Fibrinogen and factor XIII at the intersection of coagulation, fibrinolysis and inflammation

Biological Functions of Macromolecular Protein Hydrogels in Constructing Osteogenic Microenvironment

Irreversible bone defects resulting from trauma, infection, and degenerative illnesses have emerged as a significant health concern. Structurally and functionally controllable hydrogels made by bone tissue engineering (BTE) have become promising biomaterials. Natural proteins are able to establish connections with autologous proteins through unique biologically active regions. Hydrogels based on proteins can simulate the bone microenvironment and regulate the biological behavior of stem cells in the tissue niche, making them candidates for research related to bone regeneration. This article reviews the biological functions of various natural macromolecular proteins (such as collagen, gelatin, fibrin, and silk fibroin) and highlights their special advantages as hydrogels. Then the latest research trends on cross-linking modified macromolecular protein hydrogels with improved mechanical properties and composite hydrogels loaded with exogenous micromolecular proteins have been discussed. Finally, the applications of protein hydrogels, such as 3D printed hydrogels, microspheres, and injectable hydrogels, were introduced, aiming to provide a reference for the repair of clinical bone defects.

Profound Properties of Protein-Rich, Platelet-Rich Plasma Matrices as Novel, Multi-Purpose Biological Platforms in Tissue Repair, Regeneration, and Wound Healing

Autologous platelet-rich plasma (PRP) preparations are prepared at the point of care. Centrifugation cellular density separation sequesters a fresh unit of blood into three main fractions: a platelet-poor plasma (PPP) fraction, a stratum rich in platelets (platelet concentrate), and variable leukocyte bioformulation and erythrocyte fractions. The employment of autologous platelet concentrates facilitates the biological potential to accelerate and support numerous cellular activities that can lead to tissue repair, tissue regeneration, wound healing, and, ultimately, functional and structural repair. Normally, after PRP preparation, the PPP fraction is discarded. One of the less well-known but equally important features of PPP is that particular growth factors (GFs) are not abundantly present in PRP, as they reside outside of the platelet alpha granules. Precisely, insulin-like growth factor-1 (IGF-1) and hepatocyte growth factor (HGF) are mainly present in the PPP fraction. In addition to their roles as angiogenesis activators, these plasma-based GFs are also known to inhibit inflammation and fibrosis, and they promote keratinocyte migration and support tissue repair and wound healing. Additionally, PPP is known for the presence of exosomes and other macrovesicles, exerting cell-cell communication and cell signaling. Newly developed ultrafiltration technologies incorporate PPP processing methods by eliminating, in a fast and efficient manner, plasma water, cytokines, molecules, and plasma proteins with a molecular mass (weight) less than the pore size of the fibers. Consequently, a viable and viscous protein concentrate of functional total proteins, like fibrinogen, albumin, and alpha-2-macroglobulin is created. Consolidating a small volume of high platelet concentrate with a small volume of highly concentrated protein-rich PPP creates a protein-rich, platelet-rich plasma (PR-PRP) biological preparation. After the activation of proteins, mainly fibrinogen, the PR-PRP matrix retains and facilitates interactions between invading resident cells, like macrophages, fibroblast, and mesenchymal stem cells (MSCs), as well as the embedded concentrated PRP cells and molecules. The administered PR-PRP biologic will ultimately undergo fibrinolysis, leading to a sustained release of concentrated cells and molecules that have been retained in the PR-PRP matrix until the matrix is dissolved. We will discuss the unique biological and tissue reparative and regenerative properties of the PR-PRP matrix.

Multimodal imaging of the role of hyperglycemia following experimental subarachnoid hemorrhage

Hyperglycemia has been linked to worsening outcomes after subarachnoid hemorrhage (SAH). Nevertheless, the mechanisms involved in the pathogenesis of SAH have been scarcely evaluated so far. The role of hyperglycemia was assessed in an experimental model of SAH by T2 weighted, dynamic contrast-enhanced magnetic resonance imaging (T2W and DCE-MRI), [18F]BR-351 PET imaging and immunohistochemistry. Measures included the volume of bleeding, the extent of cerebral infarction and brain edema, blood brain barrier disruption (BBBd), neutrophil infiltration and matrix metalloprotease (MMP) activation. The neurofunctional outcome, neurodegeneration and myelinization were also investigated. The induction of hyperglycemia increased mortality, the size of the ischemic lesion, brain edema, neurodegeneration and worsened neurological outcome during the first 3 days after SAH in rats. In addition, these results show for the first time the exacerbating effect of hyperglycemia on in vivo MMP activation, Intercellular Adhesion Molecule 1 (ICAM-1) expression and neutrophil infiltration together with increased BBBd, bleeding volume and fibrinogen accumulation at days 1 and 3 after SAH. Notably, these data provide valuable insight into the detrimental effect of hyperglycemia on early BBB damage mediated by neutrophil infiltration and MMP activation that could explain the worse prognosis in SAH.

The calcium-clot connection: investigating the association between primary hyperparathyroidism and acute venous thromboembolism

Primary hyperthyroidism (PHPT) is a relatively uncommon disease and leads to increased calcium levels. Ionized calcium, known as clotting Factor IV, may lead to overt coagulation cascade activation, increasing the risk of venous thromboembolism (VTE). National Inpatient Sample Database was used to sample individuals with primary hyperparathyroidism, and baseline demographics and comorbidities were collected using ICD-10 codes. Patients with missing data and age less than 18 were excluded. Moreover, patients with other types of hyperparathyroidism and risk factors for VTE, such as malignancy, thrombophilia, chronic kidney and liver disease, fractures, trauma, oral contraceptive/steroid use, and organ transplant, were excluded. Greedy propensity matching using R was performed to match patients with and without primary hyperparathyroidism on age, race, gender, and 10 other comorbidities, including chronic deep venous thromboembolism. Univariate analysis pre- and post-match were performed. Binary logistic regression was performed after matching to assess whether primary hyperparathyroidism was an independent risk factor for acute VTE. A p-value of  < 0.05 was considered statistically significant. Out of 460,529 patients included in the study, 1114 (6.5%) had PHPT. Baseline comorbidities were more common in the PHPT group. On univariate analysis, patients with PHPT were more likely to have acute VTE (2.5% vs. 1.4%; p < 0.001). After 1:1 matching, PHPT patients were twice as likely to have Acute VTE. (OR: 2.1 [1.08-4.1]; p < 0.025). These findings suggest an association between PHPT and VTE, which should be further investigated to prevent the increasing incidence of VTE and its recurrence.

Abnormal bleeding after lumbar vertebrae surgery because of acquired factor XIII deficiency: A case report and literature review

RATIONALE

Abnormal bleeding due to low fibrinogen (Fib) and coagulation factor XIII (FXIII) levels after lumbar vertebral surgery is exceedingly rare. Excessive bleeding is also associated with secondary hyperfibrinolysis. This report presents a case of abnormal incision bleeding caused by coagulation factor XIII deficiency (FXIIID) and secondary hyperfibrinolysis in a state of low fibrinogen after lumbar vertebral surgery.

PATIENT CONCERNS

A middle-aged woman experienced prolonged incision and excessive bleeding after lumbar vertebral surgery.

DIAGNOSIS

Combined with coagulation factors, coagulation function tests, and thromboelastography, the patient clinical presentation supported the diagnosis of FXIIID and secondary hyperfibrinolysis in a hypofibrinogenemic state.

INTERVENTIONS

Cryoprecipitat, Fresh Frozen Plasma, Fibrinogen Concentrate, Leukocyte-depleted Red Blood Cells, Hemostatic (Carbazochrome Sodium Sulfonate; Hemocoagulase Bothrops Atrox for Injection; Tranexamic Acid).

OUTCOMES

After approximately a month of replacement therapy and symptom treatment, the patient coagulation function significantly improved, and the incision healed without any hemorrhage during follow-up.

LESSONS

Abnormal postoperative bleeding may indicate coagulation and fibrinolysis disorders that require a full set of coagulation tests, particularly coagulation factors. Given the current lack of a comprehensive approach to detect coagulation and fibrinolysis functions, a more comprehensive understanding of hematology is imperative. The current treatment for FXIIID involves replacement therapy, which requires supplementation with both Fib and FXIII to achieve effective hemostasis.

Interorgan communication with the liver: novel mechanisms and therapeutic targets

The liver is a multifunctional organ that plays crucial roles in numerous physiological processes, such as production of bile and proteins for blood plasma, regulation of blood levels of amino acids, processing of hemoglobin, clearance of metabolic waste, maintenance of glucose, etc. Therefore, the liver is essential for the homeostasis of organisms. With the development of research on the liver, there is growing concern about its effect on immune cells of innate and adaptive immunity. For example, the liver regulates the proliferation, differentiation, and effector functions of immune cells through various secreted proteins (also known as "hepatokines"). As a result, the liver is identified as an important regulator of the immune system. Furthermore, many diseases resulting from immune disorders are thought to be related to the dysfunction of the liver, including systemic lupus erythematosus, multiple sclerosis, and heart failure. Thus, the liver plays a role in remote immune regulation and is intricately linked with systemic immunity. This review provides a comprehensive overview of the liver remote regulation of the body's innate and adaptive immunity regarding to main areas: immune-related molecules secreted by the liver and the liver-resident cells. Additionally, we assessed the influence of the liver on various facets of systemic immune-related diseases, offering insights into the clinical application of target therapies for liver immune regulation, as well as future developmental trends.

