Assessment of Matrix Metalloprteinases (MMP) 1, 3 and 9 in Gluten Sensitive Enteropaty

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.