Clinical immunology review series: an approach to the patient with recurrent infections in childhood

Inborn Errors of Immunity

Inborn errors of immunity occur in 1 in 1000 to 1 in 5000 individuals and are characterized by immune deficiency and immune dysregulation. The primary care provider (PCP) should be familiar with key features of these diagnoses including recurrent and/or severe infections, hyperinflammation, malignancy, and autoimmunity and have a low threshold to refer for evaluation. The PCP can begin a laboratory evaluation before referral by sending a complete blood count (CBC) with differential, antibody levels, vaccine titers, and possibly other tests. Management approaches vary from antibiotic prophylaxis to hematopoietic stem cell transplantation depending on the specific diagnosis.

Inborn Errors of Immunity

Inborn errors of immunity occur in 1 in 1000 to 1 in 5000 individuals and are characterized by immune deficiency and immune dysregulation. The primary care provider (PCP) should be familiar with key features of these diagnoses including recurrent and/or severe infections, hyperinflammation, malignancy, and autoimmunity and have a low threshold to refer for evaluation. The PCP can begin a laboratory evaluation before referral by sending a complete blood count (CBC) with differential, antibody levels, vaccine titers, and possibly other tests. Management approaches vary from antibiotic prophylaxis to hematopoietic stem cell transplantation depending on the specific diagnosis.

Recurrent or unusual infections in children - when to worry about inborn errors of immunity

Recurrent infections are a common presenting feature in paediatrics and, while most times considered part of normal growing up, they are also a classical hallmark of inborn errors of immunity (IEI). We aimed to outline the value of currently used signs for IEI and the influence of the changing epidemiology of infectious diseases due to implementation of new vaccines and the effect of the COVID-19 pandemic on the assessment of children with recurrent infections. Warning signs for IEI have been developed, but the supporting evidence for their effectiveness is limited, and immune dysregulation is more commonly recognised as a feature for IEI, making reliable identification of children who should be screened for IEI on clinical grounds difficult. In addition, the epidemiology of infectious diseases is changing due to restrictions related to Covid-19 as well as immunisations, which may change the threshold to screen children for IEI. Treatments for IEI are evolving and are often more effective and less complicated when started early. Screening for IEI can be initiated by the non-immunologist and should be considered early to ensure optimal treatment outcomes.

AuNP array coated substrate for sensitive and homogeneous SERS-immunoassay detection of human immunoglobulin G

Owing to the high sensitivity, fast responsiveness and high specificity, immunoassays using surface-enhanced Raman scattering (SERS) as the readout signal displayed great potential in disease diagnosis. In this study, we developed a SERS-immunoassay method for the detection of human immunoglobulin G (HIgG). Upon involving well-ordered AuA on a SERSIA substrate, the LSPR effect was further enhanced to generate a strong and uniform Raman signal through the formation of sandwich structure with the addition of target HIgG and SERSIA tag. Optimization of the assay provided a wide linear range (0.1–200 μg mL⁻¹) and low limit of detection (0.1 μg mL⁻¹). In addition, the SERS-immunoassay method displayed excellent specificity and was homogeneous, which guaranteed the practical use of this method in the quantitative detection of HIgG. To validate this assay, human serum was analysed, which demonstrated the potential advantages of SERS-immunoassay technology in clinical diagnostics.

An AuNP array coated substrate was developed for the SERS-immunoassay detection of human immunoglobulin G.

Risk Factors of Inpatients Mortality of Visceral Leishmaniasis, Khartoum State, Sudan

Background:

Visceral leishmaniasis (VL) is one of the common infections in Sudan and can be associated with an increase in morbidity and mortality. The aim of this study was to assess the risk factors associated with mortality and morbidity with VL.

Materials and Methods:

This is a cross-sectional hospital-based study that recruited 150 patients with VL from two centers in Khartoum. Secondary data were extracted from the patient records, and data were analyzed using SPSS version 24.0.

Results:

The study included 2.5% of infants, 39.4% children, and 58% of adults. Male represents 77.3% of the cohort, and total mortality was 16%. Among the death reported 12.5% in infants, 16.7% were children, and 70.8% were in adults. Laboratory parameters significantly associated with mortality in univariate analysis were low white cell count, low platelets, high creatinine, and high liver enzymes. While risk factors such as infant, male, acquired infection from Eastern Sudan or White Nile, weight loss, morbid diseases, and concomitant bacterial infections were also associated with significant mortality in univariate analysis. Importantly, logistic regression analysis revealed significant association with infant (P = 0.02), concomitant bacterial infections (P = 0.003), comorbid disease (P = 0.001), low total blood cell count (P = 0.018), low platelets (P = 0.013), and high aspartate transaminase/alanine aminotransferase (P = 0.013).

