Hemostatic problems and thromboembolic complications in nephrotic children

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.

Exploring the Role of Antithrombin in Nephrotic Syndrome-Associated Hypercoagulopathy: A Multi-Cohort Study and Meta-Analysis

BACKGROUND

Nephrotic syndrome is associated with an acquired hypercoagulopathy that is thought to drive its predisposition for venous thromboembolism. Previous studies have suggested that urinary antithrombin (AT) loss leading to acquired AT deficiency is the primary mechanism underlying this hypercoagulopathy, but this hypothesis has not been directly tested. The objectives of this study were to test the influence of AT levels on hypercoagulopathy in nephrotic syndrome patient samples and perform meta-analyses to evaluate the likelihood of AT deficiency in patients with nephrotic syndrome.

METHODS

Samples from three independent nephrotic syndrome cohorts were analyzed. AT antigen and activity assays were performed using ELISA and amidolytic assays, respectively. Plasma thrombin generation, albumin, and urine protein-to-creatinine ratios were determined using established methods. Meta-analyses were performed by combining these new data with previously published data.

RESULTS

AT levels were not consistently related to either plasma albumin or proteinuria. AT was quantitatively related to hypercoagulopathy in adult nephrotic syndrome, whereas AT activity was inconsistently associated with hypercoagulopathy in childhood nephrotic syndrome. Notably, hypercoagulopathy did not differ between patients with normal AT levels and those with levels below the threshold used to define clinical AT deficiency (<70%). Moreover, ex vivo AT supplementation did not significantly alter hypercoagulopathy in AT-deficient plasma samples. The meta-analyses demonstrated that AT deficiency was not a uniform feature of nephrotic syndrome and was more common in children than adults.

CONCLUSIONS

These data suggest that AT deficiency plays only a limited role in the mechanisms underlying the acquired hypercoagulopathy of nephrotic syndrome. Moreover, AT deficiency was not present in all patients with nephrotic syndrome and was more likely in children than adults despite the higher risk for venous thromboembolism in adults than children.

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.

Haemostatic profile of children with nephrotic syndrome attending University of Nigeria Teaching Hospital Ituku-Ozalla, Nigeria

Background

Haemostatic derangements are thought to be due to an imbalance between hepatic synthesis of pro-coagulants and urinary losses of anticoagulants.

Objectives

This study evaluated the coagulation profile of Nigerian children with nephrotic syndrome and examined the relationship between coagulation variables, disease state and steroid responsiveness.

Methods

A cross- sectional hospital based study on evaluation of coagulation profile of children with nephrotic syndrome compared with their age- and gender- matched controls.

Results

The median fibrinogen level in subjects and controls was the same (2.9 g/L). Sixteen of 46 (35%) children with nephrotic syndrome had hyperfibrinogenaemia. The median fibrinogen level of children in remission was 2.3 g/L and differed significantly when compared with those of children in relapse (p = 0.001). The median APTT of children with nephrotic syndrome was 45.0 s and differed significantly compared with those of controls (42.0 s) (p value = 0.02). The median prothrombin time in children with and without nephrotic syndrome were 12.0 and 13.0 s respectively, (p = 0.004). About 90% of children with nephrotic syndrome had INR within reference range. Thrombocytosis was found in 15% of children with nephrotic syndrome. The median platelet count in children with new disease was 432 × 10³cells/mm³ and differed significantly when compared with those of controls (p = 0.01).

INR was significantly shorter in children with steroid resistant nephrotic syndrome (SRNS) (median 0.8 s; IQR 0.8 -0.9 s) compared with controls (median 1.0 s; IQR 1.0 -1.1 s) (p = 0.01). Steroid sensitivity was the strongest predictor of remission in children with nephrotic syndrome; steroid sensitive patients were 30 times more likely to be in remission than in relapse (OR 30.03; CI 2.01 – 448.04).

Conclusion

This study shows that the haemostatic derangements in childhood nephrotic involve mostly fibrinogen, APTT, PT, INR and platelet counts. Antithrombin levels are largely unaffected. Variations in fibrinogen, APTT, PT and INR values may be due to the heterogeneous nature of the disease.

Postoperative Intracardiac Thrombus in a Child with Nephrotic Syndrome

Background

Thromboembolic events are a known complication of nephrotic syndrome in children. Intracardiac thrombi are a rare location for thrombus formation but can lead to severe clinical consequences.

Case Presentation

We report an intracardiac left atrial thrombus in a child with new onset steroid-resistant nephrotic syndrome and recently repaired atrial septal defect and cor triatriatum. The thrombus was successfully treated with surgical excision.

Conclusion

Intracardiac thrombus is a rare but serious complication of nephrotic syndrome in children, especially in children with risk factors for potentially increased intracardiac thrombogenicity such as history of recent intervention.

Comprehensive coagulation and fibrinolytic potential in the acute phase of pediatric patients with idiopathic nephrotic syndrome evaluated by whole blood-based rotational thromboelastometry

BACKGROUND

Venous thromboembolism is a rare, serious complication of idiopathic nephrotic syndrome (INS) in childhood. The mechanisms responsible for the hypercoagulable state in the acute phase of INS are poorly understood, however. This study aimed to assess overall coagulation and fibrinolytic function in pediatric patients with INS.

