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PURPOSE: Gain-of-function (GOF) mutations in the signal transducer and activator of transcription 1 (STAT1) result in unbalanced STAT signaling and cause immune dysregulation and immunodeficiency. The latter is often characterized by the susceptibility to recurrent Candida infections, resulting in the clinical picture of chronic mucocutaneous candidiasis (CMC). This study aims to assess the frequency of GOF STAT1 mutations in a large international cohort of CMC patients.METHODS: STAT1 was sequenced in genomic DNA from 57 CMC patients and 35 healthy family members. The functional relevance of nine different STAT1 variants was shown by flow cytometric analysis of STAT1 phosphorylation in patients' peripheral blood cells (PBMC) after stimulation with interferon (IFN)-α, IFN-γ or interleukin-27 respectively. Extended clinical data sets were collected and summarized for 26 patients.RESULTS: Heterozygous mutations within STAT1 were identified in 35 of 57 CMC patients (61%). Out of 39 familial cases from 11 families, 26 patients (67%) from 9 families and out of 18 sporadic cases, 9 patients (50%) were shown to have heterozygous mutations within STAT1. Thirteen distinct STAT1 mutations are reported in this paper. Eight of these mutations are known to cause CMC (p.M202V, p.A267V, p.R274W, p.R274Q, p.T385M, p.K388E, p.N397D, and p.F404Y). However, five STAT1 variants (p.F172L, p.Y287D, p.P293S, p.T385K and p.S466R) have not been reported before in CMC patients.CONCLUSION: STAT1 mutations are frequently observed in patients suffering from CMC. Thus, sequence analysis of STAT1 in CMC patients is advised. Measurement of IFN- or IL-induced STAT1 phosphorylation in PBMC provides a fast and reliable diagnostic tool and should be carried out in addition to genetic testing.

OBJECTIVE: The establishment of the intestinal microbiota in newborns is a critical period with possible long-term consequences for human health. In this research, the development of the fecal microbiota of a group of exclusively breastfed neonates living in low socio-economic conditions in the city of São Paulo, Brazil, during the first month of life, was studied. METHODS: Fecal samples were collected from ten neonates on the second, seventh, and 30th days after birth. One of the neonates underwent antibiotic therapy. Molecular techniques were used for analysis; DNA was extracted from the samples, and 16S rRNA libraries were sequenced and phylogenetically analyzed after construction. A real-time polymerase chain reaction (PCR) was performed on the samples taken from the 30th day to amplify DNA from Bifidobacterium sp. RESULTS: The primary phylogenetic groups identified in the samples were Escherichia and Clostridium. Staphylococcus was identified at a low rate. Bifidobacterium sp. was detected in all of the samples collected on the 30th day. In the child who received antibiotics, a reduction in anaerobes and Escherichia, which was associated with an overgrowth of Klebsiella, was observed throughout the experimental period. CONCLUSION: The observed pattern of Escherichia predominance and reduced Staphylococcus colonization is in contrast with the patterns observed in neonates living in developed countries.

Autoinflammatory diseases are a group of disorders characterized by systemic inflammation without high-titer autoantibodies or antigen-specific T cells, and their etiology is thought to be attributable to dysregulation of innate immunity (1,2). A number of the auto-inflammatory diseases are single-gene disorders that are clinically characterized by features of recurrent or persistent systemic inflammation, such as fever and elevation in the levels of acute-phase reactants, and organ-specific manifestations, such as rashes and osteo-articular, serosal, neurologic, and ocular manifestations (1–3). The identification of these monogenic disorders in innate immune pathways has led to a better understanding of the key inflammation pathways, particularly the role of interleukin-1 (IL-1) in a number of these disorders (1). Thus far, studies have identified 3 autoinflammatory disorders that manifest predominantly with skin and bone inflammation in the newborn period, including neonatal-onset multisystem inflammatory disease (NOMID; also called chronic infantile neurologic, cutaneous, articular syndrome) (4–7), Majeed syndrome (8–11), and the recently described deficiency of interleukin-1 receptor antagonist (DIRA) syndrome (12,13). In addition to inflammation of the skin and bone, NOMID also has features of neurologic impairment and papilledema, chronic arthropathy, and persistent fever, and its etiology has been linked to mutations in NLRP3 (previously called CIAS1) (5,6). In Majeed syndrome, the clinical features include microcytic congenital dyserythropoietic anemia, and a causal mutation has been identified in LPIN2 (8). The DIRA syndrome is also characterized by perinatal-onset pustular dermatitis, multifocal aseptic osteomyelitis, periosteitis, leukocytosis, and marked elevation in the levels of acute-phase reactants, and its etiology has been linked to a loss-of-function protein that truncates mutations in IL1RN (12), a gene that encodes the IL-1 receptor antagonist (IL-1Ra), or a major deletion that involves the IL1RN locus (12,13). One of the nonsense mutations of IL1RN (identified in patients from The Netherlands), a frameshift mutation attributable to a 2-bp deletion (in patients from Newfoundland), and a genomic 175-kb deletion (in patients from Puerto Rico) are believed to be founder mutations in their respective populations (12). In the present study, we describe 2 unrelated Brazilian patients whose clinical phenotype was consistent with the DIRA syndrome. Both patients presented with a severe but distinct clinical picture, mainly involving the skin, bones, and lungs, and both were homozygous for the same 15-bp (in-frame) deletion on IL1RN (a mutation not previously described). We hypothesize that this variant is likely to be a possible founder mutation in the Brazilian population. This novel mutation of IL1RN produces a protein that does not bind the IL-1 receptor, and thus lacks functional activity.

Objective: To evaluate the frequency of primary immunodeficiencies (PID) in juvenile systemic lupus erythematosus (JSLE) patients. Methods: Some 72 JSLE patients were analyzed for levels of immunoglobulin classes and IgG subclasses and early components of the classical complement pathway. Determination of C4 gene copy number (GCN) and detection of type I C2 deficiency (D) were also performed. Results: PID was identified in 16 patients (22%): C2D in three, C4D in three, C1qD in two, IgG2D ( 0.05). Remarkably, the median of Systemic Lupus International Collaborating Clinics/ACR-damage index (SLICC/ACR-DI) was significantly higher in JSLE patients with PID compared with patients without these abnormalities ( p = 0.0033), likewise the high frequency of SLICC/ACR-DI > 1 ( p = 0.023). Conclusions: A high frequency of PID was observed in JSLE patients, suggesting that these defects may contribute to lupus development. Our findings indicate that these two groups of PID should be investigated in severe pediatric lupus.