Preoperative Fibrinogen Levels and Function as Predictive Factors for Acute Bleeding in the Hematoma Cavity After Burr Hole Drainage in Patients with CSDH

OBJECTIVE

Burr hole drainage (BHD) is the primary surgical intervention for managing chronic subdural hematoma (CSDH). However, it can lead to postoperative complications such as acute bleeding within the hematoma cavity and hematoma recurrence. The objective of this study is to identify the risk factors for these complications and develop a predictive model for acute hematoma cavity bleeding after BHD in patients with CSDH.

METHODS

This study presents a retrospective cohort investigation conducted at a single center. The clinical dataset of 308 CSDH patients who underwent BHD at a hospital from 2016 to 2022 was analyzed to develop and assess a prognostic model.

RESULTS

The nonbleeding group exhibited a significant correlation between fibrinogen (FIB) and thrombin time (TT), whereas no correlation was observed in the bleeding group. Notably, both FIB and TT were identified as risk factors for postoperative acute bleeding within the hematoma cavity. We developed a prognostic model to predict the occurrence of postoperative acute bleeding within the hematoma cavity after BHD in patients with CSDH. The model incorporated FIB, TT, coronary artery disease, and Glasgow Coma Scale scores. The model exhibited good discrimination (area under the curve: 0.725) and calibration (Hosmer-Leeshawn goodness of fit test: P > 0.1). Furthermore, decision curve analysis demonstrated the potential clinical benefit of implementing this prediction model.

CONCLUSIONS

The predictive model developed in this study can forecast the risk of postoperative acute bleeding within the hematoma cavity, thus aiding clinicians in selecting the optimal treatment approach for patients with CSDH.

A diagnostic model for differentiating tuberculous spondylitis from pyogenic spondylitis: a retrospective case-control study

The purpose of this study was to describe and compare the clinical data, laboratory examination and imaging examination of tuberculous spondylitis (TS) and pyogenic spondylitis (PS), and to provide ideas for diagnosis and treatment intervention. The patients with TS or PS diagnosed by pathology who first occurred in our hospital from September 2018 to November 2021 were studied retrospectively. The clinical data, laboratory results and imaging findings of the two groups were analyzed and compared. The diagnostic model was constructed by binary logistic regression. In addition, an external validation group was used to verify the effectiveness of the diagnostic model. A total of 112 patients were included, including 65 cases of TS with an average age of 49 ± 15 years, 47 cases of PS with an average of 56 ± 10 years. The PS group had a significantly older age than the TS group (P = 0.005). In laboratory examination, there were significant differences in WBC, neutrophil (N), lymphocyte (L), ESR, CRP, fibrinogen (FIB), serum albumin (A) and sodium (Na). The difference was also statistically significant in the comparison of imaging examinations at epidural abscesses, paravertebral abscesses, spinal cord compression, involvement of cervical, lumbar and thoracic vertebrae. This study constructed a diagnostic model, which was Y (value of TS > 0.5, value of PS < 0.5) = 1.251 * X1 (thoracic vertebrae involved = 1, thoracic vertebrae uninvolved = 0) + 2.021 * X2 (paravertebral abscesses = 1, no paravertebral abscess = 0) + 2.432 * X3 (spinal cord compression = 1, no spinal cord compression = 0) + 0.18 * X4 (value of serum A)-4.209 * X5 (cervical vertebrae involved = 1, cervical vertebrae uninvolved = 0)-0.02 * X6 (value of ESR)-0.806 * X7 (value of FIB)-3.36. Furthermore, the diagnostic model was validated using an external validation group, indicating a certain value in diagnosing TS and PS. This study puts forward a diagnostic model for the diagnosis of TS and PS in spinal infection for the first time, which has potential guiding value in the diagnosis of them and provides a certain reference for clinical work.

Coagulation profiles in patients with sepsis/septic shock identify mixed hypo-hypercoagulation patterns based on rotational thromboelastometry: A prospective observational study

INTRODUCTION

Sepsis-induced hemostatic disturbances are common and are associated with poor outcomes. Additionally, conventional coagulation tests (CCTs) overdiagnose hypocoagulation and cannot detect hypercoagulation and hyperfibrinolysis. The aim of this study was to describe the coagulation profiles of patients with sepsis/septic shock using rotational thromboelastometry (ROTEM) and to compare coagulation states between sepsis and septic shock groups and between surviving and non-surviving groups.

MATERIALS AND METHODS

This prospective, observational, single-center study was conducted in the intensive care unit (ICU) of the University Medical Center Ho Chi Minh City, from 6/2020-12/2021. Patients aged ≥18 years with sepsis or septic shock according to the Sepsis-3 criteria were included. ROTEM and CCTs were concurrently performed within the first 24 h of ICU admission.

RESULTS

In total, 161 patients were enrolled. Based on ROTEM, 72.7 % of patients with sepsis/septic shock had coagulation disorders, including 25.5 % hypercoagulation, 54.7 % hypocoagulation, 13.6 % mixed hypo-hypercoagulation patterns, and 18.6 % hyperfibrinolysis. A common mixed disorder subtype was characterized by prolonged initial clotting time (CT) with subsequently increased clot firmness. Fibrinogen levels and maximum clot formation (MCF)-fibtem were strongly correlated (rho = 0.73, p < 0.05). Hypocoagulation was observed more in the septic shock group than in the sepsis group. Compared to survivors, non-survivors had more prolonged CT-extem.

CONCLUSIONS

ROTEM could identify hypocoagulability, hypercoagulability, mixed hypo-hypercoagulability patterns, and hyperfibrinolysis in patients with sepsis/septic shock. Elevated MCF-fibtem and elevated fibrinogen levels were notably common and strongly correlated. The septic shock group had more hypocoagulation than the sepsis group. Lastly, non-survivors had more prolonged CT-extem than survivors.

Factor XIII levels, clot strength, and impact of fibrinogen concentrate in infants undergoing cardiopulmonary bypass: a mechanistic sub-study of the FIBCON trial

BACKGROUND

Acquired factor XIII (FXIII) deficiency after major surgery can increase postoperative bleeding. We evaluated FXIII contribution to clot strength and the effect of fibrinogen concentrate administration on FXIII activity in infants undergoing cardiac surgery using cardiopulmonary bypass.

METHODS

We conducted a prospectively planned, mechanistic sub-study, nested within the Fibrinogen Concentrate Supplementation in the Management of Bleeding During Paediatric Cardiopulmonary Bypass: A Phase 1B/2A, Open-Label Dose Escalation Study (FIBCON) trial, which investigated fibrinogen concentrate supplementation during cardiopulmonary bypass (ISRCTN: 50553029) in 111 infants (median age 6.4 months). The relationships between platelet number, fibrinogen concentration, and FXIII activity with rotational thromboelastometry clot strength (EXTEM-MCF) in blood taken immediately before cardiopulmonary bypass and after separation from bypass were estimated using multivariable linear regression. Changes in coagulation variables over time were quantified using a generalised linear model comparing three groups: fibrinogen concentrate-supplemented infants, placebo, and a third cohort with lower bleeding risk.

RESULTS

Overall, 48% of the variability (multivariable R²) in EXTEM-MCF clot strength was explained by three factors: the largest contribution was from FXIII activity (partial R²=0.21), followed by platelet number (partial R²=0.14), and fibrinogen concentration (partial R²=0.095). During cardiopulmonary bypass, mean platelet count fell by a similar amount in the three groups (-36% to -41%; interaction P=0.98). Conversely, fibrinogen concentration increased in all three groups: 132% in the fibrinogen concentrate-supplemented group, 26% in the placebo group, and 51% in the low-risk group. A similar increase was observed for FXIII activity (61%, 23%, and 25%, respectively; interaction P<0.0001).

CONCLUSIONS

FXIII contribution to clot strength is considerable in infants undergoing cardiac surgery. Fibrinogen concentrate supplementation also increased FXIII activity, and hence clot strength.

CLINICAL TRIAL REGISTRATION

ISRCTN: 50553029.

