Acute and Chronic Changes of Vascular Endothelial Growth Factor (VEGF)in Induced Sputum of Toluene Diisocyanate (TDI)-induced Asthma Patients

Vascular endothelial growth factor (VEGF) is a multi-functional cytokine involved in inflammation, repair and angiogenesis in asthmatic airway. This study aimed to evaluate the role of VEGF in immediate bronchoconstriction induced by TDI inhalation, and in chronic TDI-asthma patients. 11 newly diagnosed TDI-asthma patients (group I), 12 chronic TDI-asthma patients with persistent asthma symptoms followed for >4 yr and 15 unexposed healthy controls were enrolled. In group I, induced sputum and serum were collected before and 7 hr after placebo- and TDI-bronchoprovocation test (BPT). In group II, induced sputum and serum were collected every 2 yr. VEGF levels were measured by ELISA. There were no significant differences in sputum and serum VEGF levels between patients and controls. Before and after placebo and TDI-BPT, no significant changes were noted in sputum and serum VEGF levels of group I. In group II patients, sputum VEGF showed variable changes at 1-yr, then decreased significantly at 2-yr (p<0.05), while serum VEGF showed variable changes at 2-yr, which decreased significantly at 4-yr (p<0.05). These results suggest that VEGF may play a minor role in immediate bronchoconstriction after TDI-BPT. In chronic TDI-asthma, VEGF may be involved to 2 yr after the diagnosis and the contribution may decrease after then.

Teste de provocação brônquica: comparação de um protocolo encurtado recomendado pela european respiratory society com um protocolo padronizado / Bronchoprovocation test: comparison of a shortened protocol recommended for european respiratory society with one standard protocol

Introdução: o objetivo deste estudo foi testar o protocolo encurtado de provocação brônquica, modificado, recomendado pela European Respiratory Society, comparando-o com outro considerado padrão. Métodos: foram estudados 20 pacientes com sintomas respiratórios de tosse e/ou dispnéia nos quais o teste doi indicado. A técnica de provocação brônquica foi a de inalação de solução de metacolina, em etapas com concentrações crescentes, durante respiração espontânea. As concentrações de metacolina, no protocolo padrão, iniciam com 0,3mg/ml, dobrando-se, segudamente, até 16mg/ml. No protocolo encurtado, a diferença foi na dose inicial, de 0,25 à 1,0 mg/ml, na dependência das drogas usadas para controle dos sintomas. Resultados: a incidência e a intensidade dos efeitos colaterais, assim como os resultados de PC20, foram iguais em ambos os protocolos. Valores médios de PC20 foram de 3,24 e 3,47 mg/ml respectivamente nos protocolos padrão e encurtado. O tempo total gasto para a realização do teste foi significamente inferior no encurtado, reduzindo o número de etapas. Conclusão: concluímos que os protocolos, encurtado e padrão, mostraram resultados equivalentes, sendo o protocolo encurtado mais rápido.

Clinical significance of specific IgG and IgE antibodies to toluene diisocyanate ( TDi ) - human - serum albumin ( HSA ) conjugate in TDI - induceed occupational asthma / 천식및알레르기

BACKGROUND AND OBJECTIVE: TDI is known to be the most prevalent cause of occupational asthma ( OA ) in Korea. However, the pathogenesis of TDI - induced occupational asthma still remains to be further clarified. So, we evaluated clinical significance of serum specific IgG and IgE antibodies to TDI - HSA conjugate in TDI - induced occupational asthma. Subjects and METHODS: Serum specific IgG and IgE antibodies to TDI - HSA conjugate were measured by enzyme linked immunosorbent assay. Serum was collected from 50 TDI- induced OA patients ( classified as group I ), and was compared with that from 13 asthmatic subjects with negative TDI - bronchoprovocation test ( BPT, group II ), allergic asthmatics ( group III ), and unexposed healthy controls ( group IV ). RESULTS: The prevalence of specific IgG was significantly higher in group I than in group II (p = 0.01) or group III (p 0.05). However, the prevalence of specific IgE was not different between group I and group II (p> 0.05 ) or group II and group III( p> 0.05 ). There was no significant difference in prevalence of specific IgG according to the asthmatic response during TDI bronchoprovocation test ( p> 0.05 ). No statistical significance was noted between specific IgG and IgE antibodies in group I subjects ( p> 0.05 ). CONCLUSION: These findings demonstrate that presence of specific IgG to TDI - HSA conjugate is closely related to TDI - BPT results and it may contribute to the development of TDI - induced asthma.

Occupational asthma induced by tobacco leaf / 천식및알레르기

We experienced a cose of occupational asthma induced by the tobacco leaf in 49-year old man. He has worked at the Korean Tobacco and Ginseng company for 23 years but suffered from the intermittent mild wheezing and dyspnea since 6 years ago. He has not involved in the process making the tobacco directly, but just managed it at the storage barn. He showed a whole negative reaction to 55 inhalant allergens(Bencard, UK) and the allergen extracted from the yellow Korean tobacco leaf, but showed the dual asthmatic respose to the allergen bronchial provocation test with it. His basal PC is 6.35 mg/ml with methacholine inhalation challenge. Now he changed the workplace far away from the barn at the same company and is treated with bronchodilator and anti-asthmatic inhaler.