Objective: To report the experience of a tertiary care hospital with allogeneic hematopoietic stem cell transplantation in children with primary immunodeficiencies. Methods: Seven pediatric patients with primary immunodeficiencies (severe combined immunodeficiency: n = 2; combined immunodeficiency: n = 1; chronic granulomatous disease: n = 1; hyper-IgM syndrome: n = 2; and IPEX syndrome: n = 1) who underwent eight hematopoietic stem cell transplants in a single center, from 2007 to 2010, were studied. Results: Two patients received transplants from HLA-identical siblings; the other six transplants were done with unrelated donors (bone marrow: n = 1; cord blood: n = 5). All patients had pre-existing infections before hematopoietic stem cell transplants. One patient received only anti-thymocyte globulin prior to transplant, three transplants were done with reduced intensity conditioning regimens and four transplants were done after myeloablative therapy. Two patients were not evaluated for engraftment due to early death. Three patients engrafted, two had primary graft failure and one received a second transplant with posterior engraftment. Two patients died of regimen related toxicity (hepatic sinusoidal obstruction syndrome); one patient died of progressive respiratory failure due to Parainfluenza infection present prior to transplant. Four patients are alive and well from 60 days to 14 months after transplant. Conclusion: Patients’ status prior to transplant is the most important risk factor on the outcome of hematopoietic stem cell transplants in the treatment of these diseases. Early diagnosis and the possibility of a faster referral of these patients for treatment in reference centers may substantially improve their survival and quality of life.

OBJETIVO: Descrever as principais síndromes autoinflamatórias hereditárias na faixa etária pediátrica. FONTES DOS DADOS: Foi realizada uma revisão da literatura nas bases de dados PubMed e SciELO, utilizando as palavras-chave "síndromes autoinflamatórias” e "criança”, e incluindo referências bibliográficas relevantes. SÍNTESE DOS DADOS: As principais síndromes autoinflamatórias são causadas por defeitos monogênicos em proteínas da imunidade inata, sendo consideradas imunodeficiências primárias. Elas são caracterizadas clinicamente por sintomas inflamatórios sistêmicos recorrentes ou contínuos e devem ser diferenciadas das doenças infecciosas, autoimunes e outras imunodeficiências primárias. Nesta revisão, foram enfatizadas características epidemiológicas, manifestações clínicas, alterações laboratoriais, prognóstico e terapia das principais síndromes autoinflamatórias: febre familiar do Mediterrâneo; síndrome periódica associada ao receptor de fator de necrose tumoral; criopirinopatias; deficiência de mevalonato-quinase; artrite granulomatosa pediátrica; síndrome de pioderma gangrenoso, artrite piogênica e acne; síndrome de Majeed; e deficiência do antagonista do receptor de interleucina-1. As criopirinopatias discutidas foram: doença inflamatória multissistêmica de início neonatal ou síndrome neurológica, cutânea e articular crônica infantil, síndrome de Muckle-Wells e síndrome autoinflamatória familiar associada ao frio. CONCLUSÕES: É importante que o pediatra reconheça as síndromes autoinflamatórias hereditárias mais prevalentes, pois o encaminhamento ao reumatologista pediátrico pode permitir um diagnóstico precoce e uma instituição de tratamento adequado, possibilitando uma melhora da qualidade de vida dos pacientes. OBJECTIVE: To describe the most prevalent pediatric hereditary autoinflammatory syndromes. SOURCES: A review of the literature including relevant references from the PubMed and SciELO was carried out using the keywords autoinflammatory syndromes and child. SUMMARY OF THE FINDINGS: The hereditary autoinflammatory syndromes are caused by monogenic defects of innate immunity and are classified as primary immunodeficiencies. These syndromes are characterized by recurrent or persistent systemic inflammatory symptoms and must be distinguished from infectious diseases, autoimmune diseases, and other primary immunodeficiencies. This review describes the epidemiological, clinical and laboratory features, prognosis, and treatment of the main autoinflammatory syndromes, namely: familial Mediterranean fever; TNF receptor associated periodic syndrome; the cryopyrinopathies; mevalonate kinase deficiency; pediatric granulomatous arthritis; pyogenic arthritis, pyoderma gangrenosum and acne syndrome; Majeed syndrome; and deficiency of interleukin 1 receptor antagonist. The cryopyrinopathies discussed include neonatal-onset multisystem inflammatory disease (also known as chronic infantile neurologic, cutaneous and articular syndrome) Muckle-Wells syndrome, and familial cold autoinflammatory syndrome. CONCLUSIONS: Pediatricians must recognize the clinical features of the most prevalent autoinflammatory syndromes. Early referral to a pediatric rheumatologist may allow early diagnosis and institution of treatment, with improvement in the quality of life of these patients.

Immunoglobulin A deficiency (IgAD) is considered the most common form of primary immunodeficiency. The majority of IgA-deficient individuals are considered asymptomatic, even though IgAD has been associated with an increased frequency of recurrent infections, allergy, and autoimmune diseases. In this study we evaluate the Natural autoantibodies (NatAbs) reactivity to phosphorylcholine (PC) and to some pro-inflammatory molecules in IgAD with or without autoimmune disorders. We observed that in the absence of IgA there is an enhancement of IgG subclasses functioning as NatAbs against PC. Immunoglobulin G (IgG) against lipopolysaccharide, C-reactive protein, and IgA was found in IgAD, regardless of the autoimmune manifestations. Nonetheless, IgAD patients with autoimmune disease showed significantly higher IgG reactivity against pro-inflammatory molecules, such as cardiolipin, oxidized low-density lipoproteins, and phosphatidylserine, with positive correlation between them. In conclusion, the IgG NatAbs against PC may represent a compensatory defense mechanism against infections and control excess of inflammation, explaining the asymptomatic status in the IgA deficiency.

We studied the levels of immunoglobulins in colostrum, milk and sera from two common variable immunodeficiency (CVID) mothers (M1 and M2), and in sera from their newborn infants. During pregnancy they continued intravenous immunoglobulin therapy (IVIG). Antibody levels from maternal and cord blood collected at delivery and colostrum and milk, collected on the 3rd and 7th post-partum days, respectively, were analyzed. Although cord/maternal blood ratios of total immunoglobulins and subclasses, as well as specific antibodies differed between M1 and M2, both showed good placental transfer of anti-protein and anti-polysaccharide antibodies, despite lower cord/maternal blood ratios in M2. Anti-Streptococcus pneumoniae antibody avidity indexes were similar between paired maternal and cord serum. Both mothers' colostrum and milk samples showed only traces of IgA, and IgM and IgG levels in colostrum were within normal range in M1, whereas M2 presented elevated IgG and low IgM levels, when compared with healthy mothers. The study of colostrum and milk activity showed that they strongly inhibited enteropathogenic Escherichia coli adhesion in vitro. CVID patients must be informed about the relevance of regular IVIG administration during pregnancy, not only for their own health but also for their immune immature offspring. Breast-feeding should be encouraged as colostra from these CVID patients strongly inhibited E. coli adhesion to human epithelial cells thus providing immunological protection plus nutritional and psychological benefits for the infant.

