[Diagnostic value of renal phospholipase A2 receptor and serum anti-phospholipase A2 receptor antibody in membranous nephropathy].

To examine the expression of phospholipase A2 receptor (PLA2R) in renal tissues and the level of anti-PLA2R antibody in serum in patients with idiopathic membranous nephropathy (IMN) and secondary membranous nephropathy (SMN), and to evaluate their diagnostic value in IMN.
 Methods: A total of 73 patients, who were diagnosed between May, 2014 and February, 2015 in the Department of Nephrology of the Second Xiangya Hospital, Central South University, were divided into three groups: an IMN group (n=48), an SMN group (n=17) and a minimal change disease group (n=8) according to the renal biopsy. PLA2R expression in renal tissues and the level of anti-PLA2R antibody in serum were detected by indirect immunofluorescence technique.
 Results: The positive rate and fluorescence intensity for PLA2R in the renal tissues in the IMN group were higher than those in the SMN group (91.7% in the IMN group vs 29.4% in the SMN group, P<0.05), while the positive rate and serum level for anti-PLA2R antibody in the IMN group were higher than those in the SMN group (85.4% in the IMN group vs 29.4% in the SMN group, P<0.05); the expression of PLA2R in renal tissues and the serum level for anti-PLA2R antibody were not detected in the minimal change disease group. The serum level of anti-PLA2R antibody was positively correlated with 24 h urine protein (r=0.432, P<0.01) and negatively correlated with serum albumin (r=-0.307, P<0.05).
 Conclusion: The expression of PLA2R in renal tissues and the serum level of anti-PLA2R antibody might be potential markers for diagnosis of IMN.