The D-dimer assay

Impact of D-Dimer on the Prognostic Value of PARIS Thrombosis Risk Score in Acute Coronary Syndrome Patients Undergoing PCI: From a Large Prospective Cohort Study

BACKGROUND

Guideline-recommended PARIS thrombotic risk score predicts coronary thrombosis events (CTE) in Acute Coronary Syndrome (ACS) patients undergoing Percutaneous Coronary Intervention. We aim to evaluate whether D-dimer, a thrombotic biomarker, can predict long-term adverse events and improve the prognostic value of PARIS score.

METHODS AND RESULTS

This is a post-hoc analysis on a prospective cohort of 10,724 Chinese patients undergoing PCI. Patients who presented as ACS were included and stratified according to baseline D-dimer level (cutoff 0.28 µg/mL). The primary endpoint is all-cause death. Secondary endpoints are cardiac death and CTE. A total of 5139 ACS patients with PCI were analyzed, 2735 patients had D-dimer ≥ 0.28 µg/mL, while 2404 patients had D-dimer < 0.28 µg/mL. After adjusting for confounders, patients with higher D-dimer had significantly higher risk of 5-year all-cause death (HR = 1.951, 95% CI: 1.366-2.787) and cardiac death (HR = 2.513, 95% CI: 1.574-4.012), whilst a trend toward higher risk of 5-year CTE (HR = 1.285, 95% CI: 0.956-1.729) was observed. Compared with PARIS score alone, adding D-dimer to the model increased the area under the receiver operating characteristic curve on 5-year all-cause death (0.663-0.701, p = 0.006) and cardiac death (0.652-0.699, p = 0.015), both with significant net reclassification improvement (p < 0.001).

CONCLUSION

In our cohort of ACS patients undergoing PCI, D-dimer independently predicts long-term all-cause death and cardiac death, and improves the predictive value of PARIS score over 5-year all-cause death and cardiac death.

Effective management of pulmonary embolism after initial diagnosis of acute coronary syndrome: a case report highlighting differential diagnosis challenges

Pulmonary embolism (PE) often presents with symptoms similar to acute coronary syndrome (ACS), making diagnosis challenging. We report a case of a 55-year-old male with hypertension, chronic kidney disease, and hyperuricemia who developed chest pain and shortness of breath. Initial evaluation suggested ACS due to electrocardiogram changes and elevated cardiac biomarkers. However, coronary angiography (CAG) showed no significant stenosis, prompting further diagnostic workup. Computed tomography pulmonary angiography (CTPA) confirmed PE, likely secondary to deep vein thrombosis (DVT) in the right lower extremity. The patient was treated with an inferior vena cava (IVC) filter and thrombus aspiration, followed by anticoagulation therapy. This case highlights the critical need to differentiate PE from ACS and emphasizes the importance of a multidisciplinary approach in managing thromboembolic events to ensure optimal patient outcomes.

Preservation of coagulation function by normothermic machine perfusion in liver transplant as evidenced by thromboelastography parameters

The use of normothermic machine perfusion (NMP) over static cold storage in liver transplantation has been shown to reduce posttransplant risks of early allograft dysfunction, primary nonfunction, and ischemic cholangiopathy, and its increasing use has played a role in the expanded utilization of marginal livers. While studies have demonstrated improved clinical outcomes using NMP over static cold storage preservation, real-time intraoperative data reflecting the quality and viability of NMP livers is limited. This retrospective, single-center study compared NMP versus static cold storage livers in first-time recipients of liver transplants through the evaluation of synthetic coagulation function as measured by thromboelastography and conventional coagulation testing. Secondarily, transfusion utilization between the 2 cohorts was reviewed. One hundred eighty-six recipients of liver transplants receiving allografts from donors after circulatory death were included in the study, of which 99 (53%) allografts were preserved in static cold storage, and 87 (47%) allografts were placed on the TransMedics Organ Care System. Study findings showed NMP livers supported with the TransMedics Organ Care System were associated with increased synthetic coagulation function and less excess fibrinolysis in the postreperfusion period compared to static cold storage livers, and that these findings were better reflected in real-time with thromboelastography monitoring versus conventional coagulation testing. Following reperfusion, there was a significant decrease in the transfusion of blood products in the NMP group compared with that in the static cold storage group. Overall, we determined that the use of intraoperative thromboelastography can provide real-time data to assess one aspect of reperfusion liver quality and viability.