Conclusion:

Health education and awareness are needed in terms of prevention and control, especially with high mortality seen in the infant. Treatment of underlying co-morbid diseases and bacterial infections are important to enhance survival. Patients with Leishmania are vulnerable; therefore, regular routine blood tests are an essential part of management to manage complications such as renal, hepatic failure, or severe anemia.

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.

Use of biologic therapies for psoriasis during pregnancy and long-term outcomes of exposed children: A 14-year real-life experience at a tertiary center in Turkey and review of the literature

Data regarding the use of biologic therapies for psoriasis during pregnancy are scarce with even more limited knowledge about the long-term safety of in utero exposure. We retrospectively evaluated nine pregnancies in six women with psoriasis who were exposed to biologic therapies between 2006 and 2019 in our psoriasis clinic, a tertiary referral center in Turkey. Pregnancy outcomes included the delivery of seven healthy babies without any complications, one elective abortion, and one ectopic pregnancy. All exposed children, aged between 14 months and 13 years (median age: 4.0 years), showed normal growth and neuropsychological development without immunodeficiencies, allergies, malignancies or other diseases. Based on up-to-date collective data in the literature and our real-life clinical experience presented here, exposure to biologic therapies during pregnancy for psoriasis does not seem to be associated with adverse pregnancy or neonatal outcomes. Our results are also reassuring with respect to long-term outcomes of exposed children, but need to be confirmed through further large prospective studies. Nevertheless, use of biologic therapies during late pregnancy, particularly during the third trimester, should be reserved for high-need patients with psoriasis and definitely requires a delicate risk/benefit balance on a case-by-case basis.

Neutropenia Is an Underrecognized Finding in Pediatric Primary Immunodeficiency Diseases: An Analysis of the United States Immunodeficiency Network Registry

BACKGROUND

The frequency of neutropenia in pediatric primary immunodeficiency disorders (PIDDs) is unknown and potentially underappreciated. Our study aimed to determine the overall frequency and severity of neutropenia in children diagnosed with a PIDD entered in the United States Immunodeficiency Network (USIDNET) patient registry.

PROCEDURE

Neutropenia data and demographic/clinical information from 1145 patients younger than 21 years of age was obtained from the USIDNET registry.

RESULTS

Neutropenia is more common in PIDD patients entered within the USIDNET registry than previously appreciated. There was a >10% occurrence rate of neutropenia in all broad primary immunodeficiency categories as well as in nearly all individual PIDDs. Neutropenia frequency was greater in African American pediatric PIDD patients than in white or Asian patients. The degree of neutropenia did not associate with mortality in pediatric patients with a PIDD.

CONCLUSION

Although our study did not assess the frequency of PIDD in patients presenting with neutropenia, the possibility of a primary immune disorder should be considered in patients with idiopathic neutropenia.

Efficacy and safety of human intravenous immunoglobulin 5% (Ig VENA) in pediatric patients affected by primary immunodeficiency

Patients affected by primary immunodeficiencies are characterized for high susceptibility for severe infections. Our data demonstrate Kedrion 5% intravenous immunoglobulin G (IVIg) treatment effective and safe as replacement therapy for children and adolescents affected by primary immunodeficiency. The particularities of our study are the selection of a long period of follow-up (71 patient-years of follow-up), and to the best of our knowledge, our study is one of few that assesses the safety and efficacy of intravenous immunoglobulin treatment of primary immunodeficiency specifically in a pediatric population.

Primary Immunodeficiency Disorders Among North Indian Children

OBJECTIVES

To report the distribution pattern of various categories of primary immunodeficiency disorders (PIDs) in children from North India, frequency of warning signs and critical parameters for evaluation.

METHODS

In this retrospective study, 528 children below 18 y of age after clinical assessment and presentation suggestive of PID were further screened by immunophenotyping for immune cell markers by flow cytometry.

RESULTS

A total of 120 (23%) children were diagnosed with PID with median age at diagnosis being 2.5 y in males and 3.5 y in females and an average delay in diagnosis from onset of symptoms being approximately 5 y. Chronic lower respiratory tract infections, gastrointestinal symptoms like persistent diarrhea and failure to thrive were amongst the most common warning signs in these patients. PIDs were classified according to the International Union of Immunological Societies' (IUIS) criteria. The diagnosis of index study subjects included combined humoral and cellular immunodeficiency (29%), phagocytic defects (29%), followed by predominantly antibody deficiency (18%), innate immunity and dysregulation (17%) and other well-defined syndromes (7%). A family history of PID (23%), consanguineous marriage (8%) and previous sibling death (23%) were observed as major clinical predictors/clues for underlying PID. All children received prophylactic antibiotics and/or antifungals in addition to specific therapy for underlying immune deficiency.

