Fibrinogen: biochemistry, epidemiology and determinants

Comparative proteomic analysis of the changes in mare milk associated with different lactation stages and management systems

Mare milk has traditionally been attributed a number of health promoting properties. However, knowledge on its composition and functionality remains scarce, with particularly limited studies on mare milk proteomics. This study deeply characterized mare milk proteome accounting for both caseins and proteins in the whey fraction, also addressing the impact of lactation stage and different management systems. Milk samples from Basque Mountain Horse breed mares belonging to three different farms and three lactation stages were analysed after in-gel and in-solution digestion using nLC-MS/MS. Among the 469 proteins identified, the content of alpha-1 antitrypsin was significantly higher in pasture-based compared to other systems. Moreover, lactation stage significantly affected the content of beta-lactoglobulin II, immunoglobulin-like domain-containing protein, interferon alpha-inducible protein 27, lactotransferrin, polypeptide N-acetylgalactosaminyltransferase, and transforming acidic coiled-coil containing protein 2. This study contributes to the deep characterization of mare milk proteome and provides new insights into the effect of different production factors.

Fibrinogen binding to histones in circulation protects against adverse cellular and clinical outcomes

BACKGROUND

Circulating histones are released by extensive tissue injury or cell death and play important pathogenic roles in critical illnesses. Their interaction with circulating plasma components and the potential roles in the clinical setting are not fully understood.

OBJECTIVES

We aimed to characterize the interaction of histones with fibrinogen and explore its roles in vitro, in vivo, and in patient samples.

METHODS

Histone-fibrinogen binding was assessed by electrophoresis and enzyme-linked immunosorbent assay-based affinity assay. Functional significance was explored using washed platelets and endothelial cells in vitro and histone-infusion mouse models in vivo. To determine clinical translatability, a retrospective single-center cohort study was conducted on patients requiring intensive care admission (n = 199) and validated in a cohort of hospitalized patients with COVID-19 (n = 69).

RESULTS

Fibrinogen binds histones through its D-domain with high affinity (calf thymus histones, KD = 18.0 ± 5.6 nM; histone 3, KD = 2.7 ± 0.8 nM; and histone 4, KD = 2.0 ± 0.7 nM) and significantly reduces histone-induced endothelial damage and platelet aggregation in vitro and in vivo in a histone-infusion mouse model. Physiologic concentrations of fibrinogen can neutralize low levels of circulating histones and increase the cytotoxicity threshold of histones to 50 μg/mL. In a cohort of patients requiring intensive care, a histone:fibrinogen ratio of ≥6 on admission was associated with moderate-severe thrombocytopenia and independently predicted mortality. This finding was validated in a cohort of hospitalized patients with COVID-19.

CONCLUSION

Fibrinogen buffers the cytotoxic properties of circulating histones. Detection and monitoring of circulating histones and histone:fibrinogen ratios will help identify critically ill patients at highest risk of adverse outcomes who might benefit from antihistone therapy.

Influence of titanium nanoscale surface roughness on fibrinogen and albumin protein adsorption kinetics and platelet responses

Biomaterials with nanoscale topography have been increasingly investigated for medical device applications to improve tissue-material interactions. This study assessed the impact of nanoengineered titanium surface domain sizes on early biological responses that can significantly affect tissue interactions. Nanostructured titanium coatings with distinct nanoscale surface roughness were deposited on quartz crystal microbalance with dissipation (QCM-D) sensors by physical vapor deposition. Physico-chemical characterization was conducted to assess nanoscale surface roughness, nano-topographical morphology, wettability, and atomic composition. The results demonstrated increased projected surface area and hydrophilicity with increasing nanoscale surface roughness. The adsorption properties of albumin and fibrinogen, two major plasma proteins that readily encounter implanted surfaces, on the nanostructured surfaces were measured using QCM-D. Significant differences in the amounts and viscoelastic properties of adsorbed proteins were observed, dependent on the surface roughness, protein type, protein concentration, and protein binding affinity. The impact of protein adsorption on subsequent biological responses was also examined using qualitative and quantitative in vitro evaluation of human platelet adhesion, aggregation, and activation. Qualitative platelet morphology assessment indicated increased platelet activation/aggregation on titanium surfaces with increased roughness. These data suggest that nanoscale differences in titanium surface roughness influence biological responses that may affect implant integration.

Reciprocal stabilization of coagulation factor XIII-A and -B subunits is a determinant of plasma FXIII concentration

ABSTRACT

Transglutaminase factor XIII (FXIII) is essential for hemostasis, wound healing, and pregnancy maintenance. Plasma FXIII is composed of A and B subunit dimers synthesized in cells of hematopoietic origin and hepatocytes, respectively. The subunits associate tightly in circulation as FXIII-A2B2. FXIII-B2 stabilizes the (pro)active site-containing FXIII-A subunits. Interestingly, people with genetic FXIII-A deficiency have decreased FXIII-B2, and therapeutic infusion of recombinant FXIII-A2 (rFXIII-A2) increases FXIII-B2, suggesting FXIII-A regulates FXIII-B secretion, production, and/or clearance. We analyzed humans and mice with genetic FXIII-A deficiency and developed a mouse model of rFXIII-A2 infusion to define mechanisms mediating plasma FXIII-B levels. Like humans with FXIII-A deficiency, mice with genetic FXIII-A deficiency had reduced circulating FXIII-B2, and infusion of FXIII-A2 increased FXIII-B2. FXIII-A-deficient mice had normal hepatic function and did not store FXIII-B in liver, indicating FXIII-A does not mediate FXIII-B secretion. Transcriptional analysis and polysome profiling indicated similar F13b levels and ribosome occupancy in FXIII-A-sufficient and -deficient mice and in FXIII-A-deficient mice infused with rFXIII-A2, indicating FXIII-A does not induce de novo FXIII-B synthesis. Unexpectedly, pharmacokinetic/pharmacodynamic modeling of FXIII-B antigen after rFXIII-A2 infusion in humans and mice suggested FXIII-A2 slows FXIII-B2 loss from plasma. Accordingly, comparison of free FXIII-B2 vs FXIII-A2-complexed FXIII-B2 (FXIII-A2B2) infused into mice revealed faster clearance of free FXIII-B2. These data show FXIII-A2 prevents FXIII-B2 loss from circulation and establish the mechanism underlying FXIII-B2 behavior in FXIII-A deficiency and during rFXIII-A2 therapy. Our findings reveal a unique, reciprocal relationship between independently synthesized subunits that mediate an essential hemostatic protein in circulation. This trial was registered at www.ClinicalTrials.com as #NCT00978380.

The nature and timing of coagulation dysfunction in a cohort of trauma patients in the Australian pre-hospital setting

BACKGROUND

Acute Traumatic Coagulopathy (ATC) is a complex pathological process that is associated with patient mortality and increased blood transfusion requirements. It is evident on hospital arrival, but there is a paucity of information about the nature of ATC and the characteristics of patients that develop ATC in the pre-hospital setting. The objective of this study was to describe the nature and timing of coagulation dysfunction in a cohort of injured patients and to report on patient and pre-hospital factors associated with the development of ATC in the field.

METHODS

This was a prospective observational study of a convenience sample of trauma patients. Patients had blood taken during the pre-hospital phase of care and evaluated for derangements in Conventional Coagulation Assays (CCA) and Rotational Thromboelastometry (ROTEM). Associations between coagulation derangement and pre-hospital factors and patient outcomes were evaluated.

RESULTS

A total of 216 patients who had either a complete CCA or ROTEM were included in the analysis. One hundred and eighty (83 %) of patients were male, with a median injury severity score of 17 [interquartile range (IQR) 10-27] and median age of 34 years [IQR = 25.0-52.0]. Hypofibrinogenemia was the predominant abnormality seen, (CCA Hypofibrinogenemia: 51/193, 26 %; ROTEM hypofibrinogenemia: 65/204, 32 %). Increased CCA derangement, the presence of ROTEM coagulopathy, worsening INR, worsening FibTEM and decreasing fibrinogen concentration, were all associated with both mortality and early massive transfusion.

