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Severe combined immunodeficiency (SCID) represents the most lethal form of primary immunodeficiency, with mortality rates of greater than 90% within the first year of life without treatment. Hematopoietic stem cell transplantation and gene therapy are the only curative treatments available, and the best-known prognostic factors for success are age at diagnosis, age at hematopoietic stem cell transplantation, and the comorbidities that develop in between. There are no evidence-based guidelines for standardized clinical care for patients with SCID during the time between diagnosis and definitive treatment, and we aim to generate a consensus management strategy on the supportive care of patients with SCID. First, we gathered available information about SCID diagnostic and therapeutic guidelines, then we developed a document including diagnostic and therapeutic interventions, and finally we submitted the interventions for expert consensus through a modified Delphi technique. Interventions are grouped in 10 topic domains, including 123 "agreed" and 38 "nonagreed" statements. This document intends to standardize supportive clinical care of patients with SCID from diagnosis to definitive treatment, reduce disease burden, and ultimately improve prognosis, particularly in countries where newborn screening for SCID is not universally available and delayed diagnosis is the rule. Our work intends to provide a tool not only for immunologists but also for primary care physicians and other specialists involved in the care of patients with SCID., (Copyright © 2019 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Introduction and Objectives: Vitamin D plays a role in the immune system, however studies regarding this are scarce. This study aimed to evaluate the nutritional status of vitamin D in patients with Common Variable Immunodeficiency (CVID) or Ataxia-Telangiectasia (A-T) and to relate it to body composition, inflammatory and bone metabolism markers., Patients and Methods: This is a cross-sectional and controlled study involving 24 patients of both sexes (59.3% male), aged 8-56 years, with CVID (n=15) or A-T (n=9). The following variables were evaluated: body mass index (BMI), 25-hydroxyvitamin D (25 (OH) D), hepatic profile, parathormone, calcium, phosphorus, alkaline phosphatase, interleukin 6 and high-sensitivity C-reactive protein., Results: The median age was 26.0 years. A deficiency of 25 (OH) D was found in four A-T patients (44%) and two CVID patients (13%). Nine patients with CVI (60%) and six with A-T (66.7%) were overweight and underweight, respectively. There was a negative correlation between vitamin D and fat mass in the CVID group, and vitamin D and BMI in the A-T group. Vitamin D was negatively associated with the percentage of total fat among the patients (β - 0.842, 95% CI: -1.5-0.17, p=0.015), R 2 =0.21, after adjusting for sex and age., Conclusion: Vitamin D deficiency occurred in a quarter of the patients although there was no difference between the patient and the control group; without association with bone and inflammation biomarkers. The percentage of fat and BMI were negatively associated with the concentrations of 25 (OH) D., (Copyright © 2019 SEICAP. Published by Elsevier España, S.L.U. All rights reserved.)

Background: Ataxia-telangiectasia (AT) is a well-known primary immunodeficiency with recurrent sinopulmonary infections and variable abnormalities in both the humoral and cellular immune system. Dysfunctions in immunoglobulin production, reduced number of B cells, and B-cell receptor excision circles copies have been reported. We aimed to understand the immunological mechanisms involving the humoral compartment in AT patients by analysing peripheral blood B cells subsets, B-T lymphocyte cooperation through the expression of CD40 and CD40 ligand (CD40L), and cytokines involved in class-switch recombination production., Methods: We compared the proportion of B-cell subsets, the expression of CD40/CD40L, and the plasma levels of IL-6 and IFN-γ of 18 AT patients and 15 healthy age-sex-matched controls using flow cytometry., Results: We found that some steps in peripheral B cell development were altered in AT with a pronounced reduction of cell-surface CD40 expression. The proportions of transitional and naïve-mature B cells were reduced, whereas CD21-low, natural effector memory, IgM-only memory, and IgG atypical memory B cells were present in a higher proportion., Conclusions: These findings revealed a disturbed B-cell homeostasis with unconventional maturation of B lymphocyte memory cells, which can explain the consequent impairment of humoral immunity., (Copyright © 2018 SEICAP. Published by Elsevier España, S.L.U. All rights reserved.)

