Disease-specific risk of venous thromboembolic events is increased in idiopathic glomerulonephritis

Complement-coagulation crosstalk in idiopathic membranous nephropathy: The potential pathogenesis and therapeutic perspective

Idiopathic membranous nephropathy (IMN) is a glomerular disease that is prevalent in elderly males. The pathogenesis of IMN includes abnormal autoimmunity and complement activation, both of which leading to the damage of the glomerular filtration structure. Meanwhile, due to the pathological changes in the kidney, certain coagulation-related proteins are leaked from urine, resulting in the imbalance of coagulation homeostasis. Recent studies have indicated the interaction between complement and coagulation systems, while the aberration of both is common in IMN. In this review, we summarize the subsistent and underlying pathogenesis that ensue from complement-coagulation crosstalk and present the emerging evidence in this evolving field.

Nomogram for thromboembolic events in primary membranous nephropathy associated with PLA2R antibody

Patients with nephrotic syndrome, particularly those with primary membranous nephropathy (pMN), are at a heightened risk of thromboembolic events. The presence of phospholipase A2 receptor (PLA2R) antibody serves as an indicator of active primary membranous nephropathy. Identifying high-risk patients for thromboembolic events is crucial for facilitating effective communication between healthcare providers and patients, evaluating treatment outcomes, and assessing medical costs. This study aimed to develop a practical model for predicting the probability of thromboembolic events in patients with PLA2R-related primary membranous nephropathy. A total of 1384 patients diagnosed with PLA2R antibody-related primary membranous nephropathy were included in this study. The model group included 969 patients enrolled before August 2020, while the external validation group consisted of 415 patients enrolled later. Patients in the modeling group were divided into the thromboembolic and non-thromboembolic subgroups. Logistic regression analysis was performed, and a nomogram was established based on the results. The predictive performance of the nomogram was evaluated by the area under the receiver operating characteristic curve (AUC), calibration curves, and decision curve analysis (DCAs). The modeling group comprised 126 (13.0%) patients with thromboembolism, and significant differences were observed between the thromboembolism and non-thromboembolism subgroups. The risk factors included in the nomogram included age, Anti-PLA2R antibody, and 24-hour urine protein quantification. The AUC value of the nomogram was 0.741 (95% CI 0.695-0.788, P < 0.001). In addition, the calibration curves demonstrated acceptable agreement between the predicted outcomes by the nomogram and the actual values. DCA curves showed good positive net benefits in the predictive model. The external validation also confirmed the reliability of the prediction nomogram. This predictive nomogram including Anti-PLA2R antibody, age, and 24-hour urine protein quantification may facilitate the prediction of the thromboembolic risk in patients with PLA2R-related pMN.

Safety and Efficacy of Oral Direct Factor Xa Inhibitors in Patients With Nephrotic Syndrome: Results From a National Retrospective Study

Introduction

The optimal management of thromboembolism (TE) in patients with nephrotic syndrome (NS) remains challenging. Until now, anticoagulation therapy for NS consisted of vitamin K antagonists (VKAs) or heparin. Data on direct oral anticoagulant (DOAC) use in NS are limited, and their safety and convenience have been well-demonstrated in other indications.

Methods

We conducted a multicenter retrospective study of adult patients with NS treated with therapeutic-dose anticoagulation between 2014 and 2022. We compared the incidences of bleeding and TE events between patients receiving DOAC and those receiving VKAs or heparin (standard-of-care [SOC]). Patients with end-stage kidney disease were excluded.

Results

The overall population consisted of 144 patients (median [interquartile range] age of 54 [38-67] years, 34.7% women) with a median albumin level at 1.5 (1.2-1.8) g/dl and a median urinary protein-to-creatinine ratio of 8.8 (5.5-12.3)g/g. Membranous nephropathy was the main NS etiology (45.8%). No significant differences were observed between the DOAC (n = 72) and the SOC (n = 72) groups. The anticoagulant strategy was primary prophylaxis in 79.2% of patients taking DOAC and 83.3% of patients with SOC (P = 0.67). DOAC use was not associated with an increased rate of TE (4.2% vs. 0%, P = 0.25) or bleeding events (6.9% vs. 13.9%, P = 0.28) compared with the SOC group. Univariate analysis identified female sex, age > 75 years, and anticoagulant exposure > 90 days as risk factors for bleeding.

Conclusion

This study suggests that DOAC are safer and more effective than conventional anticoagulant strategies for both primary and secondary prophylaxis in patients with NS.

Efficacy and safety of low-molecular-weight-heparin plus citrate in nephrotic syndrome during continuous kidney replacement therapy: retrospective study

Background

Nephrotic syndrome (NS) is a condition often necessitating continuous kidney replacement therapy (CKRT) due to severe edema and other complications. Anticoagulation is critical in CKRT to prevent filter clotting, with regional citrate anticoagulation (RCA) being the first-line method. However, the hypercoagulable state of NS may require alternative strategies. Optimal anticoagulation therapy in NS patients undergoing CKRT is lacking.

Methods

This retrospective observational study included 251 CKRT sessions from 122 NS patients treated at Nanfang Hospital, Southern Medical University, from January 2019 to December 2022. Patients were divided into three groups based on anticoagulation method: Low-molecular-weight-heparin (LMWH) alone, RCA alone, and RCA plus LMWH. Filter lifespan, incidence of filter clotting, and adverse events were assessed to evaluate the efficacy and safety profiles of each anticoagulation methods.

Results

The combination of RCA and LMWH demonstrated a significantly longer mean filter lifespan and lower incidence of filter clotting compared to LMWH or RCA alone. RCA plus LMWH also showed a lower incidence of overall adverse events, particularly thrombosis, without an increase in bleeding complications. Multivariate Cox analysis indicated that RCA plus LMWH was particularly effective in patients with normal kidney function.

Conclusions

RCA combined with LMWH provides a superior anticoagulation strategy in NS patients undergoing CKRT, with enhanced filter lifespan and reduced clotting and thrombotic events without increasing bleeding risk. Further research is needed to optimize dosing and validate these results in broader populations.

Membranous Nephropathy

Membranous nephropathy is a glomerular disease that may be caused by exogenous risk factors in genetically predisposed individuals (primary MN) or may be associated with other autoimmune diseases, drug exposure, or cytotoxic agents (secondary MN). Primary membranous nephropathy (PMN) is an autoimmune disease in which antigens-mainly the phospholipase A2 receptor-are located in the podocytes and are targeted by circulating antibodies, leading to in situ formation of immune complexes that activate the complement system. Clinically, the disease is characterized by nephrotic syndrome (NS) and associated complications. The outcome of PMN can vary, but untreated patients with NS may progress to end-stage kidney disease (ESKD) in 35-40% of cases within 10 years. Treatment primarily aims to prevent NS complications and progression to ESKD. The most commonly used immunosuppressive drugs are rituximab, corticosteroids, cyclophosphamide, and calcineurin inhibitors. Most patients may experience an improvement of proteinuria, which can sometimes be followed by NS relapse. Fewer than 50% of patients with PMN achieve complete and stable remission. In addition to immunosuppressive therapy, antiproteinuric, anti-lipemic, and anticoagulant medicaments are often required.

The risk of thromboembolic events in patients with nephrotic syndrome and relatively high albumin levels: a study over 10 years

BACKGROUND

Low albumin level is a risk factor for thromboembolic events in patients with NS (nephrotic syndrome). However, little is known about the proportion and characteristics of patients with NS who experience thromboembolic events with relatively high albumin levels (≥ 25 g/L). Therefore, we explored the features of this specific group of patients.

METHODS

This study included all hospitalized patients in our center for the past 10 years who had diagnoses of NS and relevant thromboembolic events. We divided them into 2 groups based on their serum albumin level when the thromboembolic event occurred. The clinical data were analyzed with SPSS software.

