanding of eosinophilia.

Methods

A retrospective PubMed, and Google Scholar search using the terms “eosinophilia” and “every individual PID” as classified by Expert Committee of the International Union of Immunological Societies with the limit of the English language was performed. Results were assessed to capture case(s) which reported eosinophilia in the context of PID conditions. Absolute eosinophil counts (AEC) were retrieved from manuscripts whenever reported.

Results

In addition to the typical PID conditions described with eosinophilia, we document that MHC class II deficiency, CD3γ deficiency, STAT1 deficiency (AD form), Kostmann disease, cyclic neutropenia, TCRα deficiency, Papillon-Lefevre syndrome, CD40 deficiency, CD40L deficiency, anhidrotic ectodermal dysplasia with immune deficiency, ataxia-telangiectasia, common variable immunodeficiency disorders (CVID), Blau syndrome, CARD9 deficiency, neonatal onset multisystem inflammatory disease or chronic infantile neurologic cutaneous and articular syndrome (NOMID/CINCA), chronic granulomatous disease, MALT1 deficiency and Roifman syndrome have been noted to have elevated eosinophils. Severe eosinophilia (>5.0 × 10⁹/L) was reported in Omenn syndrome, Wiskott Aldrich syndrome, ADA deficiency, autoimmune lymphoproliferative syndrome, immunodysregulation polyendocrinopathy enteropathy X-linked, STAT3 deficiency, DOCK8 deficiency, CD40 deficiency, MHC II deficiency, Kostmann disease, Papillon-Lefevre syndrome, and CVID.

Conclusions

This literature review shows that there is an extensive list of PIDs which have been reported with eosinophilia. This list helps clinicians to consider an extended differential diagnoses when tasked with exclusion of PID as a cause for eosinophilia.

Electronic supplementary material

The online version of this article (doi:10.1186/s13223-016-0130-4) contains supplementary material, which is available to authorized users.

Family Physician Perspectives on Primary Immunodeficiency Diseases

Primary immunodeficiency diseases (PIDs) include over 250 diverse disorders. The current study assessed management of PID by family practice physicians. The American Academy of Allergy, Asthma, and Immunology Primary Immunodeficiency Committee and the Immune Deficiency Foundation conducted an incentivized mail survey of family practice physician members of the American Medical Association and the American Osteopathic Association in direct patient care. Responses were compared with subspecialist immunologist responses from a similar survey. Surveys were returned by 528 (of 4500 surveys mailed) family practice physicians, of whom 44% reported following ≥1 patient with PID. Selective immunoglobulin A deficiency (21%) and chronic granulomatous disease (11%) were most common and were followed by significantly more subspecialist immunologists (P < 0.05). Use of intravenously administered immunoglobulin and live viral vaccinations across PID was significantly different (P < 0.05). Few family practice physicians were aware of professional guidelines for diagnosis and management of PID (4 vs. 79% of subspecialist immunologists, P < 0.05). Family practice physicians will likely encounter patients with PID diagnoses during their career. Differences in how family practice physicians and subspecialist immunologists manage patients with PID underscore areas where improved educational and training initiatives may benefit patient care.

Identifying Mutations of the Tetratricopeptide Repeat Domain 37 (TTC37) Gene in Infants With Intractable Diarrhea and a Comparison of Asian and Non-Asian Phenotype and Genotype: A Global Case-report Study of a Well-Defined Syndrome With Immunodeficiency

Syndromic diarrhea/tricho-hepato-enteric syndrome (SD/THE) is a rare, autosomal recessive and severe bowel disorder mainly caused by mutations in the tetratricopeptide repeat domain 37 (TTC37) gene which act as heterotetrameric cofactors to enhance aberrant mRNAs decay. The phenotype and immune profiles of SD/THE overlap those of primary immunodeficiency diseases (PIDs). Neonates with intractable diarrhea underwent immunologic assessments including immunoglobulin levels, lymphocyte subsets, lymphocyte proliferation, superoxide production, and IL-10 signaling function. Candidate genes for PIDs predisposing to inflammatory bowel disease were sequencing in this study. Two neonates, born to nonconsanguineous parents, suffered from intractable diarrhea, recurrent infections, and massive hematemesis from esopharyngeal varices due to liver cirrhosis or accompanying Trichorrhexis nodosa that developed with age and thus guided the diagnosis of SD/THE compatible to TTC37 mutations (homozygous DelK1155H, Fs*2; heterozygous Y1169Ter and InsA1143, Fs*3). Their immunologic evaluation showed normal mitogen-stimulated lymphocyte proliferation, superoxide production, and IL-10 signaling, but low IgG levels, undetectable antibody to hepatitis B surface antigen and decreased antigen-stimulated lymphocyte proliferation. A PubMed search for bi-allelic TTC37 mutations and phenotypes were recorded in 14 Asian and 12 non-Asian cases. They had similar presentations of infantile onset refractory diarrhea, facial dysmorphism, hair anomalies, low IgG, low birth weight, and consanguinity. A higher incidence of heart anomalies (8/14 vs 2/12; P = 0.0344, Chi-square), nonsense mutations (19 in 28 alleles), and hot-spot mutations (W936Ter, 2779-2G>A, and Y1169Ter) were found in the Asian compared with the non-Asian patients. Despite immunoglobulin therapy in 20 of the patients, 4 died from liver cirrhosis and 1 died from sepsis. Patients of all ethnicities with SD/THE with the characteristic triad of T nodosa, hepatic cirrhosis, and intractable enteropathy have low IgG, poor vaccine response and/or decreased antigen-stimulated lymphocyte proliferation. This is now better classified into the subgroup of "well-defined syndromes with immunodeficiency" (the update termed as "combined immunodeficiencies with associated or syndromic features") than "predominantly antibody deficiencies" in the update PIDs classification, and requires optimal interventions.