CONCLUSION

Clinically significant, multifaceted coagulopathy develops early in the clinical course, with hypofibrinogenemia being the predominant coagulopathy. In keeping with the ED literature, pre-hospital coagulation dysfunction was associated with mortality and early massive transfusion. Further work is required to identify strategies to identify and guide the pre-hospital management of the coagulation dysfunction seen in trauma.

Development of biosensors for detection of fibrinogen: a review

Fibrinogen as a major inflammation marker and blood coagulation factor has a direct impact on the health of humanity. The variations in fibrinogen content lead to risky conditions such as bleeding and cardiovascular diseases. So, accurate methods for monitoring of this glycoprotein are of high importance. The conventional methods, such as the Clauss method, are time consuming and require highly specialized expert analysts. The development of fast, simple, easy to use, and inexpensive methods is highly desired. In this way, biosensors have gained outstanding attention since they offer means for performing analyses at the points-of-care using self-testing devices, which can be applied outside of clinical laboratories or hospital. This review indicates that different electrochemical and optical sensors have been successfully implemented for the detection of fibrinogen under normal levels of fibrinogen in plasma. The biosensors for the detection of fibrinogen have been designed based on the quartz crystal microbalance, field-effect transistor, electrochemical impedance spectroscopy, amperometry, surface plasmon resonance, localized surface plasmon resonance, and colorimetric techniques. Also, this review demonstrates the utility of the application of nanoparticles in different detection techniques.

SIRT2 counteracts primate cardiac aging via deacetylation of STAT3 that silences CDKN2B

Aging is a major risk factor contributing to pathophysiological changes in the heart, yet its intrinsic mechanisms have been largely unexplored in primates. In this study, we investigated the hypertrophic and senescence phenotypes in the hearts of aged cynomolgus monkeys as well as the transcriptomic and proteomic landscapes of young and aged primate hearts. SIRT2 was identified as a key protein decreased in aged monkey hearts, and engineered SIRT2 deficiency in human pluripotent stem cell-derived cardiomyocytes recapitulated key senescence features of primate heart aging. Further investigations revealed that loss of SIRT2 in human cardiomyocytes led to the hyperacetylation of STAT3, which transcriptionally activated CDKN2B and, in turn, triggered cardiomyocyte degeneration. Intra-myocardial injection of lentiviruses expressing SIRT2 ameliorated age-related cardiac dysfunction in mice. Taken together, our study provides valuable resources for decoding primate cardiac aging and identifies the SIRT2-STAT3-CDKN2B regulatory axis as a potential therapeutic target against human cardiac aging and aging-related cardiovascular diseases.

Treatment of Congenital Afibrinogenemia in a Neonate With Critical Pulmonary Stenosis

Fibrinogen deficiencies in neonates can lead to bleeding complications. In this report, we describe a case of congenital afibrinogenemia in a newborn with critical pulmonary stenosis who presented with bilateral cephalohematomas after an uncomplicated delivery. The initial use of cryoprecipitate was followed by administration of fibrinogen concentrate. We estimated a half-life of 24 to 48 hours with the concentrate product. This patient received fibrinogen replacement and had a subsequent successful cardiac repair. The drug's shorter half-life in this neonate contrasts with prior reports of longer half-life in older patients and is important to note in treating future neonatal patients with this diagnosis.

Fibrinogen is an independent preoperative predictor of hospital length of stay among patients undergoing coronary artery bypass grafting

OBJECTIVE

This study aims to examine the impact of preoperative fibrinogen concentration on the short-term outcomes and hospital length of stay (LOS) of patients undergoing Coronary Artery Bypass Grafting (CABG).

METHODS

Between January 2010 and June 2022, a retrospective analysis comprised 633 patients who sequentially received isolated, primary CABG. These patients were categorized into normal fibrinogen group (fibrinogen < 3.5 g/L) and high fibrinogen group (fibrinogen ≥ 3.5 g/L) according to preoperative fibrinogen concentration. The primary outcome was LOS. To correct for confounding and investigate the effect of preoperative fibrinogen concentration on the short-term outcomes and LOS, we employed propensity score matching (PSM). The correlation between fibriongen concentration and LOS in subgroups was examined using subgroup analysis.

RESULTS

We categorized 344 and 289 patients in the "normal fibrinogen group" and "high fibrinogen group", respectively. After PSM, compared to the normal fibrinogen group, the high fibrinogen group had a longer LOS [12.00 (9.00-15.00) vs. 13.00 (10.00-16.00), P = 0.028] and higher incidence of postoperative renal impairment [49 (22.1%) vs. 72 (32.4%), P = 0.014]. Cardiopulmonary bypass (CPB) or non-CPB CABG patients showed similar correlations between various fibrinogen concentrations and LOS, according to subgroup analyses.

CONCLUSIONS

Fibrinogen is an independent preoperative predictor of both the LOS and the postoperative renal impairment that occurs after CABG. Patients with high preoperative fibrinogen concentration had a higher incidence of postoperative renal impairment and a longer LOS, emphasizing the significance of preoperative fibrinogen management.

Preoperative fibrinogen/CRP score predicts survival in upper urothelial tract carcinoma patients undergoing radical curative surgery

PURPOSE

Upper tract urothelial carcinoma (UTUC) represents an often aggressive malignancy associated with poor prognosis. Therefore, finding reliable prognostic biomarkers in patients undergoing curative surgery for improved risk stratification is crucial. We evaluated the prognostic value of the Fibrinogen/C-reactive protein (FC)-score in a cohort of surgically treated UTUC patients.

METHODS

170 patients with radiologically and histologically verified UTUC who underwent radical curative surgery between 1990 and 2020, were included. The FC-score was calculated for each patient, with patients receiving 1 point each if Fibrinogen and/or CRP levels were elevated above the 25th or 75th percentile, respectively. Patients were divided into three subgroups according to their FC-score of 0, 1 or 2 point(s). Kaplan-Meier analysis, uni- and multivariable Cox proportional hazard models were implemented. We determined cancer-specific survival (CSS) as primary endpoint, whereas overall survival (OS) and recurrence-free survival (RFS) were considered secondary endpoints.

RESULTS

High FC-score (2 points) was significantly associated with adverse histological features such as vascular invasion (OR = 4.08, 95%CI 1.18-14.15, p = .0027) and tumour necrosis (OR = 6.67, 95%CI 1.35-32.96, p = 0.020). Both, uni- and multivariable Cox proportional hazard models showed the FC-score as a significant predictor for CSS (univariable analysis: FC-score = 1: HR = 1.90, 95%CI 0.92-3.93, p = 0.085 | FC-score = 2: HR = 2.86, 95%CI 1.22-6.72, p = 0.016). Furthermore, in univariable analysis, patients with higher FC-score had significantly shorter OS (FC-score = 1: HR = 1.32, 95%CI 0.70-2.49, p = 0.387 | FC-score = 2: HR = 2.19, 95%CI 1.02-4.67, p = 0.043). However, this did not prevail in multivariable analysis.

CONCLUSION

The FC-score represents a novel potential biomarker in patients with UTUC undergoing radical curative surgery.

The impact of high on-treatment platelet reactivity and fibrinogen levels on ischemic events in patients with ST elevation myocardial infarction: a prospective observational study

BACKGROUND

After treatment, high residual platelet reactivity (HRPR) is considered as an essential risk factor for recurrent ischemic events.

AIM

To evaluate the impact of fibrinogen on HRPR after implantation of emergency drug-eluting stents (DES) in patients treated with aspirin and clopidogrel or ticagrelor due to ST-elevation myocardial infarction (STEMI) and to explore the predictive values of HRPR and fibrinogen for adverse ischemic events at 12 months.

METHOD

This single-center prospective observational study analyzed patients with STEMI who underwent primary percutaneous coronary intervention (PCI) with second-generation DES implantation from January 2017 to December 2018. Platelet reactivity was measured by thromboelastography (TEG) at 60-72 h after primary PCI. HRPR was defined as the adenosine diphosphate-induced maximum amplitude (MA_ADP) > 47 mm.

