OBJECTIVES: To assess the outcomes of pediatric patients with laboratory-confirmed coronavirus disease (COVID-19) with or without multisystem inflammatory syndrome in children (MIS-C). METHODS: This cross-sectional study included 471 samples collected from 371 patients (age<18 years) suspected of having severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The study group comprised 66/371 (18%) laboratory-confirmed pediatric COVID-19 patients: 61 (92.5%) patients tested positive on real-time reverse transcription-polymerase chain reaction tests for SARS-CoV-2, and 5 (7.5%) patients tested positive on serological tests. MIS-C was diagnosed according to the criteria of the Center for Disease Control. RESULTS: MIS-C was diagnosed in 6/66 (9%) patients. The frequencies of diarrhea, vomiting, and/or abdominal pain (67% vs. 22%, p=0.034); pediatric SARS (67% vs. 13%, p=0.008); hypoxemia (83% vs. 23%, p=0.006); and arterial hypotension (50% vs. 3%, p=0.004) were significantly higher in patients with MIS-C than in those without MIS-C. The frequencies of C-reactive protein levels >50 mg/L (83% vs. 25%, p=0.008) and D-dimer levels >1000 ng/mL (100% vs. 40%, p=0.007) and the median D-dimer, troponin T, and ferritin levels (p<0.05) were significantly higher in patients with MIS-C. The frequencies of pediatric intensive care unit admission (100% vs. 60%, p=0.003), mechanical ventilation (83% vs. 7%, p<0.001), vasoactive agent use (83% vs. 3%, p<0.001), shock (83% vs. 5%, p<0.001), cardiac abnormalities (100% vs. 2%, p<0.001), and death (67% vs. 3%, p<0.001) were also significantly higher in patients with MIS-C. Similarly, the frequencies of oxygen therapy (100% vs. 33%, p=0.003), intravenous immunoglobulin therapy (67% vs. 2%, p<0.001), aspirin therapy (50% vs. 0%, p<0.001), and current acute renal replacement therapy (50% vs. 2%, p=0.002) were also significantly higher in patients with MIS-C. Logistic regression analysis showed that the presence of MIS-C was significantly associated with gastrointestinal manifestations [odds ratio (OR)=10.98; 95%CI (95% confidence interval)=1.20-100.86; p=0.034] and hypoxemia [OR=16.85; 95%CI=1.34-211.80; p=0.029]. Further univariate analysis showed a positive association between MIS-C and death [OR=58.00; 95%CI=6.39-526.79; p<0.0001]. CONCLUSIONS: Pediatric patients with laboratory-confirmed COVID-19 with MIS-C had a severe clinical spectrum with a high mortality rate. Our study emphasizes the importance of investigating MIS-C in pediatric patients with COVID-19 presenting with gastrointestinal involvement and hypoxemia.

Resumo Objetivo: descrever características clínicas, tomográficas e de função pulmonar em pacientes pediátricos com hipogamaglobulinemia primária (HP). Método: estudo de coorte retrospectivo de crianças com HP que recebiam gamaglobulina endovenosa (GEV) e antibiótico profilático entre 2005 e 2010. As características epidemiológicas, clínicas, os achados de tomografia e espirometria foram comparadas adotando níveis de significância de 5%. Resultados: foram avaliados 30 pacientes com HP. Após o início da reposição de GEV, houve redução da frequência de pneumonias (p<0,001). Os 11 pacientes que apresentavam bronquiectasias na primeira tomografia computadorizada (TC) eram mais velhos ao diagnóstico (p=0,001) e tiveram maior atraso no diagnóstico (p=0,001) quando comparados aos pacientes sem bronquiectasias. Ao final do estudo, 18 pacientes apresentavam bronquiectasias e 27/30 também apresentaram outras alterações pulmonares, isoladas ou concomitantes. O escore de Bhalla foi aplicado à última TC de 16/30 pacientes, com mediana do escore de 11 (variação 7-21), com correlação positiva entre o escore e o número de pneumonias após o início do tratamento (r=0,561; p=0,024). O escore foi ainda correlacionado com valores de volume expiratório forçado no primeiro segundo (VEF1) e capacidade vital forçada (CVF) obtidos por espirometria de 13/16 pacientes, com correlação negativa com VEF1 pré- (r=-0,778; p=0,002) e pós-broncodilatador (r=-0,837; p<0,001) e CVF (r=-0,773; p=0,002). Conclusão: complicações pulmonares foram frequentes nesta coorte, apesar da diminuição na frequência de pneumonias com o tratamento. A investigação precoce de pacientes com infecções de repetição para imunodeficiências primárias pode reduzir a frequência dessas complicações. A monitorização de alterações na espirometria pode indicar a necessidade de investigação radiológica.