METHODS

Global coagulation and fibrinolysis were examined in whole blood samples from 22 children with initial onset INS (initial-group), 22 children with relapsed INS (relapse-group), and 15 control pediatric patients using rotational thromboelastometry (ROTEM®). In the initial-group, blood samples were obtained before (week 0) and 1-4 weeks after initiation of corticosteroid therapy. EXTEM and FIBTEM were used to assess coagulation and fibrinolysis, respectively. Clot time (CT), clot formation time (CFT), maximum clot firmness (MCF), and α-angle were determined as coagulation parameters, and lysis index at 30 and 60 min (LI30 and LI60, respectively) were assessed as fibrinolytic parameters.

RESULTS

CT was significantly shortened, and MCF and α-angle were significantly greater than controls at week 0 and week 1 both in the initial-group and the relapse-group. MCF correlated with serum albumin (r = 0.70, p < 0.001) and fibrinogen level (r = 0.68, p < 0.001). The fibrinolytic parameters (LI30 and LI60) in the initial-group were stable and higher than those in controls at all time points (p < 0.01).

CONCLUSIONS

We have shown that the hypofibrinolytic defect did not improve with effective NS treatment at the early 4-week time-point. Additionally, a likely pre-thrombotic state was evident in the period before initial onset and 1 week after corticosteroid therapy in pediatric INS.

The genomics of ecological flexibility, large brains, and long lives in capuchin monkeys revealed with fecalFACS

Surviving challenging environments, living long lives, and engaging in complex cognitive processes are hallmark human characteristics. Similar traits have evolved in parallel in capuchin monkeys, but their genetic underpinnings remain unexplored. We developed and annotated a reference assembly for white-faced capuchin monkeys to explore the evolution of these phenotypes. By comparing populations of capuchins inhabiting rainforest versus dry forests with seasonal droughts, we detected selection in genes associated with kidney function, muscular wasting, and metabolism, suggesting adaptation to periodic resource scarcity. When comparing capuchins to other mammals, we identified evidence of selection in multiple genes implicated in longevity and brain development. Our research was facilitated by our method to generate high- and low-coverage genomes from noninvasive biomaterials.

Ecological flexibility, extended lifespans, and large brains have long intrigued evolutionary biologists, and comparative genomics offers an efficient and effective tool for generating new insights into the evolution of such traits. Studies of capuchin monkeys are particularly well situated to shed light on the selective pressures and genetic underpinnings of local adaptation to diverse habitats, longevity, and brain development. Distributed widely across Central and South America, they are inventive and extractive foragers, known for their sensorimotor intelligence. Capuchins have among the largest relative brain size of any monkey and a lifespan that exceeds 50 y, despite their small (3 to 5 kg) body size. We assemble and annotate a de novo reference genome for Cebus imitator. Through high-depth sequencing of DNA derived from blood, various tissues, and feces via fluorescence-activated cell sorting (fecalFACS) to isolate monkey epithelial cells, we compared genomes of capuchin populations from tropical dry forests and lowland rainforests and identified population divergence in genes involved in water balance, kidney function, and metabolism. Through a comparative genomics approach spanning a wide diversity of mammals, we identified genes under positive selection associated with longevity and brain development. Additionally, we provide a technological advancement in the use of noninvasive genomics for studies of free-ranging mammals. Our intra- and interspecific comparative study of capuchin genomics provides insights into processes underlying local adaptation to diverse and physiologically challenging environments, as well as the molecular basis of brain evolution and longevity.

Pediatric idiopathic steroid-sensitive nephrotic syndrome: diagnosis and therapy -short version of the updated German best practice guideline (S2e) - AWMF register no. 166-001, 6/2020

Idiopathic nephrotic syndrome is the most frequent glomerular disease in children in most parts of the world. Children with steroid-sensitive nephrotic syndrome (SSNS) generally have a good prognosis regarding the maintenance of normal kidney function even in the case of frequent relapses. The course of SSNS is often complicated by a high rate of relapses and the associated side effects of repeated glucocorticoid (steroid) therapy. The following recommendations for the treatment of SSNS are based on the comprehensive consideration of published evidence by a working group of the German Society for Pediatric Nephrology (GPN) based on the systematic Cochrane reviews on SSNS and the guidelines of the KDIGO working group (Kidney Disease - Improving Global Outcomes).

Nephrotic syndrome-associated hypercoagulopathy is alleviated by both pioglitazone and glucocorticoid which target two different nuclear receptors

BACKGROUND

Thrombosis is a potentially life-threatening nephrotic syndrome (NS) complication. We have previously demonstrated that hypercoagulopathy is proportional to NS severity in rat models and that pioglitazone (Pio) reduces proteinuria both independently and in combination with methylprednisolone (MP), a glucocorticoid (GC). However, the effect of these treatments on NS-associated hypercoagulopathy remains unknown. We thus sought to determine the ability of Pio and GC to alleviate NS-associated hypercoagulopathy.

METHODS

Puromycin aminonucleoside-induced rat NS was treated with sham, Low- or High-dose MP, Pio, or combination (Pio + Low-MP) and plasma was collected at day 11. Plasma samples were collected from children with steroid-sensitive NS (SSNS) and steroid-resistant NS (SRNS) upon presentation and after 7 weeks of GC therapy. Plasma endogenous thrombin potential (ETP), antithrombin (AT) activity, and albumin (Alb) were measured using thrombin generation, amidolytic, and colorimetric assays, respectively.

RESULTS

In a rat model of NS, both High-MP and Pio improved proteinuria and corrected hypoalbuminemia, ETP and AT activity (p < .05). Proteinuria (p = .005) and hypoalbuminemia (p < .001) were correlated with ETP. In childhood NS, while ETP was not different at presentation, GC therapy improved proteinuria, hypoalbuminemia, and ETP in children with SSNS (p < .001) but not SRNS (p = .330).

