Venous Thromboembolism in Kidney Diseases and Genetic Predisposition

Developing a genetic testing panel for evaluation of morbidities in kidney transplant recipients

Cardiovascular disease, infection, malignancy, and thromboembolism are major causes of morbidity and mortality in kidney transplant recipients (KTR). Prospectively identifying monogenic conditions associated with post-transplant complications may enable personalized management. Therefore, we developed a transplant morbidity panel (355 genes) associated with major post-transplant complications including cardiometabolic disorders, immunodeficiency, malignancy, and thrombophilia. This gene panel was then evaluated using exome sequencing data from 1590 KTR. Additionally, genes associated with monogenic kidney and genitourinary disorders along with American College of Medical Genetics (ACMG) secondary findings v3.2 were annotated. Altogether, diagnostic variants in 37 genes associated with Mendelian kidney and genitourinary disorders were detected in 9.9% (158/1590) of KTR; 25.9% (41/158) had not been clinically diagnosed. Moreover, the transplant morbidity gene panel detected diagnostic variants for 56 monogenic disorders in 9.1% KTRs (144/1590). Cardiovascular disease, malignancy, immunodeficiency, and thrombophilia variants were detected in 5.1% (81), 2.1% (34), 1.8% (29) and 0.2% (3) among 1590 KTRs, respectively. Concordant phenotypes were present in half of these cases. Reviewing implications for transplant care, these genetic findings would have allowed physicians to set specific risk factor targets in 6.3% (9/144), arrange intensive surveillance in 97.2% (140/144), utilize preventive measures in 13.2% (19/144), guide disease-specific therapy in 63.9% (92/144), initiate specialty referral in 90.3% (130/144) and alter immunosuppression in 56.9% (82/144). Thus, beyond diagnostic testing for kidney disorders, sequence annotation identified monogenic disorders associated with common post-transplant complications in 9.1% of KTR, with important clinical implications. Incorporating genetic diagnostics for transplant morbidities would enable personalized management in pre- and post-transplant care.

Concerns about the application of resistance exercise with blood-flow restriction and thrombosis risk in hemodialysis patients

BACKGROUND

Hemodialysis (HD) per se is a risk factor for thrombosis. Considering the growing body of evidence on blood-flow restriction (BFR) exercise in HD patients, identification of possible risk factors related to the prothrombotic agent D-dimer is required for the safety and feasibility of this training model. The aim of the present study was to identify risk factors associated with higher D-dimer levels and to determine the acute effect of resistance exercise (RE) with BFR on this molecule.

METHODS

Two hundred and six HD patients volunteered for this study (all with a glomerular filtration rate of <15 mL/min/1.73 m2). The RE + BFR session consisted of 50% arterial occlusion pressure during 50 min sessions of HD (intradialytic exercise). RE repetitions included concentric and eccentric lifting phases (each lasting 2 s) and were supervised by a strength and conditioning specialist.

RESULTS

Several variables were associated with elevated levels of D-dimer, including higher blood glucose, citrate use, recent cardiovascular events, recent intercurrents, higher inflammatory status, catheter as vascular access, older patients (>70 years old), and HD vintage. Furthermore, RE + BFR significantly increases D-dimer after 4 h. Patients with borderline baseline D-dimer levels (400-490 ng/mL) displayed increased risk of elevating D-dimer over the normal range (≥500 ng/mL).

CONCLUSION

These results identified factors associated with a heightened prothrombotic state and may assist in the screening process for HD patients who wish to undergo RE + BFR. D-dimer and/or other fibrinolysis factors should be assessed at baseline and throughout the protocol as a precautionary measure to maximize safety during RE + BFR.

Effectiveness and safety of anticoagulants among patients with venous thromboembolism and active cancer who also had prior bleed or prior renal disease

OBJECTIVE

Patients with active cancer and venous thromboembolism (VTE) have elevated risk of recurrent VTE (rVTE) and major bleeding (MB). The risk is even higher within those with a prior bleeding event or renal disease. There is a need to understand the risk of rVTE and MB of commonly used anticoagulants among these high-risk patients.

METHODS

VTE patients with active cancer and treated with apixaban, warfarin, or low molecular weight heparin (LMWH) within 30 days of VTE were identified from five claims databases in the United States. Inverse probability of treatment weighting (IPTW) was used to balance patient characteristics. The post-IPTW population was stratified by prior bleed or renal disease status. Cox proportional hazards models were used to evaluate interactions between treatment and prior bleed or renal disease on risk of rVTE and MB, with p value <.1 considered significant.

RESULTS

Study criteria were met by 30,586 VTE cancer patients: 35.0% had prior bleed and 29.0% had renal disease. For apixaban, LMWH, and warfarin cohorts, the incidence (events per 100 person-years) of MB was higher in patients with prior bleed (17.48 vs 7.58, 25.61 vs 13.11, and 20.38 vs 8.97) or renal disease (15.79 vs 8.71, 22.11 vs 15.90, and 18.49 vs 10.39) vs those without the conditions. Generally, there were no significant interactions between anticoagulant use and prior bleed or renal disease on rVTE and MB (p for interaction >.1).