Patients with antibody deficiencies are more prone to develop acute neutropenic episodes even during immunoglobulin replacement. The aims of this study were to evaluate the presence of acute neutropenia in 42 patients with primary antibody immunodeficiencies, currently receiving intravenous immunoglobulin (IVIG), and to describe the clinical and laboratory findings during neutropenic episodes. Of all patients, 10 (23.8%) presented acute neutropenia (absolute neutrophil count

TRAPS is the most common of the autosomal dominant periodic fever syndromes. It is caused by mutations in the TNFRSF1A gene, which encodes for the type 1 TNF-receptor (TNFR1). We describe here a Brazilian patient with TRAPS associated to a novel TNFRSF1A de novo mutation and the response to anti-TNF therapy. The patient is a 9-year-old girl with recurrent fevers since the age of 3 years, usually lasting 3 to 7 days, and recurring every other week. These episodes are associated with mild abdominal pain, nausea, vomiting and generalized myalgia. Recurrent conjunctivitis and erysipela-like skin lesions in the lower limbs also occur. Laboratory studies show persistent normocytic normochromic anemia, thrombocytosis, elevated erythrocyte sedimentation rate and C-reactive protein. IgD levels are normal. Mutational screening of TNFRSF1A revealed the association of a novel C30F mutation with the common R92Q low-penetrance mutation. The R92Q mutation is seen in 5% of the general population and is associated with an atypical inflammatory phenotype. The patient had a very good response to etanercept, with cessation of fever and normalization of inflammatory markers. Our report expands the spectrum of TNFRSF1A mutations associated with TRAPS, adding further evidence for possible additive effects of a low-penetration R92Q and cysteine residue mutations, and confirms etanercept as an efficacious treatment alternative.

Both systemic and organ-specific autoimmune diseases are major manifestations of IgA deficiency (IgAD), the most common primary immunodeficiency. In addition, to discuss the clinical findings of IgAD patients, we proposed a hypothesis to explain the high association with autoimmune phenomena. Based on observations, interactions of monomeric IgA with FcalphaRI result in a partial phosphorylation of FcRgamma-associated FcalphaRI, notably in the immunoreceptor tyrosine-based activation motif (ITAM) inducing the recruitment of the SHP-1 tyrosine phosphatase. This leads to deactivation of several activating pathways of the immune system including immunoreceptors that bear ITAM motif and ITAM-independent receptors. Consequently, inflammatory reactions and auto-immune process would be prevented.

The nocturnal surge of melatonin is the endocrine expression of the circadian system and is essential for organizing the timing of various endogenous processes. Previous works suggest that, in the beginning of a defense response, the increase in circulating tumor necrosis factor-alpha (TNF-alpha) leads to a transient block of nocturnal melatonin production and promotes a disruption of internal time organization. In the present paper, the concentration of melatonin and cytokines [TNF-alpha, interferon-gamma (IFN-gamma), interleukin (IL)-2, IL-4, IL-5, IL-10, IL-12] in the colostrum (postdelivery day 3) and in the milk (postdelivery days 10, 15, 20 and 30) obtained at midday and midnight from mothers who gave birth by vaginal or cesarean section were compared. The nocturnal melatonin surge observed 3 days after vaginal delivery was absent after cesarean section. IL-12 presented no daily variation in either case, while daily variations in IFN-gamma, IL-10, IL-4 and IL-5 were observed after vaginal delivery and cesarean section. On the other hand, the increase in TNF-alpha after cesarean section resulted in suppression of the nocturnal melatonin surge. Daily variation of IL-2 was only observed after recovery of the nocturnal melatonin surge, 30 days after cesarean section. The present paper supports the hypothesis of a cross-talk between the pineal gland and the immune system, which could represent a putative immune-pineal axis.

To evaluate demographic data and clinical and laboratory features at disease diagnosis in 3 different age groups of childhood-onset systemic lupus erythematosus (SLE): group A, early-onset (6 years); group B, school age (≥6 to12 years); and group C, adolescent (≥12 to18 years).This was a Brazilian multicenter cohort retrospective study in 10 pediatric rheumatology centers, including 847 childhood-onset SLE patients.Patients were divided into 3 groups: group A with 39 patients (4%), group B with 395 patients (47%), and group C with 413 patients (49%). Of 39 childhood-onset SLE patients in group A, 3 (8%) were ages2 years, 4 (10%) were ≥2 to3 years, and 32 (82%) were ≥3 and6 years. A total of 74 childhood-onset SLE patients were analyzed for C1q levels, and complete C1q deficiency was observed in 3 of 74 patients (4%), all in group A. Groups were similar regarding high frequencies of female sex, nephritis, neuropsychiatric involvement, Systemic Lupus Erythematosus Disease Activity Index 2000 score ≥8, autoantibody profile, elevated acute phase proteins, and low complement levels (P 0.05). However, the frequency of fever (78% versus 61% versus 47%; P 0.0001), hepatomegaly (42% versus 29% versus 14%; P 0.0001), splenomegaly (28% versus 12% versus 4%; P 0.0001), and discoid lupus (13% versus 4% versus 4%; P = 0.020) was significantly higher in group A compared to groups B and C. The frequency of weight loss2 kg (19% versus 28% versus 36%; P = 0.017), photosensitivity (34% versus 41% versus 51%; P = 0.006), leukopenia4,000/mmOur large multicenter study identified the finding that the initial appearance of childhood-onset SLE is characterized by comparable high frequency of internal organ involvement and some distinct clinical and laboratory features in early-onset and adolescent groups.

OBJECTIVE To determine the frequency of immunodeficiency-like states in SLE and related clinical features. METHODS Three hundred and fifteen SLE patients and 301 controls were evaluated for C4A and C4B gene copy number, immunoglobulin isotypes, IgG subclasses, total haemolytic complement (CH50), C2, C3 and neutrophil oxidative burst. C2 and C3 genes were sequenced in cases of low C2 or C3 levels. Those presenting abnormal CH50 with normal C2 and C3 underwent C1q-C9 determination. Patients with active SLE and abnormal results were re-tested after the flare or were excluded if no remission was attained. Fifteen patients were excluded on this basis. Persistent abnormal results characterized an immunodeficiency-like state. RESULTS A significantly higher percentage of SLE patients presented an immunodeficiency-like state compared with controls (28.7% vs 3.3%; P < 0.001), especially low immunoglobulin serum levels. Rigorous testing confirmed only two cases of C2 deficiency carriers among the SLE patients. There were significantly more SLE patients with less than two C4A copies compared with controls. SLE patients had higher frequency of low IgG2, IgG3, IgG4 and IgM levels compared with controls. Patients with low IgG3 or IgG4 presented higher frequency of lupus nephropathy. Patients with low IgM had longer disease duration, older age at SLE onset and lower frequency of oral ulcers. CONCLUSION An immunodeficiency-like state is present in a sizable fraction of SLE patients. Further studies are warranted to determine the impact of these immunodeficiency states and whether they are a primary condition or are secondary to confounding factors, including SLE itself.