Extensive and Persistent Extravascular Dermal Fibrin Deposition Characterizes Systemic Sclerosis

Systemic sclerosis (SSc) is an autoimmune disease characterized by progressive multiorgan fibrosis. While the cause of SSc remains unknown, a perturbed vasculature is considered a critical early step in the pathogenesis. Using fibrinogen as a marker of vascular leakage, we found extensive extravascular fibrinogen deposition in the dermis of both limited and diffuse systemic sclerosis disease, and it was present in both early and late-stage patients. Based on a timed series of excision wounds, retention on the fibrin deposit of the splice variant domain, fibrinogen αEC, indicated a recent event, while fibrin networks lacking the αEC domain were older. Application of this timing tool to SSc revealed considerable heterogeneity in αEC domain distribution providing unique insight into disease activity. Intriguingly, the fibrinogen-αEC domain also accumulated in macrophages. These observations indicate that systemic sclerosis is characterized by ongoing vascular leakage resulting in extensive interstitial fibrin deposition that is either continually replenished and/or there is impaired fibrin clearance. Unresolved fibrin deposition might then incite chronic tissue remodeling.

Fracture hematoma micro-architecture influences transcriptional profile and plays a crucial role in determining bone healing outcomes

The hematoma that forms between broken fragments of bone serves as a natural fibrin scaffold, and its removal from the defect site delays bone healing. The hypothesis of this study is that the microarchitectural and mechanical properties of the initially formed hematoma has a significant effect on the regulation of the biological process, which ultimately determines the outcome of bone healing. To mimic three healing conditions in the rat femur (normal, delayed, and non-healing bone defects), three different defect sizes of 0.5, 1.5, and 5.0 mm, are respectively used. The analysis of 3-day-old hematomas demonstrates clear differences in fibrin clot micro-architecture in terms of fiber diameter, fiber density, and porosity of the formed fibrin network, which result in different mechanical properties (stiffness) of the hematoma in each model. Those differences directly affect the biological processes involved. Specifically, RNA-sequencing reveals almost 700 differentially expressed genes between normally healing and non-healing defects, including significantly up-regulated essential osteogenic genes in normally healing defects, also differences in immune cell populations, activated osteogenic transcriptional regulators as well as potential novel marker genes. Most importantly, this study demonstrates that the healing outcome has already been determined during the hematoma phase of bone healing, three days post-surgery.

Application of coagulation parameters at the time of necrotizing enterocolitis diagnosis in surgical intervention and prognosis

Purpose

It has been shown that abnormalities of coagulation and fibrinolysis system are involved in the pathogenesis of necrotizing enterocolitis (NEC), but not well studied challenge in the context of early detection of disease progression. The present study mainly explores the predictive significance of coagulation parameters at the time of NEC diagnosis in identifying the patients who eventually received surgery and/or NEC-related deaths.

Methods

The retrospective study of 114 neonates with NEC was conducted with assessments of demographic data, laboratory results at the time of NEC diagnosis, treatment methods and prognosis. According to treatment methods, patients were divided into surgical intervention group and medical treatment group. Predictive factors were put forward and determined by receiver operating characteristic (ROC) curve analysis. An analysis of the surgical intervention and prognosis was performed.

Results

Of 114 patients, 46 (40.4%) cases received surgical intervention and 14 (12.3%) deaths. prothrombin time (PT), PT international normalized ratio, activated partial thromboplastin time (APTT), fibrinogen and platelet count at the time of NEC diagnosis were independently associated with surgical NEC. The APTT could identify patients at high risk for surgical NEC, with 67.39% sensitivity, 86.76% specificity, better than that of other serological parameters. Coagulopathy was found in 38.6% of all patients. For surgical intervention, the area under the ROC curve (AUC) of coagulopathy was 0.869 (95% confidence interval [CI]: 0.794 ~ 0.944, P < 0.001), with 82.61% sensitivity and 91.18% specificity, outperformed APTT (95% CI: 0.236 ~ 0.173, P = 0.001). Furthermore, the AUC for coagulopathy to predict mortality was 0.809 (95% CI: 0.725 ~ 0.877, P < 0.001), with 92.86% sensitivity and 69.0% specificity.

Conclusion

Coagulation parameters at the time of NEC diagnosis were conducive to early prediction of surgical NEC and -related deaths, which should be closely monitored in neonates at high risk of NEC and validated as a clinical decision-making tool.

Albumin and fibrinogen kinetics in sepsis: a prospective observational study

Background

The measurement of circulating substrate concentrations does not provide information about substrate kinetics. It, therefore, remains unclear if a decrease in plasma concentration of albumin, as seen during critical illness, is a consequence of suppressed production in the liver or increased peripheral clearance. In this study, using stable isotope tracer infusions, we measured albumin and fibrinogen kinetics in septic patients and in a control group of non-septic subjects.

Methods

With the approval from the institutional Research Ethics Board and after obtaining written informed consent from patients or their substitute decision maker, mechanically ventilated patients with sepsis and patients scheduled for elective coronary artery bypass grafting were enrolled. Patients in the non-sepsis group were studied on the day before surgery. The stable isotope L-[ring-²H₅]phenylalanine was used to measure absolute synthesis rates (ASR) of albumin and fibrinogen. A priming dose of L-[ring-²H₅]phenylalanine (4 µmol/kg) was given followed by a six-hour infusion at a rate of 0.15 µmol/kg/min. At baseline and hourly thereafter, blood was drawn to measure isotope enrichments by gas chromatography/mass spectrometry. Very low density lipoprotein apolipoprotein-B 100 isotopic enrichment was used to represent the isotopic enrichment of the phenylalanine precursor pool from which the liver synthesizes proteins. Plasma albumin and fibrinogen concentrations were also measured.

Results

Mean plasma albumin in septic patients was decreased when compared to non-septic patients, while synthesis rates were comparable. Mean plasma fibrinogen and ASR in septic patients was increased when compared to non-septic patients. In non-septic patients, no statistically significant correlation between plasma albumin and ASR was observed but plasma fibrinogen significantly correlated with ASR. In septic patients, plasma albumin and fibrinogen significantly correlated with ASR.

Conclusions

While septic patients showed lower plasma albumin levels than non-septic patients, albumin synthesis was similar in the two groups suggesting that hypoalbuminemia during sepsis was not caused by suppressed hepatic production but a result of enhanced clearance from the circulation. Hyperfibrinogenemia in septic patients was a consequence of increased fibrinogen production.

Trial registration: ClinicalTrials.gov: NCT02865408 (registered on August 12, 2016) and ClinicalTrials.gov: NCT02549443 (registered on September 15, 2015).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03860-7.

Association of Genetic Polymorphisms of Fibrinogen, Factor XIII A-Subunit and α2-Antiplasmin with Fibrinogen Levels in Pregnant Women

Fibrinogen synthesis is stimulated by proinflammatory triggers and depends on α-, β- and γ-fibrinogen (FGA, FGB, FGG) genotypes. Constellations of fibrinogen, factor XIII A-subunit (F13A) and α₂-antiplasmin (A2AP) genotypes predisposing for dense fibrin gels with high antifibrinolytic capacity (e.g., FGB rs1800790 A-allele carriage in F13A 34Val/Val or A2AP 6Arg/Arg wildtypes) are related with reduced inflammation. As both relationships are likely to influence each other, we tested whether the association of fibrinogen genotypes with fibrinogen levels is influenced by F13A and A2AP genotypes in a population under proinflammatory stress. In total, 639 women were followed during pregnancy (2218 observations). The relationship between fibrinogen genotypes and levels was statistically assessed in univariate and multivariate analyses without and with stratification for F13A Val34Leu and A2AP Arg6Trp. Strong associations with fibrinogen levels could be found for FGB rs1800790G > A, FGA rs2070016T > C and FGG rs1049636T > C. For FGB rs1800790G > A and FGA rs2070016T > C, this relationship significantly depended on F13A Val34Leu and A2AP Arg6Trp genotypes. Specifically, in F13A 34Val/Val wildtypes, carriage of FGB rs1800790A was related to significantly lower fibrinogen levels compared with FGB rs1800790GG wildtypes (p < 0.01). For A2AP 6Arg/Arg wildtypes, a comparable relationship could be found (p < 0.04). As these genotype constellations related to lower fibrinogen levels have previously been shown to be associated with reduced inflammatory activity, these findings suggest that the influence of fibrinogen, F13A and A2AP genotypes on inflammation could affect the control of fibrinogen levels and vice versa.

Fibrinogen and Bleeding in Adult Cardiac Surgery: A Review of the Literature

Background: Fibrinogen is a substrate for blood clots formation. In cardiac surgery, a number of different mechanisms lead to a decrease in fibrinogen levels and consequent impaired haemostasis. Patients undergoing cardiac surgery are therefore frequently exposed to blood loss and allogeneic blood transfusion, which are risk factors associated with morbidity and mortality. Thus, particular efforts in fibrinogen management should be made to decrease bleeding and the need for blood transfusion. Therefore, fibrinogen remains an active focus of investigations from basic science to clinical practice. This review aims to summarise the latest evidence regarding the role of fibrinogen and current practices in fibrinogen management in adult cardiac surgery. Methods: The PubMed database was systematically searched for literature investigating the role and disorders of fibrinogen in cardiac surgery and diagnostic and therapeutic procedures related to fibrinogen deficiency aimed at reducing blood loss and transfusion requirements. Clinical trials and reviews from the last 10 years were included. Results: In total, 146 articles were analysed. Conclusion: The early diagnosis and treatment of fibrinogen deficiency is crucial in maintaining haemostasis in bleeding patients. Further studies are needed to better understand the association between fibrinogen levels, bleeding, and fibrinogen supplementation and their impacts on patient outcomes in different clinical settings.

