0.05),however,there was a close correlation with area densities of stroma ( r =-0.33, P

BACKGROUND: Previous experiments have shown that transforming growth factor-?1 (TGF-?1),matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-1 (TIMP-1) play an important role in chronic allograft nephropathy,but the mechanisms remains unclear. OBJECTIVE: To investigate the expression and significance of TGF-?1,MMP-2 and TIMP-1 in the renal tissues of chronic allograft nephropathy and normal renal tissues. DESIGN,TIME AND SETTING: A histological and morphological control observational experiment of cytology was performed at Pathological Laboratory of the 175th hospital from June to October 2008. PARTICIPANTS: The transplanted renal tissues extracted from 24 patients with chronic allograft nephropathy were used in the experiment,and the normal renal tissues in 10 patients were assigned as controls. METHODS: Immunohistochemical staining was performed in all the renal tissues. All the renal tissues were fixed with formaldehyde and embedded by paraffin wax. Then the sections were prepared with a thickness of 3 ?m,and were then closed with normal non-immune serum. Subsequently,the sections were incubated as follows: primary antibody,secondary antibody,streptavidin peroxidase complex,and diaminobenzidine (DAB),followed by HE counterstaining. The sections were cleared and coverslipped. MAIN OUTCOME MEASURES: The expressions of TGF-?1,MMP-2 and TIMP-1 in the renal tissues were observed by immunohistochemical staining. The relationships among TGF-?1,MMP-2 and TIMP-1,as well as between them and the grade of chronic allograft nephropathy were analyzed. RESULTS: Qualitative analysis: The TGF-?1,MMP-2 and TIMP-1 showed strongly positive expressions in the cytoplasm and membrane of renal tubular epithelial cells in transplanted renal tissues. Quantitative analysis: There were significant differences in expression of TGF-?1,MMP-2 and TIMP-1 between in transplanted renal tissues and in normal renal tissues (P