Inflammasome is the cytoplasmic complex responsible for pro-IL1 β cleavage and secretion of IL-1β. Recently our group reported the first association between polymorphisms in the inflammasome receptor NLRP1 and adult-onset systemic lupus erythematosus (SLE) "di per se" and especially in SLE-associated renal disease, suggesting the involvement of NLRP1-inflammasome in the immune dysregulation characteristic of SLE patients. Considering that juvenile-onset SLE (JSLE) is more severe than adult SLE, and that the genetic background plays a major role in the early development of autoimmune diseases, we analysed selected polymorphisms in inflammasome genes (NLRP1, NLRP3, CARD8, IL1B, TNFAIP3) of children and adolescents with JSLE (n = 90) and in healthy controls (n = 144). A single polymorphism in IL1B, and not NLRP1, gene resulted in association with JSLE, suggesting that IL-1 β is involved in the pathogenesis of SLE, but different genes could play specific role in adult- or early-onset disease.

Autoimmune disorders (AID) have been increasingly observed in association with primary immunodeficiencies (PIDs). Here, we discuss the interface between PID and AID, focusing on autoimmune manifestations early in life, which can be diagnostic clues for underlying PIDs. Inflammatory bowel disease in infants and children has been associated with IL-10 and IL-10R deficiencies, chronic granulomatous disease, immunedysregulation-polyendocrinopathy-enteropathy-X-linked syndrome (IPEX), autoinflammatory disorders, and others. Some PIDs have been identified as underlying defects in juvenile systemic lupus erythematosus: C1q-, IgA-, IgM deficiencies, alterations of the IFN-α pathway (in Aicardi-Goutières syndrome due to TREX1 mutation). IPEX (due to FOXP3 mutation leading to Treg cell deficiency), usually appearing in the first months of life, was recently observed in miscarried fetuses with hydrops who presented with CD3+ infiltrating lymphocytes in the pancreas. Hemophagocytic lymphohistiocytosis due to perforin deficiency was also identified as a cause of fetal hydrops. In conclusion, PID should be suspected in any infant with signs of autoimmunity after excluding transferred maternal effects, or in children with multiple and/or severe AID. Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP).

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.

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 antibodyor = 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 (P0.05) for all serotypes except serotype 3. We conclude that pneumococcal polysaccharide immunization could be beneficial for these DS children.

Enterohaemorrhagic Escherichia coli (EHEC) strains are among the main causes of haemorrhagic colitis (HC) and haemolytic-uremic syndrome (HUS) in industrialised countries. In Brazil, EHEC have been detected in the faeces of patients with non-bloody diarrhoea, though an association between EHEC and HUS has been detected recently. These observations suggest that there is a pre-existing immunity triggered by the contact with EHEC and other categories of bacteria, such as EPEC, that share similar virulence factors and to which our population is highly exposed. Our aim was to evaluate the placental transfer of IgG antibodies reactive to EHEC O157:H7 antigens. We evaluated 28 paired maternal and cord sera for the presence of IgG against EHEC O157:H7 protein antigens and IgG and IgM to O157 LPS employing ELISA and IB technique. Total IgG and IgM level analyses were also made. Anti-EHEC O157:H7 and anti-LPS O157 IgG antibody levels in cord sera were equivalent to those of their maternal sera. A good correlation between the mothers' anti-LPS O157 IgM and total IgM levels was found. Anti-LPS O157 IgM levels were higher than anti-LPS O157 IgG levels in the same samples, and anti-LPS IgM antibodies were not detected in cord sera. Identical patterns of recognition of bacterial protein antigens by specific IgG were found in the paired samples and the recombinant purified variable region of gamma intimin was specifically recognized by one paired maternal and cord sample. In conclusion, although the antibody profile varied among individuals, all paired cord and maternal serum samples showed an identical recognition pattern, indicating an efficient placental transfer of IgG antibodies reactive to EHEC O157:H7 antigens.

OBJETIVO: Estudar a produção de anticorpos a antígenos polissacarídicos em pacientes com ataxia-telangiectasia CASUÍSTICA E MÉTODO: Utilizando a técnica de ELISA, determinamos os níveis de IgG aos sorotipos 1, 3, 5, 6B, 9V e 14 do pneumococo em 14 pacientes com ataxia-telangiectasia, antes e após a imunização com a vacina pneumocócica 23-valente. Resposta adequada a cada sorotipo foi definida como IgG > 1,3 µg/ml ou o incremento de quatro vezes dos níveis pós em relação aos pré-imunização. RESULTADOS: Seis pacientes (43%) não responderam a todos os sorotipos analisados, quatro a apenas um sorotipo, um paciente a dois, dois a três e apenas um paciente a quatro dos seis sorotipos analisados. Nenhum paciente apresentou resposta adequada a todos os sorotipos testados. Os níveis de IgG ao pneumococo pós-imunização foram superiores aos pré-imunização para todos os sorotipos testados, exceto o 3. Apesar disso, os valores médios pós-imunização foram inferiores a 1,3 µg/ml para todos os sorotipos analisados, exceto o 14. A média de incremento da resposta foi inferior a quatro para todos os sorotipos analisados. CONCLUSÃO: Nossos resultados sugerem que pacientes com ataxia-telangiectasia têm grande risco de apresentar resposta inadequada ao pneumococo, o que pode ser uma das causas das infecções sinopulmonares de repetição. OBJECTIVE: To analyze the production of antibodies to polysaccharide antigens in patients with ataxia-telangiectasia. PATIENTS AND METHODS: We used the ELISA technique to measure the levels of IgG antibodies to serotypes 1, 3, 5, 6B, 9V and 14 of Streptococcus pneumoniae in 14 patients with ataxia-telangiectasia before and after immunization with 23-valent polysaccharide vaccine. Adequate response to individual polysaccharide can be defined as a postimmunization antibody titer equal to or greater than 1.3 µg/ml or as a minimum fourfold increase over the baseline (preimmunization) value. RESULTS: Six (43%) patients showed an absent response to all serotypes analyzed. Four patients showed adequate response to only one serotype, one patient to two serotypes, two patients to three serotypes and only one patient to four out of six serotypes analyzed. No patient had adequate response to all serotypes tested. Postimmunization pneumococcus IgG levels were higher than preimmunization levels to all serotypes analyzed, except for serotype 3. In spite of this, the mean postimmunization levels were lower than 1.3 µg/ml in all serotypes, except for serotype 14. Mean increment was less than four in all serotypes analyzed. CONCLUSION: Our results suggest that patients with ataxia-telangiectasia are at a high risk of having an impaired response to pneumococcus, which may be one of the causes of recurrent sinopulmonary infections in these patients.