Acute effect of fine particulate matter on blood pressure, heart rate and related inflammation biomarkers: A panel study in healthy adults

Epidemiological evidence of short-term fine particulate matter (PM2.5) exposure on blood pressure (BP), heart rate (HR) and related inflammation biomarkers has been inconsistent. We aimed to explore the acute effect of PM2.5 on BP, HR and the mediation effect of related inflammation biomarkers. A total of 32 healthy college students were recruited to perform 4 h of exposure at two sites with different PM2.5 concentrations in Wuhan between May 2019 and June 2019. The individual levels of PM2.5 concentration, BP and HR were measured hourly for each participant. Blood was drawn from each participant after each visit and we measured the levels of inflammation markers, including serum high-sensitivity C-reactive protein and plasma fibrinogen. Linear mixed-effect models were to explore the acute effect of PM2.5 exposure on BP, HR, and related inflammation biomarkers. In addition, we evaluated related inflammation biomarkers as the mediator in the association of PM2.5 and cardiovascular health indicators. The results showed that a 10 μg/m3 increment in PM2.5 concentration was associated with an increase of 0.84 (95% CI: 0.54, 1.15) beats/min (bpm) in HR and a 3.52% (95% CI: 1.60%, 5.48%) increase in fibrinogen. The lag effect model showed that the strongest effect on HR was observed at lag 3 h of PM2.5 exposure [1.96 bpm (95% CI: 1.19, 2.75)], but for fibrinogen, delayed exposure attenuated the association. Increased fibrinogen levels may account for 39.07% (P = 0.44) of the elevated HR by PM2.5. Null association was observed when it comes to short-term PM2.5 exposure and BP. Short-term exposure to PM2.5 was associated with elevated HR and increased fibrinogen levels. But our finding was not enough to suggest that exposure to PM2.5 might induce adverse cardiovascular effects by the pathway of inflammation.

Abnormal Fibrinogen Level as a Prognostic Indicator in Coronavirus Disease Patients: A Retrospective Cohort Study

Purpose: The coronavirus disease (COVID-19) pandemic poses a global threat, and identification of its prognostic biomarkers could prove invaluable. Fibrinogen (FIB) could be one such indicator as coagulation and fibrinolysis abnormalities are common among COVID-19 patients. We examined the role of FIB levels in the prognosis of COVID-19.

Methods: This retrospective cohort study enrolled 1,643 COVID-19 patients from the Leishenshan Hospital in Wuhan, China. The follow-up was conducted from February 8, 2020 to April 15, 2020. The cohort was divided into three groups according to the FIB level on admission, and associations with mortality and disease severity were determined using Cox and logistic regression analyses, respectively. Further, Kaplan–Meier (K–M) analyses by log-rank tests were used to assess the survival of patients with varying FIB levels.

Results: Patients with FIB < 2.2 g/L [hazard ratio (HR): 9.02, 95% confidence interval (CI): 1.91–42.59, P = 0.006] and >4.2 g/L (HR: 4.79, 95% CI: 1.14–20.20, P = 0.033) showed higher mortality risks compared to those with FIB between 2.2 and 4.2 g/L. The survival curves showed similar results in K–M analyses (P < 0.001). Additionally, an elevated FIB level was associated with a greater risk of developing critical disease (odds ratio: 2.16, 95% CI: 1.04–4.46, P = 0.038) than a FIB level within the normal range.

Conclusion: Abnormal FIB levels may be associated with mortality risk among COVID-19 patients and could predict critical disease development. Thus, assessment of FIB levels may assist in determining the prognosis of COVID-19 patients.

Alterations of coagulation and fibrinolysis in patients with blunt splenic injury after splenic artery embolization

Background

Thrombotic complications following splenectomy have been documented. However, there has been sparse literature regarding thrombotic complications following splenic artery embolization (SAE).The objective of this study was to determine changes in coagulation and fibrinolysis and assess the thrombotic risk after SAE in patients with blunt splenic injury (BSI).

Methods

This study included 38 BSI patients who were hemodynamically stable on admission. SAE was performed if the splenic injury was classed as grade III or greater and had no requirement of immediate surgery. Platelet (PLT), fibrinogen (FIB), D‐dimers (D‐D), fibrinogen/fibrin degradation products (FDP), antithrombin III (AT III), prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), hemoglobin (Hb), and hematocrit (Hct) were measured before SAE procedures and then 1d, 3d, and 7d after SAE.

Results

The technical success rate of SAE and the splenic salvage rate were 100%. There was no mortality. Compared with pre‐SAE values, the levels of PLT, FIB, D‐D, and FDP increased significantly at 3 days and 7 days after SAE (p < 0.05). However, AT III, PT, APTT, TT, Hb, and Hct showed no statistically significant difference at 1d, 3d, and 7d after SAE (p > 0.05).

Conclusion

Alterations in PLT and hemostatic parameters might contribute to the increased risk of thrombotic complications in BSI patients undergoing SAE. Thromboembolism following SAE should be considered and thrombotic prophylaxis should be recommended.

Prognostic value of albumin-fibrinogen ratio in subarachnoid hemorrhage patients

ABSTRACT

Inflammation plays an important role in the pathophysiology of subarachnoid hemorrhage (SAH). Recent studies have indicated that the albumin to fibrinogen ratio (AFR) is a useful biomarker of inflammation.This research aimed to determine the ability of AFR to predict the prognosis of patients with SAH.A total of 440 patients with SAH who had been diagnosed within 72 hours of symptom onset were retrospectively reviewed. Clinical findings and laboratory data were retrieved from the hospital database. Functional outcome was measured according to the modified Rankin scale at 30 days. Logistic regression analysis was used to evaluate the correlation between AFR and the prognosis of patients with SAH. Receiver operating characteristic (ROC) analysis was performed to determine the prognostic ability of AFR at admission to predict the 30-day outcomes.The average age of all 440 patients with SAH was 56.75 ± 11.19 years and 31.4% (138) were male. Of these patients, 161 exhibited unfavorable outcomes at 30 days. According to the multivariate logistic regression analysis, the AFR was positively correlated with the outcome of patients with SAH (odds ratio 0.939, 95% confidence interval 0.885-0.996, P = .038). The ROC analysis revealed an area under the curve of 0.713 for AFR's ability to predict the 30-day outcomes.AFR is independently associated with the outcome of SAH patients. As a parameter that can be easily assessed at admission, AFR could be used to help the decision-making of clinical treatment.

Determinants of Increased Fibrinogen in COVID-19 Patients With and Without Diabetes and Impaired Fasting Glucose

Background:

To investigate the factors associated with elevated fibrinogen (Fbg) levels in COVID-19 patients with and without diabetes (DM) and impaired fasting glucose (IFG).

Methods:

According to whether or not their glucose metabolism was impaired, COVID-19 patients were subdivided into 2 groups: 1) with DM and IFG, 2) control group. Their demographic data, medical history, signs and symptoms, laboratory results, and final clinical results were analyzed retrospectively.

Results:

28 patients (16.3%) died during hospitalization, including 21 (29.2%) in group 1 and 7 (7.0%) in group 2 (P < 0.001). Fbg levels in groups 1 and 2 were higher than the normal range, at 5.6 g/L (IQR 4.5–7.2 g/L) and 5.0 g/L (IQR 4.0–6.1 g/L), respectively (P = 0.009). Serum ferritin levels, C-reactive protein (CRP), interleukin-6 (IL-6), IL-8, tumor necrosis factor-α (TNF-α), triglycerides (TG) were significantly increased in group 1 compared to those in the control. TG levels were 1.3 mmol/L in the control, while that in group 1 was 1.8 mmol/L. Multiple linear regression showed that the predicting factors of Fbg in the control group were serum ferritin and CRP, R² = 0.295; in group 1, serum ferritin, CRP, and TG, R² = 0.473.

Conclusions:

Fbg in all COVID-19 patients is related to serum ferritin and CRP involved in inflammation. Furthermore, in COVID-19 patients with insulin resistance, Fbg is linearly positively correlated with TG. This suggests that regulation of TG, insulin resistance, and inflammation may reduce hypercoagulability in COVID-19 patients, especially those with insulin resistance.

Fibrinogen to albumin ratio reflects the activity of antineutrophil cytoplasmic antibody-associated vasculitis

Background

We investigated whether fibrinogen to albumin ratio (FAR) at diagnosis could reflect the cross‐sectional activity and predict poor outcomes in patients with antineutrophil cytoplasmic antibody (ANCA)‐associated vasculitis (AAV).