CONCLUSIONS

Both Pio and GC diminish proteinuria and significantly alleviate hypercoagulopathy. Both Pio and MP improved hypercoagulopathy in rats, and successful GC therapy (SSNS) also improved hypercoagulopathy in childhood NS. These data suggest that even a partial reduction in proteinuria may reduce NS-associated thrombotic risk.

Pulmonary Embolism in Children: A Case Series

Background

Pulmonary embolism (PE) is a life-threatening event with a mortality of ~10%. It is relatively uncommon in children and literature regarding the condition is sparse. In adults, the classical clinical presentation is with pleuritic chest pain, hemoptysis, and dyspnea, whereas in children, the presentation is often nonspecific.

Materials and methods

Clinical features, risk factors, and outcome of children with PE presenting to our unit between December, 19 and March, 2020 were recorded.

Results

Four children [mean age: 10 (6–16) years, 3 females], all presenting with tachycardia and dyspnea were diagnosed with PE. Different risk factors such as deep vein thrombosis, nephrotic syndrome, softtissue infection, and infective endocarditis (IE) were identified in all patients. One child died while others responded to anticoagulation.

Conclusion

We aim to highlight the importance of timely recognition of PE in children with known risk factors for the same. Early recognition and timely treatment of PE are critical to save lives.

How to cite this article

Agrawal S, Shrivastava Y, Bolia R, Panda PK, Sharawat IK, Bhat NK. Pulmonary Embolism in Children: A Case Series. Indian J Crit Care Med 2020;24(12):1272–1275.

Pathogenesis and Management of Acute Kidney Injury in Patients with Nephrotic Syndrome Due to Primary Glomerulopathies

Acute kidney injury in the context of nephrotic syndrome is a serious and alarming clinical problem. Largely, acute kidney injury is a relatively frequent complication among patients with comorbidities while it has been independently associated with an increased risk of adverse outcomes, including death and chronic kidney disease. Nephrotic syndrome, without hematuria or with minimal hematuria, includes a list of certain glomerulopathies; minimal change disease, focal segmental glomerulosclerosis and membranous nephropathy. In the light of primary nephrotic syndrome, pathophysiology of acute kidney injury is differentiated by the nature of the primary disease and the severity of the nephrotic state. This review aims to explore the clinical circumstances and pathogenetic mechanisms of acute kidney injury in patients with nephrotic syndrome due to primary glomerulopathies, focusing on newer perceptions regarding the pathogenesis and management of this complicated condition, for the prompt recognition and timely initiation of appropriate treatment in order to restore renal function to its baseline level. Prompt recognition of the precise cause of acute kidney injury is crucial for renal recovery. Clinical characteristics, laboratory and serological findings along with histopathological findings, if required, will reveal the implicated pathway leading to individualized approach and management.

Delayed Death Due to Saddle Pulmonary Thromboembolus in Child With Nephrotic Syndrome Induced by Focal Segmental Glomerulosclerosis

While the characteristic features of nephrotic syndrome (ie, proteinuria, hypoalbuminemia, peripheral edema, and hyperlipidemia) are well known, the association of nephrotic syndrome and the risk of thromboembolic events is not as often appreciated and may be overlooked. This report describes a 10-year-old boy with focal segmental glomerulosclerosis who died following a saddle pulmonary thromboembolus, with near-complete occlusion of the left and right pulmonary arteries. The gross appearance of the thrombus suggested organization and histologic changes within the wall of the pulmonary artery indicated a period of at least 3 or more hours to a few days since the event occurred. Pulmonary thromboemboli in children are rare, and the number of cases in the medical literature discussing the occurrence of pulmonary thromboemboli in the background of renal disease in children is relatively small, and none apparently clearly describe saddle thromboemboli with a delay from time of occurrence until death. This case report serves as a good reminder for forensic pathologists to consider renal disease as an underlying etiology for pulmonary thromboembolus and how histologic features of the pulmonary artery may help determine a time frame for the event.

Steroid-resistentes nephrotisches Syndrom

Das steroid-resistente nephrotische Syndrom (SRNS) mit dem histomorphologischen Korrelat der fokal-segmentalen Glomerulosklerose (FSGS) stellt eine bedeutende Ursache für eine terminale Niereninsuffizienz im Kindesalter, aber auch bei erwachsenen Patienten dar. Das Erkrankungsspektrum zeichnet sich durch eine große genetische Heterogenität aus, wobei auch nicht genetische Ursachen bei der FSGS beobachtet werden. Die genetische Grundlage des SRNS/FSGS-Komplexes ist v. a. für ältere Kinder/Jugendliche und Erwachsene bisher noch unzureichend verstanden. Die eindeutige Abgrenzung genetischer SRNS/FSGS-Ursachen ist unerlässlich, da sich bereits heute hieraus eine Vielzahl an klinischen Implikationen ergeben. Die Identifikation unbekannter Erkrankungsallele oder Erkrankungsgene kann zudem Erkenntnisse bringen, die ein gänzlich neues Verständnis der Pathomechanismen ermöglichen. Durch umfassende genetische Untersuchungen besteht die Möglichkeit, die ungelöste genetische Basis der Rekurrenz der FSGS-Erkrankung bei bislang Varianten-negativen Patienten zu finden.

