Analysis Of Serum Anti-pla2r Antibody With Clinical And Pathological Characteristics Of Patients With Membranous Nephropathy

Background:Membranous nephropathy(Membranous nephropathy,MN)is a unique glomerular disease,feathered with the deposition of subepithelial immune complex and an increased excretion of urine protein.It is the most common etiology of nephrotic syndrome in adults and the main pathological type of glomerulopathy.MN can be divided into two different types,idiopathic membranous nephropathy(IMN)and secondary membranous nephropathy(SMN).SMN is mostly seen in patients with systemic lupus erythematosus(SLE),hepatitis b,infectious diseases,malignant tumor,and kind of certain medication.As for the huge difference in the treatment between IMN and SMN,it is really important to identify those two types.At present,renal biopsy is the golden standard for the diagnosis of MN.A large number of researches have showed that M type phospholipase A2 receptors(PLA2R)are the main target antigens of MN,while the specific and corresponding antibody for IMN can be detected in serum.The positive rate of the antibody is about 70%,providing important clue for the distinction.IgG4 is the main immunoglobulin subtype involved in the immune response,combining with target antigens and complements as immune complexes under the epithelium.When it shows negative of serum antibody,it helps to diagnose and treat the disease by detecting the expression intensity of PLA2R and IgG4 in renal tissue.At the same time,it is found that the serum anti-pla2r antibody level is closely related to the urine protein level,serum albumin,serum cholesterol,renal injury and other clinical indicators in IMN patients,which has important significance for monitoring the outcome and recurrence of the disease.Objective:This paper aims to investigate the clinical and pathological features of IMN and its relationship with serum anti-pla2r antibody.To explore the diagnostic value of PLA2R and IgG4 expression in renal tissue for IMN with serum anti-pla2r antibody negative.Method:Subjects:Select patients with membranous nephropathy diagnosed pathologically in the center of Shandong Provincial Hospital affiliated to Shandong University from January 2017 to December 2018.And exclude cases that are lack of clinical data,treated with glucocorticoid and immunosuppressive agents before admission.Methods:Collect the general information,clinical manifestations,assistant examinations and pathological stage of IMN patients,comparing the correlation between serum anti-pla2r antibody and clinical and pathological features.Detect the expression of PLA2R and IgG4 in renal tissues of serum anti-pla2r antibody negative IMN patients and SMN patients,analyzing the clinical diagnostic value of these two indicators.Statistical methods:Data were analyzed by SPSS22.0 program.All measurement data were tested for normality,and the data in line with the normal distribution were described as mean standard deviation.Those that do not conform to the normal distribution are expressed by the median or by inter-quartile range.Data with normal distribution and homogeneity of variance were compared by t test,while data with non-homogeneity of variance and non-normal distribution were compared by non-parametric test.The basic characteristics of the enumeration data were expressed as examples(percentages),and chi-square test or Fisher’s exact probability method were used for comparison between univariate groups.Grade data were tested by mann-whitney U test.P<0.05 was considered statistically significant.Results:1.109 cases are included and analyzed in the research,of which 103 cases are IMN,2 cases are membranous lupus nephritis(MLN),and 4 cases and HBV associated glomerulonephritis.2.There are 103 cases of IMN,among which 74 are positive for serum anti-pla2r antibody,accounting for 71.8%of the total number of cases,and 29 are negative,accounting for 28.2%of the total number of cases.There is no significant difference in the sex and age between two groups.3.In IMN patients,serum anti-pla2r antibody level is mainly related to ALB,TC and urinary protein level,but has no significant relationship with BUN,CREA and eGFR.4.The pathological staging of IMN patients is mainly stage I,and only 10%of patients are accompanied by focal segmental sclerosing changes.Both sides are independent of serum anti-pla2r antibody level.5.IMN patients with serum anti-pla2r antibody negative,positive rate of renal tissue PLA2R and IgG4 expression is 65.5%and 62.1%,respectively.The double positive rate is 48.3%,much higher than that in SMN patients.When IgG4 is negative,the PLA2R positive rate is 17.2%.And when PLA2R is negative,the positive rate of IgG4 is 13.8%.Conclusion:1.In this study,the positive rate of serum anti-pla2r antibody is 71.8%.2.For IMN patients with serum anti-pla2r antibody positive,serum albumin levels are lower,cholesterol and urine protein levels are higher,and the performance is more significant than that of patients with antibody negative.3.About 10%of IMN patients are associated with focal segmental sclerosing changes,independent of serum anti-pla2r antibody levels.4.For IMN patients with serum anti-pla2r antibody negative,the PLA2R positive rate of glomerular PLA2R is 65.5%,the IgG4 positive rate is 62.1%,the double positive rate is 48.3%,and the single positive rate of PLA2R and IgG4 is 79.3%,significantly higher than that of SMN patients.When IgG4 is negative,the PLA2R positive rate is 17.2%,indicating the presence of other IgG subtypes involved in the immune response.