RESULTS

A total of 919 patients were analyzed, of which 512 (55.8%) received aspirin and clopidogrel and 406 (44.2%) received aspirin and ticagrelor. Elevated fibrinogen levels were associated with an increased prevalence of HRPR (P < 0.001). High fibrinogen (quartile IV, ≥ 410 mg/dL) was an independent risk factor for HRPR after multivariate regression (odds ratio 6.556, 95% confidence interval [CI]: 3.200-13.431, P < 0.001). When analyzed by Kaplan-Meier survival curves, the combination of high fibrinogen and HRPR was strongly predictive for ischemic major adverse cardiac events at 12 months compared to the group without HRPR and with low fibrinogen (hazard ratio 9.681, 95% CI: 4.467-20.98, log-rank P < 0.001). Similar results were confirmed in subgroups according to different dual antiplatelet therapies.

CONCLUSION

A combination of high fibrinogen and HRPR may identify recurrent adverse ischemic events over 12 months. Ticagrelor exhibited more potent platelet inhibition and a better prognosis than clopidogrel.

Haemostasis and Inflammatory Parameters as Potential Diagnostic Biomarkers for VTE in Trauma-Immobilized Patients

Venous thromboembolism (VTE), which encompasses deep venous thrombosis (DVT) and pulmonary embolism (PE), is a major public health concern due to its high incidences of morbidity and mortality. Patients who have experienced trauma with prolonged immobilization are at an increased risk of developing VTE. Plasma D-dimer levels have been known to be elevated in trauma patients, and they were closely correlated with the number of fractures. In other words, plasma D-dimer levels cannot be used as the only indicator of VTE in trauma cases. Given the limitations, further study is needed to explore other potential biomarkers for diagnosing VTE. To date, various established and novel VTE biomarkers have been studied in terms of their potential for predicting VTE, diagnostic performance, and improving clinical therapy for VTE. Therefore, this review aims to provide information regarding classic and essential haemostasis (including prothrombin time (PT), activated partial thromboplastin time (aPTT), D-dimer, fibrinogen, thrombin generation, protein C, protein S, antithrombin, tissue factor pathway inhibitor, and platelet count) and inflammatory biomarkers (C-reactive protein, erythrocyte sedimentation rate, and soluble P-selectin) as potential diagnostic biomarkers that can predict the risk of VTE development among trauma patients with prolonged immobilization. Thus, further advancement in risk stratification using these biomarkers would allow for a better diagnosis of patients with VTE, especially in areas with limited resources.

Combining serum peptide signatures with International Federation of Gynecology and Obstetrics (FIGO) risk score to predict the outcomes of patients with gestational trophoblastic neoplasia (GTN) after first-line chemotherapy

Background

Gestational trophoblastic neoplasia (GTN) is a group of clinically rare tumors that develop in the uterus from placental tissue. Currently, its satisfactory curability derives from the timely and accurately classification and refined management for patients. This study aimed to discover biomarkers that could predict the outcomes of GTN patients after first-line chemotherapy.

Methods

A total of 65 GTN patients were included in the study. Patients were divided into the good or poor outcome group and the clinical characteristics of the patients in the two groups were compared. Furthermore, the serum peptide profiles of all patients were uncovered by using weak cation exchange magnetic beads and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Feature peaks were identified by three machine learning algorithms and then models were constructed and compared using five machine learning methods. Additionally, liquid chromatography mass spectrometry was used to identify the feature peptides.

Results

Multivariate logistic regression analysis showed that the International Federation of Gynecology and Obstetrics (FIGO) risk score was associated with poor outcomes. Eight feature peaks (m/z =1287, 2042, 2862, 2932, 2950, 3240, 3277 and 6626) were selected for model construction and validation by the three algorithms. Based on the panel combining FIGO risk score and peptide serum signatures, the neural network (nnet) model showed promising performance in both the training (AUC=0.9635) and validation (AUC=0.8788) cohorts. Peaks at m/z 2042, 2862, 2932, 3240 were identified as the partial sequences of transthyretin, fibrinogen alpha chain (FGA), beta-globin and FGA, respectively.

Conclusion

We combined FIGO risk score and serum peptide signatures using the nnet method to construct the model which can accurately predict outcome of GTN patients after first-line chemotherapy. With this model, patients can be further classified and managed, and those with poor predicted outcomes can be given more attention for developing treatment failure.

Examining the factors contributing to the association between non-albuminuric CKD and a low rate of kidney function decline in diabetes

BACKGROUND

Studies have shown that among people with diabetes, those with non-albuminuric chronic kidney disease (CKD) have a slower rate of reduction in renal function than do those with normal renal function. This suggests the presence of protective factors, the identification of which may open up targets for intervention. The aim of this study was to identify protective clinical factors and nonclinical biomarkers that contribute to the association between non-albuminuric CKD and the low rate of progression of CKD.

METHODS

We tested for significant associations of several clinical factors and 33 nonclinical biomarkers with (1) normoalbuminuria and (2) a low rate of CKD progression among participants with diabetes and CKD enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study in the United States. Factors significantly associated with both normoalbuminuria and a low rate of CKD progression were assessed in linear regression to estimate their potential contributions to the association between non-albuminuric CKD and rate of CKD progression.

RESULTS

Systolic blood pressure (SBP), glycated A1c (HbA1c), estimated glomerular filtration rate (eGFR) and six biomarkers [β-trace protein (BTP), kidney injury molecule (KIM-1), fibrinogen, fractalkine, brain natriuretic peptide (BNP) and high-sensitivity troponin-T (hsTnT)] were associated with both normoalbuminuria and a low rate of eGFR decline. The univariate β-coefficient for normoalbuminuria was 0.93 [95% confidence interval (CI): 0.82, 1.05]. When all associated factors and biomarkers were included, the regression coefficient decreased to 0.54 (95% CI: 0.40, 0.67). The factors that contributed to the association between non-albuminuric CKD and low rate of eGFR were lower levels of SBP, HbA1c, BTP, KIM-1, hsTnT, BNP, fibrinogen and fractalkine.

CONCLUSION

Lower levels of SBP and biomarkers that have pro-inflammatory and vascular modulating features may explain up to 40% of the association between non-albuminuric CKD and low rate of CKD progression. Further investigation of these biomarkers may lead to therapeutic interventions.

Comparison of Bleeding Risk Between Colistin-Tigecycline and Colistin-Carbapenem Treatment Regimens: A Retrospective Cohort Study

Background

Antibiotic combination is commonly used to treat multidrug-resistant pathogens. Reports have indicated that tigecycline use is associated with hypofibrinogenemia. However, whether the bleeding risk of tigecycline is higher than that of other antibiotics remains unknown. The aim of this study was to compare the bleeding risk between colistin–tigecycline and colistin–carbapenem treatment.

Methods

This retrospective cohort study enrolled adult patients treated with colistin along with tigecycline or carbapenems (doripenem, imipenem–cilastatin, or meropenem) for ˃72 hours during hospitalization. The primary outcome was major bleeding events, which were determined by a hemoglobin drop of ≥2 g/d and receipt of blood transfusions with whole blood or packed red blood cells. Multivariate logistic regression was applied to determine risk factors for bleeding events.

Results

In total, 106 and 268 patients in the colistin–tigecycline and colistin–carbapenem groups met the criteria for analysis, respectively. The two groups did not differ significantly in demographic data, except for alanine aminotransferase (ALT), serum creatinine (S_Cr) and ulcer disease. The colistin–tigecycline group had a higher ALT, S_Cr and a lower proportion of ulcer disease. Major bleeding events did not differ significantly between the colistin–tigecycline and colistin–carbapenem groups (12.26% vs 9.33%, P = 0.40). Antibiotic duration [OR = 1.06 (1.02–1.11), P=0.007)] and anticoagulant use [OR = 2.16 (1.05–4.42), P=0.04] were associated with major bleeding events.

Conclusion

Colistin–tigecycline treatment was not associated with a higher bleeding risk. Antibiotic duration and concurrent use of anticoagulant were the risk factors of bleeding events.

