ASSOCIATION FOR ACADEMIC SURGERY Serum Levels of Matrix Metalloproteinase-2 as a Marker of Intimal Hyperplasia

Background. A primary component in the development of intimal hyperplasia (IH) in response to vascular injury is basement membrane remodeling. Matrix metalloproteinases (MMPs) play a major role in this process by degradation of basement membrane proteins, mainly collagen type IV. Vascular injury initiates an inflammatory cascade with the release of tumor necrosis factor-alpha (TNFa), interleukin1beta (IL-1b), and C-reactive protein (CRP). We hypothesize serum levels of these elements may serve as biomarkers of the development of IH. Methods and Results. At baseline, 2, 7, 10, and 14 days post-balloon angioplasty of the carotid artery, rattissuesamples werestainedwith Massontrichrome elastin to examine IH. Intima:media ratios (I:M) increased significantly over time postinjury. Serum samples were collected at the time of tissue sampling, and levels of MMP-2, MMP-9, collagen type IV, TNFa, IL-1b, and CRP were assayed using sandwich enzymelinked immunosorbent assay (ELISA). MMP-2 serum levels at7, 10,and 14days postinjury weresignificantly elevated compared with baseline. Other elements were not significantly elevated. Conclusion. Early and persistent elevation in the serum levels of MMP-2 may be a useful biomarker of basement membrane remodeling and the presence of