X-linked recessive ectodermal dysplasia with immunodeficiency is a rare primary immunodeficiency caused by hypomorphic mutations of the IKBKG gene encoding the nuclear factor κB essential modulator (NEMO) protein. This condition displays enormous allelic, immunological, and clinical heterogeneity, and therapeutic decisions are difficult because NEMO operates in both hematopoietic and nonhematopoietic cells. Hematopoietic stem cell transplantation (HSCT) is potentially life-saving, but the small number of case reports available suggests it has been reserved for only the most severe cases. Here, we report the health status before HSCT, transplantation outcome, and clinical follow-up for a series of 29 patients from unrelated kindreds from 11 countries. Between them, these patients carry 23 different hypomorphic IKBKG mutations. HSCT was performed from HLA-identical related donors (n = 7), HLA-matched unrelated donors (n = 12), HLA-mismatched unrelated donors (n = 8), and HLA-haploidentical related donors (n = 2). Engraftment was documented in 24 patients, and graft-versus-host disease in 13 patients. Up to 7 patients died 0.2 to 12 months after HSCT. The global survival rate after HSCT among NEMO-deficient children was 74% at a median follow-up after HSCT of 57 months (range, 4-108 months). Preexisting mycobacterial infection and colitis were associated with poor HSCT outcome. The underlying mutation does not appear to have any influence, as patients with the same mutation had different outcomes. Transplantation did not appear to cure colitis, possibly as a result of cell-intrinsic disorders of the epithelial barrier. Overall, HSCT can cure most clinical features of patients with a variety of IKBKG mutations.

Introduction: diagnosis of primary immunodeficiency diseases (PID) is still a challenge in many countries in Latin America (LA), especially those that face social and economic problems. The creation of a society was fundamental to combine efforts that resulted in an effective educational program, establishment of a registry and a network to improve diagnosis. Areas covered: The focus of this article is to portray the scenario of PID in LA covering different aspects from different countries. For this, a questionnaire was sent to countries that participate in the Latin American Society for Immunodeficiencies (LASID) registry, with questions related to PID challenges in LA. We realized that today the greatest challenge is the availability of laboratory tests to investigate newly described PIDs. Expert commentary: Despite being faced with many difficulties, the Latin America Society for Immunodeficiencies is supporting clinical immunologists throughout the continent, which has resulted in a greater awareness of these diseases and an increase in the number of diagnosis.

Background: This is a prospective study that assessed pneumococcal antibody levels in PID patients under intravenous immunoglobulin (IVIG) treatment using different brands., Methods: Twenty-one patients receiving regular IVIG every 28 days were invited to participate: 12 with common variable immunodeficiency, six with X-linked agammaglobulinaemia and three with hyper-IgM syndrome. One blood sample was collected from each patient just prior to IVIG administration at a three-month time interval during one year. A questionnaire was filled in with patient's demographic data and history of infections during the study period. Streptococcus pneumoniae antibodies against six serotypes (1, 5, 6B, 9V, 14 and 19F) were assessed by ELISA both in patients' serum (trough levels) and in IVIG samples., Results: Median total IgG trough serum levels were 7.91g/L (range, 4.59-12.20). All patients had antibody levels above 0.35μg/mL to the six serotypes on all four measurements. However, only 28.6% of patients had pneumococcal antibodies for the six analysed serotypes above 1.3μg/mL on all four evaluations during the one-year period. No correlation was found between IgG trough levels and pneumococcal specific antibodies. Eighteen of the 21 patients (85.7%) had infections at some point during the 12-month follow-up, 62/64 (96.9%) clinically classified in respiratory tract infections, four of which were pneumonia., Conclusions: Pneumococcal antibodies are present in a high range of concentrations in sera from PID patients and also in IVIG preparations. Even maintaining a recommended IgG trough level, these patients can be susceptible to these bacteria and that may contribute to recurrent respiratory infections., (Copyright © 2016 SEICAP. Published by Elsevier España, S.L.U. All rights reserved.)