Construction and validation of a predictive model for intracardiac thrombus risk in patients with dilated cardiomyopathy: a retrospective study

BACKGROUND

Systemic embolic events due to exfoliation of intracardiac thrombus (ICT) are one of the catastrophic complications of dilated cardiomyopathy (DCM). This study intended to develop a prediction model to predict the risk of ICT in patients with DCM.

METHODS

Data from 632 patients with DCM from a hospital was collected. ICT was identified based on the results of transthoracic echocardiography. Basic information, vital signs, comorbidities, and biochemical data were measured and collected from each patient. The least absolute shrinkage and selection operator (LASSO) regression was used for the final model variable screening. Four classifiers including Logistic Regression, support vector machine (SVM), Random Forest, and eXtreme Gradient Boosting (XGBoost) were used for model construction respectively. The area under of the curve (AUC) with 95% confidence interval (CI), sensitivity, specificity, and accuracy of the models were calculated to assess the predictive ability of the models.

RESULTS

Of these 632 DCM patients, 88 (13.92%) had ICT and 544 (86.08%) did not. Eleven clinical variables were selected for the construction of predictive models. The AUC of the Logistic Regression model to predict ICT probability was 0.854 (95%CI: 0.811-0.896), the SVM model was 0.769 (95%CI: 0.715-0.824), the Random Forest model was 0.917 (95%CI: 0.887-0.947), and the XGBoost model was 0.947 (95%CI: 0.924-0.969). The Delong test demonstrated that the XGBoost model had the highest AUC for predicting the ICT probability compared to other models (P < 0.05). Moreover, D-dimer, age, and atrial fibrillation contributed the most to the XGBoost model among these 11 variables.

CONCLUSION

The XGBoost model has a good predictive ability in predicting ICT risk in patients with DCM and may assist clinicians in identifying ICT risk.

Severely Ill COVID-19 Patients May Exhibit Hypercoagulability Despite Escalated Anticoagulation

Introduction: Severely ill COVID-19 patients receiving prophylactic-dose anticoagulation exhibit high rates of thrombosis and mortality. The escalation of anticoagulation also does not reduce mortality and has an uncertain impact on thrombosis rates. The reasons why escalated doses fail to outperform prophylactic doses in reducing risks of thrombosis and death in severely ill COVID-19 patients remain unclear. We hypothesized that escalated anticoagulation would not effectively prevent hypercoagulability and, consequently, would not reduce the risk of thrombosis and death in some severely ill patients. Methods: We conducted a prospective multicenter study that enrolled 3860 COVID-19 patients, including 1654 severely ill. They received different doses of low-molecular-weight or unfractionated heparin, and their blood coagulation was monitored with activated partial thromboplastin time, D-dimer, and Thrombodynamics. A primary outcome was hypercoagulability detected by Thrombodynamics. Blood samples were collected at the trough level of anticoagulation. Results: We found that escalated anticoagulation did not prevent hypercoagulability in 28.3% of severely ill patients at the trough level of the pharmacological activity. Severely ill patients with such hypercoagulability had higher levels of inflammation markers and better creatinine clearance compared to severely ill patients without it. Hypercoagulability detected by Thrombodynamics was associated with a 1.68-fold higher hazard rate for death and a 3.19-fold higher hazard rate for thrombosis. Elevated D-dimer levels were also associated with higher hazard rates for thrombosis and death, while shortened APTTs were not. The simultaneous use of Thrombodynamics and D-dimer data enhanced the accuracy for predicting thrombotic events and fatal outcomes in severely ill patients. Conclusions: Thrombodynamics reliably detects hypercoagulability in COVID-19 patients and can be used in conjunction with D-dimer to assess the risk of thrombosis and death in severely ill patients. The pharmacological effect of LMWH at the trough level might be too low to prevent thrombosis in some severely ill patients with severe inflammation and better creatinine clearance, even if escalated doses are used.

