The Feasibility Analysis Of Application Of Serum Anti-PLA2R Antibody In Disease Diagnosis And Evaluation Of Idiopathic Membranous Nephropathy

Background: Membranous nephropathy(MN)is one of the main pathological types of Nephrotic syndrome.Its main feature is the deposition of immune complexes under the glomerular basement membrane,and with diffuse thickening of the basement membrane.About 20-30% of patients with MN will eventually develop to end-stage renal disease due to the disease progress.Idiopathic membranous nephropathy(IMN)accounts for about 70% of MN.In recent years,the incidence of IMN has increased significantly in China,but the pathogenesis of the disease is not very clear,which requires our in-depth research and exploration.Because renal biopsy is an invasive operation with some risks and contraindications,so it is not suitable for monitoring the patient’s condition.Therefore,we need to find a safe,fast,effective,and dynamic marker to monitor patient’s condition.Detection of Serum PLA2 R antibody can improve the accuracy of IMN diagnosis,and it can help us in differential diagnosis IMN from SMN.Objective: To study the application value of serum PLA2 R antibodies in the diagnosis of IMN.To find a safe,convenient,effective and non-invasive indicator,which can be used to diagnose IMN accurately,assessing severity of patient’s condition,and evaluating the efficacy of treatment.To find an effective biochemical indicator which suggests the possibility of IMN recurrence after kidney transplantation.Methods: A total of 98 patients with nephrotic syndrome or other primary glomerular disease,admitted to the Department of Nephrology in No.924 Hospital of Chinese People’s Liberation Army Joint Support Force from February 2018 to March 2019 were selected.All these patients were underwent renal biopsy with definitive pathological diagnosis.The incidences of IMN patients in nephrotic syndrome and nephritic syndrome were calculated,respectively.Patient’s PLA2 R antibody levels were detected by ELISA.68 patients were divided into the IMN group(35 cases)and the non-MN group(33 cases).The data of clinical data,biochemical results,serum PLA2 R antibodies levels,and kidney immunohistochemistry were collected,and the sensitivity and specificity of serum PLA2 R antibody for IMN were calculated.The correlation between serum PLA2 R antibody with urine protein quantification,plasma albumin,and renal function was analyzed.In the follow-up data of 41 patients with IMN treated with immunosuppressant,the correlation between serum PLA2 R antibodies and disease remission was analyzed.And the followup data of other 2 IMN patients with end-stage renal function and 2 IMN patients underwent kidney transplantation were also analyzed.Calculate serum PLA2 R antibody levels in different pathological stages of IMN.Results: In these patients,IMN accounted for 64% of the primary nephrotic syndrome,and 42% of the primary glomerular disease.Their average age was(48.94 ± 14.48)years.The serum PLA2 R antibody levels were(188.24 ± 311.87)RU / ml and(1.41 ± 3.25)RU / ml in the IMN group and the nonMN group respectively(P <0.05).The glomerular deposition rate of PLA2 R was 88.57% in the IMN group,and was not found in the non-MN group.Comparison of the immunoglobulin deposition in glomerular between the IMN group and non-MN group: Ig G deposition rates were 97.14% and 21.21%,Ig G1 deposition rates were 94.29% and 9.09%,Ig G4 deposition rates were 97.14% and 12.12%,and complement C3 deposition rates were 94.29% and 48.40% respectively(P < 0.05).The sensitivity and specificity of serum PLA2 R antibody for IMN were 74.3% and 100% respectively.PLA2 R antibody was positively correlated with patient’s urinary protein levels and renal dysfunction levels,and negatively correlated with their plasma albumins.Serum PLA2 R antibody levels in patients with stage II IMN were(206.08 + 67.78)RU / ml significantly higher than those in stage III(35.26 + 18.82)RU / ml(P <0.05).After the treatment of IMN patients,the clinical condition was relieved as the serum PLA2 R antibody level decreased.In the ESRD patients with IMN,the serum PLA2 R antibody decreased from 247.24 RU / ml to 0.71 RU / ml in one patient with poor renal blood supply,but in another patient with normal renal blood supply,the serum PLA2 R antibody increased from 197.75 RU / ml to 230.15 RU / ml.Renal function and proteinuria were normal in 2 patients with IMN after renal transplantation,their serum PLA2 R antibody levels were also normal(0.76 RU / ml and 0.98 RU / ml,respectively).Conclusion(s): Serum PLA2 R antibody is a specific antibody for INM,which can be used as a feasible marker for the diagnosis and differential diagnosis of IMN.Dynamic monitoring of serum PLA2 R antibody plays a very important role in the disease evaluation,the formulation and adjustment of treatment,and the evaluation of therapeutic effects of IMN patients.Detection of serum PLA2 R antibody can be used to judge the possible recurrence of IMN after kidney transplantation.Compared with renal biopsy,using ELISA to detect PLA2 R antibody is more safe,more effective,and more convenient.