RESULTS

There were 312 patients enrolled in our study. Eighty-four (26.9%) of them had relatively high albumin levels (≥ 25 g/L). Patients with NS with high albumin levels had significantly lower levels of 24-h proteinuria (P < 0.01) and a higher rate of autoimmune disease (P = 0.03) than the low-albumin group. Membranous nephropathy (MN) was the most frequent pathological type of NS in patients with thromboembolic events, regardless of their albumin level. There were significantly fewer patients with anti-PLA2R (M-type phospholipase A2 receptor)-positive MN in the high-albumin group than in the low-albumin group (P < 0.01).

CONCLUSIONS

Our study found that there was still a high risk for patients with NS and relatively high albumin levels to develop thromboembolic events.

The impact of severe nephrotic syndrome on thyroid function, nutrition and coagulation

Background

Nephrotic syndrome (NS) is characterized by urinary loss of proteins, including hormones and their carrier proteins, potentially resulting in endocrine disorders. This study aimed to assess thyroid dysfunction frequency and potential implications in NS.

Methods

In this case-control study, patients with severe NS (serum albumin ≤2.5 g/dl) and controls without proteinuria were evaluated for thyroid, haemostatic and nutritional parameters, including body composition.

Results

A total of 42 nephrotic and 40 non-proteinuric patients were enrolled. The NS group showed higher thyroid-stimulating hormone and lower free hormones, corresponding to a higher frequency of both euthyroid sick syndrome {ESS; 36% versus 5%; odds ratio [OR] 10.6 [95% confidence interval (CI) 2.2-50.0]} and hypothyroidism [31% versus 5%; OR 8.5 (95% CI 1.8-40.7)] compared with the control group. Levothyroxine supplementation was required for 11 NS patients (26% of the NS group). In addition, compared with control individuals, NS patients exhibited lower lean tissue mass and a trend towards hypercoagulability, which was evidenced by higher levels of most coagulation factors and fibrinolysis inhibitors, and reduced endogenous anticoagulants activities. Furthermore, NS patients with ESS presented with a 10.4 kg (95% CI -18.68 to -2.12) lower lean tissue mass. Those with hypothyroidism had significantly reduced activity of coagulation factor X [by -30% (95% CI -47 to -13)] and protein S [by -27% (95% CI -41 to -13)] compared with euthyroid NS individuals.

Conclusions

Thyroid dysfunction is common in severe NS, often necessitating levothyroxine supplementation, which supports routine thyroid workup. A potential link between thyroid, nutritional and coagulation disorders in NS requires further investigation.

Membranous Nephropathy: Updates on Management

Membranous nephropathy is a major etiology of nephrotic syndrome in adults and less frequently in children. Circulating antibodies to intrinsic podocyte antigens, such as M-type phospholipase A2 receptor, or to extrinsic proteins accumulate beneath the podocyte to cause damage via complement activation and/or other mechanisms. The availability of clinical testing for autoantibodies to M-type phospholipase A2 receptor has allowed noninvasive diagnosis of this form of membranous nephropathy and a means to monitor immunologic activity to guide immunosuppressive therapy. Treatment of membranous nephropathy includes optimal supportive care with renin-angiotensin-system blockers, lipid-lowering agents, diuretics, lifestyle changes, and additional immunosuppressive therapy in patients with an increased risk of progression to kidney failure. Rituximab has been recognized as a first-line immunosuppressive therapy for most membranous nephropathy patients with an increased risk of progressive disease, except those with life-threatening nephrotic syndrome or rapidly deteriorating kidney function from membranous nephropathy. This article discusses the major and minor antigens described in membranous nephropathy, the natural history of the disease, and guidelines for clinical management and immunosuppressive treatment.

Membranous nephropathy: pathogenesis and treatments

Membranous nephropathy (MN), an autoimmune disease, can manifest at any age and is among the most common causes of nephrotic syndrome in adults. In 80% of cases, the specific etiology of MN remains unknown, while the remaining cases are linked to drug use or underlying conditions like systemic lupus erythematosus, hepatitis B virus, or malignancy. Although about one-third of patients may achieve spontaneous complete or partial remission with conservative management, another third face an elevated risk of disease progression, potentially leading to end-stage renal disease within 10 years. The identification of phospholipase A2 receptor as the primary target antigen in MN has brought about a significant shift in disease management and monitoring. This review explores recent advancements in the pathophysiology of MN, encompassing pathogenesis, clinical presentations, diagnostic criteria, treatment options, and prognosis, with a focus on emerging developments in pathogenesis and therapeutic strategies aimed at halting disease progression. By synthesizing the latest research findings and clinical insights, this review seeks to contribute to the ongoing efforts to enhance our understanding and management of this challenging autoimmune disorder.

Urokinase prophylactic anticoagulation in children with nephrotic syndrome: a multicenter retrospective cohort study

OBJECTIVE

To analyze the clinical effect of urokinase on the prevention of thrombosis in children with primary nephrotic syndrome.

METHODS

A total of 370 children diagnosed with primary nephrotic syndrome (PNS) in the Children's Hospital of Soochow University and Zibo Maternal and Child Health Hospital from January 2018 to December 2022 were selected as the research objects. The patients were divided into a urokinase adjuvant therapy group and non-urokinase adjuvant therapy group according to the application of drugs. The clinical data of the children were collected, including sex, age, drug application, bleeding during treatment, and telephone follow-up, to record whether thromboembolism occurred in the acute stage and remission stage. The clinical pattern of PNS, renal biopsy, histopathological type, and related laboratory indexes before and after treatment were recorded.

RESULTS

A total of 313 patients were treated with urokinase and 57 patients were not. More thrombotic events was observed in non-urokinase group compared to the urokinase group(2 versus 0 episodes, p = 0.02). The thrombotic events observed included one patient had pulmonary embolism combined with right ventricular thrombosis, and another had intracranial venous thrombosis. More minor bleeding events occurred in urokinase group compared to the non-urokinase group(7 versus 1 episodes, p = 1.0). No major bleeding events occurred in either group.

CONCLUSION

The rational prophylactic use of urokinase anticoagulation in children with PNS can prevent the formation of thromboembolism and has good safety.

Efficacy and safety of prophylactic anticoagulation in patients with primary nephrotic syndrome: a systematic review and meta-analysis

BACKGROUND AND AIMS

Nephrotic syndrome (NS) is associated with an increased incidence of venous thromboembolism (VTE), approximately 10%. We performed a systematic review to evaluate the efficacy and safety of prophylactic anticoagulation in patients with NS.

METHODS

Studies evaluating prophylactic anticoagulation in NS were identified by an electronic search of MEDLINE and EMBASE databases until December 2021. Weighted mean proportion and 95% confidence intervals (CIs) of thromboembolic and haemorrhagic events were calculated using a fixed-effects and a random-effects model. The differences in the outcomes among groups were estimated as pooled odds ratio (OR) and corresponding 95% CI. Statistical heterogeneity was evaluated using the I2 statistic.

RESULTS

Five cohort studies, for a total of 414 adult patients, were included. Only two studies had a control group. The weighted mean incidence of pulmonary embolism (PE) and deep vein thrombosis in patients who received VTE prophylaxis was 1.8% (95% CI: 0.6-3.5%; I2 : 4.4%) and 0.9% (95% CI: 0.2-2.2%; I2 : 43.4%) respectively. The weighted mean incidence of major bleeding in patients who received VTE prophylaxis was 2.3% (95% CI: 1-4.2%; I2 : 25.4%). Patients with NS that received VTE prophylaxis had a non-significant reduced risk of PE (OR: 0.63 (95% CI: 0.03-14.8; I2 : 64.4%)) and an increased risk of major bleeding (OR: 2.08 (95% CI: 0.41-10.45; I2 : 0%)) compared to patients with NS that did not receive VTE prophylaxis.

