Mechanism Of Serum PLA2R Antibody And Monosaccharide Component Analysis In Thromboembolic Events In Primary Membranous Nephropathy

Objective:The incidence of thromboembolism in patients with membranous nephropathy(p MN)was significantly higher than that of other Primary glomerular diseases.To investigate the cause,we designed a series of clinical and laboratory studies to explore the mechanism of thromboembolism in patients with Primary membranous nephropathy(p MN).To investigate the relationship between serum Phospholipase A2 receptor(PLA2R)antibody and thromboembolic events.The relationship between the changes of serum monosaccharide components and thromboembolism in p MN patients was detected in laboratory,and the correlation with clinical indicators was analyzed.Methods: Clinical study and laboratory study.1.Clinical studies: Clinical data of newly diagnosed p MN patients who underwent serum anti-PLA2 R antibody detection in The Affiliated Hospital of Qingdao University from July 2019 to March 2021 were collected by yidouyun database of Affiliated Hospital of Qingdao University and retrieval system of HIS and LIS medical records and Laboratory of the hospital.Based on imaging evidence and d-dimer abnormalities,patients were divided into the thromboembolic group and the non-thrombotic group.Firstly,it was determined that blood PLA2R-AB was closely related to MN thromboembolism events by basic clinical data analysis.The cut-off value of this indicator was determined by Receiver Operator characteristic curve(ROC)of serum antiphospholipase A2 antibody level,and then substituted into chi-square test and logistic regression to prove that it was an independent risk factor.2.Laboratory study: Serum was collected from patients with primary membranous nephropathy who were admitted to the West Coast Hospital of Qingdao University Hospital between June 2020 and March 2021 and examined for serum anti-PLA2 R antibodies.Patients with thromboembolism were supported by imaging evidence.Two kinds of free monosaccharides and six kinds of monosaccharides were quantitatively analyzed by High Performance Liquid Chromatography(HPLC).They are Mannose(Man);Glucosamine(Gal N);Glucuronic acid(Glc UA);Glucose,Glucose(Glc);Galactosamine(Gal N);Galactose(Gal);Xylose,Xylose(Xyl);Fucose,Fucose.In addition,the ratio of serum glucose to mannose(G/M)was used by Mann-Whitney U test to compare the concentration differences of degraded monosaccharides and free monosaccharides in serum samples of the two groups,and to conduct correlation analysis with thromboembolic events and clinical indicators.(In this paper,Free monosaccharides in serum were expressed as Free;Degraded monosaccharides are denoted by DE.)Results:1.Clinical research1.1 According to rank sum test H(K),The group with PLA2 R antibody level >1500RU/m L was significantly different from the other three groups,with P values of0.001,0.021 and 0.007,respectively.Compared with the other three groups,the group with PLA2 R antibody level >1500 RU/m L showed significant difference(P =0.006,0.009,0.008,respectively).1.2 There were differences in serum PLA2 R antibody level and serum albumin among the four classification forms(P < 0.05).1.3 Serum albumin was considered as an independent risk factor in the group with increased D dimer and the group with increased D dimer or thrombi confirmed by imaging(P < 0.05).1.4 Serum PLA2 R antibody was considered as an independent risk factor in the radiographically confirmed thrombi group and d-dimer increased in the radiographically confirmed thrombi group(P < 0.05).1.5 The area under ROC curve of serum PLA2 R antibody for p MN complicated with radiographically confirmed thromboembolism was 0.756.The cut-off value was 231.85RU/m L(sensitivity: 0.667,specificity: 0.750,maximum density index: 0.517).However,for the group with elevated D-dimer and thrombi confirmed by imaging,its area under ROC curve was 0.778.The truncated titer of serum PLA2 R antibody was137.55 RU/m L(sensitivity: 0.800,specificity: 0.745,maximum approximate index:0.545).1.6 In the verification step,both the clinical and SMOTE amplification dataset showed that the history of hypertension,ABNORMAL D-dimer and serum PLA2 R antibody level > 231.85 RU/m L were the independent risk factors for thromboembolism(P < 0.05).2.Laboratory results2.1 There were differences in Man＿Free,G/M,Man＿de,GLc＿de and Gal＿de between the healthy control group and the non-thromboembolic group.There were differences in G/M,Man＿Free,Man＿de,Fuc＿de and Gal N＿de between healthy control group and thromboembolic group,and in G/M,Man＿Free,Gal N＿de and Fuc＿de between thromboembolic group and non-thromboembolic group.2.2 In correlation analysis,man-free relationship with PLA2R-AB,Red blood cell count(RBC),Hemoglobin(HGB),Erythrocyte sedimentation rate,ESR)and serum pre-albumin(PALB)were correlated.G/M was correlated with RBC and Urine protein quantitation(UPRO)at 24 h upon admission.Man-DE was correlated with Thrombin time(TT)and Fibrinogen(FIB).Glcn-de was correlated with systolic pressure(HSP)and Seroglobulin(GLOB).Galn-de was correlated with age,Diastolic blood pressure(DSP),RBC and ESR.Fuc-de and RBC,Eosinophils(EOS),GLOB,Total protein(TP),Activated partial thromboplastin time,APTT and APTT ratio were correlated.Glc-de was not associated with g AL-DE and other clinical indicators.2.3 Gal N＿de and Fuc＿de were determined as independent risk factors in multivariate logistic regression(P < 0.05).Research Conclusions:1.clinical trials1.1 The probability of radiographic thromboembolism or abnormal D-dimer in patients with primary membranous nephropathy increased with the increase of serum phospholipase A2 receptor antibody level.1.2 Serum phospholipase A2 receptor antibody level was an independent risk factor for primary membranous nephropathy with imaging thromboembolism or imaging thromboembolism with ABNORMAL D2 aggregates.1.3 When the serum phospholipase A2 level antibody reaches 231.85 RU/m L,we should be alert to the occurrence of thromboembolism and abnormal D-dimer at the same time.Serum phospholipase A2 receptor antibody levels reaching 137.55 RU/m L should be vigilant.1.4 Serum albumin is still an excellent predictor of thromboembolism.2.Laboratory test2.1 There were differences in Man＿Free,G/M,Man＿de,GLc＿de and Gal＿de between healthy control group and non-thromboembolic group.There were differences in G/M,Man＿Free,Man＿de,Fuc＿de and Gal N＿de between healthy control group and thromboembolic group,and in G/M,Man＿Free,Gal N＿de and Fuc＿de between thromboembolic group and non-thromboembolic group.2.2 Gal N＿de and Fuc＿de can be considered as independent risk factors for thromboembolic events in primary membranous nephropathy.2.3 Fucosylation of CS may occur in patients with thromboembolic complications of primary membranous nephropathy.Serum Man＿Free concentration may play an important role in the mechanism of serum phospholipase A2 receptor antibody on thromboembolic complications of primary membranous nephropathy.