CONCLUSIONS

The field of PIDs in India remains largely unexplored and we are faced with various challenges in the diagnosis of PIDs due to lack of awareness as well as absence of equipped immunological laboratory support. The authors propose a methodical step-wise laboratory diagnostic approach that can facilitate early diagnosis and timely intervention of these mis/underdiagnosed disorders.

Skin disorders are prominent features in primary immunodeficiency diseases: A systematic overview of current data

Primary immunodeficiency diseases (PIDs) are characterized by an increased risk of infections, autoimmunity, autoinflammation, malignancy, and allergic disorders. Skin disorders are also common clinical features in PIDs and may be among the presenting manifestations. Recognition of specific PID-associated skin conditions in combination with other clinical features as described in the currently used warning signs could raise suspicion of an underlying PID. We aimed to provide a systematically obtained overview of skin disorders and their prevalence in PIDs. Secondary, the prevalence of Staphylococcus (S.) aureus-associated skin disorders and atopy was reviewed, as these are the most prominent skin features in PIDs. A systematic search was performed in EMBASE, MEDLINE, Web of Science, Cochrane, and Google Scholar (up to May 9, 2018). All original observational and experimental human studies that address the presence of skin disorders in PIDs were selected. We rated study quality using the Institute of Health Economics Quality Appraisal Checklist for Case Series Studies. Sixty-seven articles (5030 patients) were included. Study quality ranged from 18.2% to 88.5%. A broad spectrum of skin disorders was reported in 30 PIDs, mostly in single studies with a low number of included patients. An overview of associated PIDs per skin disorder was generated. Data on S. aureus-associated skin disorders and atopy in PIDs were limited. In conclusion, skin disorders are prominent features in PIDs. Through clustering of PIDs per skin disorder, we provide a support tool to use in clinical practice that should raise awareness of PIDs based on presenting skin manifestations.

The Clinical Utility of Measuring IgG Subclass Immunoglobulins During Immunological Investigation for Suspected Primary Antibody Deficiencies

Measurement of IgG subclass concentrations is a standard laboratory test run as part of a panel to investigate the suspicion of antibody deficiency. The assessment is clinically important when total IgG is within the normal age-specific reference range. The measurement is useful for diagnosis of IgG subclass deficiency, to aid the diagnosis of specific antibody deficiency, as a supporting test for the diagnosis of common variable immunodeficiency, as well as for risk stratification of patients with low IgA. The measurement of IgG subclasses may also help determine a revaccination strategy for patients and support patient management. In certain circumstances, the measurement of IgG subclasses may be used to monitor a patient’s humoral immune system. In this review, we discuss the utility of measuring IgG subclass concentrations.

New insights in the use of immunoglobulins for the management of immune deficiency (PID) patients

Immunoglobulin replacement therapy (IRT) is standard treatment for patients with primary immunodeficiency (PID). Because most of the patients with PID will require long life-time immunoglobulin replacement therapy, the quality of the prescribed products is of utmost importance. The IRT is generally administered either intravenously (abbreviated IVIG), or subcutaneously (abbreviated SCIG). Both routes have been demonstrated to be effective. The preferred route may vary at different times during a given patient's life. Options are therefore not fixed and the choice of route for immunoglobulin therapy will depend on several factors, including patient characteristics, clinical indication, venous access, side effects, rural or remote location, treatment compliance and patient preference. Many years ago, immunoglobulin therapy was associated with side effects which may compromise patient's compliance and quality of life of the patients. Most of the side effects were related to impurities. Recently, major advances in the manufacturing process have been made and new processes, such as the Quality by design (QbD) approach were added into the manufacturing steps to ensure patients tolerability and safety. Due to the improved purity of the immunoglobulin products obtained by these processes, the incidence of side effects is lower, while the ways of administration of Ig therapy and the choice of the regimen has widened to suit patient's preference and needs.

Cancers Related to Immunodeficiencies: Update and Perspectives

The life span of patients with primary and secondary immunodeficiency is increasing due to recent improvements in therapeutic strategies. While the incidence of primary immunodeficiencies (PIDs) is 1:10,000 births, that of secondary immunodeficiencies are more common and are associated with posttransplantation immune dysfunction, with immunosuppressive medication for human immunodeficiency virus or with human T-cell lymphotropic virus infection. After infection, malignancy is the most prevalent cause of death in both children and adults with (PIDs). PIDs more often associated with cancer include common variable immunodeficiency (CVID), Wiskott-Aldrich syndrome, ataxia-telangiectasia, and severe combined immunodeficiency. This suggests that a protective immune response against both infectious non-self-(pathogens) and malignant self-challenges (cancer) exists. The increased incidence of cancer has been attributed to defective elimination of altered or "transformed" cells and/or defective immunity towards cancer cells. The concept of aberrant immune surveillance occurring in PIDs is supported by evidence in mice and from patients undergoing immunosuppression after transplantation. Here, we discuss the importance of PID defects in the development of malignancies and the current limitations associated with molecular pathogenesis of these diseases and emphasize the need for further knowledge of how specific mutations can modulate the immune system to alter immunosurveillance and thereby play a key role in the etiology of malignancies in PID patients.