Combination of fibrosis-4 score and D-dimer: a practical approach to identify poor outcome in COVID-19

AIM

Fibrosis-4 (FIB-4) score and D-dimer (DD) have emerged as prognostic markers in coronavirus disease 2019 (COVID-19). However, precise cutoff points remain undefined, and their combined use has been scarcely studied. We aimed to analyze FIB-4 and DD performance, individually and combined, to predict outcomes among COVID-19 patients.

METHODS

From March to December 2020, hospitalized COVID-19 patients were evaluated based on clinical and laboratory tests from their first day of hospitalization. Primary outcome was inhospital mortality, and secondary outcomes included hospital stay length, ICU admission and duration, need for hemodialysis, ventilatory support, and extent of lung involvement. Optimal FIB-4 and DD cutoff points to predict mortality were established to maximize sensitivity and specificity. A sequential diagnostic strategy using both markers was subsequently evaluated.

RESULTS

Among 518 patients (61 ± 16 years, 64% men), the inhospital mortality rate was 18%. FIB-4 outperformed DD in predicting mortality (area under the receiver operating characteristic curve: 0.76 vs. 0.65, P = 0.003) and was chosen as the first step in sequential analysis. Mortality was higher in patients with FIB-4 ≥1.76 vs. FIB-4 <1.76 (26 vs. 5%, P < 0.001) and DD ≥2000 ng/ml vs. DD <2000 ng/ml (38 vs. 16%, P < 0.001). Using FIB-4 as a screening test (cutoff = 1.76, 90% sensitivity) followed by DD (cutoff = 2000 ng/ml; 90% specificity) identified a subgroup with higher mortality when compared with FIB-4 alone (48 vs. 26%, P < 0.001), missing the identification of only 2% of deaths.

CONCLUSION

Sequential use of FIB-4 and DD represents a comprehensive strategy to identify high-risk COVID-19 patients at hospital admission, potentially minimizing unnecessary DD tests in those deemed low-risk by FIB-4.

Bullous pemphigoid and hypercoagulability: a review

INTRODUCTION

Bullous pemphigoid (BP) is an autoimmune blistering disease characterized by autoantibodies against hemidesmosomal proteins in the basal membrane zone. The presence of a high incidence of thrombotic events has led to the identification of a hypercoagulable state in BP patients.

AREAS COVERED

This review highlights the interactions between coagulation and immune-inflammatory responses based on the currently available literature, as well as individual changes in characteristic coagulation parameters in BP. This review is based on publications up to August 2024 that were retrieved by a selective search in the PubMed database.

EXPERT OPINION

The hypercoagulable state and bullous pemphigoid (BP) have a reciprocally enhancing effect on each other. For clinicians, it is crucial to closely monitor the fluctuations in circulating coagulation markers among BP patients, such as D-dimer, fibrinogen, and fibrin degradation products (FDP). Furthermore, considering the interplay between coagulation and immune-inflammatory responses in BP, targeting the shared pathways in treatment strategies could be beneficial for patients who exhibit both BP and a hypercoagulable state.