CONCLUSION

The incidence of MB was higher among those with prior bleed or renal disease. Effects of apixaban, warfarin, or LMWH were generally consistent regardless of prior bleed or renal disease status.

The Crosstalk between Nephropathy and Coagulation Disorder: Pathogenesis, Treatment, and Dilemmas

ABSTRACT

The interaction between the kidney and the coagulation system greatly affects each other because of the abundant vessel distribution and blood perfusion in the kidney. Clinically, the risks of complicated thrombosis and bleeding have become important concerns in the treatment of nephropathies, especially nephrotic syndrome, CKD, ESKD, and patients with nephropathy undergoing RRTs. Adverse effects of anticoagulant or procoagulant therapies in patients with nephropathy, especially anticoagulation-related nephropathy, heparin-induced thrombocytopenia, and bleeding, seriously worsen the prognosis of patients, which have become challenges for clinicians. Over the decades, the interaction between the kidney and the coagulation system has been widely studied. However, the effects of the kidney on the coagulation system have not been systematically investigated. Although some coagulation-related proteins and signaling pathways have been shown to improve coagulation abnormalities while avoiding additional kidney damage in certain kidney diseases, their potential as anticoagulation targets in nephropathy requires further investigation. Here, we review the progression of research on the crosstalk between the coagulation system and kidney diseases and systematically analyze the significance and shortcomings of previous studies to provide new sight into future research. In addition, we highlight the status of clinical treatment for coagulation disorder and nephropathy caused by each other, indicating guidance for the formulation of therapeutic strategies or drug development.

Thrombosis in Chronic Kidney Disease in Children

Venous thromboembolism (VTE) in children is a rare condition. An increased incidence has been observed in the last few years due to several factors, such as increased survival in chronic conditions, especially chronic kidney disease (CKD), use of catheters, and increased sensitivity of diagnostic tools. VTE includes deep vein thrombosis (DVT) and pulmonary embolism (PE). VTE in children is associated with a two to six times higher mortality risk and a 5-10% prevalence of post-thrombotic syndrome. Overall, 5% of VTE episodes in children are associated with chronic kidney disease. The etiology of VTE in chronic kidney disease covers a wide range of pathologies. Various types of thrombotic complications may occur during long-term use of a chronic dialysis catheter. VTE occurs in 3% of children with nephrotic syndrome (NS). The risks for VTE and arterial thromboembolism (ATE) were particularly high in the first 6 months after the onset of NS. Other causes of VTE are graft rejection due to thrombosis of vascular anastomoses after kidney transplantation (3%) and autoimmune diseases (lupus nephritis, antiphospholipid syndrome). In this state-of-the-art overview, we have reviewed the physiologic and pathologic mechanisms underlying pediatric thrombosis and updated current diagnostic and treatment options, emphasizing personal experience as well.

Risk factors for central venous catheter-related thrombosis in hospitalized children: a single-center a retrospective cohort study

Background

This study aimed to explore the risk factors of catheter-related thrombosis (CRT) in children in Southwest China who underwent central venous catheter (CVC) insertion.

Methods

An observational cohort study was conducted at a single tertiary center in southwest China between November 2019 and February 2020. All patients who received a CVC were enrolled and Doppler-ultrasound examination was performed weekly until CVC removal. All patients in this study were hospitalized and were observed and followed up in this hospital. Patient demographics, medication, biochemical indexes, catheter maintenance practice, activities after CVC placement data were analyzed. The Kaplan-Meier method was used to calculate the incidence of CRT, and the Cox regression model was used to analyze the factors influencing CRT.

Results

A total of 594 children were included in the study, and the median indwelling time was 10 days, with the shortest being 1 day and the longest 60 days. The overall incidence of CRT was 26.60% (158/594), the 15-day cumulative incidence rate was 30.81%, and the 45-day cumulative incidence rate was 46.27%. After 45 days, the incidence of CRT further increased. Age <12 months [hazard ratio (HR), 1.654; 95% confidence interval (CI): 1.171-2.338], use of 20% mannitol or glycerol fructose (HR, 1.593; 95% CI: 1.058-2.398), CVC placement by a pediatric intensive care unit (PICU) doctor (HR, 1.921; 95% CI: 1.347-2.740), placement length ≥9 cm (HR, 1.633; 95% CI: 1.142-2.336), and D-dimer >1.5 mg/L (HR, 1.451; 95% CI: 1.044-2.015) were risk factors for CRT. Limb exercises (HR, 0.660; 95% CI: 0.469-0.929) after placement was a protective factor for CRT.

Conclusions

The incidence of CRT was higher in children with CVCs, and the key duration of CRT monitoring should be within 15 and 45 days after placement. Patients with age <12 months, using 20% mannitol or glycerol fructose, insertion length ≥9 cm, D-dimer >1.5 mg/L before placement are more likely to happen CVC-CRT than other patient, and it is necessary to be highly vigilant and take preventive measures.