Background: To alert for the diagnosis of the 22q11.2 deletion syndrome (22q11.2DS) in patients with congenital heart disease (CHD). Objective: To describe the main CHDs, as well as phenotypic, metabolic and immunological findings in a series of 60 patients diagnosed with 22q11.2DS. Methods: The study included 60 patients with 22q11.2DS evaluated between 2007 and 2013 (M:F=1.3, age range 14 days to 20 years and 3 months) at a pediatric reference center for primary immunodeficiencies. The diagnosis was established by detection of the 22q11.2 microdeletion using FISH (n = 18) and/or MLPA (n = 42), in association with clinical and laboratory information. Associated CHDs, progression of phenotypic facial features, hypocalcemia and immunological changes were analyzed. Results: CHDs were detected in 77% of the patients and the most frequent type was tetralogy of Fallot (38.3%). Surgical correction of CHD was performed in 34 patients. Craniofacial dysmorphisms were detected in 41 patients: elongated face (60%) and/or elongated nose (53.3%), narrow palpebral fissure (50%), dysplastic, overfolded ears (48.3%), thin lips (41.6%), elongated fingers (38.3%) and short stature (36.6%). Hypocalcemia was detected in 64.2% and decreased parathyroid hormone (PTH) level in 25.9%. Decrease in total lymphocytes, CD4 and CD8 counts were present in 40%, 53.3% and 33.3%, respectively. Hypogammaglobulinemia was detected in one patient and decreased concentrations of immunoglobulin M (IgM) in two other patients. Conclusion: Suspicion for 22q11.2DS should be raised in all patients with CHD associated with hypocalcemia and/or facial dysmorphisms, considering that many of these changes may evolve with age. The 22q11.2 microdeletion should be confirmed by molecular testing in all patients. Fundamento: Alertar para o diagnóstico da síndrome da deleção 22q11.2 (SD 22q11.2) em pacientes com cardiopatias congênitas. Objetivo: Descrever as principais cardiopatias, alterações fenotípicas, metabólicas e imunológicas em uma série de 60 pacientes com a SD22q11.2. Métodos: Foram incluídos 60 pacientes com SD22q11.2 avaliados entre 2007 e 2013 (M:F = 1,3; idades entre 14 dias a 20 anos e 3 meses) em um centro pediátrico de referência para imunodeficiências primárias. O diagnóstico foi feito pela detecção da microdeleção 22q11.2 através de FISH (n = 18) e/ou MLPA (n = 42), associados a dados clínicos e laboratoriais. Foram analisadas as cardiopatias, aspectos fenotípicos evolutivos da fácies, a hipocalcemia e alterações imunológicas associadas. Resultados: Cardiopatias congênitas ocorreram em 77% dos casos, sendo que a tetralogia de Fallot ocorreu em 38,3%. Correção cirúrgica da cardiopatia foi realizada em 34 pacientes. Os dismorfismos craniofaciais foram detectados em 41 pacientes: face (60%) e/ou nariz alongados (53,3%), fenda palpebral estreita (50%), orelhas displásicas com hiperdobramento (48,3%), lábios finos (41,6%), dedos alongados (38,3%) e baixa estatura (36,6%). Hipocalcemia foi observada em 64,2% com redução do nível de paratormônio (PTH) em 25,9%. Observou-se número reduzido de linfócitos totais, CD4 e CD8 em 40%, 53,3%, e 33,3%, respectivamente. Detectou-se hipogamaglobulinemia em um paciente e redução das concentrações de imunoglobulina M (IgM) em outros dois pacientes. Conclusão: Deve-se suspeitar da SD22q11.2 em todos os portadores de cardiopatia congênita com hipocalcemia e/ou dismorfismos faciais, ressaltando-se que muitas dessas alterações podem ser evolutivas. A microdeleção 22q11.2 deve ser confirmada por testes moleculares em todos os pacientes.

Although Shiga toxin-producing Escherichia coli (STEC) has been isolated in Brazil, severe manifestations of the infection, such as haemorrhagic colitis and haemolytic-uraemic syndrome, are extremely rare in our population. Enteropathogenic Escherichia coli (EPEC) is the main aetiological agent of acute infantile diarrhoea in Brazil. There are many similarities between STEC and EPEC, such as the ability to produce attaching and effacing (A/E) lesions and some virulence-associated factors. Our aim was to investigate the presence of anti-STEC antibodies in healthy people living in an EPEC endemic area. Colostrum samples collected from 51 women living in low socio-economic conditions were analysed. Two STEC strains: O111:H- (Stx1) and O157:H7 (Stx2), and one EPEC strain (O111:H-) were used in the bacterial adhesion assays to HEp-2 cells, in the Stx1 and Stx2 cytotoxicity assays on Vero cells, in immunoblotting and in ELISA assays. All the samples strongly inhibited the adhesion of the three strains and contained SIgA antibodies reactive with antigens of EPEC O111:H-, STEC O111:H- and STEC O157:H7, mainly STEC and EPEC 94 kDa adhesin intimin. High titres of anti-LPS O111 antibodies were found in many samples. Nevertheless, the cytotoxic effect of both Stx1 and Stx2 on Vero cells was not neutralised by any sample. Conclusion: Our results suggest that Brazilian people may be exposed to Shiga toxin-producing Escherichia coli more frequently than previously thought or alternatively there may be a cross reactive immunity between enteropathogenic Escherichia coli and Shiga toxin-producing Escherichia coli.

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 Iysossomal granules of the phagocytes. Primary Immunodeficiencies are a diverse group of iIInesses 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 Iysozyme 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 agematched 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 Iysoplate method. Results There was no statistically significant difference between the Iysozyme 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 Iysozyme 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.

Enteropathogenic Escherichia coli (EPEC) is the most common etiological agent of acute diarrhea among infants living in poor social conditions in Brazil and other developing countries. This infection is rare in breast-fed infants, as well as in children older than 2 years. Over the past few years, our group has attempted to identify antibodies to EPEC virulence proteins in human milk and to establish the in vitro protective role of these antibodies. In the present study, we report the identification of antibodies to EPEC virulence proteins in sera and saliva from children of different ages, living in slums in the city of Sao Paulo, Brazil. Using EPEC and bacterial constructs (pET) for immunoblotting (IB) analysis, antibodies reacting to the main adhesins (intimin, bundle-forming pilli) and cell-signaling proteins (EPEC secreted proteins - Esp A, Esp B) were detected in sera from adults and children older than 1 year. Almost all children older than 1 year presented recognition patterns similar to those of adults in IB assays for serum IgG and secretory IgA antibodies, using EPEC outer membrane and other antigenic preparations. As previously observed for human milk, all samples from adults and older children recognized the 94 kDa molecular weight adhesin intimin strongly. In most children, previous EPEC symptomatic diarrhea could not be confirmed; however, almost all of them have presented one or more diarrhea episodes during their lifetime. These results suggest that reduction of EPEC infection frequency after 2 years of age may be associated with the development of anti-EPEC antibody repertoires.