Successful treatment of massive thrombosis in different locations with prolonged thrombolytic therapy: A life-saving intervention

Venous thrombosis is recognized as one of the most important complications of nephrotic syndrome (NS). In patients with NS, venous thrombosis may develop in the renal veins, the deep veins of the lower limb, and the inferior vena cava. Here, we describe a case report of an NS patient with multiple venous thrombosis in the right renal vein, the left iliac vein, the vena cava inferior, the right atrium, and the pulmonary arteries. Moreover, we describe the successful treatment of multiple venous thrombosis with prolonged thrombolytic treatment in spite of an increased risk of bleeding due to renal biopsy.

Acute Limb Ischemia in an 8-Year-Old Patient: A Case Report

We report the case of an 8-year-old patient with a history of nephrotic syndrome, who presented to the emergency department with right foot pain. The patient's mother described intermittent pain that woke her son from sleep and was accompanied by the foot turning purple and becoming cold to touch. Physical examination revealed capillary refill of over 10 seconds in the right and less than 2 seconds in the left foot. Ankle-brachial indices (ABIs) were 0.0 on the right and 0.96 on the left. The patient was admitted and started on therapeutic intravenous heparin. After consultation with his parents, right lower extremity angiography and thrombolysis was performed over 2 days. He subsequently underwent fasciotomy and amputation of the tip of all 5 toes. Eighteen months later, there is no leg length discrepancy, he is walking with foot inserts and has normal ABIs bilaterally.

SerpinC1/Antithrombin III in kidney-related diseases

The gene SerpinC1 encodes a serine protease inhibitor named antithrombin III (ATIII). This protease demonstrates both anticoagulant and anti-inflammatory action. ATIII is the most important coagulation factor inhibitor, and even minor changes in ATIII can significantly alter the risk of thromboembolism. ATIII can also suppress inflammation via a coagulation-dependent or -independent effect. Moreover, apart from ATIII deficiency, ATIII and its gene SerpinC1 may also be related to many diseases (e.g. hypertension, kidney diseases). The present review summarizes how ATIII affects the progress of kidney disease and its mechanism. Further studies are required to investigate how ATIII affects renal function and the treatment.

The non-immunosuppressive management of childhood nephrotic syndrome

Idiopathic nephrotic syndrome (INS) is one of the most common renal diseases found in the paediatric population and is associated with significant complications, including infection and thrombosis. A high proportion of children enter sustained remission before adulthood, and therapy must therefore mitigate the childhood complications, while minimising the long-term risk to health. Here we address the main complications of INS and summarise the available evidence and guidance to aid the clinician in determining the appropriate treatment for children with INS under their care. Additionally, we highlight areas where no consensus regarding appropriate management has been reached. In this review, we detail the reasons why routine prophylactic antimicrobial and antithrombotic therapy are not warranted in INS and emphasise the conservative management of oedema. When pharmacological intervention is required for the treatment of oedema, we provide guidance to aid the clinician in determining the appropriate therapy. Additionally, we discuss obesity and growth, fracture risk, dyslipidaemia and thyroid dysfunction associated with INS. Where appropriate, we describe how recent developments in research have identified potential novel therapeutic targets.

Risk factors for predicting venous thromboembolism in patients with nephrotic syndrome: focus on haemostasis-related parameters

PURPOSE

The venous thromboembolic events (VTE) incidence is high in nephrotic syndrome (NS). We aimed to assess prospectively the risk of VTE in a large cohort of NS patients and to identify predictive factors for VTE, especially haemostasis-related parameters.

METHODS

This is the prospective, observational study conducted in 256 adults with idiopathic NS. VTE were the study outcome. Clinical data, proteinuria, albuminuria, haemostasis and fibrinolysis parameters, and D-dimers were evaluated every 6 months.

RESULTS

Median follow-up time was 24 [IQR 12–72] months. VTE cumulative and rate incidence were 11 % and 4.4 per 100 patient-years. Baseline higher proteinuria,lower serum albumin, low antithrombin III activity, and,surprisingly, high ionized calcium were VTE independent predictors. Proteinuria and serum albumin cut-offs, and positive and negative predictive values (PPV and NPV) for VTE were 9.0 g/24 h (30 % PPV and 90 % NPV) and 1.5 g/dL (69 % PPV and 93 % NPV).

CONCLUSIONS

The rate of VTE incidence of 4.4 per 100 patient-years found in this prospective study confirms the idiopathic nephrotic syndrome as a thromboembolism-generating condition. Severe and unremitting proteinuria and hypoalbuminemia,low antithrombin III activity, and, surprisingly, high ionized calcium are independent VTE predictors.

Best practice guidelines for idiopathic nephrotic syndrome: recommendations versus reality

BACKGROUND

The optimal therapeutic regimen for managing childhood idiopathic nephrotic syndrome (INS) is still under debate. We have evaluated the choice of steroid regimen and of symptomatic treatment adopted by pediatricians and pediatric nephrologists in a large number of centers as the first step towards establishing a shared protocol

METHODS

This was a multicenter, retrospective study. A total of 231 children (132 admitted to pediatric units) aged 6 months to <15 years who presented with onset of nephrotic syndrome to 54 pediatric units and six pediatric nephrology units in Italy between 2007 and 2009 were eligible for entry into the study.

