Limited Role of Antithrombin Deficiency in Hypercoagulopathy Associated with Nephrotic Syndrome

Abstract Background: Nephrotic syndrome (NS) is associated with an acquired hypercoagulopathy that drives venous thromboembolic comorbidities. The molecular mechanisms underlying NS-associated hypercoagulopathy are incompletely understood, however previous studies proposed marked urinary loss of antithrombin (AT) as a primary etiology. We have previously demonstrated, in rodent NS models, that there is no correlation between AT antigen and thrombin generation, which we have previously used to characterize the hypercoagulopathy. The objective of this study is to examine the association between AT antigen, AT activity, and hypercoagulopathy along with NS disease severity markers (proteinuria and plasma albumin) in 2 cohorts that include both pediatric and adult NS patients. Methods: Plasma samples were obtained from both cohorts as follows: (1) Samples were obtained on presentation from 147 adult and pediatric patients participating in the NEPTUNE prospective observational cohort study (2) Samples were obtained on presentation and after 7 weeks of glucocorticoid therapy (GC) in steroid sensitive and steroid resistant pediatric patients participating in the PNRC study. AT antigen and activity assays were performed using ELISA and chromogenic assays, respectively. Thrombin generation assay, plasma albumin, and urine protein-to-creatinine ratio were determined as previously described. Results: There was no significant relationship between AT antigen or AT activity and thrombin generation parameters. AT antigen and activity also did not correlate with NS severity markers (plasma albumin and proteinuria) in the NEPTUNE cohort (Figure1). In PNRC pediatric cohort, no significant correlation was found between AT antigen and thrombin generation or other disease severity markers. However, AT activity was significantly associated with both plasma albumin and endogenous thrombin potential at presentation (Figure 2) and at follow-up. Interestingly, GC therapy significantly improved AT activity in steroid-sensitive but not steroid-resistant NS patients (Figure 3). A comprehensive literature review and meta-analysis was also performed which revealed that clinically significant AT deficiency (<0.7 IU/mL) is uncommon in both pediatric and adult NS patients. Conclusion: AT antigen does not correlate with thrombin generation-defined hypercoagulopathy in adult or pediatric NS patients. AT activity does correlate with hypercoagulopathy in pediatric NS patients and improves significantly with successful remission inducing therapy. These data suggest that pediatric NS patients may have a qualitative, but not quantitative, AT deficiency that is responsive to therapy. The mechanism underlying this qualitative deficiency should be characterized in future studies. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

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Pediatric Patients With Steroid-Sensitive Nephrotic Syndrome Have Higher Expression of T Regulatory Lymphocytes in Comparison to Steroid-Resistant Disease

Frontiers in Pediatrics ◽

10.3389/fped.2019.00114 ◽

2019 ◽

Vol 7 ◽

Cited By ~ 2

Author(s):

Fabio Tadeu Lourenço Guimarães ◽

Rodrigo Novaes Ferreira ◽

Gustavo Eustáquio Alvim Brito-Melo ◽

Etel Rocha-Vieira ◽

Wagner de Fátima Pereira ◽

...

Keyword(s):

Nephrotic Syndrome ◽

Pediatric Patients ◽

Steroid Resistant ◽

Resistant Disease ◽

Steroid Sensitive Nephrotic Syndrome ◽

Steroid Sensitive ◽

Regulatory Lymphocytes

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Biomarkers Predicting Treatment-Response in Nephrotic Syndrome of Children: A Systematic Review

Childhood Kidney Diseases ◽

10.3339/jkspn.2021.25.2.92 ◽

2021 ◽

Vol 25 (2) ◽

pp. 92-111

Author(s):

Jiwon M. Lee ◽

Yo Han Ahn ◽

Seon Hee Lim ◽

Hee Gyung Kang

Keyword(s):

