Elevated levels of plasma matrix metalloproteinase-9 in patients with atopic dermatitis: a pilot study.

Matrix metalloproteinase (MMP)-9 has been shown to play a role in the infiltration of inflammatory cells in various tissues. It is thus part of the pathogenesis of many inflammatory diseases, including asthma and allergic rhinitis/conjunctivitis. We compared plasma MMP-9 levels of 20 patients with atopic dermatitis (AD) with that of 17 control subjects. Additional outcome parameters consisted of the modified objective SCORing Atopic Dermatitis and the Three Item Severity score in patients, and peripheral blood leucocytes and eosinophils in both groups. Plasma MMP-9 levels were found to be significantly higher in patients compared with controls, supporting a role for MMP-9 in the pathogenesis of AD.