Severe SOPH syndrome due to a novel NBAS mutation in a 27-year-old woman-Review of this pleiotropic, autosomal recessive disorder: Mystery solved after two decades

Autosomal recessive SOPH syndrome was first described in the Yakuts population of Asia by Maksimova et al. in 2010. It arises from biallelic pathogenic variants in the NBAS gene and is characterized by severe postnatal growth retardation, senile facial appearance, small hands and feet, optic atrophy with loss of visual acuity and color vision, and normal intelligence (OMIM #614800). The presence of Pelger-Hüet anomaly in this disorder led to its name as an acronym for Short stature, Optic nerve atrophy, and Pelger-Hüet anomaly. Recent publications have further contributed to the characterization of this syndrome through additional phenotype-genotype correlations. We review the clinical features described in these publications and report on a 27-year-old woman with dwarfism with osteolysis and multiple skeletal problems, minor anomalies, immunodeficiency, diabetes mellitus, and multiple secondary medical problems. Her condition was considered an unknown autosomal recessive disorder for many years until exome sequencing provided the diagnosis by revealing a founder disease-causing variant that was compound heterozygous with a novel pathogenic variant in NBAS. Based on the major clinical features of this individual and others reported earlier, a revision of the acronym is warranted to facilitate clinical recognition.

Bronchiectasis in Primary Antibody Deficiencies: A Multidisciplinary Approach

Bronchiectasis, the presence of bronchial wall thickening with airway dilatation, is a particularly challenging complication of primary antibody deficiencies. While susceptibility to infections may be the primary factor leading to the development of bronchiectasis in these patients, the condition may develop in the absence of known infections. Once bronchiectasis is present, the lungs are subject to a progressive cycle involving both infectious and non-infectious factors. If bronchiectasis is not identified or not managed appropriately, the cycle proceeds unchecked and yields advanced and permanent lung damage. Severe symptoms may limit exercise tolerance, require frequent hospitalizations, profoundly impair quality of life (QOL), and lead to early death. This review article focuses on the appropriate identification and management of bronchiectasis in patients with primary antibody deficiencies. The underlying immune deficiency and the bronchiectasis need to be treated from combined immunology and pulmonary perspectives, reflected in this review by experts from both fields. An aggressive multidisciplinary approach may reduce exacerbations and slow the progression of permanent lung damage.

BCG: a vaccine with multiple faces

BCG has been recommended because of its efficacy against disseminated and meningeal tuberculosis. The BCG vaccine has other mechanisms of action besides tuberculosis protection, with immunomodulatory properties that are now being discovered. Reports have shown a significant protective effect against leprosy. Randomized controlled trials suggest that BCG vaccine has beneficial heterologous (nonspecific) effects on mortality in some developing countries. BCG immunotherapy is considered the gold standard adjuvant treatment for non-muscle-invasive bladder cancer. BCG vaccine has also been tested as treatment for diabetes and multiple sclerosis. Erythema of the BCG site is recognized as a clinical clue in Kawasaki disease. BCG administration in the immunodeficient patient is associated with local BCG disease (BCGitis) or disseminated BCG disease (BCGosis) with fatal consequences. BCG administration has been associated with the development of autoimmunity. We present a brief review of the diverse facets of the vaccine, with the discovery of its new modes of action providing new perspectives on this old, multifaceted and controversial vaccine.

Specific Antibody Deficiencies in Clinical Practice

Specific antibody deficiency (SAD) is defined as the inability to mount an antibody response to purified Streptococcus pneumoniae capsular polysaccharide antigens in the presence of normal immunoglobulin concentrations and normal antibody responses to protein antigens. In this review, we discuss the difficulties in using presently available testing methods to adequately define SAD. The fact that there are different forms of SADs to pneumococcal surface polysaccharides is detailed. The diagnostic and therapeutic implications of recognizing that, in addition to SAD, there are other forms of SAD in the response to S. pneumoniae polysaccharides are described in detail. The conclusion of this review is that assessment of immunity and therapeutic actions to deal with SADs need to be based on clinical evidence rather than solely on arbitrarily defined antibody responses.

En acción: para mejorar el acceso a la atención óptima para todos los pacientes con inmunodeficiencias primarias

Las inmunodeficiencias primarias (IDP) constituyen un grupo de más de 300 defectos innatos del sistema inmunitario, tanto en sus componentes hematopoyéticos como en los no hematopoyéticos. Dichos defectos pueden presentarse con un amplio espectro de manifestaciones clínicas, ya sea con infecciones (comunes recurrentes, comunes graves, o raras y graves), inflamación, autoinmunidad, malignidad, o alergia. Anteriormente clasificadas como “enfermedades raras”, las inmunodeficiencias primarias no son tan raras como se pensaba: actualmente se estima que éstas afectan a más de seis millones de personas en el mundo, sin distinciones geográficas, de sexo o edad.

Streptococcus pneumoniae antibody titres in patients with primary antibody deficiency receiving intravenous immunoglobulin (IVIG) compared to subcutaneous immunoglobulin (SCIG)

Intravenous immunoglobulin (IVIG) and subcutaneous immunoglobulin (SCIG) are effective in the treatment of patients with primary antibody deficiency disorders (PAD). The purpose of this study was to evaluate Streptococcus pneumoniae (Spn) antibody titres to 14 serotypes in patients receiving IVIG compared to SCIG and to correlate Spn antibody levels to clinical outcome. The doses of immunoglobulin (Ig)G/kg/month were similar in both IVIG and SCIG groups. In 11 patients treated with IVIG, Spn antibody titres were ≥ 1·3 μg/ml to 99·4 ± 2·1% of the 14 serotypes at peak IVIG but decreased to 66·9 ± 19·8% at trough IVIG. Loss of Spn titres ≥ 1·3 μg/ml was most frequent for Spn serotypes 1, 4, 9V and 23. This correlated with lower Spn antibody titres to these serotypes at peak IVIG compared to the other serotypes. In 13 patients treated with SCIG, Spn antibody titres were protective to 58·2 ± 23·3% of the serotypes 3-5 days after infusion, similar to trough IVIG. Similarly, the Spn serotypes with the least protective percentages were the same as the ones observed in trough IVIG. There were no annualized serious bacterial infections (aSBI) in either group. However, there were significantly decreased annualized other infections (aOI) in the SCIG group compared to the IVIG-treated group, 0·8 ± 0·7 versus 2·2 ± 1·2 infections/patient/year (P = 0·004). Breakthrough aOI did not correlate with protective or higher serum Spn antibody titres.