We report on a patient conceived via in vitro fertilization (IVF) with a 22q11.2 deletion due to an unusual unbalanced translocation involving chromosomes 6 and 22 in a karyotype with 45 chromosomes. Cytogenomic studies showed that the patient has a 3.3-Mb deletion of chromosome 22q and a 0.4-Mb deletion of chromosome 6p, which resulted in haploinsufficiency of the genes responsible for the 22q11.2 deletion syndrome and also of the IRF4 gene, a member of the interferon regulatory factor family of transcription factors, which is expressed in the immune system cells. The rearrangement could be due to the manipulation of the embryo or as a sporadic event unrelated to IVF. Translocation involving chromosome 22 in a karyotype with 45 chromosomes is a rare event, with no previous reports involving chromosomes 6p and 22q.

Background: PIDs are a heterogeneous group of genetic illnesses, and delay in their diagnosis is thought to be caused by a lack of awareness among physicians concerning PIDs. The latter is what we aimed to evaluate in Brazil., Methods: Physicians working at general hospitals all over the country were asked to complete a 14-item questionnaire. One of the questions described 25 clinical situations that could be associated with PIDs and a score was created based on percentages of appropriate answers., Results: A total of 4026 physicians participated in the study: 1628 paediatricians (40.4%), 1436 clinicians (35.7%), and 962 surgeons (23.9%). About 67% of the physicians had learned about PIDs in medical school or residency training, 84.6% evaluated patients who frequently took antibiotics, but only 40.3% of them participated in the immunological evaluation of these patients. Seventy-seven percent of the participating physicians were not familiar with the warning signs for PIDs. The mean score of correct answers for the 25 clinical situations was 48.08% (±16.06). Only 18.3% of the paediatricians, 7.4% of the clinicians, and 5.8% of the surgeons answered at least 2/3 of these situations appropriately., Conclusions: There is a lack of medical awareness concerning PIDs, even among paediatricians, who have been targeted with PID educational programmes in recent years in Brazil. An increase in awareness with regard to these disorders within the medical community is an important step towards improving recognition and treatment of PIDs., (Copyright © 2014 SEICAP. Published by Elsevier Espana. All rights reserved.)

Background: Ataxia-telangiectasia (A-T) is a rare and degenerative disease that leads to varying degrees of immunodeficiency, oxidative stress, and malnutrition. Vitamin A and zinc are essential for immune function and antioxidant defence., Objective: To compare levels of retinol, beta carotene, and zinc in patients with ataxia-telangiectasia and healthy controls., Methods: We performed a cross-sectional study with 14 AT patients and 14 healthy controls matched for age and gender. All participants underwent a nutritional and laboratory evaluation comprising concentrations of retinol, beta carotene, serum and erythrocyte zinc, malondialdehyde (MDA), T lymphocyte numbers (CD4(+) and CD8(+)) and immunoglobulin (IgA)., Results: The AT patients showed high rates of malnutrition with reduced lean body mass when compared to the control group. However, the concentrations of MDA, retinol, beta carotene, and serum and erythrocyte zinc in AT patients were similar to those of the control group. The retinol levels presented a negative correlation with MDA and positive correlation with IgA serum level., Conclusions: The AT patients assessed showed no change in nutritional status for vitamin A and zinc; however, they presented severe impairment in overall nutritional status observed and correlation between retinol with MDA and IgA., (Copyright © 2012 SEICAP. Published by Elsevier Espana. All rights reserved.)

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., (Copyright © 2012 SEICAP. Published by Elsevier Espana. All rights reserved.)

