ABSTRACT
BACKGROUND: The precise way in which allergen is handled by the nose is unknown. The objective of this study was to determine recovery of Der p 1 allergen following nasal administration and to determine whether Der p 1 can be detected in nasal biopsies after natural exposure and nasal challenge to allergen. METHODS: (1) 20 nonatopic non-rhinitics were challenged with Der p 1 and recovery was measured by ELISA in the nasal wash, nasal mucus and induced sputum up to 30 minutes. Particulate charcoal (<40 µm) served as control. (2) In 8 subjects (5 atopics), 30 to 60 minutes after challenge histological localisation of Der p 1 in the nasal mucosal epithelium, subepithelial mucous glands and lamina propria was performed. Co-localisation of Der p 1 with macrophages and IgE-positive cells was undertaken. RESULTS: (1) Less than 25% of total allergen was retrievable after aqueous or particulate challenge, most from the nasal mucus during 1-5 min after the challenge. The median of carbon particles recovered was 9%. (2) Prechallenge Der p 1 staining was associated with the epithelium and subepithelial mucous glands. After challenge there was a trend for greater Der p 1 deposition in atopics, but both atopics and nonatopics showed increases in the number of Der p 1 stained cells and stained tissue compartments. In atopics, increased eosinophils, macrophages and IgE positive cells co-localized with Der p 1 staining. CONCLUSIONS: Der p 1 allergen is detected in nasal tissue independent of atopic status after natural exposure. After challenge the nose effectively retains allergen, which remains mucosally associated; in atopics there is greater Der p 1 deposition and inflammatory response than in nonatopics. These results support the hypothesis that nasal mucus and tissue act as a reservoir for the inhaled Der p 1 allergen leading to a persistent allergic inflammatory response in susceptible individuals.
Subject(s)
Allergens/metabolism , Dermatophagoides pteronyssinus/immunology , Nasal Mucosa/metabolism , Adult , Animals , Female , Humans , Male , Middle Aged , Nose/immunology , Young AdultABSTRACT
OBJECTIVE: To evaluate the efficacy of three frequently used spacer devices to deliver aerosol to the lung, and to compare radioaerosol deposition with each device in different age groups. METHODS: Nine healthy, non-smoking volunteers were recruited: three adults and six children, including three toddlers and three school age children. Qualitative and semi-quantitative analysis of radioaerosol deposition in the lung were carried out. Yet, two small-volume devices (Aerochamber and Inal-Air) and one large-volume device (Flumax) were compared. Each patient inhaled 99mtechnetium-phytate. The device was filled during 30 seconds with radioaerosol. Oxygen was used as the driving gas. During 10 seconds, the patients inhaled the radioaerosol. The radiation emitted at the front and back of the chest was measured. The radiation inside the device was also measured. RESULTS: The quantitative evaluation of lung deposition revealed that the younger the patient, the less aerosol was deposited in the lung with the large-volume spacer device (Flumax). The difference between small-volume devices (Aerochamber and Inal-Air) was not significant. CONCLUSION: Small-volume spacers are the most appropriate for children. Large-volume devices should only be used by adolescents and adults.
Subject(s)
Inhalation Spacers , Lung , Technetium/administration & dosage , Administration, Inhalation , Adult , Aerosols , Age Factors , Child , Child, Preschool , Humans , Lung/chemistry , Technetium/analysisABSTRACT
OBJETIVO: Avaliar, através de estudo da deposição pulmonar de 99m tecnécio-fitato, a eficácia de três espaçadores freqüentemente utilizados na prática clínica e comparar esta deposição de acordo com diferentes faixas etárias. MÉTODOS: Nove pacientes voluntários sadios, sem história de doença pulmonar, foram estudados, sendo três adultos e seis crianças de diferentes faixas etárias. Através de verificação qualitativa e semiquantitativa da deposição de 99m tecnécio-fitato em vias aéreas, procedeu-se a análise comparativa entre dois espaçadores de pequeno volume (Aerochamber® e Inal-Air®) e um espaçador de grande volume (Flumax®). Cada paciente recebeu inalação de 99m tecnécio-fitato. O espaçador foi preenchido, durante 30 segundos, por radioaerossóis impulsionados por fluxo de oxigênio. Por 10 segundos, os pacientes procederam à inalação com máscara acoplada ao espaçador. Por 4 minutos, realizou-se contagem de radiação emitida nas faces anterior e posterior do tórax. Realizou-se, ainda, contagem de radiação presente no interior de cada espaçador. RESULTADOS: Na avaliação semiquantitativa da deposição pulmonar, verificou-se que, em todas as faixas etárias, houve uma menor deposição percentual quando se utilizou o espaçador de grande volume (Flumax®), sendo esta diferença relativa inversamente proporcional à faixa etária. Em outras palavras, quanto menor a criança, menor a deposição de aerossol radioativo ao se utilizar espaçadores de grande volume. Por outro lado, não se verificou diferença significativa entre os espaçadores de pequeno volume (Inal-Air® e Aerochamber®) nas faixas etárias estudadas. CONCLUSAO: Os dados obtidos indicam que espaçadores de pequeno volume são os mais indicados para utilização na faixa pediátrica, devendo-se restringir o uso de espaçadores de grande volume a adolescentes e adultos.