Mannose binding lectin codon 54 polymorphism and susceptibility to recurrent respiratory tract infections in children: A meta-analysis

BACKGROUND

There have been studies focused on mannose binding lectin (MBL) polymorphism and susceptibility to recurrent respiratory tract infections (RRTI) with inconclusive results. This present study is a meta-analysis of possible MBL and RRTI association in children.

METHODS

A literature search was performed using Medline and PubMed and abstracts were reviewed for relevance. Any study was considered to be eligible for inclusion if it met the following criteria: the MBL gene polymorphism at codon 54 was determined, the outcome was recurrent respiratory tract infection in children and there were at least two comparison groups. The odds ratios(OR) of the genetic MBL polymorphisms were combined and calculated, and the forest plots of the OR value distributions were drawn. Chi-squared testing of heterogeneity was done (p<0.001).

RESULTS

Five eligible studies were included in the study. There has been heterogeneity between the studies (p=0.001). Our results did not show any association between MBL genotypes AA, BB, AB, alleles A and B and RRTI.

CONCLUSIONS

Our meta-analysis of accessible, published data has demonstrated no statistically significant association between MBL2 genotype and recurrent respiratory tract infection in children. Summary of the article's main point Here are discrepancies regarding the importance of MBL polymorphism and its impact on recurrent respiratory tract infections. Our meta analysis did not find statistically significant association between MBL codon 54 polymorphism and recurrent respiratory tract infection in children.

Expanded newborn screening by mass spectrometry: New tests, future perspectives

Tandem mass spectrometry (MS/MS) has become a leading technology used in clinical chemistry and has shown to be particularly sensitive and specific when used in newborn screening (NBS) tests. The success of tandem mass spectrometry is due to important advances in hardware, software and clinical applications during the last 25 years. MS/MS permits a very rapid measurement of many metabolites in different biological specimens by using filter paper spots or directly on biological fluids. Its use in NBS give us the chance to identify possible treatable metabolic disorders even when asymptomatic and the benefits gained by this type of screening is now recognized worldwide. Today the use of MS/MS for second-tier tests and confirmatory testing is promising especially in the early detection of new disorders such as some lysosomal storage disorders, ADA and PNP SCIDs, X-adrenoleucodistrophy (X-ALD), Wilson disease, guanidinoacetate methyltransferase deficiency (GAMT), and Duchenne muscular dystrophy. The new challenge for the future will be reducing the false positive rate by using second-tier tests, avoiding false negative results by using new specific biomarkers and introducing new treatable disorders in NBS programs.

Peripheral blood monocyte and T cell subsets in children with specific polysaccharide antibody deficiency (SPAD)

Specific polysaccharide antibody deficiency (SPAD) is a well reported immunodeficiency characterized by a failure to produce antibodies against polyvalent polysaccharide antigens, expressed by encapsulated microorganisms. The clinical presentation of these patients involves recurrent bacterial infections, being the most frequent agent Streptococcus (S.) pneumoniae. In SPAD patients few reports refer to cells other than B cells. Since the immune response to S. pneumoniae and other encapsulated bacteria was historically considered restricted to B cells, the antibody deficiency seemed enough to justify the repetitive infections in SPAD patients. Our purpose is to determine if the B cell defects reported in SPAD patients are accompanied by defects in other leukocyte subpopulations necessary for the development of a proper adaptive immune response against S. pneumoniae. We here report that age related changes observed in healthy children involving increased percentages of classical monocytes (CD14++ CD16- cells) and decreased intermediate monocytes (CD14++ CD16+ cells), are absent in SPAD patients. Alterations can also be observed in T cells, supporting that the immune deficiency in SPAD patients is more complex than what has been described up to now.

Specific antibody deficiency with normal immunoglobulin concentration in children with recurrent respiratory infections

BACKGROUND

Response to polysaccharide antigens is a test to evaluate the immunological competence of children with recurrent respiratory infections (RRI) of unknown cause and no other immune system abnormality. In order to detect specific antibody deficiency (SAD), a group of children with RRI without other immunodeficiency were prospectively studied.