Emerging Elastic Micro-Nano Materials for Diagnosis and Treatment of Thrombosis

Thrombus is a blood clot that forms in a blood vessel at the point of flaking. Thrombosis is closely associated with cardiovascular diseases caused by different sources and factors. However, the current clinical methods of thrombus diagnosis and treatment still have problems with targeting, permeability, stability, and biosafety. Therefore, in recent years, based on the development of micro/nano technology, researchers have tried to develop some new strategies for the diagnosis and treatment of thrombosis. Due to the unique structural characteristics, the micro-nano materials in physiological environments show excellent transport and delivery properties such as better in vivo circulation, longer life span, better targeting ability, and controllable cellular internalization. Especially, elasticity and stiffness are inherent mechanical properties of some well-designed micro-nano materials, which can make them better adapted to the needs of thrombosis diagnosis and treatment. Herein, this review first introduces the thrombotic microenvironment to characterize the thrombus development process. Then, to fine-tune the pathological occurrence and development of thrombosis, the role of elastic micro-nano materials for thrombus diagnosis and treatment is summarized. The properties, preparation methods, and biological fate of these materials have been discussed in detail. Following, the applications of elastic micro-nano materials in biomedical imaging, drug delivery, and therapy of thrombosis are highlighted. Last, the shortcomings and future design strategies of elastic micro-nano materials in diagnosis and treatment of clinical thrombosis are discussed. This review will provide new ideas for the use of nanotechnology in clinical diagnosis and treatment of thrombus in the future.

Integrating microfluidics, hydrogels, and 3D bioprinting for personalized vessel-on-a-chip platforms

Thrombosis, a major cause of morbidity and mortality worldwide, presents a complex challenge in cardiovascular medicine due to the intricacy of clotting mechanisms in living organisms. Traditional research approaches, including clinical studies and animal models, often yield conflicting results due to the inability to control variables in these complex systems, highlighting the need for more precise investigative tools. This review explores the evolution of in vitro thrombosis models, from conventional polydimethylsiloxane (PDMS)-based microfluidic devices to advanced hydrogel-based systems and cutting-edge 3D bioprinted vascular constructs. We discuss how these emerging technologies, particularly vessel-on-a-chip platforms, are enabling researchers to control previously unmanageable factors, thereby offering unprecedented opportunities to pinpoint specific clotting mechanisms. While PDMS-based devices offer optical transparency and fabrication ease, their inherent limitations, including non-physiological rigidity and surface properties, have driven the development of hydrogel-based systems that better mimic the extracellular matrix of blood vessels. The integration of microfluidics with biomimetic materials and tissue engineering approaches has led to the development of sophisticated models capable of simulating patient-specific vascular geometries, flow dynamics, and cellular interactions under highly controlled conditions. The advent of 3D bioprinting further enables the creation of complex, multi-layered vascular structures with precise spatial control over geometry and cellular composition. Despite significant progress, challenges remain in achieving long-term stability, incorporating immune components, and translating these models to clinical applications. By providing a comprehensive overview of current advancements and future prospects, this review aims to stimulate further innovation in thrombosis research and accelerate the development of more effective, personalized approaches to thrombosis prevention and treatment.

High preoperative D-dimer increases the risk of venous thromboembolism after gynecological tumor surgeries: a meta-analysis of cohort studies

The role of preoperative D-dimer in the prediction of postoperative venous thromboembolism (VTE) with gynecological tumor remains unclear. This meta-analysis sought to assess the association between preoperative D-dimer and the risk of VTE after gynecological tumor surgeries and to identify prognostic significance of D-dimer in the prediction of postoperative VTE. This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement. Eight electronic databases were searched for cohort studies from the date of inception to April 2024. The Newcastle-Ottawa Scale scoring tool and the Risk of Bias in Non-Randomized Studies-Intervention tool were used to assess the quality of the literature and the risk of bias in cohort studies, respectively. The relative risk and 95% CIs of the highest vs the lowest category and per milligram per liter of D-dimer were pooled relative to the VTE risk after gynecological tumor surgeries. Fifteen studies that met the criteria were included. Among these studies, D-dimer was considered as a continuous variable in 8 studies. The random-effect model results showed that the VTE risk was increased by 42% (15%-69%) per milligram per liter increase in D-dimer. Furthermore, based on the cutoff thresholds of D-dimer, 7 studies that reported the effect estimates of postoperative VTE in women with gynecological tumor by D-dimer were categorized as binary variables. Compared with the reference levels, the pooled relative risk of VTE after gynecological tumor surgeries for the higher level was 2.58 (95% CI, 1.49-4.47). Elevated preoperative D-dimer was associated with higher VTE risks after gynecological tumor surgeries.

