Matrix metalloproteinase-9, but not tissue inhibitor of matrix metalloproteinase-1, increases in the sputum from allergic asthmatic patients after allergen challenge

Chest. 2002 Nov;122(5):1553-9. doi: 10.1378/chest.122.5.1553.


Objective: The aim of the study was to determine whether allergen inhalation modulates the levels of matrix metalloproteinase (MMP)-9 and tissue inhibitor of matrix metalloproteinase (TIMP)-1 in the induced sputum recovered from patients during a late-phase reaction.

Method: Eight allergic asthma patients and five healthy control subjects inhaled a dose of Dermatophagoides pteronyssinus extract corresponding to the provocative concentration of the allergen causing a 20% fall in FEV(1) and saline solution. Lung function was carefully monitored for 6 h, and an induced sputum test was performed at 6 h after sham challenge or allergen challenge. The total and differential cell counts were analyzed, and the levels of MMP-9 (by enzyme-linked immunosorbent assay [ELISA] and zymography), TIMP-1 (by ELISA), and albumin (by rocket immunoelectrophoresis) were measured.

Results: The sputum eosinophil counts (p < 0.01) and MMP-9 levels (p < 0.05) increased significantly in atopic asthma patients after undergoing the allergen challenge but did not in the control subjects. By contrast, TIMP-1 and albumin levels were not significantly increased in any group. MMP-9 levels, measured after the allergen challenge in asthmatic patients, were significantly correlated with FEV(1) variations after allergen inhalation (r = 0.51; p < 0.05) and with the sputum neutrophil percentage (r = 0.71; p < 0.01).

Conclusion: The levels of MMP-9, but not TIMP-1, increase after inhaled allergen challenge in the sputum of allergic asthmatic patients. This protease increase may lead to a transient imbalance between MMP-9 and TIMP-1 favoring proteolytic extracellular matrix degradation.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Asthma
  • Bronchial Provocation Tests
  • Female
  • Humans
  • Male
  • Matrix Metalloproteinase 9 / analysis*
  • Middle Aged
  • Sputum / chemistry*
  • Sputum / enzymology
  • Tissue Inhibitor of Metalloproteinase-1 / analysis*


  • Tissue Inhibitor of Metalloproteinase-1
  • Matrix Metalloproteinase 9