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Down syndrome (DS) is the most frequent cause of intellectual disability worldwide. DS individuals present abnormalities in the immune system that include high susceptibility to recurrent infections (RI) as well as to autoimmune diseases. Respiratory tract infections remain one of the major causes of death in DS individuals. Mannan-binding lectin (MBL) functions as an opsonina and initiates the lectin complement pathway. MBL deficiency was shown to increase the susceptibility to different infectious diseases, notably by extracellular pathogens. In the present study, MBL circulating levels were evaluated in 150 children with DS from Brazil, to clarify whether MBL deficiency is associated with the presence of RI in these patients. According to the clinical history 30.7% (46/150) of the DS children experienced RI, and MBL deficiency was seen in 34.8% (16/46) of them compared with 13.5% (14/104) of the DS children without RI (p = 0.005, odds ratio = 3.43, 95% confidence interval = 1.5-7.85). Moreover, MBL deficiency was significantly associated with the occurrence of pneumonia when compared with DS without RI (37.5%, 12/32 vs. 13.5% 14/104, p = 0.005, odds ratio = 3.68, 95% confidence interval = 1.5-6.95). These findings demonstrated that MBL deficiency increases the susceptibility to RI in DS patients and that, in the future, they could potentially benefit from MBL therapy.

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AIMS: Down syndrome (DS) patients present several immunological disturbances, with high rates of infections, malignancies and autoimmune phenomena. The present study aims to evaluate the prevalence of autoantibodies in children and adolescents with DS that are not usually investigated, and to establish possible clinical and laboratory associations. METHODS: One hundred and fifty Caucasoid DS patients from southern Brazil (93M, 57F; median age 4 years) and 105 healthy children (58M, 47F; median age 8 years) were evaluated for the presence of anti-mitochondrial (AMA), smooth-muscle (SMA), liver-kidney microsomal (LKM), nuclear (ANA), gastric parietal cell (GPC) and neutrophil cytoplasmic (ANCA) antibodies, by indirect immunofluorescence, and rheumatoid factor (RF), by turbidimetry. RESULTS: Forty-three DS patients (28.6%) showed positivity to at least one autoantibody, in comparison with eight of the controls (7.6%; P < 0.001). RF was detected in 28% of the patients and 6.7% of the controls (P < 0.001). ANCA, SMA and ANA were positive in 0.66% of the patients, while AMA, GPC and LKM were negative in all the samples. Currently, none of the RF positive patients has clinical evidence of rheumatic disease. CONCLUSIONS: Data from the present study suggest that the high incidence of positive RF observed in DS patients might be related to the senescence of the immune system or could be an earlier marker of rheumatic diseases in these patients.

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The aim of the present study was to evaluate the prevalence of anti-cyclic citrullinated peptide (CCP) antibodies in patients with Down's syndrome (DS) previously tested for IgM rheumatoid factor (RF) and to correlate the results with clinical findings. Eighty-eight patients with DS previously tested for IgM-RF were divided into two groups matched for sex and age. Group A consists of 42 RF positive patients and group B of 44 RF negative patients. The presence of anti-CCP antibody was determined using a second-generation enzyme-linked immunosorbent assay. A total of 52.3% (45/86) of DS patients were positive for anti-CCP antibodies. Twenty-four patients (57.1%) of the RF positive group and 21 (47.7%) of the RF negative group presented anti-CCP circulating antibodies. The concordance between both tests was 54.6%. None of the patients had clinical evidence of rheumatoid arthritis or juvenile idiopathic arthritis. Although a high prevalence of anti-CCP antibodies was observed in DS patients, no association has been found presently with clinical disease. Careful follow-up of these patients will be necessary to clarify the real significance of these findings.

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OBJETIVO: Determinar as concentrações de hormônio estimulante da tireóide (TSH) e a presença de anticorpos antitireoperoxidase (anti-TPO) em pacientes com síndrome de Down (SD) atendidos no ambulatório do Hospital de Clínicas da Universidade Federal do Paraná. MÉTODOS: Foram incluídos no estudo 72 pacientes com SD, não aparentados e selecionados consecutivamente, com média de idade de 6,15 anos. Oitenta crianças sadias, pareadas com os pacientes, foram utilizadas como controles. Em todas as amostras foram determinadas as concentrações séricas de TSH e de anti-TPO, através do método de dosagem imunométrica. RESULTADOS: Trinta pacientes com SD (42,9 por cento) apresentaram alterações nas concentrações de TSH, sendo que 4,3 por cento tinham valores menores que 0,5æUI/ml e 38,6 por cento, valores superiores a 5æUI/ml (5,1 a 22) (média de 5,56 ± 4,18æUI/ml). Nos controles, a concentração média de TSH foi 2,76æUI/ml (± 1,14), evidenciando-se um aumento significativo nos níveis de TSH nos pacientes com SD (p < 0,001). De forma similar, caracterizou-se uma diferença significativa na positividade para o anti-TPO nos pacientes (15,4 por cento) em relação aos controles (0 por cento; p < 0,001). Observou-se ainda aumento significativo nas concentrações de TSH nos pacientes com idade superior a 9 anos (média de 6,86 ± 4,6æUI/ml) quando comparados aos menores de 9 anos (média de 5,24 ± 3,81æUI/ml; p = 0,006), bem como na positividade do anti-TPO (6/20 vs. 5/52; p = 0,041). CONCLUSÕES: Os resultados demonstraram alta prevalência de alterações das dosagens de TSH e de doença tireoidiana nos pacientes com SD, principalmente naqueles com idade superior a 9 anos. Os dados indicam que a avaliação da função tireoidiana nos pacientes com SD deve receber atenção especial dos profissionais de saúde que atendem esses pacientes.