Methods

This cross‐sectional study included 54 immunosuppressant drug‐naïve patients with AAV who had the results of plasma fibrinogen and serum albumin at diagnosis. Clinical and laboratory data at diagnosis were collected, and all‐cause mortality, cerebrovascular accident, cardiovascular disease, end‐stage renal disease occurrences were assessed as poor outcomes. FAR was calculated by the following equation: FAR = plasma fibrinogen (g/dl)/serum albumin (g/dl).

Results

The median age was 65.5 years, and 59.3% of patients were men (33 MPA, 13 GPA and 8 EGPA). FAR was significantly correlated with Birmingham vasculitis activity score (BVAS; r = 0.271), erythrocyte sedimentation rate (ESR; r = 0.668) and C‐reactive protein (CRP; r = 0.638). High BVAS was defined as BVAS ≥16, and the cut‐off of FAR at diagnosis was set as 0.118. AAV patients with FAR at diagnosis ≥0.118 had a significantly higher risk for the cross‐sectional high BVAS than those without (RR 3.361). In the univariable linear regression analysis, CRP (β = 0.383) and FAR (β = 0.297) were significantly correlated with BVAS at diagnosis. However, in the multivariable analysis, none of them was correlated with the cross‐sectional BVAS. FAR at diagnosis could not predict poor outcomes during follow‐up in AAV patients.

Conclusions

Fibrinogen to albumin ratio at diagnosis could reflect the cross‐sectional BVAS but could not predict poor outcomes in patients with AAV.

The short- and long-term associations of particulate matter with inflammation and blood coagulation markers: A meta-analysis

Inflammation and the coagulation cascade are considered to be the potential mechanisms of ambient particulate matter (PM) exposure-induced adverse cardiovascular events. Tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), and fibrinogen are arguably the four most commonly assayed markers to reflect the relationships of PM with inflammation and blood coagulation. This review summarized and quantitatively analyzed the existing studies reporting short- and long-term associations of PM2.5(PM with an aerodynamic diameter ≤2.5 μm)/PM10 (PM with an aerodynamic diameter≤10 μm) with important inflammation and blood coagulation markers (TNF-α, IL-6, IL-8, fibrinogen). We reviewed relevant studies published up to July 2020, using three English databases (PubMed, Web of Science, Embase) and two Chinese databases (Wang-Fang, China National Knowledge Infrastructure). The OHAT tool, with some modification, was applied to evaluate risk of bias. Meta-analyses were conducted with random-effects models for calculating the pooled estimate of markers. To assess the potential effect modifiers and the source of heterogeneity, we conducted subgroup analyses and meta-regression analyses where appropriate. The assessment and correction of publication bias were based on Begg's and Egger's test and "trim-and-fill" analysis. We identified 44 eligible studies. For short-term PM exposure, the percent change of a 10 μg/m3 PM2.5 increase on TNF-α and fibrinogen was 3.51% (95% confidence interval (CI): 1.21%, 5.81%) and 0.54% (95% confidence interval (CI): 0.21%, 0.86%) respectively. We also found a significant short-term association between PM10 and fibrinogen (percent change = 0.17%, 95% CI: 0.04%, 0.29%). Overall analysis showed that long-term associations of fibrinogen with PM2.5 and PM10 were not significant. Subgroup analysis showed that long-term associations of fibrinogen with PM2.5 and PM10 were significant only found in studies conducted in Asia. Our findings support significant short-term associations of PM with TNF-α and fibrinogen. Future epidemiological studies should address the role long-term PM exposure plays in inflammation and blood coagulation markers level change.

The role of exogenous Fibrinogen in cardiac surgery: stop bleeding or induce cardiovascular disease

The surgical treatment contributes to broad variety of cardiovascular diseases (CVD). Due to many involved factors in preoperative bleeding, it is almost difficult to perform better Haemostatic approach. Fibrinogen is a major blood glycoprotein and a coagulation factor which decreases postoperative bleeding. It has a potential role in platelet activation and bleeding inhibition; it may reflect the inflammatory responses and be related to the endothelial dysfunction. Fibrinogen can act as a pro-inflammatory element via increasing some inflammatory markers including IL-6, tumor necrosis factor-α (TNF-α), monocyte chemo attractant protein (MCP-1), macrophage inflammatory protein-1 (MIP-1a and b), matrix metalloproteinase (MMP-1 and MMP-9) and Toll-like Receptors (TLRs); through activation of these factors, fibrinogen may induce some inflammatory mechanisms such as focal adhesion kinase (FAK), mitogen-activated protein kinases (MAPK) and nuclear factor κB (NF-κB) pathways. It may cause endothelial dysfunction by increasing P and E-selection, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) levels which activate MAPK and NF-κB pathways. This factor is also associated with increased exocytosed von Willebrand factor (vWF) as well as activation of Rho-GTPase mechanism. All of these data demonstrate the dual role of fibrinogen in cardiac surgeries, bleeding inhibition and CVD. Therefore, identifying the CVD factors is helpful for designing preventive strategies and alternative drugs.

A novel Cys328-terminator mutant implicated in severe coagulation factor XIII deficiency: a case report

BACKGROUND

Factor XIII (FXIII) deficiency is an extremely rare bleeding disorder that is commonly due to mutations in the FXIIIA subunit gene (F13A1), and it has been reported to have a prevalence of one per 2 million. We describe a new genetic variant in the F13A1 gene that caused a patient to suffer from lifelong hemorrhagic diathesis.

CASE PRESENTATION

We evaluated a 20-year-old female with umbilical cord bleeding after birth, an intracerebral hemorrhage at age 6, and other bleeding episodes, including hematuria and cephalohematoma, who suffered from a lifelong hemorrhagic diathesis. The clot solubility test showed that the clot of the patient was dissolved in urea solution at 10 h. Genetic testing identified a novel homozygous mutation, c.984C > A(p. Cys328stop), resulting in a premature stop codon in exon 8 of the F13A1 gene. The results obtained with ClusterX software showed that Cys328 of exon 8 in the F13A1 gene is highly conserved among species.

CONCLUSION

We reported a novel homozygous mutation in the F13A1 gene in a factor XIII (FXIII)-deficient patient, which adds a new point mutation to the mutant library. In this paper, we discuss other aspects of the disease, including laboratory examination, homogeneous sequence alignment and molecular modeling.

Clinical Characteristics of Hospitalized Neonates With Hypofibrinogenemia: A Retrospective Cohort Study

Background: Neonatal hypofibrinogenemia is often asymptomatic but can manifest as hemorrhage. Objective: This study was conducted to characterize clinical characteristics of neonates with hypofibrinogenemia and identify factors associated with hemorrhage. Methods: This was a retrospective study of neonates with plasma fibrinogen level (FIB) ≤1.0 g/L who were hospitalized at the Neonatology Department, People's Hospital, Chongqing, China, from January 2012 to December 2017. Based on severity, patients were grouped into severe, moderate, and mild hypofibrinogenemia (FIB < 0.5 g/L, 0.5 g/L ≤ FIB < 0.7 g/L, and 0.7 g/L ≤ FIB ≤ 1.0 g/L, respectively). Clinical characteristics associated with hemorrhage were analyzed. Results: Among 330 neonates, 52.7% showed mild hypofibrinogenemia, 25.5% had moderate hypofibrinogenemia, and 21.8% had severe hypofibrinogenemia. Severe hypofibrinogenemia was not associated with gestational age, but the mild form was frequent in neonates with low/normal birthweight (P = 0.018). Approximately 80.6% of neonates presented hypofibrinogenemia as variable combinations of thrombocytopenia or coagulopathies. Hemorrhage occurred in 38.8% of the cases, 60.9% of which were mild. Hemorrhage manifested as puncture site bleeding (47.7%) or spontaneous skin/mucous membrane bleeding (34.2%). The degree of hypofibrinogenemia was not associated with the severity or occurrence of hemorrhage. Among patients with hypofibrinogenemia and bleeding, 53.4% of the cases with coagulopathies showed mild hemorrhage, 85.7% of the cases with thrombocytopenia had moderate bleeding, while 53.8% of the cases with coagulopathy and thrombocytopenia showed severe hemorrhage. Conclusion: Neonatal hypofibrinogenemia is often comorbid and occurs with thrombocytopenia and/or coagulopathies. Although hemorrhage is not associated with the degree of hypofibrinogenemia, it may be severe when hypofibrinogenemia co-occurs with coagulopathies and/or thrombocytopenia.