Background: Severe combined immunodeficiency (SCID) is one of the most severe forms of primary immunodeficiency. The objectives of this study were to analyze the diagnosis, treatment, and prognosis of SCID in Brazil and to document the impact of BCG vaccine., Methods: We actively searched for cases by contacting all Brazilian referral centers., Results: We contacted 23 centers and 70 patients from 65 families. Patients were born between 1996 and 2011, and 49 (70%) were male. More than half (39) of the diagnoses were made after 2006. Mean age at diagnosis declined from 9.7 to 6.1 months (P = .058) before and after 2000, respectively, and mean delay in diagnosis decreased from 7.9 to 4.2 months (P = .009). Most patients (60/70) were vaccinated with BCG before the diagnosis, 39 of 60 (65%) had complications related to BCG vaccine, and the complication was disseminated in 29 of 39 (74.3%). Less than half of the patients (30, 42.9%) underwent hematopoietic stem cell transplantation (HSCT). Half of the patients died (35, 50%), and 23 of these patients had not undergone HSCT. Disseminated BCG was the cause of death, either alone or in association with other causes, in 9 of 31 cases (29%, no data for 4 cases)., Conclusions: In Brazil, diagnosis of SCID has improved over the last decade, both in terms of the number of cases and age at diagnosis, although a much higher number of cases had been expected. Mortality is higher than in developed countries. Complications of BCG vaccine are an important warning sign for the presence of SCID and account for significant morbidity during disease progression.

The subspecialty of pediatric allergy and immunology in Brazil is in its early years and progressing steadily. This review highlights the research developed in the past years aiming to show the characteristics of allergic and immunologic diseases in this vast country. Epidemiologic studies demonstrated the high prevalence of asthma in infants, children, and adolescents. Mortality rates and average annual variation of asthma hospitalization have reduced in all pediatric age groups. Indoor aeroallergen exposure is excessively high and contributes to the high rates of allergy sensitization. Prevalence of food allergy has increased to epidemic levels. Foods (35%), insect stings (30%), and drugs (23%) are the main etiological agents of anaphylaxis in children and adolescents. Molecular diagnosis of primary immunodeficiencies (PID) showed a high incidence of fungal infections including paracoccidioidomycosis in X-linked hyper-IgM syndrome, and the occurrence of BCG adverse reactions or other mycobacterial infections in patients with chronic granulomatous disease. Education in pediatric allergy and immunology is deficient for medical students, but residency programs are effective in training internists and pediatricians for the practice of allergy. The field of PID requires further training. Last, this review is a tribute to Prof. Dr. Charles Naspitz, one of the pioneers of our specialty in Brazil., (© 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.)

Primary immunodeficiency diseases (PIDD) are associated with significant morbidity and mortality and result in a significant public health burden. This is in part due to the lack of appropriate diagnosis and treatment of these patients. It is critical that governments become aware of this problem and provide necessary resources to reduce this impact on health care systems. Leading physicians in their respective countries must be supported by their own governments in order to implement tools and provide education and thus improve the diagnosis and treatment of PIDD. The Latin American Society of Primary Immunodeficiencies (LASID) has initiated a large number of activities aimed at achieving these goals, including the establishment of a PIDD registry, development of educational programmes and guidelines, and the introduction of a PIDD fellowship programme. These initiatives are positively impacting the identification and appropriate treatment of patients with PIDD in Latin America. Nevertheless, much remains to be done to ensure that every person with PIDD receives proper therapy., (Copyright © 2011 SEICAP. Published by Elsevier Espana. All rights reserved.)