Nephrotic Syndrome ◽

Pediatric Patients ◽

Serum Markers ◽

Urine Specimen ◽

Vitamin D Binding Protein ◽

Steroid Resistant ◽

Number Of Patients ◽

Steroid Sensitive ◽

Cellular Phenotypes ◽

Steroid Responsiveness

Purpose: Nephrotic syndrome (NS) is the most common form of glomerulopathy in children. Most pediatric patients respond to glucocorticosteroid treatment (steroid-sensitive NS, SSNS), while approximately 10–15% will remain unresponsive or later become steroid-resistant. There has been a long-standing effort to find biomarkers that may predict steroid responsiveness.Methods: We systematically reviewed current studies which investigated clinically relevant biomarkers for predicting steroid responsiveness in pediatric NS. We performed a PubMed and EMBASE search to identify eligible articles. We collected data on urinary markers, blood/serum markers (including cellular phenotypes and mRNA expression), genotypes and HLA allele frequency.Results: A total of 659 articles were identified following electronic and manual searches. After reviewing the titles, abstracts, and full texts, 72 eligible articles were finally included. Vitamin D-binding protein (VDBP) seemed to be significantly elevated in SRNS than in SSNS, in both serum and urine specimen, although further validation is required.Conclusions: The present paper narratively illustrates current understandings of potential biomarkers that may help predict steroid responsiveness. Further investigation and collaboration involving a larger number of patients are necessary.

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Distribution of serum adiponectin isoforms in pediatric patients with steroid-sensitive nephrotic syndrome

Clinical and Experimental Nephrology ◽

10.1007/s10157-021-02085-w ◽

2021 ◽

Author(s):

Tetsuro Tamai ◽

Kaori Kamijo ◽

Yoshifusa Abe ◽

Satoshi Hibino ◽

Shunsuke Sakurai ◽

...

Keyword(s):

Molecular Weight ◽

Nephrotic Syndrome ◽

Pediatric Patients ◽

Serum Adiponectin ◽

Total Serum ◽

Control Subjects ◽

Remission Period ◽

Total Adiponectin ◽

Steroid Sensitive Nephrotic Syndrome ◽

Steroid Sensitive

Abstract Background Serum adiponectin circulates in three multimeric isoforms: high-molecular-weight (HMW), middle-molecular-weight (MMW), and low-molecular-weight (LMW) isoforms. Potential change in the circulating adiponectin levels in patients with nephrotic syndrome (NS) remain unknown. This study aimed to assess the levels of total adiponectin and the distribution of its isoforms in pediatric patients with NS. Methods We sequentially measured total adiponectin and each adiponectin isoform levels at the onset of NS, initial remission, and during the remission period of the disease in 31 NS patients. We also calculated the ratios of HMW (%HMW), MMW (%MMW), and LMW (%LMW) to total adiponectin incuding 51 control subjects. Results The median of total serum adiponectin levels in patients were 36.7, 36.7, and 20.2 μg/mL at the onset, at initial remission, and during the remission period of NS, respectively. These values were significantly higher than those in control subjects. The median values of %HMW, %MMW, and %LMW values were 56.9/27.0/14.1 at the onset, 62.0/21.8/13.4 at the initial remission, and 58.1/21.7/17.5 at during the remission period of NS, respectively. Compared with control subjects, %HMW at initial remission and %MMW at the onset were high, and the %LMW values at the onset and at initial remission were low. Conclusions In patients with NS, total serum adiponectin levels increase at the onset of the disease, and the ratio of adiponectin isoforms changes during the course of the disease. Further studies are needed to delineate the mechanisms between proteinuria and adiponectin isoforms change.

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Possible mechanisms of LDL apheresis for pediatric patients with steroid resistant and refractory nephrotic syndrome

Nihon Shoni Jinzobyo Gakkai Zasshi ◽

10.3165/jjpn.23.154 ◽

2010 ◽

Vol 23 (2) ◽

pp. 154-159

Author(s):

Hiroaki Ueda ◽

Yuko Akioka ◽

Masakazu Miyamura ◽

Kiyonobu Ishizuka ◽

Mamiko Suehiro ◽

...

Keyword(s):

Nephrotic Syndrome ◽

Pediatric Patients ◽

Ldl Apheresis ◽

Steroid Resistant ◽

Refractory Nephrotic Syndrome

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Reverse Phenotyping after Whole-Exome Sequencing in Steroid-Resistant Nephrotic Syndrome

Clinical Journal of the American Society of Nephrology ◽

10.2215/cjn.06060519 ◽

2019 ◽

Vol 15 (1) ◽

pp. 89-100 ◽

Cited By ~ 15

Author(s):

Samuela Landini ◽

Benedetta Mazzinghi ◽

Francesca Becherucci ◽

Marco Allinovi ◽

Aldesia Provenzano ◽

...