OBJECTIVE: To evaluate the thyroid stimulating hormone (TSH) levels and the presence of antithyroperoxidase antibody (anti-TPO) in DownÆs syndrome (DS) patients from Hospital de Clínicas of Universidade Federal do Paraná (HC/UFPR). METHODS: Seventy-two DS patients, non-related and consecutively selected (mean age 6.15) were included in the study. Eighty matched healthy children were used as controls. The TSH measurement and the anti-TPO were determined by immunometric assay in all samples. RESULTS: Thirty patients with DS (42.9 percent) presented abnormal levels of TSH; 4.3 percent showed values below 0.5æIU/ml and 38.6 percent presented values higher than 5æIU/ml (range 5.1-22; mean 5.56 ± 4.18æIU/ml). The mean concentration of TSH in the controls was 2.76 ± 1.14æIU/ml, indicating a significant increase in TSH levels in the DS patients (p < 0.001). Similarly, a significant difference was observed in the anti-TPO positivity in the patientsÆ group (15.4 percent) when compared with the controls (0 percent; p < 0.001). In addition, the TSH levels of patients older than 9 years presented a significant increase (mean of 6.86 ± 4.6æIU/ml) when compared with the levels observed in patients younger than 9 years (mean of 5.24 ± 3.81æIU/ml; p = 0.006). The same pattern was observed in the positivity of anti-TPO (6/20 vs. 5/52; p = 0.041). CONCLUSIONS: The results demonstrated high prevalence of elevated TSH and anti-TPO in the patients from the DS ambulatory of HC/UFPR, with increased frequency in those older than 9 years. The data indicate that the evaluation of thyroid function in DS patients must receive special attention from health professionals who take care of these patients.

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OBJECTIVES: High prevalence rates of celiac disease in patients with Down syndrome have been reported in several countries. However, in Brazil there is no data regarding this association. In this study we report the prevalence of celiac disease in Down syndrome children and adolescents from southern Brazil. METHODS: Seventy-one patients (32 female and 39 male, 2-18 years) from Curitiba, Brazil, were studied. Eighty young people (42 male and 38 female, 2-19 years) were used as controls. All subjects were screened for the IgA-antiendomysium antibody (EmA) and IgA anti-tecidual transglutaminase (anti-tTG). EmA was measured by an immunofluorescence assay using umbilical cord as the substrate and anti-tTG by ELISA with tecidual transglutaminase as the antigen. The total IgA serum level was determined by turbidimetry. RESULTS: Five DS patients (7%) were positive for EmA-IgA, with titers from 1/5 to 1/80 and 14 (17.5%) for anti-tTG (21-340 units). All EmA positive patients also presented anti-tTG antibodies simultaneously. Clinical and histological findings of the intestinal mucosa confirmed celiac disease diagnoses in four patients. The other EmA positive patient was asymptomatic and was not submitted to duodenal biopsy. Patients only positive for anti-tTG presented borderline values (< 25 units) and were asymptomatic. None of the controls were positive for EmA or anti-tTG. No Down syndrome patients or controls presented IgA deficiency. CONCLUSIONS: These data indicates a high prevalence (5.6%) of confirmed celiac disease in Down syndrome patients from southern Brazil.

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OBJETIVOS: Alta prevalência de doença celíaca em pacientes com síndrome de Down tem sido descrita em vários países. No entanto, no Brasil ainda não há relatos mostrando essa associação. O presente estudo teve como objetivo avaliar a prevalência de doença celíaca em crianças e adolescentes com síndrome de Down no sul do Brasil. MÉTODOS: Setenta e um pacientes (32 do sexo feminino e 39 masculino, 2-18 anos) provenientes de Curitiba, Brasil, foram estudados. Oitenta indivíduos (42 do sexo masculino e 38 feminino, 2-19 anos) foram utilizados como controles do estudo. Todas as amostras foram investigadas para anticorpo anti-endomísio (EmA) e anti-transglutaminase tecidual (anti-tTG). O EmA foi pesquisado através de imunofluorescência indireta usando cordão umbilical como substrato e o anti-tTG através da técnica de ELISA, utilizando transglutaminase tecidual como antígeno. As dosagens de IgA foram realizadas por turbidimetria. RESULTADOS: Cinco pacientes com síndrome de Down (7 por cento) foram positivos para EmA-IgA, com títulos entre 1/5 e 1/80 e catorze (17,5 por cento) para anti-tTG (21-340 unidades). Todos os pacientes positivos para EmA apresentaram simultaneamente positividade para o anti-tTG. Os achados clínicos e histológicos na mucosa intestinal confirmaram doença celíaca em quatro pacientes. O outro paciente EmA positivo não foi submetido a biópsia duodenal. Os pacientes positivos apenas para anti-tTG apresentaram valores limítrofes (< 25 unidades) e eram assintomáticos. Nenhum indivíduo do grupo controle foi positivo para EmA ou anti-tTG. Nenhuma amostra do estudo foi deficiente para IgA. CONCLUSÕES: Os dados do presente estudo mostram alta prevalência (5,6 por cento) de doença celíaca confirmada em crianças e adolescentes com síndrome de Down da região sul do Brasil.

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