Background: Patients with common variable immunodeficiency (CVID) present with low antibody levels, impaired lymphocyte function, and chronic inflammation. Vitamin A and zinc are essential components of the immune system and can be redistributed in the body as a result of inflammation., Objective: To compare levels of retinol, beta-carotene, and zinc in patients with CVID and healthy controls after evaluating a series of parameters for each participant., Patients and Methods: We performed a cross-sectional study of CVID patients and healthy controls matched for age and gender. All participants underwent a nutritional and laboratory evaluation comprising a complete blood count and determination of levels of C-reactive protein (CRP), lipopolysaccharide (LPS), soluble CD14 (sCD14), retinol, beta-carotene, and serum and erythrocyte zinc., Results: We included 17 patients (mean age, 28.54 years) and 17 controls. Mean (SD) retinol levels were lower in patients: 1.99 (0.67) micromol/L vs 2.72 (0.96) micromol/L. Median beta-carotene levels were similar in both groups (0.30 micromol/L). Median serum zinc levels were 50.0 microg/dL (50-100 microg/dL) in the patients and 100.0 microg/dL (50-150 microg/dL) in the controls. Mean levels of erythrocyte zinc were lower among patients: 37.32 (10.51) microgZn/gHb vs 44.91 (7.67) microgZn/gHb in the controls. Median CRP levels were significantly higher among patients: 4.99 (0.15-34.51) mg/L vs 0.55 (0.17-6.06) mg/L. No differences in translocation marker levels were observed between the groups., Conclusions: CVID patients had lower levels of retinol and zinc than controls. Since micronutrient deficiency could aggravate their disease and contribute to chronic inflammation, micronutrient status should always be assessed in patients with primary immunodeficiency.

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., (Copyright © 2010 SEICAP. Published by Elsevier Espana. All rights reserved.)

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., (Copyright © 2010 SEICAP. Published by Elsevier Espana. All rights reserved.)

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.

Background: Lysozyme is a muramidase that acts on the peptideoglycan wall of Gram positive bacteria, causing cell death. It plays part in innate immunity and is present in blood, external fluid, as well in lysossomal granules of the phagocytes. Primary Immunodeficiencies are a diverse group of illnesses that, as a result of abnormalities of the immune system, increase susceptibility to infection. Among the examples of impaired natural immunity are defects in phagocytes and in the complement system. Innate immunity could be important in protecting mucosas against infections in patients with different forms of primary immunodeficiencies. The aim of this study was to investigate lysozyme concentrations in saliva from patients with primary immunodeficiencies., Methods: Lysozyme levels in saliva samples from 34 patients with primary immunodeficiency (30 children and adolescents between the age of 3-13 years and 4 adults between the age of 20-33) and 60 age-matched healthy controls (49 children and adolescents between the ages of 3-15 and 11 adults between the ages of 22-42) were determined by the lysoplate method., Results: There was no statistically significant difference between the lysozyme concentrations in the saliva of the immunodeficient subjects and those of the healthy controls., Conclusion: The results in the present work clearly show that salivary lysozyme levels in primary immunodeficient patients are equivalent to those found in healthy controls, suggesting that this enzyme still represents a remaining (but not a compensatory mechanism), contributing to the protection of there patients against infections.

Chronic granulomatous disease (CGD) is an inherited disorder of the innate immune system characterized by a defective oxidative burst of phagocytes and subsequent impairment of their microbicidal activity. Mutations in one of the NADPH-oxidase components affect gene expression or function of this system, leading to the phenotype of CGD. Defects in gp91-phox lead to X-linked CGD, responsible for approximately 70% of CGD cases. Investigation of the highly heterogeneous genotype of CGD patients includes mutation analysis, Northern blot or Western blot assays according to the particular case. The aim of the present study was to use reverse transcription (RT)-PCR for the analysis of molecular defects responsible for X-linked CGD in eight Brazilian patients and to assess its potential for broader application to molecular screening in CGD. Total RNA was prepared from Epstein B virus-transformed B-lymphocytes and reverse transcribed using random hexamers. The resulting cDNA was PCR-amplified by specific and overlapping pairs of primers designed to amplify three regions of the gp91-phox gene: exons 1-5, 3-9, and 7-13. This strategy detected defective gp91-phox expression in seven patients. The RT-PCR results matched clinical history, biochemical data (nitroblue tetrazolium or superoxide release assay) and available mutation analysis in four cases. In three additional cases, RT-PCR results matched clinical history and biochemical data. In another case, RT-PCR was normal despite a clinical history compatible with CGD and defective respiratory burst. We conclude that this new application of RT-PCR analysis--a simple, economical and rapid method--was appropriate for screening molecular defects in 7 of 8 X-linked CGD patients.