Practice parameter for the diagnosis and management of primary immunodeficiency

The American Academy of Allergy, Asthma & Immunology (AAAAI) and the American College of Allergy, Asthma & Immunology (ACAAI) have jointly accepted responsibility for establishing the "Practice parameter for the diagnosis and management of primary immunodeficiency." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion.

Guidelines for the use of human immunoglobulin therapy in patients with primary immunodeficiencies in Latin America

Antibodies are an essential component of the adaptative immune response and hold long-term memory of the immunological experiences throughout life. Antibody defects represent approximately half of the well-known primary immunodeficiencies requiring immunoglobulin replacement therapy. In this article, the authors review the current indications and therapeutic protocols in the Latin American environment. Immunoglobulin replacement therapy has been a safe procedure that induces dramatic positive changes in the clinical outcome of patients who carry antibody defects.

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

Purpose

Patients with primary immunodeficiency diseases (PIDD) may present with recurrent infections affecting different organs, organ-specific inflammation/autoimmunity, and also increased cancer risk, particularly hematopoietic malignancies. The diversity of PIDD and the wide age range over which these clinical occurrences become apparent often make the identification of patients difficult for physicians other than immunologists. The aim of this report is to develop a tool for educative programs targeted to specialists and applied by clinical immunologists.

Methods

Considering the data from national surveys and clinical reports of experiences with specific PIDD patients, an evidence-based list of symptoms, signs, and corresponding laboratory tests were elaborated to help physicians other than immunologists look for PIDD.

Results

Tables including main clinical manifestations, restricted immunological evaluation, and possible related diagnosis were organized for general practitioners and 5 specialties. Tables include information on specific warning signs of PIDD for pulmonologists, gastroenterologists, dermatologists, hematologists, and infectious disease specialists.

Conclusions

This report provides clinical immunologists with an instrument they can use to introduce specialists in other areas of medicine to the warning signs of PIDD and increase early diagnosis. Educational programs should be developed attending the needs of each specialty.

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

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

Recurrent respiratory infections, specific antibody deficiencies, and memory B cells

OBJECTIVES

To investigate the immunological phenotypes detected in children with recurrent upper and lower respiratory infections that have normal total immunoglobulin concentrations.

METHODS

A cohort of over 60 children with recurrent respiration infections was evaluated for specific antibody deficiencies (SAD) and for memory B-cell abnormalities. A control group of children without recurrent infections was also evaluated. Evaluation included a detailed history of immunizations with pneumococcal vaccines; determination of IgM, IgG, IgA, and IgE concentrations; measurement of anti-pneumococcal polysaccharide antibody levels by ELISA and expression of CD27, IgD, and IgM on peripheral CD19(+)B cells by flow cytometry to determine the proportions of naive, IgM-memory B cells, and class-switched memory B cells.

RESULTS

Patients were classified as having a SAD to either pure polysaccharides (PPV-SAD) or to conjugate polysaccharides (PCV-SAD) based on the number of polysaccharides to which they developed an adequate antibody response. A normal response to only 2 or fewer of 7 PCV or PPV serotypes was considered as evidence of SAD. Forty-one patients without SAD and 26 with SAD were identified. IgM-memory B cells were low in 3 of 41 patients without SAD; in 3 of 5 PPV-SAD patients; and in 10 of 21 PCV-SAD patients. Class-switched memory B cells were low in 19 of 41 patients without SAD; in all 5 patients with PPV-SAD; and in 11 of 21PCV-SAD patients.

CONCLUSIONS

Patients with recurrent infection with or without SAD may have low IgM- and/or class-switched memory B cells. Ongoing research aims to determine the prognostic implications of these differences in patients with SAD.

Congenital alterations of NEMO glutamic acid 223 result in hypohidrotic ectodermal dysplasia and immunodeficiency with normal serum IgG levels

BACKGROUND

Hypomorphic mutations in the nuclear factor-κB (NF-κB) essential modulator (NEMO) gene result in a variable syndrome of somatic and immunologic abnormalities. Clinically relevant genotype-phenotype associations are essential to understanding this complex disease.

OBJECTIVE

To study 2 unrelated boys with novel NEMO mutations altering codon 223 for similarity in phenotype in consideration of potential genotype-phenotype associations.

METHODS

Clinical and laboratory features, including cell counts, immunoglobulin quantity and quality, natural killer cell cytotoxicity, and Toll-like and tumor necrosis factor receptor signaling, were evaluated. Because both mutations affected NEMO codon 223 and were novel, consideration was given to new potential genotype-phenotype associations.

RESULTS

Both patients were diagnosed as having hypohidrotic ectodermal dysplasia and had severe or recurrent infections. One had recurrent sinopulmonary infections and the other necrotizing soft tissue methicillin-resistant Staphylococcus aureus infection and Streptococcus anginosus subdural empyema with bacteremia. NEMO gene sequence demonstrated a 3-nucleotide deletion (c.667_669delGAG) in one patient and a substitution (667G>A) in the other. These findings predict either the deletion of NEMO glutamic acid 223 or it being replaced with lysine, respectively. Both patients had normal serum IgG levels but poor specific antibodies. Natural killer cell cytotoxicity and Toll-like and tumor necrosis factor receptor signaling were also impaired. Serious bacterial infection did not occur in both patients after immunoglobulin replacement therapy.