Keyword(s):

Nephrotic Syndrome ◽

Exome Sequencing ◽

Whole Exome Sequencing ◽

Clinical Signs ◽

Long Term Outcome ◽

Steroid Resistant ◽

Steroid Resistant Nephrotic Syndrome ◽

Pathogenic Variants ◽

Whole Exome ◽

Steroid Sensitive

Background and objectivesNephrotic syndrome is a typical presentation of genetic podocytopathies but occasionally other genetic nephropathies can present as clinically indistinguishable phenocopies. We hypothesized that extended genetic testing followed by reverse phenotyping would increase the diagnostic rate for these patients.Design, setting, participants, & measurementsAll patients diagnosed with nephrotic syndrome and referred to our center between 2000 and 2018 were assessed in this retrospective study. When indicated, whole-exome sequencing and in silico filtering of 298 genes related to CKD were combined with subsequent reverse phenotyping in patients and families. Pathogenic variants were defined according to current guidelines of the American College of Medical Genetics.ResultsA total of 111 patients (64 steroid-resistant and 47 steroid-sensitive) were included in the study. Not a single pathogenic variant was detected in the steroid-sensitive group. Overall, 30% (19 out of 64) of steroid-resistant patients had pathogenic variants in podocytopathy genes, whereas a substantial number of variants were identified in other genes, not commonly associated with isolated nephrotic syndrome. Reverse phenotyping, on the basis of a personalized diagnostic workflow, permitted to identify previously unrecognized clinical signs of an unexpected underlying genetic nephropathy in a further 28% (18 out of 64) of patients. These patients showed similar multidrug resistance, but different long-term outcome, when compared with genetic podocytopathies.ConclusionsReverse phenotyping increased the diagnostic accuracy in patients referred with the diagnosis of steroid-resistant nephrotic syndrome.

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Association of DQB1*0302 Alloantigens in Japanese Pediatric Patients with Steroid-Sensitive Nephrotic Syndrome

Nephron ◽

10.1159/000188540 ◽

1995 ◽

Vol 70 (1) ◽

pp. 28-34 ◽

Cited By ~ 10

Author(s):

Kasumi Kuramitsu Abe ◽

Isao Michinaga ◽

Toshiki Hiratsuka ◽

Satoru Ogahara ◽

Setsuya Naito ◽

...

Keyword(s):

Nephrotic Syndrome ◽

Pediatric Patients ◽

Steroid Sensitive Nephrotic Syndrome ◽

Steroid Sensitive

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Thrombin Generation in Pediatric Patients Treated with L-asparaginase.

Blood ◽

10.1182/blood.v114.22.3983.3983 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3983-3983

Author(s):

Katerina Tousovska ◽

Ondrej Zapletal ◽

Sona Vytiskova ◽

Martina Slanska ◽

Petra Ruzickova ◽

...

Keyword(s):