Human Dental Pulp Stem Cells in Rat Mandibular Bone Defects

This study aimed to evaluate the use of human dental pulp stem cells (hDPSCs) in non-critical-sized mandibular bone defects in rats. hDPSCs from permanent teeth were isolated and engrafted in mandibular bone defects in rats for 7, 14, and 28 days; bone defects without cells formed the control group. Samples were evaluated by scanning electron microscopy (SEM), light microscopy (hematoxylin and eosin staining), and the regeneration area was measured by the Image J program. Before surgery procedures, the human dental pulp cells were characterized as dental pulp stem cells: fusiform morphology, plastic-adherent; expression of CD105, CD73, and CD90; lack of expression of CD45 and CD34, and differentiated into osteoblasts, adipocytes, and chondroblasts. The results indicated that within 7 days the control group presented a pronounced bone formation when compared with the treated group (p < 0.05). After 14 days, the treated group showed an increase in bone formation, but with no statistical difference among the groups (p > 0.05). In the final evaluated period there was no difference between the control group and the treated group (p > 0.05). There was a significant difference between 7 and 14 days (p < 0.05) and between 7 and 28 days (p < 0.05) in the treated group. In conclusion, there is no evidence that the use of hDPSCs in the conditions of this study could improve bone formation in non-critical-sized mandibular bone defects.

Fibrin as a Multipurpose Physiological Platform for Bone Tissue Engineering and Targeted Delivery of Bioactive Compounds

Although bone graft is still considered as the gold standard method, bone tissue engineering offers promising alternatives designed to mimic the extracellular matrix (ECM) and to guide bone regeneration process. In this attempt, due to their similarity to the ECM and their low toxicity/immunogenicity properties, growing attention is paid to natural polymers. In particular, considering the early critical role of fracture hematoma for bone healing, fibrin, which constitutes blood clot, is a candidate of choice. Indeed, in addition to its physiological roles in bone healing cascade, fibrin biochemical characteristics make it suitable to be used as a multipurpose platform for bioactive agents’ delivery. Thus, taking advantage of these key assets, researchers and clinicians have the opportunity to develop composite systems that might further improve bone tissue reconstruction, and more generally prevent/treat skeletal disorders.

Evaluation of Fibrin Clot Attachment on Titanium Laser-Conditioned Surface Using Scanning Electron Microscopy

OBJECTIVES

The study aimed to evaluate the effects of different titanium surface treatments on blood clot extension (bce).

METHODS

A total of 54 titanium disks with machined surface (M), laser-conditioned surface (L), and grit-blasted surface (S) were used in the present study. The surface characteristics such as contact angles and the microroughness were determined on each group (n = 4). To evaluate the bce, 0.1 mL of human blood was dropped onto the surface of each specimen and left for 7 minutes at room temperature. After fixation, dehydration, and gold sputtering treatments, the specimens were observed under scanning electron microscope. The bce values were expressed as percentage of specimen surface covered by blood clot.

RESULTS

The surface roughness (Ra ± standard deviation [SD]) was 0.75 ± 0.02 μm for M, 0.25 ± 0.02 μm for L, and 1.30 ± 0.03 μm for S. The contact angles measured in static conditions (WCA ± SD) were 71 ± 5.4° for M, 107 ± 6.6° for L, and 91 ± 7.2° for S. Regarding the bce (bce ± SD) of M samples (65.5 ± 4.3%) was statistically lower compared with both L (83.4 ± 5.1%) and S samples (72.4 ± 4.7%) (P < 0.05). Meanwhile, the L group showed the higher bce value.

CONCLUSION

The present results suggest that the laser-conditioned surface may increase the wettability and bce.

The Prognostic Value of Pretreatment Plasma Fibrinogen in Urological Cancers: A Systematic Review and Meta-analysis

Objective: Growing evidence suggests pretreatment fibrinogen can serve as a prognostic marker in various malignancies. However, there are contradictory results about the prognostic role of fibrinogen in urological cancers. We conducted a meta-analysis to evaluate the association between pretreatment plasma fibrinogen and survival outcomes in urological cancers. Methods: After a systematic search of PubMed and Embase, we included 14 studies in our meta-analysis, and estimated hazard ratios (HRs) for overall survival (OS) and cancer-specific survival (CSS) using a fixed-effect model. Results: Our results indicate that pretreatment plasma fibrinogen is a prognostic factor in urological cancers (OS: HR=2.21, 95% CI=1.91-2.57, P<0.001, CSS: HR=2.67, 95% CI=2.23-3.19, P<0.001). Elevated pretreatment plasma fibrinogen is associated with poorer survival in prostate cancer (OS: HR=2.26, 95% CI=1.47-3.48, P<0.001; CSS: HR=2.42, 95% CI=1.44-4.07, P=0.001), renal cell carcinoma (OS: HR=2.13, 95% CI=1.75-2.61, P<0.001; CSS: HR=2.99, 95% CI=2.29-3.89, P<0.001) and upper tract urothelial carcinoma (OS: HR=2.34, 95% CI=1.81-3.02, P<0.001; CSS: HR=2.43, 95% CI=1.84-3.20, P<0.001). Subgroup analyses showed that plasma fibrinogen has a more negative impact on survival in Caucasian patients (OS: HR=2.52, 95% CI=1.95-3.25, P<0.001; CSS: HR=2.83, 95% CI=1.92-4.17, P<0.001) than Asian patients (OS: HR=2.07, 95% CI=1.73-2.49, P<0.001; CSS: HR=2.63, 95% CI=2.14-3.22, P<0.001). The prognostic value of fibrinogen is also consistent when stratified by different cut-off values. Conclusions: These results show that high pretreatment plasma fibrinogen levels can predict poorer OS and CSS in patients with urological cancers.

Mast cell chymase degrades fibrinogen and fibrin

BACKGROUND

The accumulation of immunoreactants and fibrinoid necrosis of postcapillary vessel walls are common pathological features of cutaneous immune complex vasculitis. In more advanced lesions, these immunoreactants are subject to proteolysis. Mast cell chymase is a powerful enzyme that can degrade several substrates including the extracellular matrix. Heparin can influence the catalytic properties of chymase.

OBJECTIVES

To study the effects of recombinant human (rh) chymase on fibrinogen, coagulation and fibrinolysis, and to relate these effects to the pathogenesis of vasculitis.

METHODS

The colocalization of chymase and fibrin in vasculitis specimens was analysed by immunohistochemical double staining. Fibrinogen and fibrin were treated with rh-chymase and the effects were studied in vitro by sodium dodecylsulfate polyacrylamide gel electrophoresis and a variety of clotting and fibrin gel experiments. The effects of rh-chymase on vasculitis cryosections were analysed by direct immunofluorescence.

RESULTS

Chymase-positive mast cells were associated with fibrin-positive vessels in vasculitis cryosections. Rh-chymase degraded the alpha-, beta- and gamma-chains of fibrinogen, while heparin enhanced the degradation of the beta-chain. Rh-chymase pretreatment of fibrinogen prolonged thrombin-induced clotting time. Fibrinogen degradation products induced by rh-chymase increased the clotting time of human plasma. Rh-chymase degraded fibrin gel prepared from fibrinogen or human plasma. Immunofluorescence staining positivity of fibrin in vasculitis cryosections decreased after pretreatment with rh-chymase for 24 h, and heparin enhanced this effect.

CONCLUSIONS

Mast cell chymase may constitute a previously unrecognized endogenous anticoagulant and fibrinolytic enzyme, and may be involved in the clearance of fibrin from vessel walls in aged vasculitis lesions.

Inherited genetic predispositions in F13A1 and F13B genes predict abdominal adhesion formation: identification of gender prognostic indicators

Abdominal adhesions (AA) account for the most common complication of peritoneal surgery with bowel obstruction being the severest problem in the absence of effective predicting biomarkers. Anti-AA-barriers or adhesiolysis did not completely prevent bowel obstruction, although there is evidence they might reduce related complications requiring reoperation. In addition, gender-related predispositions have not been adequately investigated. We explored the role of coagulation Factor XIII (F13A1 and F13B subunit-genes) in patients following laparotomy, mostly median/lower median incision line. Globally, 426 patients (54%,♀), were PCR-SNP-genotyped for FXIIIA V34L (rs5985), FXIIIA P564L (rs5982), FXIIIA Y204F (rs3024477) and FXIIIB H95R (rs6003). Patients' clinical phenotypes were: Group-A (n = 212), those who developed AA, and 55.2% of them developed bowel obstruction (subgroup-A1), the remaining were subgroup-A2; Group B (n = 214) were those who did not develop AA (subgroup-B1; 53.3%) or symptoms/complications (subgroup-B2). Among different laparotomy, colon surgery associated with AA at a major extent (OR = 5.1; 3.24-7.8; P < 0.0001) with different gender scores (♀OR = 5.33; 2.32-12.23; P < 0.0001 and ♂OR = 3.44; 1.58-7.49; P < 0.0001). Among SNPs, P564L (OR = 4.42; 1.45-13.4; P = 0.008) and Y204F (OR = 7.78; 1.62-37.3; P = 0.01) significantly predicted bowel obstruction and survival-analyses yielded interesting gender distinctions (♀HR = 5.28; 2.36-11.8; P = 0.00005; ♂HR = 2.22; 1.31-3.85; P = 0.0034). Active compounds preventing AA belong to the anticoagulant/fibrinolysis areas, suggesting them candidate investigation targets. We identified novel prognostic markers to predict AA/bowel obstruction giving insights to design novel therapeutic and gender prevention programs.

