RESUMEN
OBJECTIVE: To determine whether abnormalities of cellular immunity are present and linked to early wheezing after bronchiolitis. METHODS: We prospectively studied 26 infants hospitalized for a first episode of bronchiolitis and without any prior immune, cardiac, or respiratory disease. Blood was obtained at the time of enrollment and 5 months later for the assessment of the total cellular and differential counts, CD4+ (helper) and CD8+ (suppressor/cytotoxic) lymphocytes, and the activation markers CD23 (low-affinity immunoglobulin E receptor) and CD25 (interleukin-2 (IL-2) receptor). The cytokines interferon gamma (T-helper (TH) type-1 cytokine) and IL-4 (TH-2) were measured in plasma and in vitro after stimulation with IL-2 or with the house-dust mite (Dermatophagoides farinae) antigen. A daily log of episodes of wheezing was kept by parents after discharge. RESULTS: We found an increase in blood eosinophils, an increased percentage of CD4+, CD25+, and CD23+ lymphocytes in subjects at 5 months compared with the time of bronchiolitis and with healthy subjects of the same age (p < 0.05). Plasma IL-4 levels, although not different from those of healthy subjects, also increased significantly. Peripheral blood lymphocytes from infants who wheezed produced more IL-4 in vitro, 5 months after bronchiolitis, in response to D. farinae antigen. In babies who wheezed, a positive correlation was found between the total number of days that wheezing occurred and the blood eosinophil count. Babies who wheezed more often (> 20 days) had more peripheral blood basophils and eosinophils, and peripheral blood lymphocytes obtained from these subjects at the time of bronchiolitis produced less interferon gamma on stimulation with IL-2. CONCLUSIONS: Bronchiolitis is followed by activation of cellular immunity, and early wheezing in infants is associated with a TH-2 response.
Asunto(s)
Bronquiolitis Viral/inmunología , Interleucina-4/sangre , Activación de Linfocitos , Ruidos Respiratorios/etiología , Linfocitos T Colaboradores-Inductores/metabolismo , Enfermedad Aguda , Alérgenos/inmunología , Animales , Bronquiolitis Viral/sangre , Bronquiolitis Viral/complicaciones , Femenino , Humanos , Inmunoglobulina E/sangre , Lactante , Interferón gamma/metabolismo , Recuento de Leucocitos , Subgrupos Linfocitarios , Masculino , Ácaros , Estudios ProspectivosRESUMEN
We compared the bronchodilator response of terbutaline delivered either by a dry powder inhaler, the Turbuhaler, or by a metered-dose inhaler attached to a Nebuhaler inhaler in 10 children with stable asthma who were 3 to 6 years of age. The bronchodilator response did not differ between the two inhalational devices. The dry powder inhaler Turbuhaler is a suitable alternative to a metered-dose inhaler in the delivery of terbutaline to preschool children with stable asthma if adequate inhalational technique is used.
Asunto(s)
Asma/tratamiento farmacológico , Nebulizadores y Vaporizadores , Terbutalina/administración & dosificación , Administración por Inhalación , Niño , Preescolar , Método Doble Ciego , Diseño de Equipo , HumanosRESUMEN
We undertook a prospective, controlled study to evaluate the effect of trimethoprim-sulfamethoxazole in children with proven Escherichia coli O157:H7 enteritis on the duration fo symptoms, on fecal excretion of pathogen, and on the risk of progression to hemolytic-uremic syndrome. There was no statistically significant effect of treatment on progression of symptoms, fecal pathogen excretion, or the incidence of HUS (2/22 vs 4/25; p = 0.67). Our results suggest that a multicentric trial using rapid diagnostic methods to permit early randomization should be carried out.