Metalloproteinase‐9 is increased after toluene diisocyanate exposure in the induced sputum from patients with toluene diisocyanate‐induced asthma

Abstract

TDI exposure leads to overproduction of MMP-9, which may induce airway inflammation and remodeling, and then contribute to persistent asthmatic symptoms in TDI-induced asthma.

Histamine Release and Inflammatory Cell Infiltration in Airway Mucosa in Methylene Diphenyl Diisocyanate (MDI)-Induced Occupational Asthma

“…In addition, eosinophils are known to be a major source of MMP-9 [31]. Given that MMP-9 levels are increased during eosinophil-mediated inflammatory processes, such as bronchial asthma [32,33] and TDI-OA [34], it is not surprising that MMP-9 levels were correlated with sputum eosinophil count in the present study. VEGF is the most potent direct-acting regulator of angiogenesis, and its level of expression is often excessive in chronic inflammation [35].…”

Occupational asthma: Current concepts in pathogenesis, diagnosis, and management

“…25,26 Isocyanate exposure also can elicit overproduction of matrix metalloproteinase 9, a finding of potential pathogenetic relevance because of the role of metalloproteinases in the structural changes of asthma. 27 Although eosinophilic inflammation may occur in OA from isocyanates, an increase in sputum neutrophils may actually be a more prominent feature of airway inflammation after acute inhalation of isocyanates. 28 Mechanistically, this might be partly explained by the observation that on exposure to isocyanates, peripheral mononuclear cells from patients with OA to isocyanates produce IL-8, a chemokine chemoattractant for neutrophils.…”

L’expectoration induite, outil de diagnostic de l’asthme professionnel

“…Outre le profil cytologique, il est instructif d'examiner le surnageant. Park et al ont relevé une augmentation de la métalloprotéinase-9 chez des travailleurs atteints d'AP après qu'ils aient été exposés aux isocyanates ; cette augmentation était même plus marquée que chez des travailleurs avec AP mais soustraits à l'exposition aux isocyanates depuis cinq ans [30]. Enfin, on peut tirer des renseignements utiles de la présence ou non des cytokines comme l'IL-8, l'IL-5 ou l'ECP (eosinophilic cationic protein) [17,31].…”