Prospective increases in depression symptoms and markers of inflammation increase coronary heart disease risk - The Whitehall II cohort study

OBJECTIVE

Stress, inflammation, and depression are associated to coronary heart disease (CHD). However, how these constructs collectively contribute to CHD incidence is not well understood. For the first time, this study explored the concurrent relationship between workplace stress, depression symptomology and levels of low-grade inflammation with future CHD incidence.

METHODS

Data from the 5-year intervals at phase 5, 7, and 9 of the Whitehall II study (N = 8348, M_age = 56) provided measures of workplace stress, depression symptomology, inflammation (interleukin-6, C-reactive protein, fibrinogen), and CHD incidence. The proposed stress-inflammation-depression-CHD pathway was assessed with a longitudinal design incorporating a structural equation model (SEM) that measured if changes in stress, depression, and inflammation between phase 5 to phase 7 predicted first-time CHD events between phases 7 and 9.

RESULTS

The SEM empirically supported this proposed pathway and demonstrated excellent model fit, χ (72) = 3582.959, p < .001, CFI = 0.896, RMSEA = 0.076 (CI₉₀ = 0.074, 0.079), while depression symptoms mediated the association between workplace stress and CHD incidence, B = 0.003 (CI₉₀ = 0.001, 0.004). Further, survival analysis indicated that individuals with higher mean scores (across phases) of depression symptoms or fibrinogen levels were more likely to experience a first time CHD event.

CONCLUSIONS

Increases in depression symptoms and fibrinogen levels may be good indicators of future CHD morbidity among older employees. Future research is encouraged to monitor negative affective states and the potential use of biobehavioural options to reduce depression and inflammation that may mitigate CHD risk.

Fibrinogen and Antifibrinolytic Proteins: Interactions and Future Therapeutics

Thrombus formation remains a major cause of morbidity and mortality worldwide. Current antiplatelet and anticoagulant therapies have been effective at reducing vascular events, but at the expense of increased bleeding risk. Targeting proteins that interact with fibrinogen and which are involved in hypofibrinolysis represents a more specific approach for the development of effective and safe therapeutic agents. The antifibrinolytic proteins alpha-2 antiplasmin (α2AP), thrombin activatable fibrinolysis inhibitor (TAFI), complement C3 and plasminogen activator inhibitor-2 (PAI-2), can be incorporated into the fibrin clot by FXIIIa and affect fibrinolysis by different mechanisms. Therefore, these antifibrinolytic proteins are attractive targets for the development of novel therapeutics, both for the modulation of thrombosis risk, but also for potentially improving clot instability in bleeding disorders. This review summarises the main properties of fibrinogen-bound antifibrinolytic proteins, their effect on clot lysis and association with thrombotic or bleeding conditions. The role of these proteins in therapeutic strategies targeting the fibrinolytic system for thrombotic diseases or bleeding disorders is also discussed.

Are elevated plasma fibrinogen associated with lung function? An 8-year follow-up of the ELSA study

Background

Fibrinogen is an important biomarker of inflammation, but findings from longitudinal studies that correlated fibrinogen with lung function in older adults are inconsistent.

Aim

To investigate the relationship between fibrinogen plasma levels and lung function impairment later in life.

Methods

Longitudinal analysis of 2,150 participants of the English Longitudinal Study of Ageing (ELSA) aged 50 years and older. Associations between changes in plasma fibrinogen between waves 2 (2004–05) and 4 (2008–09) and lung function in wave 6 (2012–13) were performed using multiple linear regression adjusted by potential confounders.

Results

Regarding the fibrinogen profile, 18.5% of the participants presented higher levels in both waves. In the adjusted models, the maintenance of high fibrinogen levels was associated with a significant reduction of lung function only for men. FEV₁ showed a reduction of 0.17L, FVC of 0.22L, and the percentages predicted were 5.16% for FEV₁ and 6.21% for FVC compared to those that maintained normal levels of fibrinogen.

Discussion

To the best of our knowledge, this was the first study investigating the relationship between changes in fibrinogen levels over a long follow-up period and lung function in older adults without pre-existing chronic diseases. ELSA has information on critical demographic and clinical parameters, which allowed to adjust for potential confounding factors.

Conclusion

It was found that the persistence of high levels of plasma fibrinogen in older English men, but not women, is associated with lung function decline. Therefore, plasma fibrinogen showed to be an important biomarker of pulmonary dysfunction in this population.

AIDeveloper: Deep Learning Image Classification in Life Science and Beyond

Artificial intelligence (AI)-based image analysis has increased drastically in recent years. However, all applications use individual solutions, highly specialized for a particular task. Here, an easy-to-use, adaptable, and open source software, called AIDeveloper (AID) to train neural nets (NN) for image classification without the need for programming is presented. AID provides a variety of NN-architectures, allowing to apply trained models on new data, obtain performance metrics, and export final models to different formats. AID is benchmarked on large image datasets (CIFAR-10 and Fashion-MNIST). Furthermore, models are trained to distinguish areas of differentiated stem cells in images of cell culture. A conventional blood cell count and a blood count obtained using an NN are compared, trained on >1.2 million images, and demonstrated how AID can be used for label-free classification of B- and T-cells. All models are generated by non-programmers on generic computers, allowing for an interdisciplinary use.

Exercise capacity improvement after cardiac rehabilitation following myocardial infarction and its association with long-term cardiovascular events

AIMS 

Cardiovascular rehabilitation (CR) improves aerobic capacity and quality of life in patients after myocardial infarction (MI). The aim was to examine the associations between exercise capacity improvement and different clinically relevant cardiovascular events.

METHODS AND RESULTS 

This was a registry-based study of post-MI patients, referred to CR. All patients were submitted to exercise testing before and after CR (36 sessions, 2-3 times/week, and combined exercise). Patients were divided into two groups, based on the difference in exercise capacity before and after the CR programme with the cut-off of two metabolic equivalents (METs) improvement. We assessed the correlation between the extent of exercise capacity improvement and the following cardiovascular events: major adverse cardiac events (MACE), cardiovascular-related hospitalizations, and unplanned coronary angiography. A total of 499 patients were included (mean age 56 ± 10 years, 20% women). Both groups significantly improved in terms of exercise capacity, natriuretic peptide levels, resting heart rate, and resting diastolic pressure; however, lipid status significantly improved only in patients with ≥2 METs difference in exercise capacity. A total of 13.4% patients suffered MACE (median follow-up 858 days); 21.8% were hospitalized for cardiovascular reasons (median follow-up 791 days); and 19.8% had at least one unplanned coronary angiography (median follow-up 791 days). Exercise capacity improvement of ≥2 METs was associated with lower rates of MACE, cardiovascular hospitalizations, and unplanned coronary angiography in all examined univariate and multivariate models.

CONCLUSION 

This study has shown that exercise improvement of ≥2 METs is associated with a significant decrease in MACE, cardiac hospitalizations, and unplanned coronary angiography.

COVID-19 and coagulation dysfunction in adults: A systematic review and meta-analysis

The outbreak of 2019 novel coronavirus disease (COVID‐19) has posed a grave threat to the global public health. The COVID‐19‐induced infection is closely related to coagulation dysfunction in the affected patients. This paper attempts to conduct a meta‐analysis and systematically review the blood coagulation indicators in patients with severe COVID‐19. A meta‐analysis of eligible studies was performed to compare the blood coagulation indicators in patients with severe and nonsevere COVID‐19. PubMed, Embase, Web of Science, and the Cochrane Library were searched for studies published between 1 December 2019 and 7 May 2020. A total of 13 studies with 1341 adult patients were enrolled in this analysis. Platelet (weighted mean difference [WMD] = −24.83, 95% confidence interval [CI]: −34.12 to −15.54; P < .001), d‐dimer (WMD = 0.19, 95% CI: 0.09‐0.29; P < .001), and fibrinogen (WMD = 1.02, 95% CI: 0.50‐1.54; P < .001) were significantly associated with the severity in patients with COVID‐19. The meta‐analysis revealed that no correlation was evident between an increased severity risk of COVID‐19 and activated partial thromboplastin time (WMD = −1.56, 95% CI: −5.77 to 2.64; P = .468) or prothrombin time (WMD = 0.19, 95% CI: −0.13 to 0.51; P = .243). The single arm meta‐analysis showed that compared with the nonsevere group, the severe group had a lower pooled platelet (165.12 [95% CI: 157.38‐172.85] vs 190.09 [95% CI: 179.45‐200.74]), higher d‐dimer (0.49 [95% CI: 0.33‐0.64] vs 0.27 [95% CI: 0.20‐0.34]), and higher fibrinogen (4.34 [95% CI: 1.98‐6.70] vs 3.19 [95% CI: 1.13‐5.24]). Coagulation dysfunction is closely related to the severity of patients with COVID‐19, in which low platelet, high d‐dimer, and fibrinogen upon admission may serve as risk indicators for increased aggression of the disease. These findings are of great clinical value for timely and effective treatment of the COVID‐19 cases.