OBJECTIVE: To report a case of rare neutrophil functional disorder with clinical and laboratory findings similar to those of chronic granulomatous disease. METHODS: Patient with extremely reduced level of glucose-6-phosphate dehydrogenase and recurrent infections that improved after continuous use of cotrimoxazole. The patient presented leukocytes with defective respiratory burst, similar to what occurs in chronic granulomatous disease. COMMENTS: The diagnosis of glucose-6-phosphate dehydrogenase deficiency in neutrophils should be considered in any patient with hemolytic anemia whose level of G6PD is extremely low or in any patient that presents recurrent infections as differential diagnosis of chronic granulomatous disease.

We studied the prevalence of asthma and related symptoms using a standard written questionnaire designed for the International Study of Asthma and Allergies in Children (ISAAC). The written questionnaire (questions 1-8 related to asthma) was applied to 3005 children aged 6-7 years and to 3008 children aged 13-14 years. The parents of the 6-7-year-old children answered the questionnaire, whereas the 13-14-year-old children answered the questionnaire themselves. Response rates were 72% in the 6-7-year-old group and 94% in the 13-14-year-old group. There was a slight predominance of females in the population studied (male:female ratio 0.94). In the group of the 6-7-year-old children, the prevalence of diagnosed asthma was 7.3% for boys and 4.9% for girls, and in the group of the 13-14-year-old children, the prevalence was 9.8% and 10.2% for boys and girls, respectively. Asthma severity was similar for both age groups, and wheezing following exercise was more frequent among the adolescents. In keeping with studies in other parts of the world, comparison between reported symptoms and diagnosed asthma revealed significantly lower frequency of diagnosed asthma, suggesting that in the population we have studied, asthma is underdiagnosed. Using a global cut-off score to define asthma, we found a significantly higher prevalence of asthma among 6-7-year-old boys, as compared to girls (23.8% vs. 20.4%), and no significant differences among adolescent boys and girls (22.5% and 21.9%, respectively).

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.

OBJECTIVE: The aim of this review is to present some aspects of the immune system.METHOD: Review of the literature, covering some of the most important aspects to the pediatrician.RESULTS: We describe characteristics of the immune system when presented to different antigens, and cells and cytokines effector functions. We also discuss aspects of immaturity of the immune system observed in the pediatric group.CONCLUSION: It is very important that the pediatrician understands how the immune system works.

We evaluated 22 paired maternal and cord sera regarding the presence of IgG and IgG subclasses against purified Escherichia coli LPS O6, O16 and O111 employing ELISA for titre and avidity analysis, isoelectric focusing associated with affinity-blotting for spectrotypic analysis, and the Western-blotting technique for recognition of the various bands in lipopolysaccharide (LPS). Levels of anti-LPS IgG antibodies in cord sera were equivalent to their respective maternal sera, showing a significant correlation (P < 0.0001). IgG1 antibody levels were higher in cord sera than in maternal sera (P < 0.005 for anti-O111, P < 0.05 for anti-O16 and P < 0.02 for anti-O6). Cord IgG2 antibody levels were not different from the maternal levels (P > 0.1). The levels of IgG3 and IgG4 were undetectable. The avidity of anti-O6 and anti-O111 IgG in 10 cord sera showed an extremely significant correlation with maternal antibody avidity (P < 0.0001). Identical patterns of recognition were found in the paired samples analysed by Western blotting. Most of the serum samples recognized the O-repetitive chains and also the region corresponding to core and lipid A. Although the antibody spectrotypes varied among individuals, paired cord and maternal serum samples showed identical patterns. Our findings suggest the occurrence of placental transfer of IgG antibodies against LPS O6, O16 and O111, mainly involving the IgG1 or IgG2 subclasses.