Pulmonary embolism in children with mycoplasma pneumonia: can it be predicted?

PURPOSE

To investigate the clinical characteristics of Mycoplasma pneumoniae (MP) pneumonia (MPP) combined with pulmonary embolism (PE) in children.

METHODS

291 hospitalized pediatric cases with MPP were enrolled from January 2018 to May 2024 and divided into the PE group (141 cases) and non-PE control group (150 cases). Clinical data of both groups were analyzed and compared.

RESULTS

C-reactive protein (CRP), D-dimer, lactate dehydrogenase (LDH), and interleukin 6 (IL-6) were significantly higher in the PE group than in the non-PE control group. There were 85 males and 56 females in the PE group. The PE group has male-to-female ratio of 3: 2,and hemoptysis was observed in 11 children (7.08%), chest pain in 29 children (20.60%), and pulmonary necrosis in 89 children (63.12%). In the receiver operator curve(ROC), the areas under the curve(AUC) for D-dimer, CRP, IL-6, and LDH were 0.964, 0.690, 0.632, and 0.765, respectively. In the ROC curve, the cutoff values for D-dimer, CRP, IL-6, and LDH were 0.8 µg/ml, 24.2 mg/L, 37.8 pg/ml, and 461 U/L, respectively.

CONCLUSION

A proportion of children with MP infection combined with PE show atypical clinical symptoms. Children with MPP and elevated D-dimer levels, IL-6, CRP, erythrocyte sedimentation rate (ESR), and LDH may be prone to develop PE.

Building and Verifying a Prediction Model for Deep Vein Thrombosis Among Spinal Cord Injury Patients Undergoing Inpatient Rehabilitation

OBJECTIVE

To explore the relevant variables that contribute to deep vein thrombosis (DVT) among spinal cord injury (SCI) patients undergoing inpatient rehabilitation and to build and validate a nomogram model that predicts DVT risk.

METHODS

By convenience sampling, 558 SCI patients who were hospitalized at a tertiary-level Grade A general hospital in Anhui Province, China between January 2017 and March 2022 were chosen as the study subjects. They were split into 2 groups at random, one for training (n = 446) and the other for validation (n = 112). The ratio was 8:2. The clinical information of patients was gathered, including sociodemographic characteristics, data about disease characteristics, and examinations pertaining to laboratories. The related factors of DVT among SCI patients undergoing inpatient rehabilitation were analyzed using both univariate and multivariate logistic regression. Using the variables identified by the multivariate logistic regression analysis, we constructed a predictive nomogram model with the aid of the R software. The model's predictive accuracy for assessing the risk of DVT was validated through the use of receiver operating characteristic curves and calibration plots.

RESULTS

Prothrombin time, D-dimer, age, and Caprini score were independent related factors for DVT among SCI patients undergoing inpatient rehabilitation, according to multivariate logistic regression analysis (odds ratio > 1, P < 0.05). These 4 variables selected by the multivariate logistic regression analysis were used to build a nomogram risk model, which was found to have strong predictive capacity for predicting the risk of DVT among SCI patients undergoing inpatient rehabilitation. The nomogram model's area under the receiver operating characteristic curve in the training group and validation group was 0.793 and 0.905, and the 95% confidence intervals were 0.750∼0.837 and 0.830∼0.980, separately, indicating good discrimination of the nomogram model. A good calibration of the model was shown by the calibration curve, which was well consistent between the model's predicted probability and the actual frequency of DVT in both the training and validation groups.

CONCLUSIONS

Prothrombin time, D-dimer level, age, and Caprini score are independent related factors for DVT among SCI patients undergoing inpatient rehabilitation. According to the variables mentioned previously, a nomogram model was constructed that can accurately and easily predict DVT risk among SCI patients undergoing inpatient rehabilitation. This facilitates the early identification of high-risk groups and the timely implementation of prevention, treatment, rehabilitation, and nursing strategies by clinical medical staff.