Coagulation dysfunction affects the prognosis of COVID‐19 patients.

Lower platelet, higher d‐dimer and fibrinogen indicate increased severity risk in COVID‐19 patients.

No difference in PT and APTT is evident between severe and non‐severe COVID‐19 patients upon admission.

Acute-phase proteins, cortisol and haematological parameters in ewes during the periparturient period

Numerous subclinical diseases in sheep occur in the periparturient period and involve inflammatory processes; therefore, determining markers, such as acute-phase proteins (APPs), can allow an early diagnosis. Therefore, the objective of the present study was to assess changes in the plasma concentration of APPs and cortisol in clinically healthy ewes in the periparturient period for use in future studies. At the same time, haematological parameters were monitored. We showed that plasma APPs and cortisol concentrations were significantly higher in pregnant ewes than before insemination. A gradual increase in the SAA concentration was observed from the 14th day before to the day of parturition, while Hp was reduced from 2 weeks before up to 2 weeks after delivery. A significant increase in the Fb concentration was detected from the 14th day before to the 1st week after delivery. The cortisol concentration did not undergo significant changes in the periparturient period. We found an increase in the SAA and Fb concentrations and decrease in Hp in the periparturient period. The direction of the change in APPs of healthy ewes in the current study may be related to their distinct regulatory mechanisms during pregnancy. The APPs are usually altered during infection, inflammation, neoplasia, stress and trauma; therefore, knowing their reference values could help lead to an early diagnosis of subclinical forms of some diseases and pregnancy complications in ewes. The haematological analysis showed that ewes in late pregnancy and postpartum compared to dry period were under metabolic stress related to pregnancy and lactation.

Fibrin Matrices as (Injectable) Biomaterials: Formation, Clinical Use, and Molecular Engineering

This review focuses on fibrin, starting from biological mechanisms (its production from fibrinogen and its enzymatic degradation), through its use as a medical device and as a biomaterial, and finally discussing the techniques used to add biological functions and/or improve its mechanical performance through its molecular engineering. Fibrin is a material of biological (human, and even patient's own) origin, injectable, adhesive, and remodellable by cells; further, it is nature's most common choice for an in situ forming, provisional matrix. Its widespread use in the clinic and in research is therefore completely unsurprising. There are, however, areas where its biomedical performance can be improved, namely achieving a better control over mechanical properties (and possibly higher modulus), slowing down degradation or incorporating cell-instructive functions (e.g., controlled delivery of growth factors). The authors here specifically review the efforts made in the last 20 years to achieve these aims via biomimetic reactions or self-assembly, as much via formation of hybrid materials.

Cannabis Use and Markers of Systemic Inflammation: The Coronary Artery Risk Development in Young Adults Study

BACKGROUND

It is unclear whether cannabis use in humans plays a role in the regulation of inflammatory responses. This study aimed to examine cannabis-attributable immunomodulation as manifested in levels of fibrinogen, C-reactive protein (CRP), and interleukin-6 (IL-6).

METHODS

The Coronary Artery Risk Development in Young Adults (CARDIA) study is a cohort of 5115 African-American and Caucasian males and females enrolled in 1985-1986, and followed up for over 25 years, with repeated measures of cannabis use. Fibrinogen levels were measured at year 5, year 7, and year 20, CRP levels were measured at year 7, year 15, year 20, and year 25, and IL-6 levels were measured at year 20. We estimated the association of cannabis use and each biomarker using generalized estimating equations adjusting for demographic factors, tobacco cigarette smoking, alcohol drinking, and body mass index.

RESULTS

Compared with never use (reference), recent cannabis use was not associated with any of the biomarkers studied here after adjusting for potential confounding variables. Former cannabis use was inversely associated with fibrinogen levels (β = -5.4; 95% confidence interval [CI], -9.9, -0.9), whereas the associations were weaker for serum CRP (β = -0.02; 95% CI, -0.10, 0.06) and IL-6 (β = -0.06; 95% CI, -0.13, 0.02).

CONCLUSIONS

A modest inverse association between former cannabis use and fibrinogen was observed. Additional studies are needed to investigate the immunomodulatory effects of cannabis while considering different cannabis preparation and mode of use.

Changes of the coronary arteries and cardiac microvasculature with aging: Implications for translational research and clinical practice

Aging results in functional and structural changes in the cardiovascular system, translating into a progressive increase of mechanical vessel stiffness, due to a combination of changes in micro-RNA expression patterns, autophagy, arterial calcification, smooth muscle cell migration and proliferation. The two pivotal mechanisms of aging-related endothelial dysfunction are oxidative stress and inflammation, even in the absence of clinical disease. A comprehensive understanding of the aging process is emerging as a primary concern in literature, as vascular aging has recently become a target for prevention and treatment of cardiovascular disease. Change of life-style, diet, antioxidant regimens, anti-inflammatory treatments, senolytic drugs counteract the pro-aging pathways or target senescent cells modulating their detrimental effects. Such therapies aim to reduce the ineluctable burden of age and contrast aging-associated cardiovascular dysfunction. This narrative review intends to summarize the macrovascular and microvascular changes related with aging, as a better understanding of the pathways leading to arterial aging may contribute to design new mechanism-based therapeutic approaches to attenuate the features of vascular senescence and its clinical impact on the cardiovascular system.

Prognostic value of pretreatment plasma fibrinogen in patients with colorectal cancer: A systematic review and meta-analysis

BACKGROUND

Growing evidence showed that high pretreatment plasma fibrinogen could be used as a potential prognostic marker in colorectal cancer (CRC). However, the conclusions were controversial. Therefore, this meta-analysis was conducted to evaluate the prognostic value of pretreatment plasma fibrinogen in patients with CRC.

METHODS

Relevant studies were searched in the databases including PubMed, EMBASE, Web of Science, Cochrane library, and China National Knowledge Infrastructure up until December 10th, 2018. Pooled hazard ratios (HRs) with their 95% confidence intervals (CIs) were used to estimate the effects.

RESULTS

A total of 17 articles with 6863 patients were included in this meta-analysis. The results revealed that elevated pretreatment plasma fibrinogen was significantly associated with both poor overall survival (univariate analysis: HR = 1.69, 95% CI 1.47-1.95, P = .000; multivariate analysis: HR = 1.50, 95% CI 1.28-1.77, P = .000) and poor disease-free survival (univariate analysis: HR = 1.90, 95% CI 1.49-2.41, P = .000; multivariate analysis: HR = 2.08, 95% CI 1.52-2.86, P = .000) in patients with CRC.

CONCLUSIONS

High pretreatment plasma fibrinogen level is significantly associated with worse survival outcomes in CRC patients. Plasma fibrinogen may be used as an effective prognostic marker and potential therapeutic target. Further studies are required to support these results.