Summary Objective: To describe clinical features, tomographic findings and pulmonary function in pediatric patients with primary hypogammaglobulinemia (PH). Method: A retrospective cohort study of children with PH who received intravenous immunoglobulin (IVIG) and prophylactic antibiotics between 2005 and 2010. Epidemiological and clinical features, computed tomography (CT) findings, and spirometric data were compared, assuming a 5% significance level. Results: We evaluated 30 patients with PH. After the start of IVIG replacement, there was a decline in the frequency of pneumonia (p<0.001). The 11 patients with bronchiectasis in their first CT scan were older at diagnosis (p=0.001) and had greater diagnostic delay (p=0.001) compared to patients without bronchiectasis. At the end of the study, 18 patients had bronchiectasis and 27 also had other lung disorders, alone or in combination. The Bhalla score was applied to the last CT scan of 16 patients, with a median score of 11 (range 7-21), with a positive correlation between the score and the number of pneumonias after the start of treatment (r=0.561; p=0.024). The score was also correlated with forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) values in 13/16 patients, with negative correlation to FEV1 previously to bronchodilator (r=-0.778; p=0.002) and after bronchodilator (r =-0.837; p<0.001) and FVC (r=-0.773; p=0.002). Conclusion: Pulmonary complications were common in this cohort, despite the decrease in the frequency of pneumonia with treatment. Early investigation of patients with recurrent infections for primary immunodeficiencies can reduce the frequency of these complications. The monitoring of changes in spirometry may indicate the need to carry out radiological investigation.

OBJECTIVES: The purpose of this study was to investigate the association between T cell receptor excision circle levels in peripheral blood mononuclear cells and regulatory T cells that co-express CD25 and Foxp3 in healthy children and adolescents of different ages. MATERIALS AND METHODS: The quantification of signal-joint T-cell receptor excision circle levels in the genomic DNA of peripheral blood mononuclear cells was performed using real-time quantitative PCR. The analysis of CD4, CD8, CD25, and Foxp3 expression was performed using flow cytometry. RESULTS: Ninety-five healthy controls (46 females and 49 males) ranging in age from 1 to 18 years were analyzed. The mean T-cell receptor excision circle count in all individuals was 89.095¡36.790 T-cell receptor excision circles per microgram of DNA. There was an inverse correlation between T-cell receptor excision circles counts and age (r = -0.846; p<0.001) as well as between the proportion of CD4+CD25+Foxp3+ T cells and age (r = -0.467; p = 0.04). In addition, we observed a positive correlation between the amount of CD4+CD25+Foxp3+ T cells and the amount of Tcell receptor excision circles per microgram of DNA in individuals of all ages (r = -0.529; p = 0.02). CONCLUSIONS: In this study, we observed a decrease in the thymic function with age based on the fact that the level of T-cell receptor excision circles in the peripheral blood positively correlated with the proportion of regulatory T cells in healthy children and adolescents. These findings indicate that although T-cell receptor excision circles and regulatory T cells levels decrease with age, homeostasis of the immune system and relative regulatory T cells population levels are maintained in the peripheral blood.

OBJETIVO: Nós pretendemos investigar se o aumento de velocidade de infusão de gamaglobulina intravenosa (IVIG), está associada com alterações metabólicas e hematológicas em pacientes com deficiência de anticorpo. CASUÍSTICA E MÉTODO: Nós estudamos sete pacientes (2-16 anos) com deficiência primária de anticorpo que já estavam em tratamento com reposição regular de IgG, na dose de 350-600 mg/kg a cada três semanas em preparados a 3%, por períodos de seis meses a quatro anos. Inicialmente a concentração dos preparados de IVIG foi aumentando para 6, 9 e 12% em infusões consecutivas numa velocidade constante 4 mg/kg/min. Subseqüentemente, na segunda fase do estudo, mantivemos a concentração a 12% e a velocidade de infusão foi aumentando para 8, 12, e 16 mg/kg/min. RESULTADOS: Clinicamente, todos os pacientes toleraram o aumento da concentração de IVIG na velocidade constante de 4 mg/kg/min. Entretanto, 3 pacientes apresentaram efeitos colaterais quando a velocidade de infusão aumentou para 8 e 16 mg/kg/min. CONCLUSÃO: Nós concluímos que alterações metabólicas e hematológicas podem ocorrer quando se administra preparados de IVIG em altas concentração e velocidade mesmo que os pacientes tolerem bem clinicamente. As vantagens de utilizar velocidades elevadas na infusão de IVIG devem ser reavaliadas.

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.