F13A1 Gene Variant (V34L) and Residual Circulating FXIIIA Levels Predict Short- and Long-Term Mortality in Acute Myocardial Infarction after Coronary Angioplasty

Factor XIIIA (FXIIIA) levels are independent predictors of early prognosis after acute myocardial infarction (AMI) and the Valine-to-Leucine (V34L) single nucleotide polymorphism (SNP) seems associated with lower AMI risk. Since the long-term AMI prognosis merits deeper investigation, we performed an observational study evaluating relationships between FXIIIA residual levels, cardiovascular risk-factors, and inherited genetic predispositions. FXIIIA V34L was genotyped in 333 AMI patients and a five-year follow-up was performed. FXIIIA levels assessed at day-zero (d0) and four days after AMI (d4), and conventional risk factors were analyzed, focusing on the development of major adverse cardiovascular events (MACE). FXIIIA assessed at d0 and d4 was also an independent MACE predictor in the long-term follow-up (FXIIIA_d0, Odds Ratio (OR) = 3.02, 1.79–5.1, p = 0.013; FXIIIA_d4, OR = 4.46, 2.33–8.55, p = 0.0001). FXIIIA_d4 showed the strongest MACE association, suggesting that the FXIIIA protective role is maximized when high levels are maintained for longer time. Conversely, FXIIIA levels stratified by V34L predicted MACE at a lesser extent among L34-carriers (Hazard Risk (HR)_VV34 = 3.89, 2.19–6.87, p = 0.000003; HR_L34-carriers = 2.78, 1.39–5.57, p = 0.0039), and V34L did not predict all MACE, only multiple-MACE occurrence (p = 0.0087). Finally, in survival analysis, heart failure and death differed significantly from stroke and recurrent ischemia (p = 0.0013), with FXIIIA levels appreciably lower in the former (p = 0.05). Overall, genetically-determined FXIIIA levels have a significant long-term prognostic role, suggesting that a pharmacogenetics approach might help to select those AMI patients at risk of poor prognosis in the need of dedicated treatments.

Serum global metabolomics profiling reveals profound metabolic impairments in patients with MPS IIIA and MPS IIIB

The monogenic defects in specific lysosomal enzymes in mucopolysaccharidosis (MPS) III lead to lysosomal storage of glycosaminoglycans and complex CNS and somatic pathology, for which the detailed mechanisms remain unclear. In this study, serum samples from patients with MPS IIIA (age 2-9 yr) and MPS IIIB (2-13 yr) and healthy controls (age 2-9 yr) were assayed by global metabolomics profiling of 658 metabolites using mass spectrometry. Significant alterations were detected in 423 metabolites in all MPS III patients, of which 366 (86.5%) decreased and 57 (13.5%) increased. Similar profiles were observed when analyzing data from MPS IIIA and MPS IIIB samples separately, with only limited age variations in 36 metabolites. The observed metabolic disturbances in MPS III patients involve virtually all major pathways of amino acid (101/150), peptide (17/21), carbohydrate (19/23), lipid (221/325), nucleotide (15/25), energy (8/9), vitamins and co-factors (8/21), and xenobiotics (34/84) metabolism. Notably, detected serum metabolite decreases involved all key amino acids, all major neurotransmitter pathways, and broad neuroprotective compounds. The elevated metabolites are predominantly lipid derivatives, and also include cysteine metabolites and a fibrinogen peptide fragment, consistent with the status of oxidative stress and inflammation in MPS III. This study demonstrates that the lysosomal glycosaminoglycans storage triggers profound metabolic disturbances in patients with MPS III disorders, leading to severe functional depression of virtually all metabolic pathways, which emerge early during the disease progression. Serum global metabolomics profiling may provide an important and minimally invasive tool for better understanding the disease mechanisms and identification of potential biomarkers for MPS III.

Can biomarkers of coagulation, platelet activation, and inflammation predict mortality in patients with hematological malignancies?

BACKGROUND

Patients with cancer commonly demonstrate laboratory evidence for hypercoagulability. Coagulation and inflammation play a role in the pathophysiology of hematological malignancies and the correlation between hypercoagulability and inflammation with tumor outcomes and the patient's prognosis are well studied.

OBJECTIVE

To identify an association between hemostasis activation, fibrinolysis and inflammation with mortality in patients with hematological malignancies to determine their prognostic significance.

METHODS

This study is a prospective observational cohort study; Hypercoagulability and inflammatory biomarkers including:(1) Coagulation and fibrinolysis activation Markers (D-dimer, Fibrinogen, Antithrombin, plasminogen activator inhibitor 1 [PAI-1]);(2) Endothelium and platelet activation Markers (von Willebrand Factor [vWF], soluble P-selectin); and (3) Inflammation Markers (Tumor necrosis factor alpha [TNF-α], Interleukin-6 [IL-6]) were assayed on a group of 171 patients with hematological malignancies at time of diagnosis. They have been followed up for an average period of 416.8 days with an endpoint of mortality.

RESULTS

Sixty patients died during follow up. There were statistically significant associations between Plasma cell dyscrasias mortality and ECOG performance status (P value:<0.005), Hemoglobin level (P value: 0.04), serum Albumin level (P value: 0.001), vWF (P value: 0.006) and IL-6 (P value 0.015), and between lymphoproliferative disorders mortality and presence of B symptoms (P value: 0.02), ECOG performance status (P value:<0.02), serum Albumin level (P value: 0.038), Antithrombin (P value: 0.004).

CONCLUSION

Some biomarkers of coagulation and inflammation showed statistically significant associations with plasma cell dyscrasias mortality (vWF and IL-6) and lymphoproliferative disorders mortality (Antithrombin) and potentially could be used as prognostic markers.

Recombinant factor XIII prophylaxis is safe and effective in young children with congenital factor XIII-A deficiency: international phase 3b trial results

Essentials Prophylaxis is the standard of care for congenital factor XIII-A (FXIII-A) deficiency. Six children with FXIII-A deficiency received once-monthly prophylaxis with recombinant FXIII-A. Prophylaxis was well tolerated and no anti-FXIII antibodies were detected. Prophylaxis was effective with an annualized bleeding rate of zero.

SUMMARY

Background Factor XIII deficiency is a rare, severe congenital bleeding disorder. Monthly prophylaxis with recombinant FXIII A-Subunit (rFXIII) has demonstrated favorable safety and efficacy in patients aged ≥ 6 years, and may similarly benefit younger children. Objective To evaluate the long-term safety and efficacy of rFXIII in children aged < 6 years with congenital FXIII A-subunit deficiency. Patients/methods Six children, who had previously completed a single-dose pharmacokinetic trial of rFXIII, received 35 IU kg-1 rFXIII every 28 days (± 2 days) for a minimum of 52 weeks, and were evaluated for bleeding and adverse events. The Berichrom FXIII activity assay was used to monitor FXIII activity. Results The children, three girls and three boys, had an average age of 3.0 years (range: 1-4 years) at enrollment. The total treatment duration was 1.8-3.5 years, giving a total of 16.6 patient-years. No antibody development, thromboembolic events or allergic reactions occurred. There were 93 mild and seven moderate adverse events. Two adverse events (lymphopenia and gastroenteritis) were reported as probably or possibly related to rFXIII in two children. Two serious adverse events, unrelated to rFXIII, were reported in a single child, each related to head injury, and neither resulting in intracranial hemorrhage. The geometric mean FXIII activity trough was 0.19 IU mL-1 . No bleeding episodes requiring treatment with an FXIII-containing hemostatic agent occurred during the trial; thus, the annualized bleeding rate was 0. Conclusions Consistent with data from older age groups, prophylaxis with rFXIII appears to be safe and effective in young children with congenital FXIII A-subunit deficiency.

Serum exosomal protein profiling for the non-invasive detection of cardiac allograft rejection

BACKGROUND

Exosomes are cell-derived circulating vesicles that play an important role in cell-cell communication. Exosomes are actively assembled and carry messenger RNAs, microRNAs and proteins. The "gold standard" for cardiac allograft surveillance is endomyocardial biopsy (EMB), an invasive technique with a distinct complication profile. The development of novel, non-invasive methods for the early diagnosis of allograft rejection is warranted. We hypothesized that the exosomal proteome is altered in acute rejection, allowing for a distinction between non-rejection and rejection episodes.

METHODS

Serum samples were collected from heart transplant (HTx) recipients with no rejection, acute cellular rejection (ACR) and antibody-mediated rejection (AMR). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of serum exosome was performed using a mass spectrometer (Orbitrap Fusion Tribrid).

RESULTS

Principal component analysis (PCA) revealed a clustering of 3 groups: (1) control and heart failure (HF); (2) HTx without rejection; and (3) ACR and AMR. A total of 45 proteins were identified that could distinguish between groups (q < 0.05). Comparison of serum exosomal proteins from control, HF and non-rejection HTx revealed 17 differentially expressed proteins in at least 1 group (q < 0.05). Finally, comparisons of non-rejection HTx, ACR and AMR serum exosomes revealed 15 differentially expressed proteins in at least 1 group (q < 0.05). Of these 15 proteins, 8 proteins are known to play a role in the immune response. Of note, the majority of proteins identified were associated with complement activation, adaptive immunity such as immunoglobulin components and coagulation.