Polymorphisms -455G/A and -148C/T and Fibrinogen Plasmatic Level as Risk Markers of Coronary Disease and Major Adverse Cardiovascular Events

Some polymorphisms in genes codifying for fibrinogen have been correlated with plasma levels of this protein, and several studies reported their associations with acute cardiovascular events. In the present study, 118 subjects with unstable and stable coronary diseases were enrolled to determinate the associations among fibrinogen gene polymorphisms, plasma fibrinogen levels, and major cardiovascular adverse events in a sample of southwestern Mexico. The groups, including 81 control subjects, were matched for age, sex, body mass index, and sedentarism. Plasma fibrinogen levels and the polymorphisms 455G/A, -148C/T, +1689T/G, and Bcl I of the gene of fibrinogen were compared in all groups. Plasma fibrinogen levels (>465 mg/dl) were significant in patients with coronary disease. Fibrinogen plasma values > 450 mg/dl were associated with cardiovascular mortality during the follow-up analysis of the unstable coronary disease group (p = 0.04). The allelic loads of -455A and -148T were associated with plasma fibrinogen levels > 450 mg/dl (p < 0.003 and p = 0.03, respectively) and with coronary disease (p = 0.016 and p < 0.006, respectively). The follow-up of posterior events after an acute coronary event showed that the genetic load of the -148T allele was associated with major adverse cardiovascular events (RR = 1.8, 95%CI = 1.01‐3.35, p = 0.04). Fibrinogen plasmatic levels > 450 mg/dl and the fibrinogen polymorphisms -455G/A and 148C/T had association with MACE and coronary disease. This study suggests that these gene polymorphisms are associated with cardiovascular risk.

Metabolic syndrome is an inflammatory disorder: A conspiracy between adipose tissue and phagocytes

Metabolic syndrome (MetS) describes a cluster of cardio-metabolic factors that predispose to type 2 diabetes mellitus (T2DM) and atherosclerotic cardiovascular disease (ASCVD). While 35% of Americans suffer from this disorder, the specific pathways related to this disease are largely underexplored. The prevailing consensus is that inflammatory pathways contribute to the pathogenesis of this disease, and therefore new research has uncovered how inflammation plays a critical role in the development and progression of MetS. The purpose of this review is to understand the role of major inflammatory mechanisms and their role in MetS. Our review identifies that adipose tissue (AT) contributes to the inflammatory pathways through the release of pro-inflammatory adipokines such as leptin and chemerin and dysregulation of anti-inflammatory adiponectin. Chemokines and cytokines deriving from monocytes are also altered and promote inflammation and insulin resistance. Circulating inflammatory biomarkers including C-reactive protein (CRP), fibrinogen, Serum amyloid A (SAA), cytokines, and chemokines have also been linked to the pathogenesis of MetS. Researchers have identified the significance of CRP levels in predicting future sequelae of MetS such as ASCVD. Mast cells in subcutaneous adipose tissue (SAT) promote both inflammation and fibrosis. Thus, both AT and phagocyte activity define MetS as an inflammatory disorder.

Carbon monoxide releasing molecule enhances coagulation and decreases fibrinolysis in canine plasma exposed to Crotalus viridis venom in vitro and in vivo

Carbon monoxide releasing molecule-2 (CORM-2), an emerging therapeutic in human medicine, enhances plasmatic coagulation and attenuates fibrinolysis in vitro in human, rabbit and horse plasma and ameliorates hypocoagulation and hyperfibrinolysis secondary to venom exposure in human plasma in vitro. Fibrinogenases in rattlesnake venom cause decreased clot strength, and in the presence of tissue plasminogen activator (tPA) in vitro, a markedly increased rate of clot lysis. CO interacts with a haem group on fibrinogen, changing its configuration so that the fibrin clot is strengthened and more resistant to fibrinolysis. We hypothesized that CORM-2 enhances coagulation and attenuates fibrinolysis in canine plasma exposed to C viridis venom. We measured the effects of C viridis venom on clot strength, rates of coagulation and fibrinolysis in both pooled canine plasma and plasma from individual naturally envenomed dogs, with and without CORM-2, using thromboelastography (TEG). We tested venom effects on coagulation using tissue factor (TF) activated TEG and on both coagulation and fibrinolysis using TF-activated TEG with added tPA. We found that 17.9 µg/mL of venom causes a mean 26.4% decrease in clot strength, a 61.8% decrease in maximum rate of thrombus generation, 75% faster clot lysis, a 226% increase in maximum rate of lysis and a 92% decrease in total clot life span (CLS). CORM-2 ameliorated these effects, increasing CLS in the presence of venom by 603%. Additionally, we showed that CORM-2 has similar effects in vitro on plasma from naturally envenomed dogs, showing promise as an adjunct therapy for snake envenomation.

Mendelian randomization evaluation of causal effects of fibrinogen on incident coronary heart disease

BACKGROUND

Fibrinogen is an essential hemostatic factor and cardiovascular disease risk factor. Early attempts at evaluating the causal effect of fibrinogen on coronary heart disease (CHD) and myocardial infraction (MI) using Mendelian randomization (MR) used single variant approaches, and did not take advantage of recent genome-wide association studies (GWAS) or multi-variant, pleiotropy robust MR methodologies.

METHODS AND FINDINGS

We evaluated evidence for a causal effect of fibrinogen on both CHD and MI using MR. We used both an allele score approach and pleiotropy robust MR models. The allele score was composed of 38 fibrinogen-associated variants from recent GWAS. Initial analyses using the allele score used a meta-analysis of 11 European-ancestry prospective cohorts, free of CHD and MI at baseline, to examine incidence CHD and MI. We also applied 2 sample MR methods with data from a prevalent CHD and MI GWAS. Results are given in terms of the hazard ratio (HR) or odds ratio (OR), depending on the study design, and associated 95% confidence interval (CI). In single variant analyses no causal effect of fibrinogen on CHD or MI was observed. In multi-variant analyses using incidence CHD cases and the allele score approach, the estimated causal effect (HR) of a 1 g/L higher fibrinogen concentration was 1.62 (CI = 1.12, 2.36) when using incident cases and the allele score approach. In 2 sample MR analyses that accounted for pleiotropy, the causal estimate (OR) was reduced to 1.18 (CI = 0.98, 1.42) and 1.09 (CI = 0.89, 1.33) in the 2 most precise (smallest CI) models, out of 4 models evaluated. In the 2 sample MR analyses for MI, there was only very weak evidence of a causal effect in only 1 out of 4 models.

CONCLUSIONS

A small causal effect of fibrinogen on CHD is observed using multi-variant MR approaches which account for pleiotropy, but not single variant MR approaches. Taken together, results indicate that even with large sample sizes and multi-variant approaches MR analyses still cannot exclude the null when estimating the causal effect of fibrinogen on CHD, but that any potential causal effect is likely to be much smaller than observed in epidemiological studies.

Correlation of plasma coagulation tests and fibrinogenClauss with rotational thromboelastometry parameters and prediction of bleeding in dogs

Background

Correlation of plasma fibrinogen concentration (fibrinogen_Clauss) with rotational thromboelastometry (ROTEM) parameters has not been investigated in dogs.

Objectives

To determine the correlation between plasma coagulation tests and fibrinogen_Clauss with ROTEM parameters and to evaluate their ability to predict bleeding in dogs.

Animals

Ninety‐seven dogs with concurrent determination of fibrinogen_Clauss and fibrin polymerization test (FIBTEM) analysis.

Methods

Signalment, pretreatment, clinical signs of bleeding, fibrinogen_Clauss, plasma coagulation test results, hematocrit, platelet count, FIBTEM, extrinsic (EXTEM) and intrinsic (INTEM) activated ROTEM assays were retrieved retrospectively. Correlations between fibrinogen_Clauss and FIBTEM maximum clot firmness (MCF_FIBTEM) and between prothrombin time (PT) or activated partial thromboplastin time (aPTT) and ROTEM parameters were determined. Dogs were further assigned to groups with or without clinical signs of bleeding. The prognostic significance of significantly different parameters to predict bleeding was evaluated.

Results

Fibrinogen_Clauss showed strong correlation with MCF_FIBTEM (r = 0.860, n = 97, P < .001). PT showed strong correlation with EXTEM clotting time (CT_EXTEM) (r = 0.839, n = 53, P < .001), and aPTT was strongly correlated with INTEM CT (CT_INTEM) (r = 0.664, n = 31, P < .001). Platelet count, PT/aPTT, EXTEM clot formation time (CFT_EXTEM), MCF_EXTEM, EXTEM maximum clot elasticity (MCE_EXTEM), and CT_INTEM were significantly different between groups. A CT_INTEM >149 seconds was 100% sensitive to detect bleeding.