CONCLUSIONS

Our findings suggest that prophylactic anticoagulation in adult patients with primary NS may reduce the risk of VTE, even if it may be associated with a not negligible bleeding risk.

Thromboembolic phenomena in patients with nephrotic syndrome: pathophysiology, risk factors, prophylaxis and treatment

Thromboembolic events resulting from disturbances in the body's balance of thrombotic and antithrombotic abilities are among the most life-threatening complications of nephrotic syndrome. Certain causes of nephrotic syndrome leave the patient particularly susceptible to thromboembolism. The severity of proteinuria and degree of hypoalbuminaemia are other common predictors of risk. Timely initiation of prophylactic therapy can help prevent morbidity and mortality associated with this complication in patients with nephrotic syndrome. The duration of treatment and choice of therapeutic agent depends on several factors, including the degree of hypoalbuminaemia, risk factors for thrombosis and risk of bleeding. This article reviews current understanding of the pathophysiology and risk factors for thromboembolism associated with nephrotic syndrome, and summarises recommendations and strategies for preventing and treating thromboembolic events in patients with nephrotic syndrome.

Comparison of the prophylactic antithrombotic effect of indobufen and warfarin in patients with nephrotic syndrome: a randomized controlled trial

PURPOSE

The risk of thromboembolic events is elevated in patients with nephrotic syndrome, and warfarin use has been associated with an increased risk of bleeding. Indobufen, a selective cyclooxygenase-1 inhibitor, is currently being evaluated for the prevention of thromboembolic events in nephrotic syndrome. This study aimed to compare the efficacy and safety of indobufen with that of warfarin in patients with nephrotic syndrome.

MATERIALS AND METHODS

This multicenter, randomized, three-arm, open-label, parallel controlled trial involved a total of 180 adult patients with nephrotic syndrome from four centers in China. Patients were randomly assigned to receive 100 mg indobufen (bid), 200 mg indobufen (bid), and 3 mg warfarin (qd) daily for 12 weeks. The primary endpoints included thromboembolic and bleeding events, while laboratory results and adverse events constituted secondary endpoints.

RESULTS

No thromboembolic events occurred in the high-/low-dose indobufen and warfarin groups. Moreover, the use of a low dose of indobufen significantly reduced the risk of minor bleeding events compared with warfarin use (2% versus 18%, p < .05). Finally, adverse events were more frequent in warfarin-treated patients.

CONCLUSIONS

This study found that indobufen therapy provided equivalent effects in preventing thromboembolic events compared with warfarin therapy, while low dose of indobufen was associated with a reduced risk of bleeding events, thus it should be recommended for the prevention of thromboembolic events in clinical practice in patients with nephrotic syndrome.

TRIAL REGISTRATION NUMBER

ChiCTR-IPR-17013428.

Association of circulating proprotein convertase subtilisin/kexin type 9 concentration with coagulation abnormalities in patients with primary membranous nephropathy

OBJECTIVES

The aims of the study were to explore the potential associations between plasma proprotein convertase subtilisin/kexin type 9 (PCSK9) and coagulation indexes in patients with primary membranous nephropathy (PMN).

METHODS

A total of 87 patients diagnosed with PMN were enrolled in our study. 30 healthy participants were recruited to match PMN participants. Plasma PCSK9 concentrations were tested by enzyme-linked immunosorbent assay (ELISA). Correlations between PCSK9 and coagulation abnormalities in patients with PMN were analyzed using univariate and multiple linear regression analysis.

RESULTS

Plasma PCSK9 levels in patients with PMN were significantly higher than that in healthy controls [232.0 (143.5, 359.5) ng/mL vs. 166.8 (129.7, 199.7) ng/mL; p = 0.001]. Plasma levels of PCSK9 were positively correlated with factor VIII, factor IX, factor XI, log-transformed tissue factor, protein C and protein S (r = 0.267, p = 0.013; r = 0.496, p < 0.001; r = 0.217, p = 0.045; r = 0.584, p < 0.001; r = 0.372, p = 0.001; r = 0.282, p = 0.011). In multiple linear regression analysis, PCSK9 concentration was independently and positively correlated with factor VIII, factor IX, and tissue factor (β = 0.186, p = 0.047; β = 0.325, p = 0.001; β = 0.531, p < 0.001; respectively). PCSK9 concentration was independently and negatively correlated with PT (β= -0.343, p = 0.011).

CONCLUSION

Plasma PCSK9 levels had good positive correlations with procoagulant clotting factors and negative correlations with PT in PMN, which might provide novel information with regard to PCSK9 and hypercoagulability in PMN.

Serum PLA2R antibody as a predictive biomarker for venous thromboembolism risk in primary membranous nephropathy

BACKGROUND

Patients with nephrotic syndrome are at high risk of venous thromboembolism (VTE), especially for primary membranous nephropathy (PMN). The phospholipase A2 receptor (PLA2R) is a marker of primary membranous nephropathy activity. This study investigated the predictive value of PLA2R antibodies in PMN for VTE.

METHODS

In this retrospective study, we included 97 PMN patients and evaluated the predictive value of serum PLA2R antibodies for VTE risk. Lower extremity venous ultrasound, renal vein ultrasound, or spiral computed tomography pulmonary arteriography were used to assess VTE events. Serum anti-PLA2R antibodies were detected by enzyme-linked immunosorbent assay (ELISA). The risk of VTE was stratified according to serum albumin levels.

RESULTS

Twenty PMN patients (21%) had thromboembolic events. Eight (15%) of patients with serum albumin >25g/l developed VTE, 6 of whom were positive for serum PLA2R antibodies. Positive serum PLA2R antibodies were significantly associated with VTE events in patients with serum albumin >25g/l (p=0.01). Age, sex, blood creatinine, serum albumin, and 24-h urine protein levels were not statistically different between the two groups. Kaplan-Meier analysis using the log-rank test revealed anti-PLA2R positive membranous nephropathy patients had more probability of VTE events than anti-PLA2R negative patients. Univariate Cox proportional hazards analysis revealed that lnPLA2R-Ab is an unfavorable predictor for VTE events in patients with serum albumin >25g/l (hazard ratio (HR) 2.1, p=0.01).

CONCLUSIONS

The PLA2R antibody was a risk predictor for thromboembolic events in patients with primary membranous nephropathy with serum albumin >25g/l.

How to Choose the Right Treatment for Membranous Nephropathy

Membranous nephropathy is an autoimmune disease affecting the glomeruli and is one of the most common causes of nephrotic syndrome. In the absence of any therapy, 35% of patients develop end-stage renal disease. The discovery of autoantibodies such as phospholipase A2 receptor 1, antithrombospondin and neural epidermal growth factor-like 1 protein has greatly helped us to understand the pathogenesis and enable the diagnosis of this disease and to guide its treatment. Depending on the complications of nephrotic syndrome, patients with this disease receive supportive treatment with diuretics, ACE inhibitors or angiotensin-receptor blockers, lipid-lowering agents and anticoagulants. After assessing the risk of progression of end-stage renal disease, patients receive immunosuppressive therapy with various drugs such as cyclophosphamide, steroids, calcineurin inhibitors or rituximab. Since immunosuppressive drugs can cause life-threatening side effects and up to 30% of patients do not respond to therapy, new therapeutic approaches with drugs such as adrenocorticotropic hormone, belimumab, anti-plasma cell antibodies or complement-guided drugs are currently being tested. However, special attention needs to be paid to the choice of therapy in secondary forms or in specific clinical contexts such as membranous disease in children, pregnant women and patients undergoing kidney transplantation.

