Urinary Matrix Metalloproteinase-9 and Nephrin in Idiopathic Membranous Nephropathy: A Cross-Sectional Study.

AIM: Idiopathic membranous nephropathy (IMN) has a varied clinical course that requires accurate prediction as a prerequisite for treatment administration. Currently, its prognosis relies on proteinuria, a clinical parameter whose onset lags behind kidney injury. Increased urinary excretion of matrix metalloproteinase-9 (MMP-9) and nephrin has been reported in a number of IMN-like glomerular diseases in which they reflected disease severity. However, little or nothing is known of the importance of these biomarkers in IMN, a major cause of adult nephrotic syndrome. To highlight their potential, we measured both biomarkers and assessed their relationships with key parameters of renal function in IMN. METHODS: We quantified urinary MMP-9 and nephrin in 107 biopsy-proven IMN patients and 70 healthy subjects by enzyme-linked immunosorbent assay (ELISA). We then compared biomarker levels between patients and healthy subjects and among patients with different clinical features. We also determined the relationship of each biomarker with proteinuria and the estimated glomerular filtration rate (eGFR). RESULTS: Urinary MMP-9 and nephrin were significantly higher in IMN compared to healthy controls. Unlike nephrin, MMP-9 correlated significantly with proteinuria and was significantly higher among patients with nephrotic range proteinuria. Both biomarkers were correlated with eGFR, but only MMP-9 was significantly higher in patients with eGFR less than 90 ml/min/1.73 m2. CONCLUSION: Our findings suggest that urinary MMP-9 holds a greater potential than urinary nephrin in monitoring the severity of IMN.

Urine markers of podocyte dysfunction: a review of podocalyxin and nephrin in selected glomerular diseases.

Urinary podocalyxin and nephrin are urine markers of podocyte dysfunction that may reflect the integrity of kidney's filtration barrier. Studies on their respective roles in glomerular diseases are still underway. However, the isolated and unsystematic manner in which they are being studied does not permit proper identification of their roles in each glomerular disease. As such, there is little or no appreciation of what research has already achieved and what remains to be achieved as the research direction is not clearly defined. We explored the recent studies and outlined the major findings regarding the value of both biomarkers in each of the three glomerular disease entities. Our review covered diabetic nephropathy, membranous nephropathy and IgA nephropathy.

Comparison of two methods to detect M-phospholipase A2 receptor antibodies in serum / 中国免疫学杂志

Objective:To compare the difference of serum levels of M-phospholipaseA2 receptor ( PLA2R) antibodies in patients with idiopathic membranous nephropathy(IMN) detected by two different methods and evaluate the diagnostic value of two methods. Methods:Patients diagnosed as membranous nephropathy and other diseases with biopsy-proven from december 2014 to october 2015 in Shengjing Hospital of China Medical University were enrolled and devided into IMN group and non-IMN group. The serum levels of anti-PLA2R antibody were detected by both indirect immunofluorescence assay(IFA) and enzyme linked immunosorbent assay(ELISA). Results:The sensitivity of IFA and ELISA in IMN were 71. 3% and 68. 5%,and the specificities of two methods were the same as 100%. The area under ROC curves of anti-PLA2R antibody for IMN diagnosis were 0. 860 and 0. 839. The diagnostic value of IFA and ELISA was no statistically significant differences in IMN ( P>0. 05 ) , and the consistency of two methods was better (κ=0. 876). The IMN patients of positive anti-PLA2R antibody be susceptible to the low level of serum albumin (P<0. 05). The higher levels of PLA2R antibody were linked with the worse hypoproteinemia and the higher rate of nephrotic-range proteinuria in IMN patients. Conclusion:Two methods of detecting sera PLA2R antibody have higher sensitivity and specificity,so the sera anti-PLA2R antibody was a better biomarker in the diagnosis of idiopathic membranous nephropathy.