CONCLUSIONS

Two different novel mutations affecting NEMO glutamic acid 223 resulted in clinically relevant similar phenotypes, providing further evidence to support genotype-phenotype correlations in this disease. They suggest NEMO residue 223 is required for ectodermal development and immunity and is apparently dispensable for quantitative IgG production but may be required for specific antibody production.

Primary immunodeficiency diseases in Latin America: proceedings of the Second Latin American Society for Immunodeficiencies (LASID) Advisory Board

Early diagnosis and appropriate therapy are essential for the best prognosis and quality of life in patients with primary immunodeficiency diseases (PIDDs). Experts from several Latin American countries have been meeting on a regular basis as part of an ongoing effort to improve the diagnosis and treatment of PIDD in this region. Three programmes are in development that will expand education and training and improve access to testing facilities throughout Latin America. These programmes are: an educational outreach programme (The L-Project); an immunology fellowship programme; and the establishment of a laboratory network to expand access to testing facilities. This report provides the status of these programmes based on the most recent discussions and describes the next steps toward full implementation of these programmes.

Critical issues and needs in management of primary immunodeficiency diseases in Latin America

Experts from six Latin American countries met to discuss critical issues and needs in the diagnosis and management of primary immunodeficiency diseases (PIDD). The diagnosis of PIDD is generally made following referral to an immunology centre located in a major city, but many paediatricians and general practitioners are not sufficiently trained to suspect PIDD in the first place. Access to laboratory testing is generally limited, and only some screening tests are typically covered by government health programmes. Specialised diagnostic tests are generally not reimbursed. Access to treatment varies by country reflecting differences in healthcare systems and reimbursement policies. An online PIDD Registry Programme for Latin America has been available since 2009, which will provide information about PIDD epidemiology in the region. Additional collaboration across countries appears feasible in at least two areas: a laboratory network to facilitate the diagnosis of PIDD, and educational programmes to improve PIDD awareness. In total, these collaborations should make it possible to advance the diagnosis and management of PIDD in Latin America.

Novel mechanism for the generation of human xeno-autoantibodies against the nonhuman sialic acid N-glycolylneuraminic acid

The nonhuman sialic acid N-glycolylneuraminic acid (Neu5Gc) is metabolically incorporated into human tissues from certain mammalian-derived foods, and this occurs in the face of an anti-Neu5Gc “xeno-autoantibody” response. Given evidence that this process contributes to chronic inflammation in some diseases, it is important to understand when and how these antibodies are generated in humans. We show here that human anti-Neu5Gc antibodies appear during infancy and correlate with weaning and exposure to dietary Neu5Gc. However, dietary Neu5Gc alone cannot elicit anti-Neu5Gc antibodies in mice with a humanlike Neu5Gc deficiency. Other postnatally appearing anti-carbohydrate antibodies are likely induced by bacteria expressing these epitopes; however, no microbe is known to synthesize Neu5Gc. Here, we show that trace exogenous Neu5Gc can be incorporated into cell surface lipooligosaccharides (LOS) of nontypeable Haemophilus influenzae (NTHi), a human-specific commensal/pathogen. Indeed, infant anti-Neu5Gc antibodies appear coincident with antibodies against NTHi. Furthermore, NTHi that express Neu5Gc-containing LOS induce anti-Neu5Gc antibodies in Neu5Gc-deficient mice, without added adjuvant. Finally, Neu5Gc from baby food is taken up and expressed by NTHi. As the flora residing in the nasopharynx of infants can be in contact with ingested food, we propose a novel model for how NTHi and dietary Neu5Gc cooperate to generate anti-Neu5Gc antibodies in humans.

Antibody response to pneumococcal capsular polysaccharide vaccine in Down syndrome patients

The majority of children with Down syndrome (DS) tend to have frequent bacterial infections including recurrent respiratory infections. Our objective was to evaluate the production of antibodies to pneumococcal polysaccharide antigens after active immunization in DS subjects. IgG antibodies to pneumococcal serotypes (1, 3, 6B, 9V, and 14) were measured before and 6 weeks after immunization with a 23-valent pneumococcal vaccine (Pneumo23, Pasteur-Merrieux) in 6- to 13-year-old DS children (N = 17) and in aged-matched normal controls (N = 30). An adequate response was defined as a 4-fold increase over baseline or a post-immunization level of specific pneumococcal serotype antibody > or = 1.3 microg/mL. After immunization, all DS children had an increase in post-immunization levels against all serotypes analyzed. A 4-fold or more increase was observed in all DS children concerning serotypes 1 and 14, in 90% of subjects for serotypes 3 and 9V, and in 65% for serotype 6B. Regarding this increase, 8 of the 17 DS children had an adequate response to all serotypes analyzed, 8/17 patients to 4 serotypes and 1/17 to 3 serotypes. However, when we compared post-immunization levels between DS children and controls, we observed lower levels in the former group (P < 0.05) for all serotypes except serotype 3. We conclude that pneumococcal polysaccharide immunization could be beneficial for these DS children.