METHODS

We included 20 children (12 male), age range 3-14 years, with six or more annual episodes of respiratory infections (RI); one or more monthly episodes of RI during the winter months; or three or more annual episodes of lower RI. The children were immunised with 23-valent polysaccharide anti-pneumococcal vaccine, and ELISA was used to measure anti-polysaccharide IgG antibody levels for 10 pneumococcal serotypes at baseline (T0), and 45 days (T1) and one year post-immunisation (T2). Post-immunisation response above 1.3 μg/ml for more than 50% of the serotypes was considered normal for children 2-5 years, and for more than 70% of the serotypes in children older than 5 years.

RESULTS

At T1 19/20 children showed a normal response for their age, and only one patient showed a deficient response, suggestive of classic moderate SAD. At T2, 8/20 patients showed deficient responses, suggestive of impaired persistence of specific antibodies. There was a noteworthy association between deficient response and asthma and allergic rhinitis.

CONCLUSIONS

We propose first ruling out local or systemic causes, then performing serum immunoglobulin IgM, IgG, IgA, IgE and IgG subclass levels, and finally measuring response to polysaccharide pneumococcal antigens for detection of SAD.

An ultrasensitive electrochemical immunosensor for the detection of human immunoglobulin G based on Ag@BSA microspheres

Ag@BSA microspheres were applied as electroactive labels for signal amplification and the ultimate immunosensor exhibited an ultralow detection limit.

Retrospective observational study to investigate Sinerga, a multifactorial nutritional product, and bacterial extracts in the prevention of recurrent respiratory infections in children

In this retrospective observational clinical study, 167 children, aged 3 to 7 years, of both sexes, with a clinical history of recurrent respiratory infections, administered with bacterial extracts of first and second generation or Sinerga a nutritional product containing palmitoylethanolamide, bovine colostrum, phenylethylamine and the new generation of probiotic kluyveromyces FM B0399, were observed. The goal of the study was to compare the supplementation with Sinerga with the supplementation with bacterial extracts, for the effect on the frequency of episodes of respiratory infection that had resulted in a prescription for antibiotics. The study focused retrospectively on the months from March 2013 to November 2012. The results showed a greater reduction in the frequency of respiratory infections with antibiotic therapy in the group of children supplemented with Sinerga than in the group treated with bacterial extracts. In particular, it was observed that 49.3% of the children supplemented with Sinerga, against 5% of those supplemented with extracts, had no infectious episodes requiring the administration of an antibiotic. 100% of subjects supplemented with Sinerga have had no more than two episodes of respiratory infection, while this condition, in the cohort treated with bacterial extracts, was observed in only 51% of cases.

Profile of the patients who present to immunology outpatient clinics because of frequent infections

AIM

We aimed to determine the rate of primary immune deficiency (PID) among children presenting to our immunology outpatient clinic with a history of frequent infections and with warning signs of primary immune deficiency.

MATERIAL AND METHODS

The files of 232 children aged between 1 and 18 years with warning signs of primary immune deficiency who were referred to our pediatric immunology outpatient clinic with a complaint of frequent infections were selected and evaluated retrospectively.

RESULTS

Thirty-six percent of the subjects were female (n=84) and 64% were male (n=148). PID was found in 72.4% (n=164). The most common diagnosis was selective IgA deficiency (26.3%, n=61). The most common diseases other than primary immune deficiency included reactive airway disease and/or atopy (34.4%, n=22), adenoid vegetation (12.3%, n=8), chronic disease (6.3%, n=4) and periodic fever, aphtous stomatitis and adenopathy (4.6%, n=3). The majortiy of the subjects (90.5%, n=210) presented with a complaint of recurrent upper respiratory tract infection. PID was found in all subjects who had bronchiectasis. The rates of the diagnoses of variable immune deficiency and Bruton agammaglubulinemia (XLA) were found to be significantly higher in the subjects who had lower respiratory tract infection, who were hospitalized because of infection and who had a history of severe infection compared to the subjects who did not have these properties (p<0.05 and p<0.01, respectively). Growth and developmental failure was found with a significantly higher rate in the patients who had a diagnosis of severe combined immune deficiency or hyper IgM compared to the other subjects (p<0.01). No difference was found in the rates of PID between the age groups, but the diagnosis of XLA increased as the age of presentation increased and this was considered an indicator which showed that patients with XLA were being diagnosed in a late period.

CONCLUSIONS

It was found that the rate of diagnosis was considerably high (72.4%), when the subjects who had frequent infections were selected by the warning signs of PID.

Risk factors for adverse prognosis and death in American visceral leishmaniasis: a meta-analysis

BACKGROUND

In the current context of high fatality rates associated with American visceral leishmaniasis (VL), the appropriate use of prognostic factors to identify patients at higher risk of unfavorable outcomes represents a potential tool for clinical practice. This systematic review brings together information reported in studies conducted in Latin America, on the potential predictors of adverse prognosis (continued evolution of the initial clinical conditions of the patient despite the implementation of treatment, independent of the occurrence of death) and death from VL. The limitations of the existing knowledge, the advances achieved and the approaches to be used in future research are presented.