CONCLUSIONS

Characterizing of circulating exosomal proteome in different cardiac disease states reveals unique protein expression patterns indicative of the respective pathologies. Our data suggest that HTx and allograft rejection alter the circulating exosomal protein content. Exosomal protein analysis could be a novel approach to detect and monitor acute transplant rejection and lead to the development of predictive and prognostic biomarkers.

Ischemia/Reperfusion Injury following Acute Myocardial Infarction: A Critical Issue for Clinicians and Forensic Pathologists

Acute myocardial infarction (AMI) is a leading cause of morbidity and mortality. Reperfusion strategies are the current standard therapy for AMI. However, they may result in paradoxical cardiomyocyte dysfunction, known as ischemic reperfusion injury (IRI). Different forms of IRI are recognized, of which only the first two are reversible: reperfusion-induced arrhythmias, myocardial stunning, microvascular obstruction, and lethal myocardial reperfusion injury. Sudden death is the most common pattern for ischemia-induced lethal ventricular arrhythmias during AMI. The exact mechanisms of IRI are not fully known. Molecular, cellular, and tissue alterations such as cell death, inflammation, neurohumoral activation, and oxidative stress are considered to be of paramount importance in IRI. However, comprehension of the exact pathophysiological mechanisms remains a challenge for clinicians. Furthermore, myocardial IRI is a critical issue also for forensic pathologists since sudden death may occur despite timely reperfusion following AMI, that is one of the most frequently litigated areas of cardiology practice. In this paper we explore the literature regarding the pathophysiology of myocardial IRI, focusing on the possible role of the calpain system, oxidative-nitrosative stress, and matrix metalloproteinases and aiming to foster knowledge of IRI pathophysiology also in terms of medicolegal understanding of sudden deaths following AMI.

Should We Replace the Terms Intrinsic and Extrinsic Coagulation Pathways With Tissue Factor Pathway?

Present review highlights some new aspects of the role of individual components of blood coagulation process and proposes a modified concept of hemocoagulation cascade. The role of FXII in the initiation of the so-called intrinsic coagulation system is currently questioned. Its role has been recently demonstrated mainly in the thrombus propagation and final stabilization together with factors XI and XIII. The edited concept underlines the common part of the tissue factor (TF) in the initiation of both the intrinsic and extrinsic pathways of the coagulation system and therefore may make it not improperly be called the TF coagulation pathway. The search for new antithrombotic agents shows that the level of the coagulation system blockade depends on which step in the coagulation cascade is targeted and results in different degrees of the antithrombotic efficiency and the risk of bleeding complications.

Risk of venous thromboembolism in neuromyelitis optica patients hospitalized for acute relapse

Background:

Neuromyelitis optica spectrum disorder (NMOSD) patients may be at increased risk of venous thromboembolism (VTE) not only due to ambulatory disability but also due to systemic autoimmune and inflammatory mechanisms altering the hemostatic balance.

Objective:

To compare the risk of VTE in NMOSD versus multiple sclerosis (MS) patients hospitalized for acute relapses.

Methods:

Hospital admissions for MS or NMOSD exacerbations were retrospectively identified. Demographics and medical history were recorded. The relationship between visit diagnosis and presence of VTE within 6 weeks of relapse onset was assessed by univariate logistic regression. A multivariate model evaluated the relationship between diagnosis, age, race, gender, body mass index (BMI), disease modifying therapy use, oral corticosteroid use, oral contraceptive use, smoking, length of stay (LOS), and ambulatory status on VTE risk.

Results:

A total of 30 NMOSD patients had 55 hospitalizations; 179 MS patients had 264 hospitalizations. Six NMOSD patients and one MS patient had VTE. NMOSD visits compared to MS visits had an odds ratio (OR) of VTE of 32.2 ( p = 0.002). NMOSD was more likely to be associated with VTE (OR = 17.4; p = 0.01) controlling for age, LOS, and ambulatory disability.

Conclusion:

NMOSD may be a risk factor for VTE. Larger prospective studies are required to confirm this risk and determine implications for prophylaxis.

Adsorption and conformational modification of fibronectin and fibrinogen adsorbed on hydroxyapatite. A QCM-D study

Hydroxyapatite is a bioactive ceramic frequently used for bone engineering/replacement. One of the parameters that influence the biological response to implanted materials is the conformation of the first adsorbed protein layer. In this work, the adsorption and conformational changes of two fibroid serum proteins; fibronectin and fibrinogen adsorbed onto four different hydroxyapatite powders are studied with a Quartz Crystal Microbalance with Dissipation (QCM-D). Each of the calcined apatites adsorbs less protein than their corresponding synthesized samples. Adsorption on synthesized samples yields always an extended conformation whereas a reorganization of the layer is observed for the calcined samples. Fg acquires a "Side on" conformation in all the samples at the beginning of the experiment except for one of the synthesized samples where an "End-on" conformation is obtained during the whole experiment. The Extended conformation is the active conformation for Fn. This conformation is favored by apatites with large specific surface area (SSA) and on highly concentrated media. Apatite surface features should be considered in the selection or design of materials for bone regeneration, since it is possible to control the conformation mode of attachment of Fn and Fg by an appropriate selection of them. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2585-2594, 2016.

Shock-induced systemic hyperfibrinolysis is attenuated by plasma-first resuscitation

BACKGROUND

We developed a hemorrhagic shock animal model to replicate an urban prehospital setting where resuscitation fluids are limited to assess the effect of saline versus plasma in coagulopathic patients. An in vitro model of whole blood dilution with saline exacerbated tissue plasminogen activator (tPA)-mediated fibrinolysis, while plasma dilution did not change fibrinolysis. We hypothesize that shock-induced hyperfibrinolysis can be attenuated by resuscitation with plasma while exacerbated by saline.

METHODS

Sprague-Dawley rats were hemorrhaged to a mean arterial pressure of 25 mm Hg and maintained in shock for 30 minutes. Animals were resuscitated with either normal saline (NS) or platelet-free plasma (PFP) with a 10% total blood volume bolus, followed by an additional 5 minutes of resuscitation with NS to increase blood pressure to a mean arterial pressure of 30 mm Hg. Animals were observed for 15 minutes for the assessment of hemodynamic response and survival. Blood samples were analyzed with thrombelastography paired with protein analysis.

RESULTS

The median percentage of total blood volume shed per group were similar (NS, 52.5% vs. PFP, 55.7; p = 0.065). Survival was 50% in NS compared with 100% in PFP. The change in LY30 and tPA levels from baseline to shock was similar between groups (LY30 PFP, 10; interquartile range [IQR], 4.3-11.2; NS, 4.5; IQR, 4.1-14.2; p = 1.00; tPA PFP, 16.6 ng/mL; IQR, 13.7-27.8; NS, 22.4; IQR, 20.1-25.5; p = 0.240). After resuscitation, the median change in LY30 was greater in the NS group (13.5; IQR, 3.5-19.9) compared with PFP (-4.9%; IQR, -9.22 to 0.25 p = 0.004), but tPA levels did not significantly change (NS, 1.4; IQR, -6.2 to 7.1 vs. PFP, 1.7; IQR, -5.2 to 6.8; p = 0.699).

CONCLUSION

Systemic hyperfibrinolysis is driven by hypoperfusion and associated with increased levels of tPA. Plasma is a superior resuscitation fluid to NS in a prehospital model of severe hemorrhagic shock as it attenuates hyperfibrinolysis and improves systemic perfusion.

Hepatocytes: a key cell type for innate immunity

Hepatocytes, the major parenchymal cells in the liver, play pivotal roles in metabolism, detoxification, and protein synthesis. Hepatocytes also activate innate immunity against invading microorganisms by secreting innate immunity proteins. These proteins include bactericidal proteins that directly kill bacteria, opsonins that assist in the phagocytosis of foreign bacteria, iron-sequestering proteins that block iron uptake by bacteria, several soluble factors that regulate lipopolysaccharide signaling, and the coagulation factor fibrinogen that activates innate immunity. In this review, we summarize the wide variety of innate immunity proteins produced by hepatocytes and discuss liver-enriched transcription factors (e.g. hepatocyte nuclear factors and CCAAT/enhancer-binding proteins), pro-inflammatory mediators (e.g. interleukin (IL)-6, IL-22, IL-1β and tumor necrosis factor-α), and downstream signaling pathways (e.g. signal transducer and activator of transcription factor 3 and nuclear factor-κB) that regulate the expression of these innate immunity proteins. We also briefly discuss the dysregulation of these innate immunity proteins in chronic liver disease, which may contribute to an increased susceptibility to bacterial infection in patients with cirrhosis.