Ten-year surveillance of pneumococcal infections in Temuco, Chile: implications for vaccination strategies

We monitored Streptococcus pneumoniae serotypes causing invasive infections in patients admitted to one hospital in southern Chile during a 10-year period (1994 to 2004). All specimens isolated from patients with invasive S. pneumoniae infections were serotyped at the CDC in Atlanta, GA. A total of 508 isolates belonged to 58 serotypes. There were 95 infections in patients <2 years old, 33 infections in patients 2 to 4 years old, 61 infections in patients 5 to 14 years old, 66 infections in patients 15 to 44 years old, 134 infections in patients 45 to 64 years old, and 120 infections in patients >or=65 years old. The 10 serotypes isolated with the highest frequency in all groups were, in decreasing order, 1, 3, 14, 5, 19F, 6B, 7F, 12F, 23F, and 6A. The 10 most frequent isolates in children under 2 years of age were 1, 6B, 14, 19F, 5, 23F, 6A, 9V, and 7F. In patients >or=65 years old, the most common serotypes were 3, 7F, 1, 14, 19A, 23F, 19F, 35B, 4, and 5. Penicillin resistance was detected in 14 (2.7%) clinical specimens isolated since 1998, with 13 resistant strains identified since 2001. Vaccine coverage for the 7-valent conjugate vaccine was 42% for children <2 years of age. This study is important for the design of vaccines for this region and to evaluate public health measures to decrease pneumococcal infections.

Primary immunodeficiency diseases in Latin America: the second report of the LAGID registry

This is the second report on the continuing efforts of LAGID to increase the recognition and registration of patients with primary immunodeficiency diseases in 12 Latin American countries: Argentina, Brazil, Chile, Colombia, Costa Rica, Honduras, Mexico, Panama, Paraguay, Peru, Uruguay, and Venezuela. This report reveals that from a total of 3321 patients registered, the most common form of primary immunodeficiency disease was predominantly antibody deficiency (53.2%) with IgA deficiency reported as the most frequent phenotype. This category was followed by 22.6% other well-defined ID syndromes, 9.5% combined T- and B-cell inmunodeficiency, 8.6% phagocytic disorders, 3.3% diseases of immune dysregulation, and 2.8% complement deficiencies. All countries that participated in the first publication in 1998 reported an increase in registered primary immunodeficiency cases, ranging between 10 and 80%. A comparison of the estimated minimal incidence of X-linked agammaglobulinemia, chronic granulomatous disease, and severe combined immunodeficiency between the first report and the present one shows an increase in the reporting of these diseases in all countries. In this report, the estimated minimal incidence of chronic granulomatous disease was between 0.72 and 1.26 cases per 100,000 births in Argentina, Chile, Costa Rica, and Uruguay and the incidence of severe combined immunodeficiency was 1.28 and 3.79 per 100,000 births in Chile and Costa Rica, respectively. However, these diseases are underreported in other participating countries. In addition to a better diagnosis of primary immunodeficiency diseases, more work on improving the registration of patients by each participating country and by countries that have not yet joined LAGID is still needed.

Development of multiple food allergies in children taking tacrolimus after heart and liver transplantation

Angioedema and chronic diarrhea in patients taking immunosuppressants are not always because of side effects and could be a new onset of food allergy. Our aim is to discuss the pathogenesis and treatment of the post-transplant development of food allergies. The first patient was receiving tacrolimus subsequent to heart transplantation and developed angioedema after consumption of dairy products at 12 months after transplantation. He was found to be allergic to multiple foods by both RAST and ImmunoCAP tests. The second patient with argininosuccinic aciduria, post-liver transplant, also received tacrolimus and developed chronic non-mucoid/bloody diarrhea at seven months following transplantation. ImmunoCAP test was positive only for egg white and peanuts. Biopsy showed eosinophilic infiltration of the mucosa from the stomach to the rectum. Elimination diets in both patients resolved the symptoms. These cases suggest a direct relationship between tacrolimus and development of food allergy.

Use of intravenous immunoglobulin in human disease: A review of evidence by members of the Primary Immunodeficiency Committee of the American Academy of Allergy, Asthma and Immunology

Human immunoglobulin prepared for intravenous administration (IGIV) has a number of important uses in the treatment of disease. Some of these are in diseases for which acceptable treatment alternatives do not exist. In this review we have evaluated the evidence underlying a wide variety of IGIV uses and make specific recommendations on the basis of these data. Given the potential risks and inherent scarcity of IGIV, careful consideration of the indications for and administration of IGIV is warranted.

Immunological evaluation of allergic respiratory children with recurrent sinusitis

The objective of this study was to evaluate humoral immunity of allergic respiratory children with chronic/recurrent sinusitis. Twenty-seven allergic respiratory (persistent mild/moderate asthma and persistent allergic rhinitis) children (7-15-year old) with chronic or recurrent sinusitis were evaluated. Patients had symptoms and abnormal computer tomography scan even after two adequate treatments (long-lasting antibiotics, decongestants, and short-term oral corticosteroids). clinical examination, sweat test, total blood cell count, measurement of serum levels of: total and specific IgE, immunoglobulins (G, M, A), IgG subclasses, antibodies to Haemophilus influenza type b (IgG anti-Ps Hib) and pneumococcal serotypes (IgG anti-Ps 1, 3, 5, 6B, 9V, and 14) before and after active immunization (Act-Hib and Pneumo23, Aventis Pasteur SA, Lyon, France), Rubella neutralizing antibody titers and human immunodeficiency virus antibodies. Specific IgE to inhalant allergens higher than class III were observed in 24/27 patients. One patient had IgA plus IgG2 deficiency and other an IgG3 deficiency. Eight and 12 of 27 patients had IgG2 and IgG3 serum levels below 2.5th percentile, respectively. Immunological responses to protein and polysaccharide antigens were normal in all patients. Although our patients have been appropriately treated of their allergic diseases, they persisted with chronic/recurrent sinusitis and 60% of them had a documented osteomeatal complex blockade. In spite of the diagnosis of IgA plus IgG2 deficiency and an isolated IgG3 deficiency, in all patients an adequate response to Ps antigens was observed. Primary and/or secondary humoral immunodeficiency seems not to be the main cause of chronic/recurrent sinusitis in patients with respiratory allergic disease.