Nephrotic syndrome: pathophysiology and consequences

In patients with kidney disease, nephrotic syndrome can lead to several complications including progressive kidney dysfunction. Proteinuria may lead to the formation of cellular or fibrous crescents with reciprocal development of rapidly progressive glomerulonephritis or focal glomerulosclerosis. Proteinuria may also cause overload and dysfunction of tubular epithelial cells, eventually resulting in tubular atrophy and interstitial fibrosis. Hypoalbuminemia is usually associated with increased risk of mortality and kidney dysfunction. Dyslipidemia may increase the risk of atherosclerotic complications, cause podocyte dysfunction and contribute to vascular thrombosis. Urinary loss of anticoagulants and overproduction of coagulation factors may facilitate a hypercoagulable state. Edema, hypogammaglobulinemia, loss of complement factors, and immunosuppressive therapy can favor infection. Treatment of these complications may reduce their impact on the severity of NS. Nephrotic syndrome is a kidney disorder that can worsen the quality of life and increase the risk of kidney disease progression.

Acute Myocardial Infarction in a Patient With Focal Segmental Glomerulosclerosis Tip Lesion: Hit With a Double Whammy

Nephrotic syndrome is associated with venous and arterial thrombotic complications and is related to the imbalance between pro-thrombotic and anti-thrombotic factors. With an underlying nephrotic syndrome, arterial thromboses are infrequent, and coronary artery thromboses are much rarer. We present the case of a young male, with nephrotic syndrome, who suffered an acute anterior wall ST-segment elevation myocardial infarction. He was subsequently diagnosed to have focal segmental glomerulosclerosis (FSGS)-tip lesion. The patient was successfully managed with thrombolysis, steroids, anticoagulation, antiplatelets, and statins.

Establishment of 11-dehydro-thromboxane B2 time-resolved immunoassay and application in membranous nephropathy

BACKGROUND

11-Dehydro-thromboxane B2 (11-dehydro-TXB2) is the final stable metabolite of thromboxane A2 (TXA2) and is involved in thrombus formation. Patients with membranous nephropathy (MN) are prone to thromboembolism events.

METHODS

Time-resolved fluorescence immunoassay (TRFIA) for 11-dehydro-TXB2 was established by indirect competitive method. The coated 11-dehydro-TXB2-BSA conjugate was used to bind the 11-dehydro-TXB2 antibody competitively to the 11-dehydro-TXB2 antigen in the samples, followed by Eu3+-labeled goat anti-mouse IgG antibody, to detect 11-dehydro-TXB2. This study measured 11-dehydro-TXB2 concentrations in serum samples from healthy individuals and patients with MN.

RESULTS

The linear range of TRFIA was 16.38-2000 pg/mL, the sensitivity was 4.70 pg/mL, the average coefficients of variation from intra-assay and inter-assay were 3.50% and 4.95%, respectively, and the recovery was 99.38%. The serum level of 11-dehydro-TXB2 in patients with MN was significantly higher than that in healthy subjects (P < 0.05). The serum 11-dehydro-TXB2 concentration detected by TRFIA was highly consistent with that by ELISA (ρ = 0.900).

DISCUSSION

This study successfully established a new highly sensitive method for the detection of 11-dehydro-TXB2 in serum. 11-Dehydro-TXB2 has great potential in evaluating the risk of thromboembolic events in patients with MN and is expected to be applied to other thromboembolic-related diseases.

Thromboembolism in nephrotic syndrome: controversies and uncertainties

Thromboembolism is one of the most serious complications of nephrotic syndrome, including both arterial and venous thromboembolic events. Rates of thromboembolism depend on a multitude of factors, including the severity and cause of nephrotic syndrome, with primary membranous nephropathy having the highest reported rates. In relation to arterial thromboembolism, the risk can be as high as 8 times that of an age- and sex-matched population. However, extrapolating risks is challenging, with published studies not being homogeneous, several being single center and retrospective, and including different causes of primary nephrotic syndrome. Determining thromboembolic risk in nephrotic syndrome is essential to enable decision making on preventive strategies. However, lack of proven strategies to help estimate risk-benefit aspects underpins variations in clinical practice. Although the use of anticoagulation following a thrombotic event is clear, this still leaves us with a clinical dilemma as to if, and who, should receive prophylactic anticoagulation, with what agent, and for how long. In the absence of clear evidence to answer these questions, prophylactic anticoagulation strategies for nephrotic syndrome currently rely on expert consensus opinion, such as in the recently published 2021 Kidney Disease Improving Global Outcomes glomerular disease guidelines. In the mainstay, these recommendations relate to patients with membranous nephropathy. Here, we detail the current controversies still faced by clinicians around the risk of thromboembolism in nephrotic syndrome, use of prophylactic anticoagulation in nephrotic syndrome and propose ways of advancing existing knowledge and practice in this field to unravel the conundrum.

KDOQI US Commentary on the 2021 KDIGO Clinical Practice Guideline for the Management of Glomerular Diseases

The KDIGO 2021 Clinical Practice Guideline for the Management of Glomerular Diseases represents the first update to this set of recommendations since the initial set of KDIGO guideline recommendations was published in 2012. The pace of growth in our molecular understanding of glomerular disease has quickened and a number of newer immunosuppressive and targeted therapies have been introduced since the original set of guideline recommendations, making such an update necessary. Despite these updates, many areas of controversy remain. In addition, further updates since the publication of KDIGO 2021 have occurred which this guideline does not encompass. With this commentary, the KDOQI work group has generated a chapter-by-chapter companion opinion article that provides commentary specific to the implementation of the KDIGO 2021 guideline in the United States.

Nephrotic Syndrome for the Internist

Nephrotic syndrome (NS) is a key clinical entity for the internist to recognize and understand. A wide range of infectious, metabolic, malignant, and autoimmune processes drive nephrosis, leading to a syndrome defined by proteinuria, edema, and hypoalbuminemia. NS occurs due to increased permeability to proteins at the level of the glomerulus, which allows for passage of albumin and other proteins into the urine. Proteinuria leads to a cascade of clinical complications characterized by fluid accumulation, kidney inflammation, and dysregulation of coagulation and immunity. In this article, the authors review the clinically important etiologies of NS that should inform an initial clinical evaluation.

Comparative outcomes of anticoagulation alone versus anticoagulation plus endovascular intervention in adults with isolated renal vein thrombosis

BACKGROUND

Limited therapeutic strategies are available for adults with isolated renal vein thrombosis (RVT). In the present study, we explore and compare the efficacy of anticoagulation therapy alone vs anticoagulation plus endovascular intervention in the treatment of this rare disease.

METHODS

In the present study, we analyzed the clinical data of RVT patients treated in a tertiary referral center in urban China from April 2012 to April 2022. These patients were classified into anticoagulation therapy (best medical treatment [BMT]) and endovascular intervention (endovascular-based treatment [EBT]) groups. The primary end points, including thrombus clearance and renal function changes, were evaluated by measuring the serum creatinine levels and glomerular filtration rates (GFRs).

RESULTS

A total of 40 consecutive patients with RVT (25 men and 15 women) were included in the present study, with a median age of 37 years (range, 18-72 years). Some patients developed symptoms, including 12 with low back pain (30%), 11 with lower extremity edema (28%), and 10 with abdominal pain (30%). Nephrotic syndrome was the underlying etiology for most patients (30 of 40; 75%). Additionally, 28 patients (70%) developed unilateral RVT, including 18 cases of left RVT (45%). Of the 40 patients, 17 had received BMT (42%) and 23 had received EBT (58%). In the acute phase of RVT, defined as <14 days from symptom onset, the EBT group had higher thrombus clearance and better improvement of creatinine and GFR after treatment compared with the BMT group (P < .05). In the subacute phase, defined as 14 to 30 days after symptom onset, thrombus clearance was higher in the EBT group than in the BMT group (P < .05). However, the improvement in creatinine and GFR were insignificantly different between the two groups (P > .05).