É relatado o caso de uma menina de sete anos de idade com infecções de vias aéreas de repetição (otites, pneumonias e sinusites) desde os cinco meses de vida. A avaliação imunológica demonstrou produção inadequada de anticorpos ao Streptococcus pneumoniae após imunização para todos os sorotipos (1, 3, 5, 6, 9 e 14) testados, embora a paciente apresentasse níveis normais de imunoglobulinas. A avaliação radiológica, no momento da admissão, demonstrou presença de atelectasias difusas associadas a bronquiectasias. Após início do tratamento com imunoglobulina endovenosa e fisioterapia respiratória houve esvaecimento gradual até reversão das alterações radiológicas. Demonstrou-se, assim, a importância de um diagnóstico preciso para início de tratamento específico, com melhora gradual do quadro clínico e radiológico, evitando seqüelas pulmonares irreversíveis.

IgY, the egg yolk immunoglobulin, equivalent to the IgG from mammals, has been used in veterinary practice for passive immunisation against bacterial or viral infectious diseases. Enteropathogenic Escherichia coli (EPEC) is the main etiological agent of infantile diarrhoea in Brazil and other developing countries. Our aims were to isolate immunoglobulin IgY from egg yolk laid by EPEC -immunised Leghorn chickens and to study its reactivity to the antigens from this pathogen, including some virulence factors. Leghorn chickens were immunised with a bacterial suspension intramuscularly (three hens) or intravenously (three hens) or with PBS (two hens). Eggs were collected over a period of 17 weeks. IgY isolation procedures were carried out by salt precipitation (ammonium sulphate, in solid form) followed by centrifugations and dialysis. Final preparations were submitted to sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS - PAGE), enzyme-linked immunosorbent assay (ELISA) and immunoblotting. All immunised animals developed good levels of antibodies reactive to whole bacteria or lipopolysaccharide (LPS), in contrast to the control ones. Immunoblottings allowed the recognition of several antigenic fractions of bacterial antigens, some of which had a molecular weight compatible with bacterial virulence factors, confirming the efficacy of the immunisation and the adequacy of the method.

Objetivo: comparar os dados clinicos e laboratoriais no pre e pos-tratamento de pacientes portadores de leishmaniose visceral (LV), admitidos em hospital pediatrico localizado em area nao-endemica, destacando a importância do reconhecimento da LV na faixa etaria pediatrica. Metodos: avaliacao dos dados clinicos, laboratoriais e de tratamento de pacientes portadores de LV no periodo compreendido entre 1981 e 1992, comparando-se os valores medios de hemoglobina, leucocitos, neutrofilos, plaquetas, albumina, gamaglobulina, classes e subclasses de imunoglobulinas, tamanho do figado e baco antes e apos o tratamento, utilizando-se o teste "t" para amostras pareadas. Resultados: foram incluidos 78 pacientes, com idade variando entre 8 meses e 13,5 anos, sendo 44 casos do sexo masculino e 61 provenientes da Bahia. Febre e esplenomegalia estavam presentes em 96,1% e 100% dos casos, respectivamente. O diagnostico parasitologico foi obtido em 74/78 pacientes, com positividade pelo mielograma e/ou mielocultura em 67 casos (85,7%), 5 pela biopsia hepatica e 2 pela puncao esplenica. Os valores hematologicos e a albumina serica apresentaram melhora significante ao termino do tratamento (p

Clinical manifestations of Immunoglobulin A Deficiency (IgAD) include recurrent infections, atopy and autoimmune diseases. However, to our knowledge, the concomitant evaluations of autoimmune diseases and autoantibodies in a cohort of IgAD patients with current age10 years-old and their relatives have not been assessed.To evaluate autoimmune diseases and the presence of autoantibodies in IgAD patients and their first-degree relatives.A cross-sectional study was performed in 34 IgAD patients (current age10 years-old) and their first-degree relatives. All of them were followed at a tertiary Brazilian primary immunodeficiency center: 27 children/adolescents and 7 of their first-degree relatives with a late diagnosis of IgAD. Autoimmune diseases and autoantibodies (antinuclear antibodies, rheumatoid factor, and anti-thyroglobulin, anti-thyroperoxidase and IgA class anti-endomysial antibodies) were also assessed.Autoimmune diseases (n=14) and/or autoantibodies (n=10, four of them with isolated autoantibodies) were observed in 18/34 (53%) of the patients and their relatives. The most common autoimmune diseases found were thyroiditis (18%), chronic arthritis (12%) and celiac disease (6%). The most frequent autoantibodies were antinuclear antibodies (2%), anti-thyroglobulin and/or anti-thyroperoxidase (24%). No significant differences were observed in the female gender, age at diagnosis and current age in IgAD patients with and without autoimmune diseases and/or presence of autoantibodies (p0.05). The frequencies of primary immunodeficiency's in family, autoimmunity in family, atopy and recurrent infections were similar in both groups (p0.05).Autoimmune diseases and autoantibodies were observed in IgAD patients during follow-up, reinforcing the necessity of a rigorous and continuous follow-up during adolescence and adulthood.

With the substantial socio-economic progress of recent decades, diseases resulting from malnutrition and infection have declined in several South American (SA) countries. Therefore, more investment has been allocated to the diagnosis and treatment of rarer diseases of genetic nature, such as primary immune deficiency diseases (PIDDs). However, PIDDs still represent a little known and understudied subject in most medical schools and professional associations, with the exception of some university centers in the largest cities. Thus, awareness of PIDDs remains low among pediatricians and general practitioners in SA countries. South America comprises 13 countries: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, French Guyana, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela. When comparing countries with each other, and even different regions within a country, there is considerable heterogeneity in the degree of development. GDP (gross domestic product) per capita varied from US$4800 in Bolivia to $17,400 in Argentina, in 2011. South America has a population of approximately 400 million people, half of whom live in Brazil, and there are approximately 5.5 million births per year. This chapter reviews aspects of PIDD unique to South America.

In this chapter we characterized trisomy 21-driven transcriptional alterations in human thymus through gene coexpression network (GCN) analysis. We used whole thymic tissue (corticomedullar sections)—obtained at heart surgery from Down syndrome (DS) and karyotipically normal individuals (CT)—and a network-based approach for GCN analysis allowing the study of interactions between all the system’s constituents based on community detection. Changes in the degree of connections observed for hierarchically important hubs in DS and CT gene networks corresponded to sub-network changes, i.e. module (communities) changes. Distinct communities of highly interconnected gene sets were topologically identified for DS and CT networks. Trisomy 21 gene dysregulation in thymus may therefore be viewed as the breakdown and altered reorganization of functional modules.

