Association Between Proteinuria And Podocyte Injure In Patients With IgA Nephropathy

Objective: To investigate the association between proteinuria and podocyte injure in patients with IgA nephropathy.Methods: Collection of all clinical data of patients who underwent renal biopsy pathological and diagnosed IgA nephropathy in the Department of Nephrology of the First Affiliated Hospital of Fujian Medical University from2009-01to2014-04, excluding secondary IgA nephropathy, under15-year-old and without complete clinical data. According to the24-hour-proteinuria results, all qualified IgA nephropathy patients were divided into2groups: Low proteinuria(<1.0g/24h) and High proteinuria(≥1.0g/24h). And stratified random sampling6patients in each group, with renal biopsy specimens for immunohistochemical, observe podocytes’ markers expression of nephrin, CD2AP and synaptopodin.Results:1. Factors affecting the levels of proteinuria in IgAN are hyperlipidemia (OR=4.534, P=0.001) and blood creatinine (OR=1.022, P=0.003).2. There is statistically significant correlation between proteinuria and IgAN pathological types (r=0.236, P=0.013<0.05).3. Nephrin stretches along the capillary loops linear granular distribution in normal renal tissues. Compared with the control group, nephrin in IgAN significantly decreased(P<0.05). And in glomerular hardened zone, there was less or none expression of nephrin. Differential expression of nephrin between the two groups of IgAN has statistical significance (P<0.05).4. CD2associated protein (CD2AP) stretches along the capillary loops linear granular continuous distribution in normal renal tissues. Compared with the control group, particles in the cytoplasm of IgAN group reduced, segment deletion appeared with uneven distribution. There was less or none expression of CD2AP in glomerular hardened zone. Comparing to the control group, there is no statistical significance in Low proteinuria (P=0.639) but in Hight proteinuria (P<0.05). And differential expression of CD2AP between the two groups of IgAN has statistical significance (P<0.05).5. Synaptopodin is along the capillary loops of a granular distribution in normal renal tissues. Compared with the control group, particles in the cytoplasm of IgAN group reduced, distribution was uneven. There was less or none expression of synaptopodin in glomerular hardened zone. Comparing to the control group, there is statistical significance in both Low proteinuria and High proteinuria (P<0.05). And differential expression of synaptopodin between the two groups of IgAN has statistical significance (P<0.05).6. Negative relationship has observed between proteinuria and nephrin （r=-0.805, P<0.05）, CD2AP（r=-0.728, P<0.05）, synaptopodin（r=-0.752，P<0.05）.Conclusions:1.Podocytes injury may participate proteinuria occurred in the IgAN. The more severe podocytes injury is, the more proteinuria.2.There is a relationship between IgAN damage and pathological grading of podocyte podocyte injury, but whether it is an independent risk factor for IgAN pathological grades is looking for further study.3.Hyperlipidemia and blood creatinine influence proteinuria in IgA nephropathy.