METHODS/PRINCIPAL FINDINGS

The full texts of 14 studies conforming to the inclusion criteria were analyzed and their methodological quality examined by means of a tool developed in the light of current research tools. Information regarding prognostic variables was synthesized using meta-analysis. Variables were grouped according to the strength of evidence considering summary measures, patterns and heterogeneity of effect-sizes, and the results of multivariate analyses. The strongest predictors identified in this review were jaundice, thrombocytopenia, hemorrhage, HIV coinfection, diarrhea, age <5 and age >40-50 years, severe neutropenia, dyspnoea and bacterial infections. Edema and low hemoglobin concentration were also associated with unfavorable outcomes. The main limitation identified was the absence of validation procedures for the few prognostic models developed so far.

CONCLUSIONS/SIGNIFICANCE

Integration of the results from different investigations conducted over the last 10 years enabled the identification of consistent prognostic variables that could be useful in recognizing and handling VL patients at higher risk of unfavorable outcomes. The development of externally validated prognostic models must be prioritized in future investigations.

Non-specific immune stimulation in respiratory tract infections. Separating the wheat from the chaff

Parents of children suffering from recurrent respiratory infections can be persuaded by advertisements to pressure their family physicians and pediatricians for "immune-stimulating enhancements". However, the evidence base behind these immune stimulants is usually lacking. Often there is no peer-reviewed studies available that support claims made by "immune-booster" supplements. In this review, we critically analyze most of the marketed immuno-active drugs (including vitamin preparations, dietary supplements, homeopathic remedies, Ecchinacea, bacterial lysates, and probiotics) and identify the necessity to exclude an immunodeficiency in every child suffering from recurrent respiratory tract infections.

Diagnostic approach to primary immunodeficiency disorders

Primary immunodeficiency disorders (PIDs) are a heterogeneous group of inherited disorders that affect different components of the immune system. There are more than 150 different disorders which have been described till date. Despite major advances in the molecular characterization of PIDs over the last 20 years, many patients remain undiagnosed or are diagnosed too late with severe consequences. Recognizing different clinical manifestations of PID is the first most important step. It should be followed by use of appropriate diagnostic tools from a vast number of investigations available. This review will focus on important presenting features of PID and laboratory approach for diagnosis of suspected cases of PID.

Impact of anti-tumor necrosis factor alpha antibodies administered to pregnant women with inflammatory bowel disease on long-term outcome of exposed children

BACKGROUND

Prenatal exposure to anti-tumor necrosis factor α (TNF-α) antibodies seems to be safe for fetal development. Data on long-term outcome of exposed children are missing. Our aim was to assess long-term postnatal development of children exposed to anti-TNF-α during pregnancy.

METHODS

Consecutive children aged ≥ 12 months exposed to anti-TNFs prenatally for maternal inflammatory bowel disease in 3 centers in the Czech Republic were enrolled. Data on psychomotor development, infections, antibiotics, vaccination, and allergy were retrospectively obtained from mothers, treating pediatricians, and children's vaccination cards. Furthermore, standardized laboratory tests on humoral and cellular immunity were performed.

RESULTS

Twenty-five children exposed to biologicals were included (median age, 34 mo; range, 14-70 mo). All children had normal growth, and all but 1 had normal psychomotor development. Majority (80%) experienced at least 1 infection (mainly respiratory), and 60% of infants received antibiotics, 32% of those within the first year of life. Vaccination was undertaken according to vaccination protocol to 23 infants (92%). Fifteen children also had tuberculosis vaccination without serious complication. Immunological investigation was performed with 17 children (68%). Cellular immunity was normal in all infants, and 7 children had mild decrease in IgA and/or IgG immunoglobulins without clinical significance. All children had a detectable serologic response to vaccination.

CONCLUSIONS

Exposure to anti-TNF-α antibodies seems to be safe for growth and psychomotor development of children, although clinical significance of relatively high frequency of infections and antibiotic use among infants remains questionable because of the lack of a control group. Continuous follow-up of exposed children is absolutely warranted.

Immune deficiencies in children: an overview

Primary immune deficiencies (PIDs) are disorders of the immune system that result in increased susceptibility to infectious disease, autoimmunity and malignancy. They are challenging to paediatricians as they can present anytime from birth to adolescence with a wide variety of signs and symptoms. It is important to diagnose PIDs promptly, especially more severe forms to prevent significant morbidity and mortality. However, significant challenges exist in deciding which children to investigate and when. We aim to give a basic understanding of the human immune system, the different presentations in a child that should alert a paediatrician about the possibility of PID and the possible underlying diagnosis. Additionally, we have developed a framework for a stepwise approach to investigating these children.