Colostrum plays an important role in protecting newborn infants against acute gastrointestinal and respiratory infections. IgA antibodies have been considered the major effector component; however, the role of their receptors on colostral phagocytes, especially neutrophils, has not been studied. Here, we demonstrate that CD15+ colostrum neutrophils express IgA Fc receptors (FcαR, CD89) at levels similar to those of blood neutrophils. Most colostral cells (70%) bear secretory IgA (SIgA) on their surface (and intracellularly), whereas blood cells do not. The FcαR on colostral neutrophils was identified as the a.1 isoform with a similar molecular mass (55–75 kDa) as that identified for blood neutrophils. Removal of N-linked carbohydrates revealed a major protein core of 32 kDa for both cell types. In contrast, co-immunoprecipitation and immunoblot experiments using a mild detergent, digitonin, revealed a lack of γ chain association with FcαR (γ-less) exclusively on colostral neutrophils. The functional role of these γ-less FcαR cells was evaluated by measuring superoxide release and killing of SIgA-coated enteropathogenic E. coli. No increase in superoxide release was observed in colostral cells compared with blood neutrophils, whereas optimal release was obtained with PMA stimulation. Furthermore, despite similar bacterial phagocytosis index between both cell types, IgA-mediated bacterial-killing was not detectable with colostral neutrophils, whereas killing was detectable on blood cells. These results reveal exclusive expression of γ-less FcαR on colostral neutrophils associated with receptor hyperoccupation by IgA and with low, bacterial-killing activity, which suggest that this receptor may mediate noninflammatory effects of SIgA.

SUMMARY Background: enteropathogenic Escherichia coli (EPEC) is the main etiological agent of infantile diarrhea in Brazil and other developing countries. Human milk IgA protects newborn intestinal mucosa by inhibiting bacterial adhesion to epithelial cells and this effect is shown by in vitro assays of EPEC adhesion to HEp-2 cultured cells. Bovine milk, if effective in promoting this protection, could be an useful tool in the absence of the natural breastfeeding, in high-risk nurseries or in hospital infections. Methods: the effect of colostrum, milk, and serum from dairy cows on the adherence to EPEC to HEp-2 cells was investigated. Colostrum from immunized and control animals and industrialized milk formulas were fractionated through a membrane device with a molecular weight cut off 10 kDa. The high molecular weight fraction (HMWF) of bovine colostrum was depleted of IgG through an affinity column and absorbed with an EPEC adherent strain. Antibodies were searched by ELISA and immunoblotting (IB). Results: colostrum and milk from EPEC-immunized animals showed and inhibitory activity on adherence similar to that of contol non-immunized animals. The inhibitory effect on adhesion was related to the HMWF. IgG-depleted colostrum partially retained the inhibitory effect, whereas IgG-rich eluate lost this property. The EPEC-absorbed fraction retained the inhibitory property. Industrialized milk formulas and respective HMWF also inhibited bacterial adherence. In IB assays, colostrum and milk samples from immunized animals recognized proteins of 30-40 kDa and 94 kDa, a molecular weight consistent with the adhesin intimin, in EPEC extracts. Conclusions: the inhibitory effect of EPEC adherence may be mediated by HMWF components, and IgG was not the only component responsible for this phenomenon.

Background: Fanconi`s anemia (FA) is a rare recessive chromosomal instability disorder, characterized by progressive bone marrow failure and congenital defects. Patients with FA present with recurrent infections, particularly those of the respiratory tract. Objective: The aim of the present study was to evaluate whether patients with FA have altered antibody-mediated immune responses. Methods: A group of 12 patients with FA, 5–32 years old (6 males) was studied. Serum levels of IgG, IgM, IgA and IgG subclasses, isohemagglutinin titers and specific IgG antibodies to poliovirus and measles were determined using standard methods. Immediate skin tests to common inhalant allergens were performed, and total and specific serum IgE was quantitated using a fluoroenzymatic assay (Uni-CAP, Pharmacia). Antipneumococcal antibodies were measured by ELISA before and 4–8 weeks after immunization with pneumococcal vaccine (Pneumo 23, Pasteur Mérieux Connaught). Responses to serotypes 1, 3, 5, 6B, 9V and 14, which are the most prevalent in our country, were studied. Results: Ten patients had elevated IgE levels in sera, and 7 of them had detectable specific IgE and positive immediate skin tests. An inadequate response to pneumococcal vaccination was found in 2 of the 12 patients. Isohemagglutinin titers and levels of IgG, IgM, IgA and IgG subclasses and antipoliovirus and antimeasles antibodies were within the normal limits for age in all patients. Two patients had undetectable IgG4 levels (below 5 mg/dl). Conclusions: The results indicate that a proportion of patients with FA (2/12) in our study had inadequate responses to pneumococcal vaccination. No other significant abnormalities of the immune system were found in these patients.

Rubinstein-Taybi syndrome (RTS) is a rare developmental disorder characterized by craniofacial dysmorphisms, broad thumbs and toes as well as mental and statural deficiencies.1 RTS has a prevalence of 1 in 330,000 births2 and usually occurs sporadically, although it can be inherited as an autosomal dominant disorder.2,4 The diagnosis is based on characteristic features.3 The main clinical symptoms are failure to thrive, cardiac defects and recurrent respiratory infections.4 Other variable findings are colobomas, cataracts, renal anormalities3,4 and oro-dental anomalies.5 RTS patients also have an increased risk of developing neoplasias.6,7 Several tumors have been reported in RTS patients, including meningiomas, rhabdomyosarcomas, neuroblastomas, oligodendromas, seminomas, choristomas and leukemias.6,7 CREBBP and EP300 are the only genes associated with RTS.8,11 Microdeletions at band 16p13.3 occur in 10%–25% of RTS patients.9 Sequence analyses have detected CREBBP mutations in another 56% of affected individuals. Schorry et al. (2008)8 evaluated genotype-phenotype correlations in 93 RTS patients and performed complete sequencing of all 31 coding regions of the CREBBP gene. The authors concluded that there were no statistically significant differences in the classic dysmorphic findings of RTS patients (e.g., typical facial aspects and broad thumbs and toes) with and without CREBBP mutations. Mutations in EP300 have been identified in 3% of RTS patients.7,9 RTS typically occurs as a de novo mutation in a family.2 Most individuals represent simplex cases (i.e., the only affected member in a family); in most instances, the parents of an individual with RTS are not affected.2,4 In this case, the empiric recurrence risk for siblings is approximately 0.1%. Although individuals with RTS rarely reproduce, the theoretical risk for the offspring is 50%.2 Prenatal testing for at-risk pregnancies is possible if the disease-causing CREBBP mutation or deletion in the family is known.7

