Analysis Of Risk Factors For Idiopathic Membranous Nephropathy Complicated With Venous Thromboembolism

Objective:The clinical data of patients with idiopathic membranous nephropathy(IMN)complicated with venous thromboembolism(VTE)were retrospectively analyzed to investigate the clinical characteristics and risk factors of IMN complicated with VTE.Methods:One hundred and twenty-nine of patients diagnosed with primary nephrotic syndrome(PNS)were collected from China-Japan Union Hospital of Jilin University from September 2015 to December 2017.The patients were divided into IMN group and non-IMN group according to the renal biopsy results.The general clinical data and baseline laboratory parameters of the two groups were collected and compared.The distribution of venous thromboembolism(VTE)in different pathological types of PNS and characteristics of VTE in IMN group were analyzed.Patients in IMN group were divided into VTE group and non-VTE group.The general clinical data,laboratory indexes,pathological stage,and immunosuppressive treatment were collected and recorded.Multivariate stepwise logistic regression analysis was performed on the items with statistically significant differences to investigate the risk factors for VTE in IMN patients.The data was analyzed with SPSS 22.0 statistical software and P<0.05 was considered statistically significant.Results:1.Among 129 patients with PNS,there were 52 patients in group IMN and 77 patients in non-IMN group including 35 patients with IgAN,30 patients with MCD,7 patients with FSGS and 5 patients with MPGN.The incidence of VTE in group IMN was significantly higher than that in non-IMN group,and the difference was statistically significant(P<0.01).2.A total of 19 sites of VTE occurred in 16 patients with IMN.Among them,deep venous thrombosis(DVT)was the most common,accounting for 42.11% of the total number of thrombus sites(8/19).The second common VTE was pulmonary embolism(PE),accounting for 31.58% of the total number of thrombus sites(6/19).Others were renal venous thrombosis(RVT)and inferior vena cava thrombosis,accounting for 21.05%(4/19)and 5.26%(1/19)respectively.3.Of the 16 patients with VTE in IMN group,the proportion of patients with VTE occurring within 6 months after IMN diagnosis was 75.00%(12/16),and the proportion of VTE from 6 months to 1 year after IMN diagnosis was 12.50%(2/16),and the proportion of VTE after 1 year since the diagnosis of IMN was 12.50%(2/16).4.Comparison of clinical data between VTE group and non-VTE group with IMN was shown below.The urinary protein excretion in VTE group were significantly higher than that in non-VTE group(P<0.05).The serum albumin in VTE group were significantly lower than that in non-VTE group(P<0.05).The level of platelet in VTE group was significantly lower than that in non-VTE group(P<0.05).The level of D-dimer and fibrinogen in VTE group was significantly higher than that in non-VTE group(P<0.05).There was no significant difference in positive rate and serum level of anti-M type phospholipase A2 receptor(PLA2R)antibody between VTE group and non-VTE group(P>0.05).There was no significant difference in the proportion of patients with different renal pathological stage between VTE group and non-VTE group(P>0.05).The proportion of patients treated with glucocorticoid in the VTE group was higher than that in the non VTE group(P<0.05).There was no significant difference in the proportion of using tacrolimus alone and non-immunotherapy patients between the two groups(P>0.05).There was no significant difference in complete remission rate,partial remission rate,and total remission rate at 4 weeks,8 weeks,12 weeks,and 24 weeks after treatment between the two groups(P>0.05).5.Multivariate stepwise logistic regression analysis of the urinary protein excretion,serum albumin,platelet,fibrinogen,D-dimer,and glucocorticoid use with VTE onset in IMN patients revealed that serum albumin(OR: 0.734,95%CI: 0.542-0.995,P=0.046),D-dimer(OR: 1.002,95%CI: 1.001-1.004,P=0.005)are independent risk factors for VTE in IMN patients.Conclusions:1.PNS patients are hypercoagulable and prone to VTE.Among the different pathological types of PNS,the incidence of VTE in IMN patients was the highest.The most common VTE sites of PNS patients were DVT,PE and RVT.DVT was the most common distribution of VTE in IMN patients,followed by PE.2.In patients with IMN combined with VTE,VTE mostly occurs within 6 months after IMN diagnosis.3.The urinary protein excretion,serum albumin,platelet,fibrinogen,D-dimer and the use of glucocorticoids in IMN patients may correlate to the occurrence of VTE.Serum albumin and D-dimer are independent risk factors for VTE in IMN patients.4.There was no correlation between either renal pathological stage or serum anti-PLA2 R antibody and VTE in IMN patients.Therefore,the occurrence of VTE in IMN patients cannot be predicted by pathological staging and anti-PLA2R antibody.