Revival of Hop Japanese pollinosis in asthmatic subjects in Kyungki area / 천식및알레르기

BACKGROUND: Hop Japanese (Hop J) pollens are abundant in the air of Korea during the autumn season. Their significances as a source of allergenic sensitization have been underestimated in this country. MATERIAL AND METHOD: In other to observe clinical features of Hop J-sensitive asthmatic patients in this country, skin prick test with Hop J pollen was performed. The serum specific IgE antibodies to Hop J pollen antigen were detected by enzyme linked immunosorbent assay (ELISA) in positive responders (>2+ of A/H ratio) on skin prick test. To confirm the respiratory sensitization, bronchoprovocation test was performed in 17 asthmatic patients sensitive to this pollen. RESULT: Ten asthmatic subjects showed a significant bronchoconstriction following the inhalation of Hop J pollen extract (6 early and 4 dual astmatic responses) and all of them had high serum specific IgE bindings, with minimal bindings in negative responders. They have suffered from seasonal aggravation of asthmatic symptoms with or without rhinitis, and/or conjunctivitis symptoms. The skin reactivity to Hop J had more than 5+ of A/H ratio on skin prick test in nine positive responders, whlie negative responders showed from 1+ to 3+ response. Moreover, four (40%) asthmatic subjects showed a positive response to only the Hop J pollen on skin prick test and an isolated positive asthmatic response to the Hop J bronchoprovocation test. CONCLUSION: We believe that the Hop J pollen should be considered as an allergen during the Autumn season, and thus included in skin test batteries in this area. Some labelled having intrinsic asthma or rhinitis might be sensitized to this pollen or other unknown allergens.

Isocyanate-induced occupational asthma: challenge and immunologic studies

Isocyanate is the most prevalent agent in occupational asthma(OA) in Korea. We analyzed 43 toluene diisocyanate(TDI) induced OA patients of whom 81% were found to be spray painters. The bronchial sensitivity of all subjects was confirmed by TDI-bronchial challenge test. Serum-specific IgE antibodies to isocyanate-human serum albumin(HSA) conjugate were detected by RAST technique(Pharmacia, Sweden). Bronchial challenge test results revealed 21(57%) early, 5 late only, 4 dual, and 12 atypical responders(5 prolonged immediate, 6 square-shaped, 1 progressive). Four(9%) subjects had negative results on the methacholine bronchial challenge test. High levels of serum specific IgE antibody to isocyanate-HSA were found in 17(40%) patients. The prevalence of a specific IgE antibody was not associated with a type of TDI-bronchial challenge test response, smoking and atopic status, presence of rhino-sinusitis and systemic symptoms, or a degree of airway hyperresponsiveness to methacholine(p> 0.05). The period of latency, ranging from 3 to 132 months, was significantly longer in high specific IgE responders (p< 0.05). These data suggest that 40% of isocyanate-induced occupational asthma patients had high specific IgE antibody to isocyanate-HSA conjugate. The presence of specific IgE antibody does not seem to correlate with clinical parameters.

Bronchial challenge responses in asthmatic patients sensitized to Artemisia spp. pollen

To characterize the patients whose asthma may be caused by Artemisia pollen extracts, we studied the bronchoprovocation test with Korean Artemisia pollen extracts (1:20 w/v), methacholine bronchial challenge test and wormwood-RAST in 32 asthmatic patients sensitized to Artemisia pollen. Twenty-six(81%) developed a 15% or greater decrease in FEVI after the inhalation of Artemisia pollen extracts and 13 patients showed early responses, 8 dual, and 5 late only. Thirteen(50%) out of 26 positive responders complained of seasonal aggravation of their asthmatic symptoms. Seven(53.8%) of the 13 seasonal type patients, 10(76.9%) of the 13 perennial type and 5(100%) of the 5 negative responders showed concurrent positive responses in the house dust bronchoprovocation test. The bronchial responsiveness to allergen(PD15) was more dependent upon the specific IgE level(bound radioactivity on wormwood-RAST) and multiple regression analysis revealed that the specific IgE level and methacholine PC20 may be contributory to allergen PD15. These results suggested that specific IgE to Artemisia pollen appears to be the major contributor to susceptibility to Artemisia bronchial challenges and this pollen may be considered as one of the important allergenic etiologies of atopic asthma in this country.

The significance of specific IgE and IgG to dermatophagoides farinae according to the types of asthmatic reaction in house dust asthmatics

To investigate the role of specific IgE and IgG in the various types of asthmatic reaction, we measured specific IgE and IgG levels to Dermatophagoides farinae (D.farinae) using the D. farinae-radioallergosorbent test (RAST) and Phadebas IgG-RAST in 39 house dust asthmatics (11 early responders, 21 dual responders and 7 isolated late responders) and 12 negative responders on house dust bronchoprovocation. There were significant differences in the D. farinae-specific IgE level and skin reactivity to D. farinae and house dust among the 4 groups (p less than 0.05) and the specific IgE level of dual asthmatic responders was the highest and was significantly higher than that of early responders (p less than 0.05). The specific IgG level showed no differences among the 4 groups. These results suggested that the types of asthmatic reaction in house dust asthmatics were closely related to specific IgE level to D. farinae and the specific IgG level seemed not to be related to an isolated late response.