CONCLUSIONS

The etiologies of RVT can and should be investigated. In the present study, RVT was primarily caused by nephrotic syndrome in young patients and also was attributed to malignancy and lupus nephritis. In addition to anticoagulation therapy, endovascular intervention, including catheter-directed thrombolysis and mechanical thrombectomy, contributed to the improvement of renal function in patients with acute RVT. Endovascular intervention markedly promoted thrombus clearance in patients in the subacute phase but did not improve renal function. Therefore, endovascular intervention should be considered if RVT is diagnosed in the acute phase.

Cerebral venous thrombosis in an adult with relapsing minimal change disease

Minimal change disease (MCD) is a well-known cause of fulminant acute nephrotic syndrome (NS) and has been associated with thrombotic complications. We report the case of a 51-year-old woman with previously biopsy-proven MCD in remission who presented with headache and encephalopathy shortly after a relapse of the NS and was diagnosed with cerebral venous thrombosis (CVT) complicated by intracranial hemorrhage and midline shift. One month prior, she had been initiated on an oral contraceptive agent during remission of the NS. After initiation of systemic anticoagulation, her condition rapidly deteriorated, and she passed away before being able to undergo catheter-based venous thrombectomy. We conducted a systematic literature review and identified 33 case reports of adults with NS-associated CVT. The most common symptoms were headache (83%), nausea or vomiting (47%), and altered mental status (30%). 64% of patients presented at time of initial diagnosis of the NS and 32% during a relapse. Mean urinary protein excretion was 9.32 g/day and mean serum albumin was 1.8 g/dL. 91% of patients received systemic anticoagulation, and 19% died. The outcome in the remaining cases was favorable with only one report (5%) of residual neurological deficit. Of the available kidney biopsy results, MCD was the most common diagnosis (70%), raising the hypothesis that the fulminant acute onset of the NS might be a predisposing factor for this serious thrombotic complication. Clinicians should have a high index of suspicion for CVT in patients with the NS who present with new-onset neurological symptoms, including headache and nausea.

Research progress of nephrotic syndrome accompanied by thromboembolism

Thromboembolism (TE) is a common and serious complication of nephrotic syndrome (NS). NS is associated with hypercoagulability, which may be induced by changes in coagulation, anticoagulant, and fibrinolytic factors. Moreover, accumulating evidence supports the hypothesis that the complex interactions between genetic and acquired risk factors in TE should be considered and that genetic susceptibility should not be ignored. Extracellular vesicles (EVs) also play unique roles. Further research on EVs may provide new insights into the discovery and treatment of TE associated with NS. The occurrence of NS accompanied by TE may be associated with various risk factors. Preventive anticoagulant therapy can not only reduce the risk of TE in patients but also aggravate the risk of bleeding. Heparin and vitamin K antagonists (VKAs), traditional anticoagulant drugs, have been extensively applied in the prevention and treatment of thromboembolic diseases, and emerging direct oral anticoagulants (DOACs) also provide an alternative choice. Owing to the particularity of NS, the safe application of DOACs still needs to be addressed. This review aimed to comprehensively describe the pathophysiology of TE in NS, as well as analyze the associated risk factors, the opportunity for preventive anticoagulation, and current anticoagulant information.

Yi Shen An, a Chinese traditional prescription, ameliorates membranous glomerulonephritis induced by cationic bovine serum albumin in rats

CONTEXT

Yi Shen An (YSA) is an investigational composite of traditional Chinese medicine (Reference: 2010L000974) for the treatment of renal disease.

OBJECTIVE

To investigate the protective effects of YSA against membranous glomerulonephritis (MGN).

MATERIALS AND METHODS

Male Sprague-Dawley rats were injected with cationic bovine serum albumin (C-BSA) to create a model of MGN. Then, rats were orally treated with YSA at doses of 0.25, 0.5, 1 and 2 g/kg for 35 successive days; prednisone (5 mg/kg) was used as a positive control. At the end of the experimental period, we performed a series of tests, including 24 h urinary protein, and biochemical, immunological, antioxidative, coagulation indices, and histopathological examination.

RESULTS

YSA-1 g/kg significantly lowered urinary protein from 68.37 to 30.74 mg (p < 0.01). Meantime, total protein (TP) and albumin (ALB) recovered from 66.26 and 20.51 g/L to 76.08 and 35.64 g/L (p < 0.01), respectively. YSA removed the deposition of immunoglobulin G (IgG) and complement 3c (C3c), prevented inter-capillary cell hyperplasia on the glomerular basement membrane (GBM), and reduced electron-dense deposits and fusion of podocytes. In addition, serum IgG and superoxide dismutase were significantly elevated. In contrast, malondialdehyde, total cholesterol, triglyceride, circulating immune complex (CIC), and immunoglobulin M decreased in the YSA-treated group. Moreover, the blood coagulation dysfunction was adjusted.

DISCUSSION AND CONCLUSIONS

These findings indicate YSA may exert a therapeutic effect against MGN through the inhibition of CIC formation, and the removal of IgG and C3c deposition from the GBM, thus supporting the development of further clinical trials.

Macrophage migration inhibitory factor levels are associated with disease activity and possible complications in membranous nephropathy

Membranous nephropathy (MN) is an autoimmune disease characterized by the deposition of immunoglobulin G (IgG) and complementary components in the epithelium of the glomerular capillary wall. Macrophage migration inhibitory factor (MIF) is an inflammatory mediator released by macrophages. MIF plays a key regulatory function in the pathogenesis of immune-mediated glomerulonephritis. This study aimed to investigate whether MIF level could be associated with the activity of MN. Plasma and urine samples from 57 MN patients and 20 healthy controls were collected. The MIF levels in plasma and urine were determined by an enzyme-linked immunosorbent assay (ELISA) kit. The expression of MIF in the renal specimens from 5 MN patients was detected by immunohistochemistry (IHC). The associations of the plasma and urinary levels of MIF and glomerular MIF expression with clinical and pathological characteristics were analyzed. It was revealed that with the increase of MIF levels in plasma and urine, the severity of renal pathological injury in MN patients gradually increased. Correlation analysis showed that the MIF levels in plasma were positively correlated with the platelet (PLT) count (r = 0.302, P = 0.022), and inversely correlated with the prothrombin time (PT) (r =  - 0.292, P = 0.028) in MN patients. The MIF levels in plasma were positively correlated with the C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR) (r = 0.651, P < 0.0001; r = 0.669, P < 0.0001) in MN patients. The urinary levels of MIF were positively correlated with ESR (r = 0.562, P < 0.0001). IHC suggested that MIF was expressed in glomerular basement membrane and tubulointerstitial areas. MIF levels in plasma and urine could reflect the severity of MN, and MIF levels in plasma and urine could be associated with venous thrombosis and infectious complications in MN patients. The glomerular MIF expression could be used to indicate the activity of MN.

Efficacy and Safety of Rituximab in the Treatment of Idiopathic Membranous Nephropathy: A Meta-Analysis

Background

Primary membranous nephropathy (MN), sometimes referred to as idiopathic membranous nephropathy (IMN), is a kind of MN whose pathogenesis is yet unclear. According to research reports, the incidence of IMN is about 9.8-26.8%, and it is on the rise.

Methods

The computer retrieves eight databases to obtain controlled trials at home and abroad on the rituximab (RTX) actions in IMN management. After a rigorous literature quality evaluation, software called RevMan 5.3 was used for data analysis.

Results

This meta-analysis finally contained 8 papers. They were all regarded as controlled trials. Six studies reported serum creatinine (standardized mean difference [SMD]: -6.87; 95% CI: -14.09, 0.35; P = 0.062), ALB (SMD: 1.91; 95% CI: -0.31, 4.14; P = 0.092), and adverse reactions (OR: 0.56; 95% CI: 0.36, 0.90; P < 0.01), all of which were significantly higher in the test group than in the control group (OR: 1.37; 95% CI: 1.07, 1.76; P < 0.01).