RESULTS

Median steroid dosing was 55 (range 27-75) mg/m(2)/day. The overall median cumulative dose regimen for the first episode was 3,440 (1,904-6,035) mg/m(2), and the median duration of the therapeutic regimen was 21 (9-48) weeks. The total duration and cumulative steroid dose were significantly higher in patients treated by pediatricians than in those treated by pediatric nephrologists (p = 0.001 and p = 0.008). Among the patient cohort, 55, 64 and 22 % received albumin infusions, diuretics and acetyl salicylic acid treatment, respectively, but the laboratory and clinical data did not differ between children treated or not treated with symptomatic drugs. Albumin and diuretic use did not vary between patients in pediatric units and those in pediatric nephrology units.

CONCLUSIONS

This study shows major differences in steroid and symptomatic treatment of nephrotic syndrome by pediatricians and pediatric nephrologists. As these differences can influence the efficacy of the treatments and the appearance of side-effects, shared guidelines and their implementation through widespread educational activities are necessary.

Hemostatic Markers in Congestive Heart Failure Dogs with Mitral Valve Disease

Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, D-dimer, antithrombin III (AT III), protein C (PC), factor VII (F.VII), and factor VIII (F.VIII), as well as hematocrit (HCT), platelets number (PLT), total plasma protein (TP), and albumin (ALB), were studied on fifty-eight congestive heart failure (CHF) dogs with mitral valve disease (MVD) and fifty control dogs. All of variables of MVD group, except APTT, were significantly different (P < 0.5) from control group. The variables were also compared among functional classes of CHF dogs and control dogs. It was determined that the higher the functional class of CHF dogs was, the greater the levels of fibrinogen and D-dimer were, whereas the lesser the activities of AT III and PC were presented. Additionally, TP had linear correlation with fibrinogen, D-dimer, HCT, and PLT (r = 0.31, 0.30, 0.43, and 0.38, resp., P < 0.5). These findings suggested that fibrinogen and D-dimer were the factors predisposing hypercoagulability through an increase in blood viscosity. The hemorheological abnormalities would shift an overall hemostatic balance toward a more thrombotic state in CHF dogs with MVD.

Venous thromboembolism in pediatric nephrotic syndrome

Childhood nephrotic syndrome (NS) is one of the most common pediatric kidney diseases, with an incidence of 2-7 per 100,000. Venous thromboembolism (VTE) is associated with significant morbidity and mortality, and occurs in ∼3 % of children with NS, though incidence approaches 25 % in high-risk groups. VTE etiology is multifactorial, with disease-associated coagulopathy thought to be a significant contributor. Other risks include age, disease severity, and treatment-related hazards, such as the presence of central venous catheters. Non-pharmacologic preventive measures such as ambulation and compression stockings are recommended for patients with identified VTE risks. Central venous catheters should be avoided whenever possible. Symptoms of VTE include venous catheter dysfunction, unilateral extremity symptoms, respiratory compromise, flank pain, and gross hematuria. When VTE is suspected, confirmatory imaging studies should be obtained, followed by appropriate laboratory evaluation and treatment. Therapeutic goals include limiting thrombus growth, extension, and embolization by early institution of anticoagulant therapy. Anticoagulation is recommended for a minimum of 3 months, but should be continued until NS remission is achieved. Further studies are necessary to identify VTE-risk biomarkers and optimal therapeutic regimens. Observational cohort studies are needed to identify VTE-risk groups who may benefit from thromboprophylaxis and to define disease-specific treatment algorithms.

Clinical syndromes associated with acquired antithrombin deficiency via microvascular leakage and the related risk of thrombosis

Antithrombin (AT) is a 65kDa glycoprotein belonging to a group of inhibitory factors known as serpins (serine protease inhibitors). It plays a critical role in the inhibition of coagulation and inflammation processes within the environment of the vascular endothelium. Inadequate levels of functional AT in plasma results in an increased risk of thrombotic events, both venous and arterial. AT deficiency can be inherited or acquired. Congenital AT deficiency is the most severe inherited thrombophilic condition with an odds ratio of 20 for the increased risk of venous thrombosis. Acquired AT deficiency occurs in a variety of physiologic and pathologic medical conditions with similar risks of increased thrombosis. In this article, we review clinical settings characterized by an acquired AT deficiency largely or partly subsequent to protein microvascular leakage. Other different mechanisms of AT depletion are implied in some clinical conditions together with endothelial loss, and, therefore, outlined. In addition, we provide a description of the current knowledge on the specific mechanisms underlying endothelial AT leakage and on the consequences of this protein decrease, specifically looking at thrombosis. We identify potential directions of research that might prove useful in patients with acquired AT deficiency.

Increasing frequency of acute kidney injury amongst children hospitalized with nephrotic syndrome

BACKGROUND

Nephrotic syndrome (NS) is among the most common kidney diseases seen in children. The major complications of NS include infection, acute kidney injury (AKI), and thromboembolism (TE). The objective of this study was to analyze long-term trends in the epidemiology of major complications of pediatric NS.

METHODS

We used the Healthcare Cost and Utilization Project Kids' Inpatient Database for the years 2000-2009 to perform an analysis of U.S. hospitalizations of children diagnosed with NS with or without infection, AKI or TE.

RESULTS

The frequency of NS hospitalizations complicated by AKI increased by 158 % between 2000 and 2009 (p < 0.001). The frequency of NS hospitalizations with infection and TE remained stable overall. Pneumonia was the most common infectious complication while peritonitis decreased by 50 % (p < 0.001). Importantly, development of any of these major complications of NS resulted in ∼2-3-fold increases in both hospital charges and length of stay.