Conclusions and Clinical Importance

The MCF_FIBTEM can be used to evaluate the effect of fibrinogen on hemostasis as an alternative to determination of fibrinogen_Clauss. In addition, CT_EXTEM and CT_INTEM are strongly correlated with PT and aPTT, respectively.

Effect of non-surgical periodontal therapy on the fibrinogen levels in chronic periodontitis patients

Objective

This study aimed to evaluate the effect of non-surgical periodontal therapy on the fibrinogen levels in chronic periodontitis patients when compared to the levels seen in healthy subjects.

Materials and methods

A total of 30 subjects, with an average age of 38 ± 25 years, were enrolled in the present study. They were divided into two groups, namely Group 1 (15 periodontally healthy subjects) and Group 2 (15 moderate to severe chronic periodontitis patients). The periodontal condition of each periodontitis patient was assessed by recording the probing pocket depth (PD), clinical attachment level (CAL), plaque index (PI), and bleeding index (BI) both before and after periodontal therapy had been administered for one month. Additionally, blood samples were collected from the healthy subjects and the periodontitis patients before and after the periodontal treatment in order to assay the plasma fibrinogen levels.

Results

The clinical parameters were found to be improved after one month of periodontal therapy, with the statistical difference in the mean values of the BI and PD being highly significant (P < 0.01), while the statistical differences concerning the PI and CAL were significant (P < 0.05). The fibrinogen levels (mg/dL) for the periodontitis patients before and after treatment were 342.26 ± 69.00 and 352.93 ± 64.3 mg/dL, respectively. The level was 269.85 ± 43.68 mg/dL for the healthy subjects. In terms of the between-group comparison, the fibrinogen levels of the healthy subjects were observed to be highly significantly lower than the levels of the periodontitis patients before and after the treatment (P < 0.01), in contrast the statistical analysis showed a non-significant difference in the fibrinogen levels (P > 0.05) before and after the periodontal treatment. In addition, the statistical analysis revealed non-significant correlation between the fibrinogen levels and all the periodontal parameters (P > 0.05).

Conclusion

The non-surgical periodontal therapy proved to be effective in improving the clinical periodontal condition of the periodontitis patients, while the plasma fibrinogen levels were not found to be influenced by the periodontal therapy. Further studies are needed to evaluate the fibrinogen levels over a longer duration after periodontal treatment in patients following a periodontal maintenance program.

Inflammation, adiposity, and progression of arterial stiffness in adolescents with type 1 diabetes: The SEARCH CVD Study

AIMS

We examined the association between inflammation and progression of arterial stiffness in a population of youth with type 1 diabetes (T1D).

METHODS

A total of 287 youth with T1D (median age 13 years) from SEARCH CVD, an ancillary study to the SEARCH for Diabetes in Youth, were included. Markers of inflammation (CRP, IL-6, fibrinogen, leptin, and adiponectin) and measures of pulse wave velocity (PWV) of the arm (PWV-R), trunk (PWV-T), and lower extremity (PWV-LE) were measured at baseline. Measures of PWV were repeated approximately five years later.

RESULTS

PWV-R (0.50 m/s), PWV-T (0.65 m/s), and PWV-LE (1.0 m/s) significantly increased over the follow-up (p < 0.001 for each). A significant interaction was found between waist circumference and fibrinogen (p = 0.036) on the progression of PWV-T, suggesting that fibrinogen is more strongly associated with PWV progression in lean participants.

CONCLUSIONS

Improved understanding of adiposity, inflammation, and functional changes in the vascular system in patients with T1D is crucial.

DNA methylation age is associated with an altered hemostatic profile in a multiethnic meta-analysis

Many hemostatic factors are associated with age and age-related diseases; however, much remains unknown about the biological mechanisms linking aging and hemostatic factors. DNA methylation is a novel means by which to assess epigenetic aging, which is a measure of age and the aging processes as determined by altered epigenetic states. We used a meta-analysis approach to examine the association between measures of epigenetic aging and hemostatic factors, as well as a clotting time measure. For fibrinogen, we performed European and African ancestry-specific meta-analyses which were then combined via a random effects meta-analysis. For all other measures we could not estimate ancestry-specific effects and used a single fixed effects meta-analysis. We found that 1-year higher extrinsic epigenetic age as compared with chronological age was associated with higher fibrinogen (0.004 g/L/y; 95% confidence interval, 0.001-0.007; P = .01) and plasminogen activator inhibitor 1 (PAI-1; 0.13 U/mL/y; 95% confidence interval, 0.07-0.20; P = 6.6 × 10-5) concentrations, as well as lower activated partial thromboplastin time, a measure of clotting time. We replicated PAI-1 associations using an independent cohort. To further elucidate potential functional mechanisms, we associated epigenetic aging with expression levels of the PAI-1 protein encoding gene (SERPINE1) and the 3 fibrinogen subunit-encoding genes (FGA, FGG, and FGB) in both peripheral blood and aorta intima-media samples. We observed associations between accelerated epigenetic aging and transcription of FGG in both tissues. Collectively, our results indicate that accelerated epigenetic aging is associated with a procoagulation hemostatic profile, and that epigenetic aging may regulate hemostasis in part via gene transcription.

The 95RGD97 sequence on the Aα chain of fibrinogen is essential for binding to its erythrocyte receptor

Background

Erythrocyte aggregation, a cardiovascular risk factor, is increased by high plasma fibrinogen levels. Here, the effect of different fibrinogen mutations on binding to its human erythrocyte receptor was assessed in order to identify the interaction sites.

Methods

Three fibrinogen variants were tested, specifically mutated in their putative integrin recognition sites on the Aα chain (mutants D97E, D574E and D97E/D574E) and compared with wild-type fibrinogen.

Results

Atomic force microscopy-based force spectroscopy measurements showed a significant decrease both on the fibrinogen-erythrocyte binding force and on its frequency for fibrinogen with the D97E mutation, indicating that the corresponding arginine-glycine-aspartate sequence (residues 95-97) is involved in this interaction, and supporting that the fibrinogen receptor on erythrocytes has a β₃ subunit. Changes in the fibrin clot network structure obtained with the D97E mutant were observed by scanning electron microscopy.

Conclusion

These findings may lead to innovative perspectives on the development of new therapeutic approaches to overcome the risks of fibrinogen-driven erythrocyte hyperaggregation.

Buprenorphine Analgesia Leads to Coagulopathy and Increased Plasma Fibrinogen in Healthy Rats: Implications For Small Animal Research

INTRODUCTION

Buprenorphine is the recommended analgesic for post-surgical pain and associated stress in small animal research. Our aim was to examine the effect of isoflurane anesthesia and buprenorphine analgesia on blood coagulation in the rat using rotational thromboelastometry.

METHODS

Adult male Sprague Dawley rats were randomly assigned to one of four groups (n = 6): baseline (Thiobarb anesthesia), 5% isoflurane anesthesia, isoflurane-buprenorphine (0.05-mg/kg s.c.), and buprenorphine alone. After 1 h, animals were anesthetized and blood was sampled.

RESULTS

We report that isoflurane or buprenorphine had little or no effects on clotting times, clot formation, or clot lysis in EXTEM or INTEM. However, buprenorphine significantly increased FIBTEM alpha-angle, clot formation rates, and maximum clot formation velocities. Buprenorphine also increased EXTEM, FIBTEM, and INTEM A10 (clot strength), maximum clot firmness (clot quality), and maximum clot elasticity ( (clot elasticity). The combination of isoflurane and buprenorphine significantly increased clot amplitude but not to the same extent. The fibrinogen contribution to clot strength was 1.9-fold higher than baseline in the buprenorphine group, and 1.4-fold higher in the isoflurane-buprenorphine group. Plasma fibrinogen levels were 2.5-fold higher in both groups compared with the baseline value or isoflurane group (6.1 g/L vs. 2.4 g/L, P < 0.05).