Conclusion

The overall effective rate, serum creatinine, adverse effects, and ALB of this trial indicate that RTX may be beneficial for individuals with IMN, but further high-quality research is required to confirm these findings.

Bilateral Renal Vein Thrombosis in Membranous Nephropathy: Hypoalbuminemia Predictive of Venous Thromboembolism in Nephrotic Syndrome

Nephrotic syndrome is a known clinical syndrome in which there is increased permeability in the glomerular basement membrane leading to proteinuria, >3.5g/24h, and hypoalbuminemia. The primary causes of nephrotic syndrome include membranous nephropathy, focal segmental glomerulosclerosis, and minimal change disease. Secondary causes include lupus nephritis, diabetes mellitus, multiple myeloma, amyloidosis, and other systemic conditions. Clinically, nephrotic syndrome presents with edema, hyperlipidemia, and increased risk of thromboembolism, the primary focus of this paper. Nephrotic syndrome is often associated with thromboembolic events, especially in patients with membranous nephropathy. It has been shown that hypoalbuminemia is the most significant independent predictor of venous thromboembolic risk. We present the case of a 32-year-old male who first presented with pleuritic chest pain and was found to have multiple bilateral pulmonary emboli treated with oral anticoagulation. On subsequent visits, prompted by either chest pain or edema, he was found to have increasing pulmonary emboli, as well as downtrending serum albumin levels at each visit. Eventually, bilateral non-occlusive renal vein thrombi were discovered. Lab work indicated membranous nephropathy as the most likely etiology secondary to the patient’s presentation. Serum anti-phospholipase A2 receptor antibody positivity confirmed the diagnosis, and the patient was treated appropriately.

Childhood nephrotic syndrome and the clinical profile of thromboembolism: a systematic review and meta-analysis

Nephrotic syndrome (NS) is a common kidney disease of childhood, affecting 2-7 children per 100,000. A potentially life-threatening complication affecting children with NS is thromboembolism (TE). However, there remains a paucity of information regarding the burden of TE and its associated risk factors in this population. A systematic review was performed on observational studies examining TE events in children with NS, published in Medline, Embase, CINAHL, and CENTRAL, until May 2021. Meta-analyses were separately conducted on the prevalence of TE within articles exclusively studying children with congenital NS and among articles including all forms of NS. Out of 13,626 articles, 22 were included (14,290 children). The pooled prevalence of symptomatic TE among articles including patients with all forms of NS was 3.60% (95% CI 1.95-5.63), which increased to 8.70% (95% CI 5.11-12.96) in articles with exclusively congenital NS patients. Children with steroid-resistant NS were at a higher risk of TE compared to steroid-sensitive children (OR 4.40, 95% CI 1.34-15.59, p = 0.013). Focal segmental glomerulosclerosis was the most common histology present in patients with TE (51.2%). Children diagnosed with NS have a significant risk of TE, particularly in patients with congenital NS and steroid resistance. IMPACT: The prevalence of symptomatic thromboembolic (TE) events in children with nephrotic syndrome (NS) was 3.60% (95% CI 1.95-5.63), which increased more than two-fold in children with congenital NS to 8.70% (95% CI 5.11-12.96). Potential risk factors for TE events in this population include congenital forms of NS and steroid resistance. This review provides a better estimate of the prevalence of TE in children with NS, while identifying potentially higher-risk populations who may benefit from TE screening and thromboprophylaxis.

Nephrotic Syndrome – Different Risk of Venous Thromboembolism with Different Approaches to Justify Prophylactic Anticoagulation

All of the circumstances influencing any of the elements of Virchow’s Triad can increase the risk of venous thromboembolism. Assessing prothrombotic factors can sometimes be difficult. One of the examples of such a condition is nephrotic syndrome. In this condition at least two elements of Virchow’s triad are affected: physiological blood composition and the venous blood flow which is slowed down by the edema. Except for the cases mentioned in KDIGO (Kidney Disease: Improving Global Outcomes), the use of anticoagulant drugs in the prophylaxis of VTE (Venous Thromboembolism) in nephrotic syndrome seems unclear. Nevertheless, due to the increased risk of VTE, it is worth implementing mechanical anticoagulant prophylaxis, which can also improve the quality of life of patients by reducing swelling. The article analyzes the current knowledge on the field and gives some proposals with low bleeding risk.

Anti-PLA2R antibody measured by ELISA predicts the risk of vein thrombosis in patients with primary membranous nephropathy

Background

Primary membranous nephropathy (PMN) is associated with the highest risk for developing venous thrombosis compared with other nephrotic diseases. The aim of the study was to assess the predictive value of the pathognomonic anti-phospholipase A2 receptor (PLA2R) antibody with regard to incidence of venous thrombosis in PMN.

Methods

A total of 365 in-hospital patients diagnosed with PMN were enrolled in the study. Anti-PLA2R antibody was detected by commercial enzyme-linked immunosorbent assay. Multivariate logistic regression was used to detect the independent risk factors for venous thrombosis.

Results

Thirty-seven patients (10.14%) had venous thrombosis. Patients with venous thrombosis had higher levels of cholesterol (CHOL), low-density lipoprotein (LDL), and D-dimer than those without venous thrombosis (p < .05). Patients with venous thrombosis had significantly lower levels of albumin (23.95 ± 5.53 vs. 26.18 ± 6.59 g/L, p = .049). No significant differences were found in proteinuria, serum creatinine, estimated glomerular filtration rate, platelets, and fibrinogen between patients with and without thrombosis. Anti-PLA2R antibody levels in patients with venous thrombosis were significantly higher than in patients without it (p = .002). In the univariate logistic regression, Ln anti-PLA2R antibody (OR: 1.340; p = .004), albumin (OR: 0.945; p = .050), CHOL (OR: 1.191; p = .006), and LDL (OR: 1.271, p = .006) were associated with venous thrombosis. Ln anti-PLA2R antibody (OR = 1.269; 95%CI: 1.032–1.561), and LDL (OR = 1.213; 95%CI: 1.017–1.448) were the independent risk factors for venous thrombosis (p < .05) in multivariate analysis.

Conclusions

Anti-PLA2R antibody was the independent risk factor for venous thrombosis in PMN. Larger prospective studies were warranted to verify the results in future.

Membranous nephropathy

Membranous nephropathy (MN) is a glomerular disease that can occur at all ages. In adults, it is the most frequent cause of nephrotic syndrome. In ~80% of patients, there is no underlying cause of MN (primary MN) and the remaining cases are associated with medications or other diseases such as systemic lupus erythematosus, hepatitis virus infection or malignancies. MN is an autoimmune disease characterized by a thickening of the glomerular capillary walls due to immune complex deposition. Identification of the phospholipase A2 receptor (PLA2R) as the major antigen in adults in 2009 induced a paradigm shift in disease diagnosis and monitoring and several other antigens have since been characterized. Disease outcome is difficult to predict and around one-third of patients will undergo spontaneous remission. In those at high risk of progression, immunosuppressive therapy with cyclophosphamide plus corticosteroids has substantially reduced the need for kidney replacement therapy. Owing to carcinogenic risk, other treatments (calcineurin inhibitors and CD20-targeted B cell depletion therapy (rituximab)) have been developed. However, disease relapses are frequent when calcineurin inhibitors are stopped and the remission rate with rituximab is lower than with cyclophosphamide, particularly in patients with high PLA2R antibody titres. Other new drugs are already available and antigen-specific immunotherapies are being developed.

