Occupational Asthma Reference

Maestrelli P, Occari P, Turato G, Papiris SA, Di Stefano A, Mapp CE, Milani GF, Fabbri LM, Saetta M, Expression of interleukin (IL)-4 and IL-5 proteins in asthma induced by toluene diisocyanate (TDI), Clin Exp Allergy, 1997;27:1292-1298,

Keywords: Italy, TDI, mechanism, challenge, T-lymphocyte, IL-4, IL-5

Known Authors

Leo Fabbri, University of Moderna and Reggio Emilia Leo Fabbri

Piero Maestrelli, Padova University, Italy Piero Maestrelli

Christina Mapp, Padova University Christina Mapp

If you would like to become a known author and have your picture displayed along with your papers then please get in touch from the contact page. Known authors can choose to receive emails when their papers receive comments.

Abstract

BACKGROUND: TDI-induced asthma exhibits clinical, functional and morphological similarities with allergen-induced asthma, suggesting that an immunological mechanism is involved in the sensitization to TDI. In vitro studies using the technique of cloning lymphocytes demonstrated that a great proportion of T-cell clones derived from bronchial mucosa of subjects with TDI-induced asthma produced IL-5 and interferon-gamma, but not IL-4, upon in vitro stimulation.

OBJECTIVES: To investigate in vivo the role of IL-4 and IL-5 on the inflammatory response of the bronchial mucosa to TDI in sensitized subjects, we performed a quantitative analysis of bronchial biopsies.

METHODS: We obtained bronchial biopsies from six subjects with TDI asthma 48 h after an asthmatic reaction induced by TDI challenge (challenged group), in six subjects with TDI asthma 1-4 weeks after the last exposure to TDI (chronic group), and in six non-asthmatic controls. The number of eosinophils, mast cells, T-lymphocytes, and IL-4 and IL-5 protein positive cells was determined by immunohistochemistry in the area 100 microm beneath the epithelial basement membrane.

RESULTS: The characteristic increase of submucosal eosinophils, but not of mast cells and T-lymphocytes, was observed in the subjects with TDI-induced asthma when compared with controls. No differences were detected between the two groups of asthmatics. In the subjects with TDI-induced asthma, cell immunoreactivity for IL-5 was increased when compared with normal controls. There was no difference in the expression of IL-5 protein between challenged and chronic asthmatics. In contrast, the expression of IL-4 protein was increased only in the asthmatic subjects tested after recent exposure to TDI.

CONCLUSIONS: We demonstrated that TDI asthma 48 h after specific bronchial challenge was associated with increased numbers of cells expressing IL-4 and IL-5, whereas chronic TDI asthma was associated with increased expression of IL-5, but not of IL-4. The results suggest that subjects who developed TDI asthma exhibit increased production of IL-5 even in the absence of a recent trigger by the exogenous sensitizer and that production of TH2-like cytokines in TDI-induced asthma may not always be co-ordinately regulated in vivo

Full Text

Full text of this reference not available

Please Log In or Register to add the full text to this reference

Associated Questions

There are no associations for this paper.

Please Log In or Register to put forward this reference as evidence to a question.

Comments

Please sign in or register to add your thoughts.


Oasys and occupational asthma smoke logo