Thrombin Generation ◽

Pediatric Patients ◽

Fibrinogen Level ◽

Conflicts Of Interest ◽

Lymphoblastic Leukemia ◽

Coagulation Cascade ◽

Induction Treatment ◽

Bleeding Episodes ◽

Almost All

Abstract Abstract 3983 Poster Board III-919 Introduction Treatment with L-asparaginase is associated with an disturbance of coagulation cascade. Increased thrombin generation is the most frequently cited coagulation anomaly associated with L-asparaginase treatment. Until now, almost all studies aimed on estimation of thrombin generation, have used circulating procoagulant markers such are thrombin/antithrombin complexes(TAT),D dimers(DD),prothrombin fragments (F1,F2).Calibrated automated thrombogram (CAT) allows the precise estimation of the whole amount of thrombin generated in vivo at present time. We show the first data on thrombin generation measured by CAT among pediatric patients with acute lymphoblastic leukemia treated with L-asparaginase. Patients and methods Thrombin generation was measured in platelet poor plasma of 18 patients (age 7-17years) by means of CAT. Samples were obtained at pre-defined time points during the induction and reinduction phase of protocol ALL-IC BFM 2000. We simultaneously checked the APTT,PT,AT III,fibrinogen and DD from each blood sample. Detailed patientsx data were collected prospectively. Results We collected 22 series of CAT measurements from 18 patients. The average endogenous thrombin potential (ETP) value was 1237,64±334,49nM/min during protocol I(PI) and 892,31±405,03 during protocol II resp.III(PII/III) (p .000013). Maximum ETP was reached on day 24 in PI (1310,15±256,3nM/min) and on day 15 in PII/III (978,20±262,30 nM/ min). The average ETP value in 20 healthy controls was 1218,12±129,00 nM/min. Three patients developed deep venous thrombosis (DVT) during the study period, all of them on PI. Their average ETP value on the last measurement before thrombosis was 1510,54±78,6 nM/min. Four patient had an infection gr. III/IV, according WHO, during the study period. Their average ETP value after the infection was 1711,43±106,0 nM/min. Two of those four patient developed DVT within 5 resp.8 days after the first sign of infection. Fibrinogen level <1g/l was detected in 19 samples out of 104. From those 19 samples with fibrinogen < 1,0,the ETP value from the same sample was normal in 14 cases and low in 5 cases. There were no bleeding episodes in that time. Conclusions Thrombin generation is preserved in majority of patients treated with L-asparaginase in accordance with ALL-IC BFM 2000 protocol, despite the associated hypofibrinogenemia. Patients on induction treatment generate significantly more thrombin than patients on reinduction treatment. Our results show the sharp increase in ETP right after the infection with risk of DVT. Our data should be proved on larger group of patients. Disclosures: No relevant conflicts of interest to declare.

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Influence Of Antithrombin Deficiency On Symptomatic Recurrent Venous Thromboembolism (VTE) In Children: A Multicenter Cohort Study

Blood ◽

10.1182/blood.v122.21.3619.3619 ◽

2013 ◽

Vol 122 (21) ◽

pp. 3619-3619

Author(s):

Gili Kenet ◽

Verena Limperger ◽

Neil A Goldenberg ◽

Christine Heller ◽

Susanne Holzhauer ◽

...

Keyword(s):

Multivariate Analysis ◽

Venous Thromboembolism ◽

Pediatric Patients ◽

Cox Regression ◽

Conflicts Of Interest ◽

Antithrombin Deficiency ◽

Increased Risk ◽

Recurrent Venous Thromboembolism ◽

At Deficiency ◽

Recurrent Vte

Abstract Objective To determine the importance of antithrombin [AT] deficiency as risk factor or predictor for fatal/non-fatal recurrent venous thromboembolism (VTE) in children. Methods In the present cohort of 874 consecutively enrolled pediatric patients with VTE aged newborn to <18 years the rate of VTE recurrence and the time to recurrence in relation to AT-deficiency [confirmed by underlying gene mutations; type 1 deficiency n=17; type 2 deficiency n=3], age and sex was determined. Twenty of 874 patients [2.4%] suffered from AT-deficiency. From the same cohort 150 VTE children carrying the heterozygous F5 G1691A mutation [F5: 17.7%] served as controls. Patients were prospectively followed for a median of 84 months. Data were pooled across participating sites to increase power and to enhance the generalisability of the data. Incidence rates were given as events per 1000 person-years. Results Of the 170 children enrolled 26 [AT n=9; F5 n=17] had recurrent VTE at a median of 15 months [95%CI: 12-36] following VTE onset: two of nine [AT] and two of 17 [F5] children suffered recurrent VTE while on anticoagulation with warfarin. The overall incidence rate of recurrence was 61.5 in patients with AT-deficiency compared to 23.5 for pediatric F5 carriers [p=0.02]. The recurrent-free survival probability is shown in the figure [logrank p-value: p=0.001]. When comparing AT patients and F5 children multivariate analysis [Cox regression] adjusted for age, sex and duration of anticoagulation treatment showed that AT deficiency [HR/95%CI: 4.1/1.8-9.4] significantly influenced the hazard for recurrent VTE. Conclusions Based on multivariate analysis, the presence of AT deficiency was associated with an increased risk of VTE recurrence. AT-deficiency in pediatric patients should be identified at VTE onset and the possible influence of intensified treatment protocols on recurrence should be studied in future prospective international studies. Condensed abstract To determine the relative importance of antithrombin deficiency or factor V (FV) mutations as risk factors for fatal/non-fatal recurrence in pediatric thromboembolism (VTE). Antithrombin deficiency influenced the hazard for recurrent VTE. Disclosures: No relevant conflicts of interest to declare.