CONCLUSIONS

We conclude buprenorphine analgesia significantly increased clot strength without affecting fibrinolysis, and increased plasma fibrinogen, implying that the drug increased liver fibrinogen synthesis and release. Possible implications for small animal research are discussed.

Putative salivary protein biomarkers for the diagnosis of oral lichen planus: a case-control study

BACKGROUND

Salivary protein biomarkers for screening and diagnosis of oral lichen planus (OLP) are not well-defined. The objective of this study was to identify putative protein biomarkers for OLP using proteomic approaches.

METHODS

Pooled unstimulated whole saliva was collected from five OLP patients and five healthy control participants. Saliva samples were then subjected to two-dimensional gel electrophoresis, followed by mass spectrometry to identify putative protein biomarkers. Subsequently, a subset of these putative biomarkers were validated in 24 OLP patients and 24 age-matched healthy control subjects, using an enzyme-linked immunosorbent assay (ELISA). Immunoblotting analyses were then performed in 3 pairs of age- and sex-matched OLP patients and healthy controls to confirm results from the ELISA study.

RESULTS

Thirty-one protein spots were identified, corresponding to 20 unique proteins. Notably, fibrinogen fragment D and complement component C3c exhibited increased expression in OLP patients, while cystatin SA exhibited decreased expression in OLP patients, compared with healthy control subjects. ELISA analyses indicated increased expression of fibrinogen fragment D and complement component C3c, and decreased expression of cystatin SA, in the saliva of OLP patients. Statistical differences in the expression of salivary complement C3c were observed between OLP patients and healthy control subjects. Immunoblotting analyses confirmed the results of our ELISA study.

CONCLUSION

Complement C3c, fibrinogen fragment D and cystatin SA may serve as salivary biomarkers for screening and/or diagnosis of OLP.

Computational predictions of cysteine cathepsin-mediated fibrinogen proteolysis

Fibrin clot formation is a proteolytic cascade of events with thrombin and plasmin identified as the main proteases cleaving fibrinogen precursor, and the fibrin polymer, respectively. Other proteases may be involved directly in fibrin(ogen) cleavage, clot formation, and resolution, or in the degradation of fibrin-based scaffolds emerging as useful tools for tissue engineered constructs. Here, cysteine cathepsins are investigated for their putative ability to hydrolyze fibrinogen, since they are potent proteases, first identified in lysosomal protein degradation and known to participate in extracellular proteolysis. To further explore this, we used two independent computational technqiues, molecular docking and bioinformatics sequence analysis (PACMANS), to predict potential binding interactions and sites of hydrolysis between cathepsins K, L, and S and fibrinogen. By comparing the results from these two objective, computational methods, it was determined that cathepsins K, L, and S do bind and cleave fibrinogen α, β, and γ chains at similar and unique sites. These differences were visualized experimentally by the unique cleaved fibrinogen banding patterns after incubation with each of the cathepsins, separately. In conclusion, human cysteine cathepsins K, L, and S are a new class of proteases that should be considered during fibrin(ogen) degradation studies both for disease processes where coagulation is a concern, and also in the implementation and design of bioengineered systems.

The longitudinal relation of stress during the menopausal transition to fibrinogen concentrations: results from the Study of Women's Health Across the Nation

OBJECTIVE

Life course theory suggests that exposures during critical or sensitive periods have particularly profound effects on health. Most research on this subject has focused on the occurrence of such windows early in life. We investigated whether perimenopause, a period of dramatic neuroendocrine changes at midlife, represents a sensitive period for response to stress by evaluating the relation of perceived stress to fibrinogen, a biomarker for inflammation.

METHODS

The study sample was composed of participants in the Study of Women's Health Across the Nation, a longitudinal study on women's health during the menopausal transition (n = 3,287). We fitted linear mixed effects models to estimate the longitudinal relationship between stress and menopausal stage and the association between stress and fibrinogen over the menopausal transition.

RESULTS

Women in early and late perimenopause reported perceiving higher levels of stress than premenopausal women (P < 0.05), adjusted for confounding variables. This increased perception of stress during perimenopause, however, was unrelated to changes in fibrinogen.

CONCLUSIONS

Although neuroendocrine changes during the menopausal transition may exacerbate the negative health effects of stress, the findings of this study do not suggest such interaction, as measured by changes in fibrinogen. The significant association observed between perceived stress and menopause status, however, may still have important implications, given prior literature linking perceived stress with numerous health outcomes.

Water T2 as an early, global and practical biomarker for metabolic syndrome: an observational cross-sectional study

Background

Metabolic syndrome (MetS) is a highly prevalent condition that identifies individuals at risk for type 2 diabetes mellitus and atherosclerotic cardiovascular disease. Prevention of these diseases relies on early detection and intervention in order to preserve pancreatic β-cells and arterial wall integrity. Yet, the clinical criteria for MetS are insensitive to the early-stage insulin resistance, inflammation, cholesterol and clotting factor abnormalities that characterize the progression toward type 2 diabetes and atherosclerosis. Here we report the discovery and initial characterization of an atypical new biomarker that detects these early conditions with just one measurement.

Methods

Water T₂, measured in a few minutes using benchtop nuclear magnetic resonance relaxometry, is exquisitely sensitive to metabolic shifts in the blood proteome. In an observational cross-sectional study of 72 non-diabetic human subjects, the association of plasma and serum water T₂ values with over 130 blood biomarkers was analyzed using bivariate, multivariate and logistic regression.

Results

Plasma and serum water T₂ exhibited strong bivariate correlations with markers of insulin, lipids, inflammation, coagulation and electrolyte balance. After correcting for confounders, low water T₂ values were independently and additively associated with fasting hyperinsulinemia, dyslipidemia and subclinical inflammation. Plasma water T₂ exhibited 100% sensitivity and 87% specificity for detecting early insulin resistance in normoglycemic subjects, as defined by the McAuley Index. Sixteen normoglycemic subjects with early metabolic abnormalities (22% of the study population) were identified by low water T₂ values. Thirteen of the 16 did not meet the harmonized clinical criteria for metabolic syndrome and would have been missed by conventional screening for diabetes risk. Low water T₂ values were associated with increases in the mean concentrations of 6 of the 16 most abundant acute phase proteins and lipoproteins in plasma.

Conclusions

Water T₂ detects a constellation of early abnormalities associated with metabolic syndrome, providing a global view of an individual’s metabolic health. It circumvents the pitfalls associated with fasting glucose and hemoglobin A1c and the limitations of the current clinical criteria for metabolic syndrome. Water T₂ shows promise as an early, global and practical screening tool for the identification of individuals at risk for diabetes and atherosclerosis.

Electronic supplementary material

The online version of this article (10.1186/s12967-017-1359-5) contains supplementary material, which is available to authorized users.

Serum peptidome profiling for the diagnosis of colorectal cancer: discovery and validation in two independent cohorts

Colorectal cancer (CRC) is one of the most common malignant neoplasms worldwide. Except for the existing fecal occult blood test, colonoscopy and sigmoidoscopy, no widely accepted in vitro diagnostic methods have been available. To identify potential peptide biomarkers for CRC, serum samples from a discovery cohort (100 CRC patients and 100 healthy controls) and an independent validation cohort (91 CRC patients and 91 healthy controls) were collected. Peptides were fractionated by weak cation exchange magnetic beads (MB-WCX) and analysed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Five peptides (peaks at m/z 1895.3, 2020.9, 2080.7, 2656.8 and 3238.5) were identified as candidate biomarkers for CRC. A diagnostic panel based on the five peptides can discriminate CRC patients from healthy controls, with an accuracy of 91.8%, sensitivity of 95.6%, and specificity of 87.9% in the validation cohort. Peptide peaks at m/z 1895.3, 2020.9 and 3238.5 were identified as the partial sequences of complement component 4 (C4), complement component 3 (C3) and fibrinogen α chain (FGA), respectively. This study potentiated peptidomic analysis as a promising in vitro diagnostic tool for diagnosis of CRC. The identified peptides suggest the involvement of the C3, C4 and FGA in CRC pathogenesis.