Inherited Risk Factors of Thromboembolic Events in Patients with Primary Nephrotic Syndrome

Case report: cerebral venous sinus thrombosis and pulmonary embolism as the initial presentation in a child with asymptomatic primary nephrotic syndrome

Background

Cerebral venous sinus thrombosis (CVST) is rare, but potentially life-threatening. The clinical course definitely become more unpredictable and fatal in patients complicated by pulmonary embolism (PE). Nephrotic syndrome (NS) is an uncommon etiology of CVST. Concurrence of CVST and PE at the initial onset of NS is extremely unusual and rarely reported. Considering that edema might be absent in NS individuals, thromboembolic events probably become unrecognized, thereby causing a missed or delayed diagnosis and poor outcome. Herein, we described an extraordinary case of an adolescent boy presenting with both CVST and PE initially just within 5 days of disease onset, who was ultimately diagnosed with asymptomatic NS, aiming to emphasize a high index of suspicion of these diseases in patients with conditions of hypercoagulability.

Case presentation

A 13-year-old male child presented acutely with dizziness, fever and dyspnea, with signs of shock but undetected edema. Initial laboratory investigations revealed hypoalbuminemia, typical images of pneumonia, and normal radiographic findings on non-enhanced computed tomography of head. Despite evidence of hypoalbuminemia and neurological symptoms, the child was still misdiagnosed as pneumonia. His dyspnea and period of headache deteriorated even if hemodynamic stability and undetected fever after initial therapy. The delayed urinalysis and 24-h urine examination both showed massive proteinuria. A computed tomography angiography of chest along with cranial magnetic resonance imaging/magnetic resonance venography were subsequently performed, consistent with the imaging features of PE and CVST, respectively. The diagnosis of asymptomatic primary NS complicated by PE and CVST was ultimately confirmed. The patient received corticosteroids and antithrombotic therapy with satisfactory results.

Conclusion

A persistent clinical suspicion of CVST should be borne in mind in patients with a sudden, new or worsening headache, specifically among those with prothrombotic conditions. NS should always be considered in the differential diagnosis of risk factors for CVST, even in absence of edema. Since CVST and PE can be present simultaneously at extraordinary early-onset of NS, early radiological diagnosis is clinically substantial to proper management and satisfactory long-term outcomes.

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.

Venous Thromboembolism in Kidney Diseases and Genetic Predisposition

BACKGROUND

Many renal diseases have been associated with profound clinical effects on thrombosis. To our knowledge, patients with nephrotic syndrome (NS) and chronic kidney disease (CKD) display an elevated risk of vein thrombosis, which is among the common causes of mortality in patients with renal diseases. In addition, venous thrombosis, as a complication, has also been reported in a variety of other renal diseases such as glomerulonephritis without the NS, hypertensive nephropathy, and polycystic kidney disease. With the increasing incidence of kidney diseases and the deeper understanding of the disease, clinicians are becoming more and more aware of the complications of thrombus formation in kidney disease.

SUMMARY

We reviewed recent publications of vein thrombosis in kidney diseases, including primary and secondary glomerular diseases, CKD, hereditary kidney disease, renal transplantation, and hemodialysis-induced, catheter-related thrombus, focusing mainly on the main clinical manifestations, possible mechanisms, related risk factors as well as hereditary influencing factors.

KEY MESSAGES

Vein thrombosis is a complicated complication of a wide spectrum of kidney diseases due to different possible underlying mechanisms.

Nephrotic Syndrome Complications - New and Old. Part 1

Nephrotic syndrome is a rare condition with an incidence of 2-7 cases/100.000 children per year and three new cases/100.000 adults per year. It occurs as a result of severe alteration of the glomerular filtration barrier of various causes, allowing proteins, mostly albumin, to be lost in the urine. Nephrotic syndrome complications are driven by the magnitude of either proteinuria or hypoalbuminemia, or both. Their frequency and severity vary with proteinuria and serum albumin level. Besides albumin, many other proteins are lost in urine. Therefore, nephrotic patients could have low levels of binding proteins for ions, vitamins, hormones, lipoproteins, coagulation factors. The liver tries to counterbalance these losses and will increase the unselective synthesis of all types of proteins. All of these changes will have different clinical consequences. The present paper aims to discuss the pathophysiological mechanism and new therapeutic recommendations for nephrotic syndrome edema and thromboembolic complications.

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.