The Expression And Significance Of Matrix Metalloproteinase-9 In Human Lupus Nephritis

Objective: To investigate the expression of Matrix Metalloproteinase-9 (MMP-9) in renal tissue of patients with lupus nephritis (LN) and their relationships with clinical and pathology manifestations. Methods: The expression of MMP-9 in 31 renal tissue of patients with LN was detected by immunohistochemical staining. We also examined possible association between the expression of MMP-9 in renal tissue and systemic lupus erythematosus (SLE) activity and renal lesions. Results: There is no obvious expression of MMP-9 in normal glomerular areas while mild expression of the same components exist in normal renal tubular areas. Compared with the normal control group, it was significantly higher that the expression of MMP-9 in renal tissue of patientswith LN( P<0.01). Among WHO class â…¡ III and IV LN, the expression of MMP-9 in renal tissue with LN in class IV was the highest (P<0.01) while that of in class II was the lowest( P<0.05). Furthermore, glomerular MMP-9 was positively correlated with the level of serum creatinine the quantity of 24 hours proteinuria , SLE disease activity index (SLEDAI) and LN renal activity index (RAI)( P<0.05), renal tubular MMP-9 was also positively correlated with RAI( P<0.05). Conclusion: This study has demonstrated that the expression of MMP-9 in renal tissue is notably elevated in patients with LN. Overexpression of renal tissue MMP-9 is correlated with pathological type of LN. In addition, glomerular MMP-9 could reflect the degree of renal function the disease activity and the severity of renal leisions. Therefore, the expression of MMP-9 in renal areas may play important roles in mediating progressive renal damage in human LN.