CONCLUSIONS

It is concerning that the frequency of AKI in children hospitalized with NS has more than doubled in the past decade. Strategies to prevent or initiate earlier treatments for complications of NS could have a major impact on both morbidity and health care expenses.

High dose urokinase against massive pulmonary embolism in nephrotic syndrome

Patients with nephrotic syndrome carry a high risk of pulmonary embolism due to the abnormalities in coagulation and fibrinolysis. Thrombolytic therapy for critical pulmonary embolism in nephrotic syndrome patients was rarely reported and remains controversial in the regimen selection so far. We reported a case of fatal pulmonary embolism, complicating in hepatitis B virus-associated nephrotic syndrome. The patient presented with chest pain, hemoptysis and shortness of breath on admission and his initial vital signs showed a high risk of developing hypotension. Urgent radiological examinations confirmed massive embolisms in bilateral pulmonary arteries. Prompt thrombolytic therapy was performed right after the diagnosis of pulmonary embolism with an intravenous infusion of urokinase (20 000 U/kg) in 2 h. Complete resolution of pulmonary embolism was achieved after urokinase administration and the patient was discharged in good conditions. This report highlighted the efficacy and safety of prompt thrombolytic therapy with urokinase for nephrotic syndrome patients presented with massive pulmonary embolism. In this study, we also briefly discuss the recent findings on the current state of urokinase in the clinical practice of thrombolysis.

Platelet functions and coagulation changes in Indian children with nephrotic syndrome

INTRODUCTION

Only little is known on the effect of the platelet function in the paediatric nephrotic syndrome. The earlier studies which had been done on hypercoagulability have mainly featured the secondary forms of the nephrotic syndrome and the data on the minimal change type of disease is limited. We therefore, made an effort to study the platelet functions and the coagulation profile in children with the nephrotic syndrome,to find the relationship between the steroid response and the coagulation profile, and to look for the correlation between thromboembolism and the hypercoagulable states.

METHODOLOGY

Twenty nine children with the steroid responsive nephrotic syndromewere studied to see the platelet aggregation and the coagulation parameters and their response to the steroid therapy. Doppler studies were done for the renal vein and the inferior vena cava (IVC) thrombus.

RESULTS

It was seen that an increased aggregability of the platelets occurred with Adenosine diphosphate (ADP) and collagen (out of the four agonists, ADP, Collagen, Ristocetin and Arachidonic acid) which were used as agonists for the assay. We also observed that the Partial thromboplastin time (PTT) had become prolonged and a significant decline in the high values of the procoagulant proteins (Protein C and Protein S) was seen after the steroid therapy and when the children went into remission. These findings were suggestive of a reversibility of the changes in the steroid responsive nephrotic syndrome with the steroid therapy. One child was found to have thrombosis of the inferior vena cava (IVC) on Doppler studies, which resolved with treatment subsequently.

CONCLUSIONS

An increased platelet aggregability contributes to the hypercoagulable states, that may increase the incidence of thrombosis in such patients. Although the incidence of such complications is very low, in a given child with the hypercoagulable states, Doppler may be used to look for any evidence of a latent thrombus and, an early intervention could be instituted. A change in the coagulation parameters points to the reversibility of the changes which are produced in a diseased state.

Over- or underfill: not all nephrotic states are created equal

Blessed were the days when it all made sense and the apparent mechanism for edema formation in nephrotic syndrome was straightforward: the kidneys lost protein in the urine, which lowered the plasma oncotic pressure. Thus, fluid leaked into the interstitium, depleting the intravascular volume with subsequent activation of renin/aldosterone and consequent avid renal sodium retention. As simple as that! Unfortunately, a number of clinical and laboratory observations have raised serious concerns about the accuracy of this "underfill" hypothesis. Instead, an "overfill" hypothesis was generated. Under this assumption, the nephrotic syndrome not only leads to urinary protein wasting, but also to primary sodium retention with consequent intravascular overfilling, with the excess fluid spilling into the flood plains of the interstitium, leading to edema. Recently, an attractive mechanism was proposed to explain this primary sodium retention: proteinuria includes plasma proteinases, such as plasmin, which activate the epithelial sodium channel in the collecting duct, ENaC. In this edition, further evidence for this hypothesis is being presented by confirming increased plasmin content in the urine of children with nephrotic syndrome and demonstrating ENaC activation. If correct, this hypothesis would provide a simple treatment for the edema: pharmacological blockade of ENaC, for instance, with amiloride. Yet, how come clinicians have not empirically discovered the presumed power of ENaC blockers in nephrotic syndrome? And why is it that some patients clearly show evidence of intravascular underfilling? The controversy of over- versus underfilling demonstrates how much we still have to learn about the pathophysiology of nephrotic syndrome.

A large intracardiac thrombus in a child with steroid-resistant nephrotic syndrome

Intracardiac thrombus is a rare complication of nephrotic syndrome in children, and only a few cases have been reported. We report the case of a 3.5-year-old child diagnosed with Henoch-Schönlein Purpura and steroid-resistant nephrotic syndrome for 2 months. The patient had massive oedema but no cardiovascular instability. Echocardiography displayed a large thrombus within the right atrium and the patient was successfully managed with enoxoparine.

The spectrum of renal thrombotic microangiopathy in lupus nephritis

INTRODUCTION

Among various lupus renal vascular changes, thrombotic microangiopathy (TMA) presented with the most severe clinical manifestations and high mortality. The pathogenesis of TMA in systemic lupus erythematosus (SLE) was complicated. The aim of this study was to assess clinical manifestations, laboratory characteristics, pathological features and risk factors for clinical outcomes of lupus nephritis patients co-existing with renal TMA in a large cohort in China.