In 40 children with Haemophilus influenzae b (Hib) meningitis, we determined serum levels (mg/dl) of IgG subclasses using the radial immunodiffusion method; 67.8 per cent of these children were less than 24 months old. In 14 children of the sample we measured serum IgG and IgG2 anti-ribosyl-ribitolphosphate (anti-PRP) (by enzyme-linked immunosorbent assay, ELISA) in the acute and convalescent phases of the disease. Lower IgG2 levels than those of the control group were obtained in all age ranges: 3-12 months, 1-2 years (p < 0.01), and 2-5 years (p < 0.001). IgG4 was also present in lower levels in patients of all age ranges (p < 0.05, p < 0.001, and p < 0.01 respectively). Serum levels of IgG anti-PRP and IgG2 anti-PRP measured were very low in the acute phase of the disease in all age ranges and there was no notable increase in levels during the convalescent phase of the disease. This result indicates that children less than 24 months old do not produce sufficient levels of IgG and IgG2 anti-PRP even after Hib meningitis.

The aim of this study was to evaluate the relationship between the secretory immune system and dental caries. Forty-nine 3-5-year-old children with primary dentition were classified into three groups according to their caries indices: no caries (group I), one or two surfaces with caries lesions (group II) and rampant caries (group III). Lower numbers of mutans streptococci were found in group I in relation to groups II and III. Secretory IgA and anti-S. mutans IgA, IgM and IgG antibody levels were not significantly different among the groups. Western blotting analysis showed that some S. mutans proteins, including the 39, 59, 97 and 150 kDa molecular mass bands, were recognized by almost all the saliva samples. Antibodies against the 185 kDa band, known as antigen I/II, were present in all adults' saliva and in only one child in group III. The absence of antibodies to the 185 kDa band in children's saliva suggest a specific immunologic immaturity. Further prospective studies will be necessary to establish the possible effect of reactivity to this antigen on the S. mutans colonization in this age group.

In the present study we determined the HLA-A, B and DR antigenic and haplotypic frequencies in unrelated Brazilian Caucasian paediatric patients with IgA deficiency (IgA-D). Out of 17 IgA-D subjects typed for HLA A and B specificities, 12 (71%) presented B8 and/or B14; of 15 patients also typed for HLA-DR specificities, 14 (93%) were positive for at least one of the HLA markers previously reported to be associated with IgA-D, i.e. B8, B14, DR1, DR3 or DR7. The haplotypes B8, DR3, B14, DR1 and B13, DR7 were present in 43, 21 and 14% of the cases, respectively, while they have a frequency in the general population of 2, 2 and 1%, respectively. The concomitant association with the three IgA-associated haplotypes found in our study probably reflects the admixture of European genetic influences present in the Brazilian Caucasian population of Sao Paulo.

The Latin American Group for Primary Immunodeficiencies, formed in 1993, presently includes 12 countries. One goal was to study the frequency of primary immunodeficiencies in various regions of the American continent and to enhance knowledge about these diseases among primary-care physicians, as well as allergist-immunologists. Important for this purpose was the development of a registry of primary immunodeficiencies using a uniform questionnaire and computerized database. To date, eight countries have collected information on a total of 1428 patients. Predominantly antibody deficiencies were reported in 58% of patients, followed by cellular and antibody immunodeficiencies associated with other abnormalities in 18%, immunodeficiency syndromes associated with granulocyte dysfunction in 8%, phagocytic disorders in 9%, combined cellular and antibody immunodeficiencies in 5%, and complement deficiencies in 2% of patients. The information gathered from this initial analysis of data will serve to expand the patient database to more areas within participating countries and to new countries and to increase collaboration toward better diagnosis and treatment of these diseases.

One hundred sixty-six cases of primary immunodeficiency diseases (PID) (95 males, 71 females), diagnosed according to WHO criteria, have been registered at the Children's Hospital, University of Sao Paulo, Brazil. The following frequencies were found: predominantly humoral defects, 60.8% (n = 101); T cell defects, 4.9% (n = 8); combined ID, 9.6% (n = 16); phagocyte disorders, 18.7% (n = 31); and complement deficiencies, 6% (n = 10). IgA deficiency was the most frequent disorder (n = 60), followed by transient hypogammaglobulinemia (n = 14), chronic granulomatous disease (n = 14), and X-linked agammaglobulinemia (n = 9). In comparison to other (national) reports, we observed higher relative frequencies of phagocyte and complement deficiencies. Recurrent infections were the cause of death in 12.7%. Allergic symptoms were observed in 41%, mainly in IgA-deficient, hypogammaglobulinemic, or hyper-IgE patients, and autoimmune disorders in 5%, predominantly in IgA and complement deficiencies. Five patients suffered from BCG dissemination; two of them died. This is the first Brazilian report on PID over an observation time of 15 years.

B+NK+SCID (severe combined immunodeficiency) due to IL7Rα deficiency represents approximately 10% of American SCID cases. To better understand the spectrum of autoimmune disorders associated with IL7Rα deficiency, we describe two unrelated IL7Rα-deficient female SCID infants whose clinical picture was dominated by autoimmune manifestations: one with intrauterine Omenn syndrome (OS) and another with persistent thrombocytopenic purpura since 4months of age. The OS baby harbored a homozygous p.C118Y mutation in IL7R. She presented dense eosinophilic infiltrates in several organs, including pancarditis, which may have contributed to her death (on the 2nd day of life). B cells were observed in lymph nodes, spleen, bone marrow and thymus. The second patient harbored compound heterozygous p.C118Y and p.I121NfsX8 mutations. She underwent a successful unrelated cord blood transplant. In conclusion, early OS can be observed in patients with IL7R mutations, and autoimmune cytopenias could also complicate the clinical course of SCID babies with this type of defect.

Activation-induced cytidine deaminase (AID) is a DNA editing protein that plays an essential role in three major events of immunoglobulin (Ig) diversification: somatic hypermutation, class switch recombination and Ig gene conversion. Mutations in the AID gene ( AICDA ) have been found in patients with autosomal recessive Hyper-IgM (HIGM) syndrome type 2. Here, two 9- and 14-year-old Brazilian sisters, from a consanguineous family, were diagnosed with HIGM2 syndrome. Sequencing analysis of the exons from AICDA revealed that both patients are homozygous for a single C to G transversion in the third position of codon 15, which replaces a conserved Phenylalanine with a Leucine. To our knowledge, this is a new AICDA mutation found in HIGM2 patients. Functional studies confirm that the homologous murine mutation leads to a dysfunctional protein with diminished intrinsic cytidine deaminase activity and is unable to rescue CSR when introduced in Aicda −/− stimulated murine B cells. We briefly discuss the relevance of AICDA mutations found in patients for the biology of this molecule.