Primary Nephrotic Syndrome and Risks of ESKD, Cardiovascular Events, and Death: The Kaiser Permanente Nephrotic Syndrome Study

BACKGROUND

Little population-based data exist about adults with primary nephrotic syndrome.

METHODS

To evaluate kidney, cardiovascular, and mortality outcomes in adults with primary nephrotic syndrome, we identified adults within an integrated health care delivery system (Kaiser Permanente Northern California) with nephrotic-range proteinuria or diagnosed nephrotic syndrome between 1996 and 2012. Nephrologists reviewed medical records for clinical presentation, laboratory findings, and biopsy results to confirm primary nephrotic syndrome and assigned etiology. We identified a 1:100 time-matched cohort of adults without diabetes, diagnosed nephrotic syndrome, or proteinuria as controls to compare rates of ESKD, cardiovascular outcomes, and death through 2014, using multivariable Cox regression.

RESULTS

We confirmed 907 patients with primary nephrotic syndrome (655 definite and 252 presumed patients with FSGS [40%], membranous nephropathy [40%], and minimal change disease [20%]). Mean age was 49 years; 43% were women. Adults with primary nephrotic syndrome had higher adjusted rates of ESKD (adjusted hazard ratio [aHR], 19.63; 95% confidence interval [95% CI], 12.76 to 30.20), acute coronary syndrome (aHR, 2.58; 95% CI, 1.89 to 3.52), heart failure (aHR, 3.01; 95% CI, 2.16 to 4.19), ischemic stroke (aHR, 1.80; 95% CI, 1.06 to 3.05), venous thromboembolism (aHR, 2.56; 95% CI, 1.35 to 4.85), and death (aHR, 1.34; 95% CI, 1.09 to 1.64) versus controls. Excess ESKD risk was significantly higher for FSGS and membranous nephropathy than for presumed minimal change disease. The three etiologies of primary nephrotic syndrome did not differ significantly in terms of cardiovascular outcomes and death.

CONCLUSIONS

Adults with primary nephrotic syndrome experience higher adjusted rates of ESKD, cardiovascular outcomes, and death, with significant variation by underlying etiology in the risk for developing ESKD.

Prevalence and Associated Risk Factors of Pulmonary Embolism in Children and Young Adults With Nephrotic Syndrome: A Chinese Large Cohort Study

PURPOSE

Nephrotic syndrome (NS) is highly associated with an increased risk of pulmonary embolism (PE) in children and young adults. However, few studies have specified the risk factors of PE in children and young adults with NS. We sought to determine the prevalence and associated factors of PE confirmed with computed tomography pulmonary angiography in Chinese children and young adults with NS.

METHODS

Data from 444 children and young adults with NS who had computed tomography pulmonary angiography from December 2010 to October 2018 were retrospectively analyzed. The prevalence of PE was estimated for different age, sex, and histopathologic types of NS. Multivariable logistic regression was used to identify independent risk factors of PE in children and young adults with NS. Models incorporating the independent risk factors were evaluated using receiver operation characteristic curves. Area under the curve was used to determine the best-performing prognosticators for predicting PE.

RESULTS

There were 444 patients in the study cohort (310 male patients, 134 female patients; mean age 19±3 y; range: 6 to 25 y). PE was present in 24.8% of the participants (110 of 444, 18.2% female). Children and young adult NS patients with PE tend to be older, male, to have a previous thromboembolism history and smoking, and have a higher level of proteinuria, D-dimer, and serum albumin (P<0.05 for all). Children and young adults with membranous nephropathy are likely to have a higher incidence of PE than those with other types of nephropathy. Membranous nephropathy and proteinuria were significant predictors of PE in children and young adults with NS (P<0.05 for all). The area under the curves of each model for the presence of PE in children and young adults with NS based on biochemical parameters and clinical information (model 1), adjusted for proteinuria (model 2), and adjusted for membranous nephropathy (model 3) were 0.578, 0.657, and 0.709, respectively. Compared with model 1, model 2, and model 3 showed statistically significant differences (model 1 vs. model 2, P=0.0336; model 1 vs. model 3, P=0.0268). There was no statistically significant difference between model 2 and model 3 (P=0.2947).

CONCLUSION

This study identified membranous nephropathy and proteinuria as independent associated factors of PE in children and young adults with NS, which can be noted as a risk factor to guide clinician management in this population.

The Association of Syndecan-1, Hypercoagulable State and Thrombosis and in Patients With Nephrotic Syndrome

The aim of this study is to investigate whether Syndecan-1 (SDC-1), an indicator of endothelial glycocalyx injury, would increase the risk of hypercoagulable state and thrombosis in patients with nephrotic syndrome (NS). The prospective study was conducted among patients undergoing renal biopsy in the Department of Nephrology in our hospital from May to September 2018. We enrolled in patients with NS as the experimental group and patients with normal serum creatinine and proteinuria less than 1 g as the control group. Patients’ characteristics including age, sex, laboratory test results and blood samples were collected for each patient. The blood samples were taken before the renal biopsy. The samples were immediately processed and frozen at −80°C for later measurement of Syndecan-1. One hundred and thirty-six patients were enrolled in the study. Patients with NS and hypercoagulability had a higher level of SDC-1 compared with control group. Patients with membranous nephropathy occupied the highest SDC-1 level (P = 0.012). Logistic regression showed that highly increased level of SDC-1 (>53.18 ng/ml) was an independent predicator for predicting hypercoagulable state. The elevated level of SDC-1 indicated that endothelial injury, combined with its role of accelerating hypercoagulable state, might be considered of vital importance in the pathophysiological progress of thrombosis formation in patients with NS.

Rituximab in Membranous Nephropathy

Membranous nephropathy (MN) is the most common cause of primary nephrotic syndrome among adults. The identification of phospholipase A2 receptor (PLA2R) as target antigen in most patients changed the management of MN dramatically, and provided a rationale for B-cell depleting agents such as rituximab. The efficacy of rituximab in inducing remission has been investigated in several studies, including 3 randomized controlled trials, in which complete and partial remission of proteinuria was achieved in approximately two-thirds of treated patients. Due to its favorable safety profile, rituximab is now considered a first-line treatment option for MN, especially in patients at moderate and high risk of deterioration in kidney function. However, questions remain about how to best use rituximab, including the optimal dosing regimen, a potential need for maintenance therapy, and assessment of long-term safety and efficacy outcomes. In this review, we provide an overview of the current literature and discuss both strengths and limitations of "the new standard."

Nephrotic syndrome disease activity is proportional to its associated hypercoagulopathy

INTRODUCTION

Nephrotic syndrome (NS) is associated with an acquired hypercoagulopathy that drives its strong predilection for life-threatening thrombosis. We previously demonstrated that hypercoagulopathy is proportional to NS disease severity in animal models. Therefore, hypercoagulopathy and disease severity may inform thrombosis risk and better guide therapeutic decision making. The objective of this study was thus to establish the relationship between disease severity and hypercoagulopathy in human NS.

MATERIALS AND METHODS

Thrombin generation assays (TGA) were performed on biorepository plasma samples from a prospective longitudinal NS cohort study. TGA was also determined on a separate cohort of incident NS patients. Multivariable regression was used to build NS-hypercoagulopathy relationship models.

RESULTS

Endogenous thrombin potential (ETP) was the TGA parameter most strongly correlated with NS severity and was proportional to conventional measures of NS disease activity including proteinuria, hypercholesterolemia, and hypoalbuminemia. The overall disease activity model was well correlated with ETP (R² = 0.38). The relationship with disease activity was confirmed in the second cohort. These models further revealed that ETP is related to disease activity in a manner dependent on remission status.

CONCLUSION

Consistent with our previously reported animal model observations, we found that the combination of proteinuria, hypercholesterolemia, and hypoalbuminemia correlated with ETP-defined hypercoagulopathy. Hypercoagulopathy improved significantly with partial or complete NS remission. These data are expected to inform studies designed to stratify thrombotic risk for patients with NS.

