Sex dimorphisms in coagulation: Implications in trauma-induced coagulopathy and trauma resuscitation.

Trauma-induced coagulopathy (TIC) is one of the leading causes of preventable death in injured patients. Consequently, it is imperative to understand the mechanisms underlying TIC and how to mitigate this mortality. An opportunity for advancement stems from the awareness that coagulation demonstrates a strong sex-dependent effect. Females exhibit a relative hypercoagulability compared to males, which persists after injury and confers improved outcomes. The mechanisms underlying sex dimorphisms in coagulation and its protective effect after injury have yet to be elucidated. This review explores sex dimorphisms in enzymatic hemostasis, fibrinogen, platelets, and fibrinolysis, with implications for resuscitation of patients with TIC.

Prothrombin Knockdown Protects Podocytes and Reduces Proteinuria in Glomerular Disease.

Chronic kidney disease (CKD) is a leading cause of death, and its progression is driven by glomerular podocyte injury and loss, manifesting as proteinuria. Proteinuria includes urinary loss of coagulation zymogens, cofactors, and inhibitors. Importantly, both CKD and proteinuria significantly increase the risk of thromboembolic disease. Prior studies demonstrated that anticoagulants reduced proteinuria in rats and that thrombin injured cultured podocytes. Herein we aimed to directly determine the influence of circulating prothrombin on glomerular pathobiology. We hypothesized that (pro)thrombin drives podocytopathy, podocytopenia, and proteinuria. Glomerular proteinuria was induced with puromycin aminonucleoside (PAN) in Wistar rats. Circulating prothrombin was either knocked down using a rat-specific antisense oligonucleotide or elevated by serial intravenous infusions of prothrombin protein, which are previously established methods to model hypo- (LoPT) and hyper-prothrombinemia (HiPT), respectively. After 10 days (peak proteinuria in this model) plasma prothrombin levels were determined, kidneys were examined for (pro)thrombin co-localization to podocytes, histology, and electron microscopy. Podocytopathy and podocytopenia were determined and proteinuria, and plasma albumin were measured. LoPT significantly reduced prothrombin colocalization to podocytes, podocytopathy, and proteinuria with improved plasma albumin. In contrast, HiPT significantly increased podocytopathy and proteinuria. Podocytopenia was significantly reduced in LoPT vs. HiPT rats. In summary, prothrombin knockdown ameliorated PAN-induced glomerular disease whereas hyper-prothrombinemia exacerbated disease. Thus, (pro)thrombin antagonism may be a viable strategy to simultaneously provide thromboprophylaxis and prevent podocytopathy-mediated CKD progression.

Glucocorticoid- and pioglitazone-induced proteinuria reduction in experimental NS both correlate with glomerular ECM modulation.

Idiopathic nephrotic syndrome (NS) is a common glomerular disease. Although glucocorticoids (GC) are the primary treatment, the PPARγ agonist pioglitazone (Pio) also reduces proteinuria in patients with NS and directly protects podocytes from injury. Because both drugs reduce proteinuria, we hypothesized these effects result from overlapping transcriptional patterns. Systems biology approaches compared glomerular transcriptomes from rats with PAN-induced NS treated with GC vs. Pio and identified 29 commonly regulated genes-of-interest, primarily involved in extracellular matrix (ECM) remodeling. Correlation with clinical idiopathic NS patient datasets confirmed glomerular ECM dysregulation as a potential mechanism of injury. Cellular deconvolution in silico revealed GC- and Pio-induced amelioration of altered genes primarily within podocytes and mesangial cells. While validation studies are indicated, these analyses identified molecular pathways involved in the early stages of NS (prior to scarring), suggesting that targeting glomerular ECM dysregulation may enable a future non-immunosuppressive approach for proteinuria reduction in idiopathic NS.

Intracardiac thrombi in pediatrics: anticoagulation approach and treatment outcomes.

Background: Intracardiac thrombi (ICT) are associated with significant morbidity and mortality. Anticoagulation is the first line of treatment and may be complemented by thrombectomy or thrombolysis. However, optimal anticoagulant duration remains ill-defined. High-risk features of ICT that may warrant long-term anticoagulation therapy have not been established. Objectives: To describe anticoagulation duration and patterns of ICT resolution. To identify potential risk factors for persistent ICT despite anticoagulation. Methods: A single-institution retrospective chart review identified patients diagnosed with ICT by echocardiogram between January 2014 and March 2022. Descriptive statistics and logistic regression were used. Results: Fifty-one patients with ICT were identified. Median age at diagnosis was 9.2 years (IQR, 0.4-15.2). The most common underlying diagnoses were congenital heart disease (41%), infection (25%), and malignancy (24%). The majority of ICT were in the right atrium (n = 30). The median longest ICT dimension was 1.5 cm (range, 0.4-4.0). The median duration of anticoagulation was 4.3 months (IQR, 2.2-9.1). Among 48 patients who received anticoagulation as first-line treatment, 32 had partial or complete response with 3 to 6 months of anticoagulation, while remaining 16 patients had no response to anticoagulation. Patients with a central venous line had a delayed resolution of ICT [hazards ratio = 0.45 (95% CI, 0.22-0.93)]. Conclusion: Our study demonstrates the wide variability in duration of anticoagulation for children with ICT. Majority of the individuals benefit from 3-to-6 month treatment; however, individuals with a central venous line may benefit from a longer course of anticoagulation. Further large-scale studies are recommended to validate our findings.