Primary Immunodeficiency May Be Misdiagnosed as Cow's Milk Allergy: Seven Cases Referred to a Tertiary Pediatric Hospital

Introduction. The presence of eczema and gastrointestinal manifestations are often observed in cow's milk allergy (CMA) and also in some primary immunodeficiency diseases (PID). Objective. To describe 7 patients referred to a tertiary allergy/immunology Center with a proposed diagnosis of CMA, who were ultimately diagnosed with PID. Methods. This was a retrospective study based on clinical and laboratory data from medical records. Results. Seven patients (6 males) aged between 3 mo and 6 y were referred to our clinic with a proposed diagnosis of CMA. They presented with eczema and/or gastrointestinal symptoms. Five were receiving replacement formula. All patients presented with other clinical features, including severe/recurrent infections unrelated to CMA, and two of them had a positive family history of PID. Laboratory tests showed immune system dysfunctions in all patients. Hyper-IgE and Wiskott-Aldrich syndromes, CD40L deficiency, severe combined immunodeficiency, X-linked agammaglobulinemia, transient hypogammaglobulinemia of infancy, and chronic granulomatous disease were diagnosed in these children. In conclusion, allergic diseases and immunodeficiency are a result of a different spectrum of abnormalities in the immune system and may be misdiagnosed. Educational programs on PID among clinical physicians and pediatricians can reduce the occurrence of this misdiagnosis.

Newborn screening for severe combined immunodeficiency: an opportunity for intervention

Severe combined immunodeficiency (SCID) is a potentially fatal disorder characterized by defective T- and B-lymphocyte function. We describe a 34-week female twin who had developed feeding intolerance, perioral cyanosis, abdominal distension and neutropenia at 1 month of age. Despite several evaluations including an 'inconclusive' newborn screening result for SCID, the presence of profound lymphopenia was unappreciated. Eventually a diagnosis of SCID in association with adenosine deaminase deficiency was made. This case serves to emphasize the importance of newborn screening for SCID in the context of careful evaluation of clinical and laboratory findings that may be overlooked and result in a delay in the diagnosis of a potentially life-threatening condition.

The child with recalcitrant dermatitis: when to worry?

Dermatitis is a frequent cause for referral to the pediatric dermatologist. In this article, a brief overview is given of common childhood dermatoses as well as some rarer dermatoses that may give the clinician cause for concern. Widespread scaling and erythema, described as erythroderma, are a cause of frustration for patients, families, and their physician(s). Both unusual and common skin disorders can present in this fashion. Just as recognizing common dermatoses is important, it is also important to recognize when a dermatitis fails to fit the common pattern and may prompt further investigation.

Recurrent lower respiratory tract infections in children: a practical approach to diagnosis

Many children are affected by recurrent lower respiratory tract infections (LRTIs), but the majority of them do not suffer from serious lung or extrapulmonary disease. The challenge for clinicians is to distinguish the recurrent RTIs with self-limiting or minor problems from those with underlying disease. The aim of this review is to describe a practical approach to children with recurrent LRTIs that limits unnecessary, expensive and time-consuming investigations. The children can be divided into three groups on the basis of their personal and family history and clinical findings: 1) otherwise healthy children who do not need further investigations; 2) those with risk factors for respiratory infections for whom a wait-and-see approach can be recommended; and 3) those in whom further investigations are mandatory. However, regardless of the origin of the recurrent LRTIs, it is important to remember that prevention by means of vaccines against respiratory pathogens (i.e. type b Haemophilus influenzae, pertussis, pneumococcal and influenza vaccines) can play a key role.

Autosomal recessive chronic granulomatous disease presenting with cutaneous dermatoses and ocular infection

Dermatoses such as eczematous dermatitis and cutaneous infection are recognized presentations of primary immunodeficiency (PID). However, atopic dermatitis affects approximately 10% of infants, and cutaneous infections are not uncommon in children, therefore the challenge for the dermatologist is to distinguish the few patients that have PID from the many that do not. We report on a 6-year-old girl who was ultimately diagnosed with autosomal recessive chronic granulomatous disease (AR-CGD) after presenting to various hospitals with dermatitis, scalp plaques recalcitrant to treatment, and recurrent infections over a 3-year period, and describe some aspects of her diagnosis and management. This report highlights the importance of considering rare disorders such as AR-CGD in the differential diagnosis of recurrent or recalcitrant dermatological infections in children.

