RESUMO
BACKGROUND: Experimental data show that type I interferon has a key role in innate immune response against influenza infection. OBJECTIVE: We compared nasal levels of interferon-α2 and ß among inpatients and outpatients with influenza. STUDY DESIGN: Children younger than 5 years of age with influenza-like illness seeking care at the emergency department within the first 72 h of disease onset were prospectively included. Clinical and demographic data and secretions through nasal wash were obtained. Influenza infection was assessed through reverse-transcription polymerase chain reaction and nasal levels of interferon-α2 and ß were measured by enzyme-linked immunosorbent assay. All patients followed until the end of the disease. RESULTS: One hundred patients were included, of which 24 had confirmed influenza infection, and 5 of them were hospitalized. Subtypes A (H3N2) and B were confirmed in 10 and 14 patients, respectively. Seventy-six patients without influenza, including 48% of outpatients, were recruited as controls. All hospitalized patients were significantly younger regardless of influenza status (age <6 months in 59% vs. 23.2%, p < 0.001). All other data were similar among the groups. Comparing median levels of interferon-α2 among children with influenza, levels were significantly higher in outpatients than in hospitalized patients and were 263.2 pg/mL (25-75 interquartile range: 58.3-634) and detectable in only one patient (90 pg/mL), respectively. The levels of interferon-α2 in controls and those of interferon-ß in all groups were not detected. CONCLUSIONS: Higher levels of interferon-α2 in patients with less severe influenza reinforce experimental evidence about the protective role of interferon-α2 against influenza infection.
Assuntos
Imunidade Inata , Influenza Humana/imunologia , Interferon Tipo I/análise , Nariz/imunologia , Infecções Respiratórias/imunologia , Secreções Corporais/virologia , Pré-Escolar , Estudos de Coortes , Feminino , Hospitalização , Humanos , Lactente , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/imunologia , Pacientes Internados/estatística & dados numéricos , Interferon Tipo I/imunologia , Interferon alfa-2/análise , Interferon alfa-2/imunologia , Interferon beta/análise , Interferon beta/imunologia , Masculino , Nariz/virologia , Pacientes Ambulatoriais/estatística & dados numéricos , Infecções Respiratórias/virologiaRESUMO
Objetivos: Identificar a prevalência de sibilância e fatores associados em crianças com idade inferior a três anos de uma amostra populacional de baixa renda e medir outros marcadores de gravidade associados à sibilância e à asma nos primeiros anos de vida.Métodos: Os pais ou responsáveis das crianças incluídas foram entrevistados no centro de saúde de atenção primária de uma região de baixa renda da cidade de Porto Alegre, Rio Grande do Sul, e responderam a um questionário desenvolvido para estimar a prevalência de sibilância e avaliar os fatores associados, denominado EISL (Estudo Internacional de Sibilância em Lactentes). Foram incluídos pacientes com idade até 36 meses que consultavam para puericultura e/ou vacinação. Pacientes trazidos na emergência não foram incluídos.Resultados: O estudo avaliou um total de 153 crianças com idade média de 12,6±9,5 meses. Destes, 63% tiveram episódios de sibilância relatados, que ocorreram uma ou mais vezes durante os primeiros três anos de vida. A média de idade do primeiro episódio de sibilância foi 4,9±5,3 meses. Utilizaram β2-agonistas, corticoides orais e corticoides inalatórios 58,2%, 32,7% e 19% dos pacientes, respectivamente. Mais de 58% dos pacientes foram à emergência por sibilância e 13% foram hospitalizados pelo menos uma vez nos primeiros anos de vida.Conclusões: Este estudo mostrou que a prevalência de sibilância foi alta entre as crianças pequenas atendidas em um centro de saúde de uma região de baixa renda da cidade de Porto Alegre, sendo que os primeiros sintomas geralmente ocorreram durante os primeiros dois anos de vida. Além disso, alta frequência de uso de medicamentos e internação hospitalar demonstram o impacto da doença pulmonar obstrutiva neste grupo etário...
Aims: To identify the prevalence of wheezing and associated factors in children younger than three years of age in a sample of low income region, and to measure other markers associated with severity and risk of asthma in early life.Methods: Parents or legal guardians of infants were interviewed at the primary health center in a low-income area from Porto Alegre, Rio Grande do Sul state, and answered a questionnaire designed to estimate the prevalence of wheezing and evaluate the associated risk factors, called EISL (International Study of Wheezing in Infants). We included patients up to 36 months of age visiting for routine examination or vaccination. Patients brought to emergency room were not included.Results: The study evaluated a total of 153 children with a mean age of 12.6±9.5 months. Of them, 63% had at least one episode of wheezing reported, which occurred one or more times during the first year of life. The average age of the first episode of wheezing was 4.9±5.3 months. Use of β2-agonists, oral and inhaled corticosteroids was reported by 58.2%, 32.7% and 19%, respectively. More than 59% of the patients visited an emergency unit due to wheezing episodes and 13% were hospitalized at least once in the first years of life because of wheezing.Conclusions: This study has shown that the prevalence of wheezing on young children is high in a low-income area from Porto Alegre, and the symptoms usually occur during the first two years of life. In addition, high frequency of medication usage and hospitalization demonstrates the impact of obstructive lung disease in this age group...