OBJECTIVETo investigate the expressions of matrix metalloprotein-2 (MMP-2) and tissue inhibitor of metallopeptidase inhibitor-1 (TIMP-1) in the renal allografts of patients with chronic active antibody-mediated rejection (ABMR), and explore their role in the pathogenesis of ABMR.

METHODSImmunohistochemistry and computer-assisted image analysis were used to detect the expression of MMP-2 and TIMP-1 in the renal allografts of 46 patients with interstitial fibrosis and tubular atrophy (IF/TA), with 15 normal renal tissue specimens as the control. The association of MMP-2 and TIMP-1 with the pathological grade of IF/TA in ABMR was analyzed.

RESULTSThe expressions of MMP-2 and TIMP-1 significantly increased in the renal tissues of the patients as compared with the normal renal tissues (P<0.05). MMP-2 expression tended to decrease, while TIMP-1 and serum creatinine increased with the pathological grades of IF/TA (P<0.05). In IF/TA group, the expression of TIMP-1 was positively correlated to serum creatinine level (r=0.718, P=0.00<0.05).

CONCLUSIONAbnormal expressions of MMP-2 and TIMP-1 can promote the development of renal fibrosis in chronic ABMR.