Statins can benefit patients with primary membranous nephropathy on venous thromboembolism

Objective

The aim of this study was to investigate the role of prophylactic use of statin in venous thromboembolism (VTE) in patients with primary membranous nephropathy (PMN).

Methods

A total of 734 patients with PMN were consecutively enrolled in this retrospective study. 564 patients had received statins prescription, while 170 patients did not. Kaplan–Meier methods were used for cumulative incidence plots of thromboembolic events and Cox proportional hazards regression models were used to assess risk factors. Finally, the effects of different potency of statins were evaluated.

Results

In the cohort, 37 patients (5.0%) experienced VTE. In a univariate Cox proportional hazard model, the hazard ratio (HR) for VTE in statin users versus statin non-users was 0.5 (95% CI 0.3–0.8, p = .03). Multivariable model proportional-hazards analysis corrected for co-medications and risk factors revealed that adjusted HR was 0.4 (95% CI 0.1–0.7, p = .03). According to the type and dose, statin users were assigned into 3 groups: high-intensity group (n = 278), moderate-intensity group (n = 186), and low-intensity group (n = 49). In comparison, incidences of VTEs in the three groups were similar (2.9% vs 4.8% vs 2.0%, p = .45).

Conclusions

The prophylactic use of statins could effectively decrease the occurrence of VTE in patients with PMN, and the benefits have no difference in different potency of statins.

Incidence and risk factors of venous thromboembolism in ANCA-associated vasculitis: a metaanalysis and metaregression

The incidence of venous thromboembolism (VTE) in ANCA-associated vasculitis patients varies in different populations. Moreover, the risk factors for VTE in these patients are poorly described due to the small number of events. Ovid MEDLINE, EMBASE, and the Cochrane Library were searched for eligible articles. The inclusion criteria included observational studies that enrolled patients age ≥ 18 years diagnosed with ANCA-associated vasculitis. The incidence of VTE is the outcome of interest. Of 1362 citations, a total of 21 studies (n = 4422) dated from 2006 to 2019 were included in the systematic review. The mean age was 54.2 ± 4.0 years. Most were male (52.0%) and Caucasian (80.9%). With a mean follow-up duration of 5.2 ± 2.8 years, the pooled incidence of VTE in ANCA-associated vasculitis patients was 12.4% (95% CI, 8.8-17.2). Of these, 63.4% (95% CI, 57.3-69.1) had deep vein thrombosis and 26.3% (95% CI, 17.6-37.4) had pulmonary embolism. Recurrent VTE occurred in 10.0% (95% CI, 5.2-18.6). From the metaregression adjusted for age, sex, and ethnicity; positive MPO-ANCA, increasing Birmingham Vasculitis Activity Score at time of vasculitis diagnosis, and presence of renal involvement were positively associated with increased VTE events. Positive PR3-ANCA profile was inversely associated with increased VTE events. Increasing follow-up duration was not associated with increased VTE events. VTE in ANCA-associated vasculitis is common. Positive MPO-ANCA, increasing vasculitis activity, and presence of renal involvement were significant risk factors for VTE while positive PR3-ANCA was inversely associated with increased VTE. Key Points • Venous thromboembolism (VTE) is common in ANCA-associated vasculitis with a pooled incidence of 12.4% • Deep vein thrombosis accounts for two-third of total VTE cases • Positive MPO-ANCA profile, higher disease activity at ANCA-associated vasculitis diagnosis, and renal involvement are risk factors for VTE • Positive PR3-ANCA profile is protective factor for VTE.

The correlation of anti-β2-glycoprotein I antibody with complement activation in patients with idiopathic membranous nephropathy

PURPOSE

This study evaluated the correlation of anti-β2-glycoprotein I (anti-β2-GPI) antibodies with complement activation in patients with idiopathic membranous nephropathy (IMN).

METHODS

Thirty-two IMN patients with positive anti-β2-GPI antibody were enrolled, and 32 age- and sex-matched IMN patients with negative anti-β2-GPI antibody were randomly enrolled as controls. The frozen serum samples of these 64 patients were collected for detection of anti-phospholipase A2 receptor (PLA2R) antibody and the activity of three complement pathways. Paraffin specimens of the kidney tissues of these 64 patients were collected for immunohistochemical staining of C4d.

RESULTS

IMN patients with positive anti-β2-GPI antibody had a significant decline of the residual complement activity of alternative pathway than those with negative anti-β2-GPI antibody (37.4 ± 21.2% vs 65.7 ± 50.5%, P = 0.021). The positive rate of kidney C4d staining in IMN patients with and without anti-β2-GPI was 65.6 and 81.2%, with no significant difference (P = 0.257). Patients with and without anti-β2-GPI had the same positive rate of anti-PLA2R antibody.

CONCLUSION

Anti-β2-GPI antibody was associated with alternative complement activation in patients with IMN.

Measurement of serum albumin in nephrology: we need to improve

Serum albumin is a widely used biomarker in clinical nephrology. Serum albumin cut-off values are used to define disease, to predict outcome, and to guide patient care. The available commercial assays to measure serum albumin rely on different analytical principles, all with their own (analytical) specifications. This paper provides an overview of the different clinical applications of serum albumin measurements in nephrology, the (dis)advantages of the available assays and the estimates of the effects of the measurement uncertainty between different assays in clinical decision making. This paper concludes that harmonisation of serum albumin assay results are needed.

Nephrotic Syndrome

Nephrotic syndrome is one cause of end-stage kidney disease. Because edema is a common presenting feature and hypertension and dyslipidemia are often present in nephrotic syndrome, it is important for the primary care physician to suspect this entity. Common causes in adults include diabetic nephropathy, focal segmental glomerulosclerosis, and membranous nephropathy. In adults, many primary causes are due to an underlying disease. A cause of the nephrotic syndrome should be established with serologic workup and renal consultation. Renal biopsy is necessary in those with an unknown cause to or classify disease. Treatment focuses on symptoms, complications, and the primary cause.

Clinicopathologic characteristics, pathology, and prognosis of 77 dogs with focal segmental glomerulosclerosis

BACKGROUND

Focal segmental glomerulosclerosis (FSGS) is a common cause of nonimmune complex glomerulopathy and the prognosis and clinicopathologic findings associated with this condition have not been described in dogs.

OBJECTIVE

To characterize the presentation and identify clinical factors associated with the survival of dogs with FSGS.

ANIMALS

Seventy-seven dogs diagnosed with FSGS based on evaluation of renal biopsy samples submitted to the International Veterinary Renal Pathology Service.

METHODS

Retrospective review of medical records of dogs biopsied for evaluation of proteinuria between January 2015 and May 2017.

RESULTS

The incidence of FSGS among all dogs biopsied for proteinuria was 26%. Significantly more females (48; 62.3%) than males (29; 37.7%) were affected (P = .04). At the time of biopsy, median serum creatinine concentration (SCr) was 1.2 mg/dL (range, 0.3-8.7), median serum albumin concentration (Alb) was 2.8 g/dL (range, 1.1-4.6), median systolic blood pressure was 153.5 mm Hg (range, 95-260), and median urine protein : creatinine ratio was 5.9 (range, 1.4-22). Median survival time after biopsy was 258 days (range, 26-1003) for dogs that died from all causes (n = 32). Factors that were associated with a shorter survival time included SCr ≥ 2.1 mg/dL (P < .01) and Alb < 2 g/dL (P < .01).

CONCLUSIONS AND CLINICAL IMPORTANCE

Most dogs with FSGS were female, and although commonly hypertensive, azotemia, severe hypoalbuminemia and ascites or edema were observed infrequently. Variables significantly associated with survival time were SCr and Alb.