METHODS

Clinical and renal histopathological data of 148 patients with biopsy-proven lupus nephritis were retrospectively analyzed. Serum complement factor H, A Disintegrin and Metalloprotease with Thrombospondin type I repeats 13 (ADAMTS-13) activity, antiphospholipid antibodies and C4d deposition on renal vessels were further detected and analyzed.

RESULTS

In the 148 patients with lupus nephritis, 36 patients were diagnosed as co-existing with renal TMA based on pathological diagnosis. Among the 36 TMA patients, their clinical diagnoses of renal TMA were as followings: 2 patients combining with thrombotic thrombocytopenic purpura-hemolytic uremic syndrome, 2 patients combining with anti-phospholipid syndrome, 2 patients with malignant hypertension, 1 patient with scleroderma and the other 29 patients presenting with isolated renal TMA. Compared with the non-renal TMA group, patients with renal TMA had significantly higher urine protein (7.09±4.64 vs. 4.75±3.13 g/24h, P=0.007) and serum creatinine (159, 86 to 215 vs. 81, 68 to 112 μmol/l, P<0.001), higher scores of total activity indices (AI) (P<0.001), endocapillary hypercellularity (P<0.001), subendothelial hyaline deposits (P=0.003), interstitial inflammation (P=0.005), glomerular leukocyte infiltration (P=0.006), total chronicity indices (CI) (P=0.033), tubular atrophy (P=0.004) and interstitial fibrosis (P=0.018). Patients with renal TMA presented with poorer renal outcome (P=0.005) compared with the non-TMA group. Renal TMA (hazard ratio (HR): 2.772, 95% confidence interval: 1.009 to 7.617, P=0.048) was an independent risk factor for renal outcome in patients with lupus nephritis. The renal outcome was poorer for those with both C4d deposition and decreased serum complement factor H in the TMA group (P=0.007).

CONCLUSIONS

There were various causes of renal TMA in lupus nephritis. Complement over-activation via both classical and alternative pathways might play an important role in the pathogenesis of renal TMA in lupus nephritis.

Epidemiology and predictors of end-stage renal disease in Taiwanese children with idiopathic nephrotic syndrome

Background

The incidence of idiopathic nephrotic syndrome (INS) varies among countries, with Asia reporting a higher incidence in comparison with Western countries. We investigated the epidemiologic features of INS and attempted to identify factors that predispose individuals to develop end-stage renal disease (ESRD).

Methods

Claims data from the Taiwanese National Health Insurance program from 1996 to 2008 were used to investigate the epidemiologic features and clinical variables of INS (International Classification of Diseases, Ninth Revision, Clinical Modification code, 581) in children younger than 18 years.

Results

We enrolled 4083 children (male-female ratio, 1.91:1). During the 13 years of observation, annual incidence decreased from 9.91 to 3.36 per 100 000 children. Annual number of hospital admissions progressively decreased during the first 3 years after diagnosis. At 3.14 ± 2.77 years after INS onset, ESRD had developed in 145 (3.6%) children. Independent predictors of ESRD included older age at onset, acute renal failure (ARF), hypertensive encephalopathy, and a histologic subtype with focal segmental glomerulosclerosis (FSGS).

Conclusions

Pediatric INS in Taiwan was more frequent in boys. Unlike India, the current incidence of pediatric INS in Taiwan is very similar to that reported in Western studies. Older age at disease onset, ARF, hypertensive encephalopathy, and FSGS on biopsy are important predictors of poor renal outcome.

Epidemiology and pathophysiology of nephrotic syndrome-associated thromboembolic disease

After infections, thromboembolism is considered by many experts to be the most significant life-threatening complication of nephrotic syndrome. The purpose of this review is to summarize the epidemiology, clinical and molecular pathophysiology, and management of this complication. Children (2.8%) are less likely than adults (26.7%) with nephrotic syndrome to develop thromboembolism. However, infants and children aged >12 years are at much greater risk. Membranous histologic changes increase thromboembolic risk at all ages; in particular, adults with membranous nephropathy have the highest reported risk (37.0%) and children with membranous histology have a rate (25%) that approaches the overall adult rate. There are striking, but variable, pathologic alterations of molecular hemostasis associated with nephrotic syndrome. No clear molecular therapeutic targets have been identified, but most studies show that the major pathologic changes involve antithrombin, fibrinogen, and factors V and VIII. There is inadequate evidence to support routine prophylactic therapy. Therapy includes anticoagulation in all cases, with thrombolysis reserved for those with the most severe thromboembolic disease. Future hemostatic research in nephrotic syndrome should focus on identifying cohorts at highest risk for thrombosis through the use of clinical markers and biomarkers as well as searching for molecular targets to correct the prothrombotic pathophysiology of this disease.

Pulmonary thromboembolism as the initial manifestation in a child with antiphospholipid syndrome in the emergency department

Antiphospholipid syndrome is characterized by recurrent arterial or venous thrombosis at any level of the vascular tree and the presence of circulating antiphospholipid antibodies. The syndrome may be idiopathic or secondary to an underlying autoimmune disorder. The disease is uncommon in children, and manifestations are diverse and underreported. We report the case of a 10-year-old boy who presented with features of pulmonary thromboembolism in the emergency department. Subsequently, he proved to have systemic lupus erythematosus with circulating antiphospholipid antibodies. He had no signs of systemic lupus erythematosus at presentation. In conclusion, antiphospholipid syndrome should also be kept as a possibility in children presenting for the first time with pulmonary thromboembolism in the emergency department.

