Characterization of thromboelastography of patients with different pathological types of nephrotic syndrome

Proteomics of Plasma and Plasma-Treated Podocytes: Application to Focal and Segmental Glomerulosclerosis

Focal and segmental glomerulosclerosis (FSGS) is a severe form of idiopathic nephrotic syndrome (INS), a glomerulopathy of presumably immune origin that is attributed to extrarenal pathogenic circulating factors. The recurrence of FSGS (rFSGS) after transplant occurs in 30% to 50% of cases. The direct analysis of patient plasma proteome has scarcely been addressed to date, mainly due to the methodological difficulties associated with plasma complexity and dynamic range. In this study, first, we compared different methods of plasma preparation, second, we compared the plasma proteomes of rFSGS and controls using two preparation methods, and third, we analyzed the early proximal signaling events in podocytes subjected to patient plasma, through a combination of phosphoproteomics and lipid-raft proteomics (raftomics). By combining immunodepletion and high pH fractionation, we performed a differential proteomic analysis of soluble plasma proteins and of extracellular vesicles (EV) obtained from healthy controls, non-INS patient controls, and rFSGS patients (n = 4). In both the soluble- and the EV-protein sets from the rFSGS patients, we found a statistically significant increase in a cluster of proteins involved in neutrophil degranulation. A group of lipid-binding proteins, generally associated with lipoproteins, was found to be decreased in the soluble set from the rFSGS patients. In addition, three amino acid transporters involved in mTORC1 activation were found to be significantly increased in the EV from the rFSGS. Next, we incubated human podocytes for 30 min with 10% plasma from both groups of patients. The phosphoproteomics and raftomics of the podocytes revealed profound differences in the proteins involved in the mTOR pathway, in autophagy, and in cytoskeleton organization. We analyzed the correlation between the abundance of plasma and plasma-regulated podocyte proteins. The observed changes highlight some of the mechanisms involved in FSGS recurrence and could be used as specific early markers of circulating-factor activity in podocytes.

Thromboelastography in the Perioperative Period: A Literature Review

Assessing coagulation status is essential for prompt intervention to reduce morbidity and mortality related to bleeding and thrombotic complications during the perioperative period. Traditional coagulation tests such as platelet count, activated partial thromboplastin time (aPTT), prothrombin time (PT), international normalized ratio (INR), and activated clotting time (ACT) provide only static evaluation. These tests are not designed for assessment of dynamically changing coagulation conditions during the perioperative time. However, viscoelastic coagulation testing such as thromboelastography (TEG) produces a rapid numerical and graphical representation that helps to detect and direct targeted hemostatic therapy. Searching the literature through PubMed, Medline, Ovid, CINAHL, and ClinicalTrials.gov we retrieved 210 studies, which represent the use of TEG in the perioperative period. The included studies were categorized under various settings such as trauma, obstetrics, orthopedics, intensive care unit (ICU), cardiovascular, transplant, and miscellaneous scenarios. TEG showed promising results in trauma surgeries in predicting mortality, hypercoagulability, and bleeding even when it was compared to conventional methods. TEG was also useful in monitoring anticoagulant therapy in orthopedic and obstetric surgeries; however, its role in predicting thrombotic events, hypercoagulability, or complications was questionable. In ICU patients, it showed promising results, especially in the prediction or improvement of sepsis, coagulopathy, thrombotic events, ICU duration, hospital stay, and ventilator duration. TEG parameters effectively predicted hypercoagulation in transplant surgeries. Regarding cardiovascular surgeries, they were effective in the prediction of the need for blood products, coagulopathy, thrombotic events, and monitoring anticoagulation therapy. More randomized clinical trials comparing TEG parameters with standardized tools are needed to produce robust results to standardize its use in different perioperative settings.

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.