Effects of absorption with pneumococcal type 22F polysaccharide on maternal, cord blood, and infant immunoglobulin G antipneumococcal polysaccharide antibodies

The aim of this study was to evaluate the effect of absorption with pneumococcal type 22F polysaccharide on antipneumococcal antibody titers in unimmunized Chilean pregnant women and on antibodies in their offspring at birth and 3, 6, and 12 months of age. Sera from 10 healthy pregnant women and from their offspring at birth and at 3, 6, and 12 months of age were studied. Immunoglobulin G antibodies against serotypes 1, 3, 4, 5, 6B, 9V, 14, 18, 19F, and 23F were measured by a standardized enzyme-linked immunosorbent assay method. All sera were absorbed with polysaccharide C, and aliquots of each serum were absorbed with polysaccharide 22F. Individual results were expressed in mug/ml based on the standard serum pool 89-SF. Absorption with polysaccharide 22F reduced antibody concentrations in all samples and to all 10 serotypes studied. Reduction was highest in maternal sera and in cord blood, but it was also present at 3, 6, and 12 months of age. The percent reduction ranged from 24% for serotype 14 to 50% for serotype 1 in maternal samples and from 20% for serotype 18C to 49% for serotype 4 in cord blood samples. The percentages of transplacental transmission were similar for nonabsorbed and absorbed maternal fetal pairs. Absorption with serotype 22F had a significant impact on antipneumococcal antibody concentrations in unimmunized pregnant women and in their offspring. Our results suggest that absorption with 22F polysaccharide needs to be performed in studies of transplacental transmission of antipneumococcal antibodies.

Influence of patient age on Streptococcus pneumoniae serotypes causing invasive disease

All clinical S. pneumoniae specimens isolated from patients with invasive or sterile-site infections admitted to one regional general hospital in southern Chile were collected during a 5-year period (February 1994 to September 1999). A total of 247 strains belonging to 50 serotypes were isolated in this survey: 69 in patients under 5 years of age, 129 in patients 5 to 64 years old, and 49 from patients 65 years and older. Eight serotypes were identified in all age groups, while all other serotypes were found exclusively in one age group or in patients over 4 years of age. Serotype 3 was never found in patients under 5 years old, and serotype 14 was not found in patients >64 years of age. There was no difference in the serotypes causing infection in each one of the 5 years of the survey. Our results suggest that both bacterial virulence factors and host factors play an important role in the selection of S. pneumoniae serotypes causing invasive infection. Possible host factors include age-related differences in the immune response. Comparative studies with other areas of the world may help to further understanding of our observations in southern Chile.

Up-regulation of CD40 ligand and induction of a Th2 response in children immunized with pneumococcal polysaccharide vaccines

We wished to determine whether pneumococcal polysaccharide antigens induce mRNA expression of CD40 ligand (CD40L) and Th1 or Th2 cytokines in unimmunized individuals in vitro and whether immunization with the 23-valent pneumococcal polysaccharide vaccine induces changes in CD40L and cytokine mRNA expression. Children with recurrent respiratory infections were studied before and 4 to 6 weeks after receiving the pneumococcal vaccine. One patient who failed to respond to the polysaccharide vaccine subsequently received a single dose of the experimental 7-valent pneumococcal conjugate vaccine. Unimmunized healthy adults were included as controls. Quantification of mRNA expression of CD40L, interleukin-4 (IL-4), IL-12p40, and gamma interferon (IFN-gamma) was performed by reverse transcription-PCR and enzyme-linked immunosorbent assay (ELISA)-PCR with resting and stimulated peripheral blood mononuclear cells. Serum immunoglobulin G (IgG) anti pneumococcal antibody levels were measured by ELISA. The results showed a significant increase in the expression of mRNAs for CD40L and IL-4, but not IL-12p40 or IFN-gamma, in stimulated cultures from unimmunized individuals. CD40L and IL-4 mRNA expression was significantly higher in postimmunization than in preimmunization samples stimulated with the individual pneumococcal serotypes. These results suggest that pneumococcal polysaccharide antigens specifically up-regulate CD40L expression and induce a Th2 response in vitro which parallels the increase in IgG antipneumococcal antibody levels in serum.

Antibody deficiency syndromes

Antibodies have a crucial role in protecting against infections, and antibody deficiencies are the commonest primary and secondary immunodeficiencies. Antibody deficiencies may be the only abnormality present in a patient, or they may be present and aggravate the symptoms of various other conditions. Because the presence of an antibody deficiency is difficult to predict from clinical presentation, physicians should perform an evaluation of antibody-mediated immunity, even knowing that, in many cases, the results are normal. When immunizations are included as a part of the evaluation, many patients experience a benefit from enhanced immunity against common pathogens. Some alternative practical approaches to the evaluation of patients with recurrent infections are outlined in Figure 8. Referral to a clinical immunologist can be based on the presence of recurrent infections, a positive family history without prior evaluation by a pediatrician, or abnormal immunologic findings that require an advanced evaluation. In any case, a close collaboration between pediatrician and immunologist likely will result in an accurate diagnosis and better treatment of patients with antibody-deficiency syndromes and their families.

Distribution of primary immunodeficiency diseases diagnosed in a pediatric tertiary hospital

BACKGROUND

Advances in immunologic techniques in recent years have led to increased recognition of primary immunodeficiency disorders, with IgA deficiency the most common phenotype reported by most registries. There have also been reports of increased associated incidence of autoimmunity, allergy, and other diseases.

OBJECTIVES

We wished to determine the percentage of different primary immunodeficiency disorders seen in a pediatric tertiary hospital and to determine the association of primary immunodeficiency disorders with other diseases that are not part of classic immunodeficiency disorders.

METHODS

We performed a retrospective review of the patients referred to our allergy/immunology clinic for immunologic evaluation of recurrent infections during an 8-year period. We also reviewed pathology reports with postmortem diagnosis of immunodeficiencies not identified while patients were alive.