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Thrombin Generation Is Directly Correlated To Proteinuria Severity In An Experimental Model Of Nephrotic Syndrome

Blood ◽

10.1182/blood.v122.21.3615.3615 ◽

2013 ◽

Vol 122 (21) ◽

pp. 3615-3615

Author(s):

Amanda P. Waller ◽

William E. Smoyer ◽

Melinda A. Chanley ◽

Marvin T. Nieman ◽

Bryce A. Kerlin

Keyword(s):

Nephrotic Syndrome ◽

Thrombin Generation ◽

Conflicts Of Interest ◽

Linear Regression Analysis ◽

Vena Cava ◽

Surrogate Marker ◽

Urinary Protein ◽

Thrombotic Risk ◽

Α Angle ◽

Dose Dependent

Abstract Introduction Thromboembolism is a common complication of nephrotic syndrome (NS). The massive urinary protein loss (proteinuria) of NS results in an acquired, complex hypercoagulopathy. Recent epidemiologic studies have demonstrated that severity of proteinuria in patients with NS is independently predictive for thrombotic risk. Nephrotic-range proteinuria is known to result in acquired deficiencies of antithrombin and free protein S as well as accumulation of procoagulants such as factors V and VIII and von Willebrand factor. However, published cohort studies reveal that the severity of these derangements are quite variable, thus the net effect of proteinuria on thrombotic potential remains unknown. Therefore, we hypothesized that proteinuria severity directly correlates with extent of hypercoagulopathy. Methods PAN (puromycin aminonucleoside)-induced rat NS is known to induce glomerular injury with peak proteinuria at day ∼9 following intravenous injection. Severity of proteinuria and global hemostasis were compared in five groups of male Wistar rats (body weight ∼150 g) receiving a single i.v. injection of PAN at 0 (saline), 25, 50, 100, or 150 mg/kg (n=4/group). Morning spot urines collected on days 0 (before PAN injection) & 9 were analyzed for urinary [protein]:[creatinine] ratio (uPr:Cr). After urine collection on day 9 the rats were anesthetized with isoflurane and blood was collected from the inferior vena cava into 0.32% NaCitrate/1.45 µM Corn Trypsin Inhibitor [final concentrations]. Rotational thromboelastometry (ROTEM) was performed on whole blood within 20 min of collection, using the INTEM (activated intrinsic pathway) assay with and without urokinase (35 ng). Platelet poor plasma (PPP) was prepared from the remaining blood sample. Thrombin generation assays (Technothrombin TGA) were performed on PPP diluted 1:1 with buffer. Results As expected, PAN-treated rats displayed escalating dose-dependent increases in proteinuria at 9 days post-injection (Fig A). The highest dose groups exhibited differential derangements in ROTEM parameters, such that clot formation time (CFT) was decreased and α-angle was increased in rats receiving 100 & 150 mg/kg PAN vs. the sham group (P<0.05; Table). Maximum clot firmness (MCF), amplitude at 10 min (A10) & 20 min (A20), and lysis index at 60 min (LI60) were also significantly higher with the 100 & 150 mg/kg doses, compared to the 0, 25, & 50 groups (P<0.05). Linear regression analysis of uPr:Cr and all measured ROTEM parameters demonstrated that proteinuria was negatively correlated with CFT (R2=0.612, P<0.001), and positively correlated with MCF, A10, A20, & α-angle (respective R2=0.662, R2=0.496, R2=0.536, & R2=0.674; P<0.001 for each parameter). The amount of urokinase-induced fibrinolysis at 60 min was inversely related to proteinuria (LI60; R2=0.674, P<0.001). TGA parameters also exhibited a dose-dependent effect (Table & Fig B). Peak thrombin and endogenous thrombin potential (ETP) were higher in the 100 & 150 mg/kg dose groups vs. 0, 25 & 50 mg/kg groups (P<0.05). There was a positive correlation between uPr:Cr and parameters of thrombin generation (peak thrombin R2=0.751; ETP R2=0.854; P<0.001; Fig C & D). Conclusion These experiments demonstrate that proteinuria severity in the PAN-induced rat NS model is directly proportional to hypercoagulability as assessed by ROTEM and TGA. This suggests that proteinuria may have biologic relevance as an easily measured surrogate marker for hypercoagulopathy severity in NS. Analysis of inducible thrombus formation in PAN-induced rat NS is currently underway to determine the physiologic relevance of these findings. Disclosures: No relevant conflicts of interest to declare.

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