Patient-centred screening for primary immunodeficiency, a multi-stage diagnostic protocol designed for non-immunologists: 2011 update

Members of the European Society for Immunodeficiencies (ESID) and other colleagues have updated the multi-stage expert-opinion-based diagnostic protocol for non-immunologists incorporating newly defined primary immunodeficiency diseases (PIDs). The protocol presented here aims to increase the awareness of PIDs among doctors working in different fields. Prompt identification of PID is important for prognosis, but this may not be an easy task. The protocol therefore starts from the clinical presentation of the patient. Because PIDs may present at all ages, this protocol is aimed at both adult and paediatric physicians. The multi-stage design allows cost-effective screening for PID of the large number of potential cases in the early phases, with more expensive tests reserved for definitive classification in collaboration with a specialist in the field of immunodeficiency at a later stage.

Lessons learned from phagocytic function studies in a large cohort of patients with recurrent infections

BACKGROUND

There is a paucity of data on the relationship between demographic characteristics, specific clinical manifestations, and neutrophil dysfunction, guiding physicians to decide which clinical signs and symptoms are a code for an underlying phagocytic disorder.

METHODS

The data over a 21-year period of all adult and pediatric patients referred to our Laboratory for Leukocyte Functions with recurrent pyogenic infections were analyzed. Neutrophil function studies included chemotaxis, superoxide production (SOP), bactericidal activity (BA), and specific studies in case of suspected primary phagocytic disorder (PPD).

RESULTS

Neutrophil dysfunction was found in 33.6% of 998 patients; chemotaxis in 16.6%, SOP in 6%, and BA in 24.5%. The younger the patient and the more organ systems involved, the greater the probability of finding phagocytic impairment. Impaired chemotaxis correlated with recurrent aphthous stomatitis, infections associated with elevated IgE, and purulent upper respiratory tract infections. Impaired SOP and BA correlated with deep-seated abscesses, recurrent lymphadenitis, sepsis, and bone and joint and central nervous system infections. PPDs were identified in 5.7%, chronic granulomatous disease in 4.8%, neutrophil glucose-6-phosphate dehydrogenase deficiency in 0.3%, leukocyte adhesion deficiency type 1 in 0.4%, and myeloperoxidase deficiency in 0.2%. Phagocytic evaluation contributed to the diagnosis of hyperimmunoglobulin-E syndrome (n = 21) and Chediak-Higashi syndrome (n = 3).

CONCLUSIONS

PPDs are identified in 5.7% of patients with recurrent pyogenic infections; in the remainder, phagocytic dysfunction may be related to deleterious effects of persistent infection, drug consumption, or disorders not yet established.

Children with frequent infections: a proposal for a stepwise assessment and investigation of the immune system

Although many children develop frequent infections, only a few have an underlying immune disorder. Children with dysfunction of the immune system develop frequent infections and/or recurrent, persistent, severe, and rare infections. The aim of this review is to provide to the clinician a valuable tool for recognizing any 'discords' of the 'immune-system symphonic orchestra'. By following a reverse route, it will be possible to brighten up the dark and winding road of immunodeficiencies and identify the exact point of immune dysfunction. This is fundamental and crucial to perceive etiologic management and subsequently achieve the best for these young patients and their families.

Clinical immunology review series: An approach to the management of pulmonary disease in primary antibody deficiency

The sinopulmonary tract is the major site of infection in patients with primary antibody deficiency syndromes, and structural lung damage arising from repeated sepsis is a major determinant of morbidity and mortality. Patients with common variable immunodeficiency may, in addition, develop inflammatory lung disease, often associated with multi-system granulomatous disease. This review discusses the presentation and management of lung disease in patients with primary antibody deficiency.

Approach to the child with recurrent infections

Children with a history of recurrent, severe, or unusual infections present a diagnostic challenge. It is important to maintain a high index of suspicion for the diagnosis of immunodeficiency, for early diagnosis and treatment can improve outcome. Differentiation between infections caused by common risk factors, or immune dysfunction should be based on a detailed history and physical examination and, if indicated, followed by appropriate laboratory studies. This paper aims at providing guidelines for the evaluation of children with recurrent infections. It provides an overview of the diagnostic approach including important details required from the history, physical examination, and an appropriate choice of screening test to be ordered.

Clinical immunology review series: an approach to the patient with recurrent superficial abscesses

Patients may be referred to the immunology clinic for investigation of recurrent superficial abscess formation. In the majority of adult patients this clinical presentation does not equate with an underlying primary immune deficiency. Nevertheless, recurrent mucocutaneous abscesses can be associated with significant morbidity and long-term complications, including scarring and fistula formation, and may be associated with underlying immune-mediated disease. This review sets out an approach to the patient with recurrent superficial abscesses, focusing on the differential diagnoses, investigation and management of both the common causes and those associated with specific immune deficiency.