RESULTS

Of the 91 patients with primary immunodeficiency disorders evaluated, the majority had predominantly antibody deficiencies (67%). The most common phenotype was specific antibody deficiency with normal immunoglobulins (23.1%), defined as inability to mount an adequate response to pneumococcal polysaccharides followed by IgG2 subclass deficiency (17.6%). These two phenotypes were diagnosed mostly in the last 2 years of the survey. Associated diseases, found in 40% of patients, were mostly allergic conditions followed by syndromic/chromosomal disorders.

CONCLUSION

The study reveals that specific antibody deficiency with normal immunoglobulins followed by IgG2 subclass deficiency was the most frequently diagnosed primary immunodeficiency disorder in our patient population. It also indicates that immunodeficiency disorders should be considered in patients with other abnormalities like allergic and syndromic/chromosomal disorders that present with recurrent infections.

Increase in granulocyte-macrophage-colony-stimulating factor secretion and the respiratory burst with decreased L-selectin expression in hyper-IgE syndrome patients

BACKGROUND

The hyper-IgE syndrome is a primary immunodeficiency characterized by severe recurrent abscesses, pneumonia with pneumatocele formation, and elevated serum IgE. Eosinophilia, neutrophil chemotactic defects, and marked tissue damage are frequently present in this syndrome.

OBJECTIVE

To study whether functional changes in cytokines, adhesion molecules, and neutrophils might help explain these clinical observations.

METHODS

The following functions were analyzed in patients with the hyper-IgE syndrome and in controls: (1) production of granulocyte-macrophage-colony-stimulating factor by peripheral blood mononuclear cells by ELISA; (2) respiratory burst and reactive oxygen intermediates production by peripheral neutrophils using the luminol-enhanced chemiluminescense technique; and (3) expression of L-selectin on granulocytes and lymphocytes by flow cytometry.

RESULTS

Patients with hyper-IgE syndrome had significantly increased production of granulocyte-macrophage-colony-stimulating factor by resting or stimulated mononuclear cells, increased generation of reactive oxygen intermediates by neutrophils treated with opsonized zymosan, and reduced L-selectin expression on quiescent and activated granulocytes and lymphocytes.

CONCLUSIONS

Our results suggest that an important feature of the hyper-IgE syndrome is the increased production of granulocyte-macrophage-colony-stimulating factor, which may explain the reduced L-selectin expression, decreased chemotaxis, and increased oxygen radical production and tissue damage in this disease.

CD40-CD40 ligand interaction is central to cell-mediated immunity against Toxoplasma gondii: patients with hyper IgM syndrome have a defective type 1 immune response that can be restored by soluble CD40 ligand trimer

Cell-mediated immunity that results in IL-12/IFN-gamma production is essential to control infections by intracellular organisms. Studies in animal models revealed contrasting results in regard to the importance of CD40-CD40 ligand (CD40L) signaling for induction of a type 1 cytokine response against these pathogens. We demonstrate that CD40-CD40L interaction in humans is critical for generation of the IL-12/IFN-gamma immune response against Toxoplasma gondii. Infection of monocytes with T. gondii resulted in up-regulation of CD40. CD40-CD40L signaling was required for optimal T cell production of IFN-gamma in response to T. gondii. Moreover, patients with hyper IgM (HIGM) syndrome exhibited a defect in IFN-gamma secretion in response to the parasite and evidence compatible with impaired in vivo T cell priming after T. gondii infection. Not only was IL-12 production in response to T. gondii dependent on CD40-CD40L signaling, but also, patients with HIGM syndrome exhibited deficient in vitro secretion of this cytokine in response to the parasite. Finally, in vitro incubation with agonistic soluble CD40L trimer enhanced T. gondii-triggered production of IFN-gamma and, through induction of IL-12 secretion, corrected the defect in IFN-gamma production observed in HIGM patients. Our results are likely to explain the susceptibility of patients with HIGM syndrome to infections by opportunistic pathogens.

CD40-CD40 Ligand Interaction Is Central to Cell-Mediated Immunity Against Toxoplasma gondii: Patients with Hyper IgM Syndrome Have a Defective Type 1 Immune Response That Can Be Restored by Soluble CD40 Ligand Trimer

Cell-mediated immunity that results in IL-12/IFN-γ production is essential to control infections by intracellular organisms. Studies in animal models revealed contrasting results in regard to the importance of CD40-CD40 ligand (CD40L) signaling for induction of a type 1 cytokine response against these pathogens. We demonstrate that CD40-CD40L interaction in humans is critical for generation of the IL-12/IFN-γ immune response against Toxoplasma gondii. Infection of monocytes with T. gondii resulted in up-regulation of CD40. CD40-CD40L signaling was required for optimal T cell production of IFN-γ in response to T. gondii. Moreover, patients with hyper IgM (HIGM) syndrome exhibited a defect in IFN-γ secretion in response to the parasite and evidence compatible with impaired in vivo T cell priming after T. gondii infection. Not only was IL-12 production in response to T. gondii dependent on CD40-CD40L signaling, but also, patients with HIGM syndrome exhibited deficient in vitro secretion of this cytokine in response to the parasite. Finally, in vitro incubation with agonistic soluble CD40L trimer enhanced T. gondii-triggered production of IFN-γ and, through induction of IL-12 secretion, corrected the defect in IFN-γ production observed in HIGM patients. Our results are likely to explain the susceptibility of patients with HIGM syndrome to infections by opportunistic pathogens.

