Background. Matrix metalloprotenases (MMPs) are a group of proteolytic enzymes that degrade extracellular
matrix (ECM) components. During inflammation MMPs are implicated in tissue destruction.
Aim. To investigate the expression of matrix metalloproteinases in the small intestinal
from patients with coeliac disease (CD) and dermatitis herpetiformis (DH).
Methods. Paraffin embedded duodenal sections from 10 untreated coeliac disease (UTCD), 10
treated coeliac disease (TCD), 10 dermatitis herpetiformis (DH) patients and 10 normal
subjects were examined. UTCD patients had moderate to severe mucosal damage. Five
of ten TCD patients had mild to moderate gut lesions. The majority of DH patients
had normal intestinal mucosa. Immunoperoxidase staining was used to detect the intracellular
expression of MMP 1, 3, and 9 enzymes. The number of stained cells in the lamina propria
was counted. The results were expressed as the percentage of positive cells per total
number of cells.
Results. Significantly higher expression of all MMPs was observed in mucosal cells from UTCD
(60%-70%), TCD (40%-50%) and DH (40%-50%) compared with cells from normal control
individuals (15%-25%). The percentage of stained cells was reduced in TCD and DH in
comparison to UTCD patients. The intensity of the expression of MMPs was closely related
to the grade of mucosal damage. Conclusion. Matrix metalloproteinases 1, 3 and 9 are strongly expressed in the small intestinal
mucosa of patients with CD and DH. Intensity of expression appeared to correlate with
the grade of mucosal damage. The results of our study suggest a role for these enzymes
in the process of tissue remodelling and destruction in gluten sensitive enteropathy.