Evaluation of right ventricle function in children with primary nephrotic syndrome

BACKGROUND

We aimed to evaluate right ventricle (RV) function in children with primary nephrotic syndrome (PNS).

METHODS

RV hemodynamics were evaluated by Doppler echocardiography in 50 children with PNS (aged 2.5-12 years), either at PNS onset (n = 37) or relapse (n = 13), and in 50 normal controls. Heart rate, stroke volume, cardiac output, RV enddiastolic and end-systolic volume, RV ejection fraction, RV end-diastolic pressure, RV peak systolic and end-systolic pressure were determined from pressure-volume loops. The maximal rates of RV pressure upstroke and fall (dP/d t(max) and dP/d t(min), respectively) were calculated. Effective pulmonary arterial elastance was calculated as end-systolic pressure divided by stroke volume. Plasma tumor necrosis factor-alpha (TNF-alpha) and insulin-like growth factor 1 (IGF-1) were also measured.

RESULTS

RV end-diastolic pressure was increased by an average of 20% in 39 of the patients with PNS, whereas RV ejection fraction was reduced by an average of 15% compared with controls (p < 0.05 for both). Cardiac output and stroke volume were maintained, indicating compensation at the expense of increased RV end-diastolic and end-systolic volumes and increased RV filling pressure (p < 0.05). Plasma TNF-alpha was elevated in patients with PNS (326 +/- 117 kU/L vs. 75 +/- 23 kU/L, p < 0.05); IGF-1 was similar in PNS patients and controls.

CONCLUSION

Right ventricle function was impaired in children with PNS. The characteristics were unrelated to blood pressure and IGF-1, but may be correlated with TNF-alpha and disease duration. Further studies are needed to evaluate the etiology and clinical implications of this abnormality.

Nephrotic syndrome complicated by life-threatening pulmonary embolism in an adult patient

We report a 23-year-old male presenting with edema. He was originally admitted for an elective renal biopsy for diagnosis of renal pathology. Unfortunately, because of acute abdominal pain an exploratory laparotomy was done. Progressive azotemia and oliguria then developed, and he required temporary hemodialysis. However, he suffered from sudden-onset severe respiratory distress, and blood gas analysis showed profound hypoxemia with a marked arterial-alveolar oxygen difference. Assessment of a pulmonary embolism by radioisotope imaging was not possible because of his dependence on mechanical ventilation. Subcutaneous low molecular weight heparin and intravenous methylprednisolone were given to treat the presumed pulmonary embolism and the underlying nephrotic syndrome. His partial oxygen level gradually increased after continuous heparin and steroid administration. Complete obliteration of one major pulmonary artery and partial obliteration of other smaller arteries were revealed by magnetic resonance angiography. He was discharged and followed-up as an outpatient, and was given oral warfarin and prednisolone. Follow-up magnetic resonance angiography 5 months later showed a normal pulmonary tree with no residual lesions.

Thrombosis in the pediatric population

Whereas thrombotic events in critically ill children do not occur as commonly as in adults, they are being recognized with increasing frequency in the pediatric intensive care unit. The reasons for this are not clear but likely include an increased awareness of the problem and the ability to make a diagnosis using relatively noninvasive tests. In this section, I attempt to define the extent of the problem, summarize and discuss the relevant literature (pointing out where published experience in the pediatric population differs from that in adult patients), and suggest some guidelines regarding thrombophilia treatment and the management of thrombotic events.

Management of childhood onset nephrotic syndrome

The therapeutic approach to childhood nephrotic syndrome is based on a series of studies that began with an international collaborative effort sponsored by the International Study of Kidney Disease in Children in 1967. The characteristics of children presenting with nephrotic syndrome have changed over recent decades with greater frequency of the challenging condition focal segmental glomerulosclerosis and a greater prevalence of obesity and diabetes mellitus, which may be resistant to glucocorticoids in the former and exacerbated by long-term glucocorticoid therapy in the latter 2 conditions. The Children's Nephrotic Syndrome Consensus Conference was formed to systematically review the published literature and generate a children's primary nephrotic syndrome guideline for use in educational, therapeutic, and research venues.

Testing children for inherited thrombophilia: more questions than answers

Thrombotic events in children have become an increasingly common problem, particularly in paediatric tertiary care hospitals. The prevalence of inherited thrombophilia in children who develop thrombosis varies substantially depending on the population. Children who develop thrombosis, as well as those who have not but have a positive family history, are frequently tested for inherited thrombophilia. The clinical utility of performing such tests has been questioned, in both adults and children. This review will examine the practise of testing for inherited thrombophilia in children, focusing on the rationale for testing and highlighting areas in which more evidence is needed prior to making strong recommendations. Future studies, many of which are currently being performed or proposed, are necessary to address many of the unanswered questions.

Pulmonary thrombosis as the first manifestation of systemic lupus erythematosus in a 14-year-old boy

We describe the case of a 14-year-old boy who presented with pulmonary embolism and who was subsequently found to have nephrotic syndrome due to lupus membranous nephropathy. He had no other signs of nephrotic syndrome or of systemic lupus erythematosus, such as edema or circulating lupus anticoagulants (antiphospholipid or anticardiolipin antibodies), and no hereditary coagulopathy. This case contributes to our understanding of unusual clinical presentations of systemic lupus erythematosus in children.