Evaluating children with respiratory tract infections: the role of immunization with bacterial polysaccharide vaccine

Antibody deficiency syndromes are an important cause of recurrent infections in children. Today it is possible to perform a complete evaluation of antibody-mediated immunity leading to a definitive diagnosis of either normal or abnormal immunity in most patients. However, the interpretation of the results of IgG subclass determinations and specific antibody responses is still being defined. At this time our recommendation is that patients who meet the criteria for an evaluation of antibody-mediated immunity be referred to subspecialists trained in this evaluation until better criteria for normal have been developed. The possibility that protective amounts of antibodies against pneumococcal serotypes may develop only transiently must be considered in patients with recurrent infections after initial improvement after immunization, especially if IgG2 subclass deficiency is also present. In the future it may be possible to use a faster and more economical approach to evaluate patients with recurrent infections by immunization with pneumococcal vaccine and then measuring IgM, IgG and IgA along with postimmunization specific antipneumococcal antibody titers 4 to 6 weeks later. For this approach to become feasible, further studies comparing the information obtained from the evaluation of pre- and postimmunization antibody concentrations with that obtained from the evaluation of postimmunization concentrations alone are needed.

Transplacental transmission of serotype-specific pneumococcal antibodies in a Brazilian population

The highest incidence of severe pneumococcal infections in children occurs in the first 6 months of life; however, immunization of infants with the existing polysaccharide vaccines is ineffective. We wished to determine the prevalence of immunoglobulin G (IgG) pneumococcal antibodies in unimmunized Brazilian mothers and their transplacental transmission to term and preterm infants. Total IgG, IgG1 and -2 subclass levels, and IgG antibodies against Streptococcus pneumoniae serotypes 1, 3, 6B, 9V, and 14 were determined in 15 pairs of mothers and term newborns (gestational age, >/=37 weeks) and in 18 pairs of mothers and preterm newborns (gestational age, 32 to 36 weeks). Serotype-specific anti-pneumococcal antibodies were detected by a recently standardized enzyme-linked immunosorbent assay calibrated with the 89-SF reference serum. Varying percentages of the mothers had antibody concentrations below arbitrarily defined protective levels: 33% for serotype 1, 67% for serotype 3, 30% for serotype 6B, 52% for serotype 9V, and 22% for serotype 14. In term newborns, IgG1 concentrations were slightly higher than maternal concentrations; in preterm newborns, the concentrations were much lower. Concentrations of IgG2 in term and preterm infants were significantly lower than in the mothers. Transplacental transmission of antibodies to serotypes 3 and 14 was clearly different from that of antibodies to serotypes 1, 6B, and 9V. Concentrations of IgG antibodies against serotypes 3 and 14 were similar to or higher than those of the mothers; against serotypes 1, 6B, and 9V they ranged from 77 to 83% of maternal concentrations in term newborns and also in preterm infants, although transplacental transmission of antibodies was proportionally lower for each specific serotype in preterm than in term infants. These data are relevant for developing strategies to protect infants against pneumococcal infections in the first months of life. Our findings and a review of existing information stress the importance of understanding the relationships among pneumococcal immunization, IgG subclass antibodies to individual serotypes, transplacental transport, half-life, and antibody function and their protective values against infection.

Interleukin 4 and interferon-gamma secretion by antigen and mitogen-stimulated mononuclear cells in the hyper-IgE syndrome: no TH-2 cytokine pattern

BACKGROUND

Enhanced production of TH-2 cytokines plays a key role in increased IgE production in allergic diseases. Reports about the cytokine profile secreted by peripheral blood mononuclear cells of patients with hyper-IgE syndrome, however, are controversial, suggesting alternative causes for increased IgE production in this syndrome.

OBJECTIVE

We wished to determine whether mononuclear cells from patients with hyper-IgE syndrome have a pattern of interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) production characteristic of a predominance of TH-2 cells and whether the cytokine production pattern is constant over time.

METHODS

IL-4 and IFN-gamma secretion by peripheral blood mononuclear cells stimulated with phytohemagglutinin and D. pteronyssinus was measured by ELISA in culture supernatants. Patients with the hyper-IgE syndrome were evaluated 3 times at 4-week intervals and compared with asthmatic patients and normal subjects.

RESULTS

In PHA-stimulated cultures, patients with hyper-IgE syndrome had an IL-4 and IFN-gamma secretion similar to that of controls, while asthmatic patients had increased IL-4 and decreased IFN-gamma production. Cultures stimulated with D. pteronyssinus showed a variable pattern of secretion for both cytokines.

CONCLUSIONS

In allergic diseases, increased serum IgE level is the result of a TH-2 pattern of cytokine production, with high IL-4 and decreased IFN-gamma protein secretion. The increased serum IgE concentration typical of the hyper-IgE syndrome is likely the result of a different immunoregulatory process.

Topical sodium cromoglycate in the treatment of moderate-to-severe atopic dermatitis

BACKGROUND

Unsatisfactory treatment results for severe atopic dermatitis have led to many experimental therapies, including cromolyn sodium in various vehicles at concentrations ranging from 1% to 10%. Results suggest that the vehicle used to deliver the cromolyn is relevant to its effectiveness.

OBJECTIVE

To test the efficacy of low concentrations of cromolyn in a water-soluble vehicle in the treatment of moderate-to-severe atopic dermatitis in a double-blind, placebo-controlled study.

METHODS

Twenty-six pediatric patients who had failed to respond to conventional therapy were randomized into 2 treatment groups: patients in group A used the study drug for 1 month (phase I), then received the placebo for 1 month (phase II); and patients in group B used the placebo for 1 month, then received the study drug for 1 month. The study drug was cromolyn sodium inhalation solution mixed into a water-based emollient cream to a final concentration of 0.21%. Upon enrollment and at each follow-up visit, every patient was given a severity score based on extent and severity of skin involvement.

RESULTS

At enrollment, there were no significant differences between groups A and B in severity scores, age, sex, race, skin test and/or RAST positivity, eosinophil levels, IgE concentrations, or the presence of concomitant rhinitis or asthma. After the first phase of the study treatment, severity scores had decreased significantly for both groups with a significant difference between group A (cromolyn) and group B (placebo). After crossover, both groups had significantly lower severity scores than at entry into the study.

CONCLUSION

Treatment with topical cromolyn in a hydrophilic emollient vehicle has a significant anti-inflammatory effect on moderate-to-severe atopic dermatitis. We have now incorporated this treatment into our clinical practice.

Metabolic and hematologic changes occurring after rapid intravenous infusion of gammaglobulin in patients with antibody deficiency syndromes

OBJECTIVE

We wished to investigate whether increased IgG infusion rates are associated with metabolic and hematologic changes in pediatric patients with antibody deficiency syndromes.

METHODS

We studied 7 patients (2-16 years old) with primary antibody deficiencies who had been on regular IgG replacement treatment, 350-600 mg/kg/dose every 3 weeks with a 3% IVIG preparation, for periods ranging from 6 months to 4 years. Initially, the IgG concentration of IVIG preparations was increased to 6, 9 and 12% in consecutive infusions at a constant IgG infusion rate of 4 mg/kg/min. Subsequently, the infusion rates were increased to 8, 12, and 16 mg/kg/min using the IVIG 12% preparation.

RESULTS

Clinically, all patients tolerated increases in IVIG concentrations while the infusion rate was 4 mg/kg/min. However, 3 patients presented side effects when the infusion rate was increased to 8 and 16 mg/kg/min.

CONCLUSION

We conclude that metabolic and hematologic sides effects occur with rapid infusion of IVIG even in patients who tolerate the increased infusion rate clinically. The advantages of using high infusion rates have to be re-evaluated.

Influence of age on the response to Streptococcus pneumoniae vaccine in patients with recurrent infections and normal immunoglobulin concentrations

BACKGROUND

A deficient antibody response to polysaccharide antigens is determined by measuring the response to the 23-valent pneumococcal polysaccharide vaccine. However, the diagnosis of this specific antibody deficiency is hampered by the lack of sufficient data and standardized testing of the response to pneumococcal polysaccharides.

METHODS

All patients evaluated in our allergy/immunology clinic for recurrent respiratory infections between 1995 and 1997 without immunoglobulin, IgG subclass, or other known primary or secondary immunodeficiency were included in this analysis. IgG antipneumococcal serotypes 1, 3, 4, 6B, 9V, 14, 18C, 19F, and 23F were determined by a modified ELISA protocol. An adequate IgG antibody response to an individual serotype was arbitrarily defined as a postimmunization antibody titer of 1.3 microg/ml or greater or at least four times the baseline value.

RESULTS

A total of 113 patients fulfilling the criteria for inclusion in this analysis were divided into five age groups. The geometric means for preimmunization and postimmunization pneumococcal antibody titers for all serotypes increased with age. For post-immunization antibody concentrations, there was a sharp increase in the specific antibody concentrations in adults in comparison with all pediatric age groups ranging in age from 7 months to 16 years. Similarly, the number of serotypes to which there was an adequate response also increased with age.

CONCLUSION

We conclude that the definition of what constitutes an adequate response to pneumococcal immunization needs further definition. It is clear, however, that age has an important influence on the intensity of the response to most pneumococcal polysaccharides. Correlation studies between antibody concentrations in different IgG subclasses, functional studies, and protection studies against mucosal and invasive pneumococcal infections are in progress, and these should contribute to a refined definition of a normal response. The availability of a standardized method for the measurement of IgG antibodies against relevant pneumococcal serotypes is an important step toward this goal.

Response to a heptavalent conjugate Streptococcus pneumoniae vaccine in children with recurrent infections who are unresponsive to the polysaccharide vaccine

OBJECTIVE

To determine whether children with recurrent respiratory infections who failed to respond to the conventional polysaccharide vaccine would respond to a pneumococcal conjugate vaccine.

METHODS

Children referred to our clinic for recurrent respiratory infections who had no known primary or secondary immunodeficiencies were immunized with a 23-valent pneumococcal polysaccharide vaccine. IgG antibodies to pneumococcal serotypes 1, 3, 4, 6B, 9V, 14, 18C, 19F and 23F were determined by enzyme-linked immunosorbent assay before and 4 to 6 weeks after immunization. An adequate IgG antibody response to an individual serotype was arbitrarily defined as a postimmunization antibody titer > or =1.3 microg/ml or at least 4 times the preimmunization value. Immunization with an experimental CRM197-heptavalent pneumococcal conjugate vaccine was offered to patients without an adequate response to 4 or more vaccine serotypes (nonresponders). Post-conjugate immunization antibody concentrations were measured 4 to 6 weeks later.

RESULTS

In nonresponder patients (n = 17) geometric mean post-conjugate immunization (C) serum antibody concentrations (microg/ml) compared with post-polysaccharide (PS) concentrations were: (serotype, C vs. PS) 4, 1.11 vs. 0.30 (P = 0.000227); 6B, 0.46 vs. 0.20 (P = 0.017267); 9V, 0.82 vs. 0.29 (P = 0.002163); 14, 1.88 vs. 0.27 (P = 0.000615); 18C, 0.98 vs. 0.32 (P = 0.021962); 19F, 1.24 vs. 0.34 (P = 0.002844); and 23F, 0.87 vs. 0.16 (P = 0.000194). In responder patients (n = 67), after 1 dose of the polysaccharide vaccine, geometric mean antibody concentrations were: 4, 1.05; 6B, 0.96; 9V, 1.55; 14, 1.65; 18C, 1.62; 19F, 1.30; and 23F, 1.02.

CONCLUSIONS

Our results show that a pneumococcal conjugate vaccine is capable of inducing an IgG response in patients with recurrent infections who had failed to mount an adequate response to the polysaccharide vaccine. Conjugate vaccines may be of value in the management of children with recurrent pneumococcal respiratory infections.