Lower red blood cell count is a risk factor for higher D-dimer level in patients with spinal cord injury: A five year retrospective cross-sectional study

OBJECTIVES

This study aims to elucidate the relationship between red blood cell (RBC) count and D-dimer levels in patients with spinal cord injury, with the goal of identifying potential therapeutic targets for minimizing D-dimer levels.

STUDY DESIGN

An observational, retrospective, cross-sectional, single center study.

SETTING

Individuals with SCI (576 cases) admitted to a rehabilitation medicine department.

OUTCOME MEASURES

After exclusions, we divided the participants (n = 308) into two groups based on their D-dimer levels: Group 1 (≤0.5  mg/L, n = 64) and Group 2 (>0.5  mg/L, n = 244). Key variables such as deep vein thrombosis (DVT), anticoagulant therapy, pulmonary infection, injury characteristics, and hematological parameters were analyzed for their association with RBC counts and D-dimer levels.

RESULTS

DVT and anticoagulant therapy emerged as significant covariates. A comprehensive analysis identified a negative linear correlation between RBC counts and D-dimer levels, markedly more pronounced in Group 2. For every 1.00 × 1012/L increase in RBC, D-dimer levels decreased by 1.93  mg/L in Group 2, compared to a 0.02  mg/L decrease in Group 1.

CONCLUSIONS

Higher RBC counts might be associated with lower D-dimer levels in patients with SCI, especially in those with higher initial D-dimer levels. This association highlights a potential therapeutic focus on managing RBC counts to decrease D-dimer level, which may mitigate the risk of DVT formation in patients with SCI.

Can we predict bleeding at admission in Crimean-Congo hemorrhagic fever?

BACKGROUND

In Crimean-Congo hemorrhagic fever, bleeding has a significant impact on the prognosis of the disease. In our study, we aimed to identify independent risk factors for the development of bleeding in Crimean-Congo hemorrhagic fever and to contribute to the management of the disease.

METHODS

Cases with a definitive diagnosis of Crimean-Congo hemorrhagic fever were divided into two groups: those who developed bleeding and those who did not. Demographic, clinical and laboratory parameters were subjected to logistic regression analysis in terms of risk factors for bleeding development. Cut-off values for numerical variables were determined by receiver operating characteristics.

RESULTS

A total of 74 patients diagnosed with CCHF were included in the study. Bleeding occurred in at least one defined focus in 21 patients. In the multivariate logistic regression model, procalcitonin, days from symptom onset to admission, platelet count, and d-dimer were identified as independent risk factors for bleeding development. Procalcitonin had the most significant effect, with an approximately 5.3-fold increase in bleeding risk for each unit increase in its level. For discriminate bleeding, LDH and ferritin exhibited the highest sensitivity, while procalcitonin showed the highest specificity.

CONCLUSION

This study demonstrates the potential use of specific clinical and laboratory variables to predict bleeding development in CCHF patients. Procalcitonin elevation and the time from symptom onset to hospital admission have a significant effect in predicting bleeding.

Type of D-dimer assay determines the diagnostic yield of computed tomography in patients suspected for pulmonary embolism

Background

Pulmonary embolism (PE) is a life-threatening condition with high morbidity and mortality. The diagnosis of PE is challenging due to nonspecific symptoms, making reliable diagnostic tools essential. This study addresses the clinical impact of interassay variability in D-dimer measurements on the utilization and diagnostic yield of computed tomography pulmonary angiography (CTPA).

Objectives

To investigate the effect of different D-dimer assays on the decision to perform CTPA and the subsequent diagnostic yield in patients with suspected PE.

Methods

This retrospective, multicenter cohort study analyzed data from 3 teaching hospitals in the southwest region of the Netherlands, covering the years 2018, 2019, 2022, and 2023. The study included data from 40,096 clinically requested D-dimer results and 11,372 CTPA records of patients with suspected PE. The D-dimer assays used were the Roche Tina-quant and Siemens INNOVANCE.

Results

The study found significant differences in CTPA utilization and diagnostic yield based on the D-dimer assay used. In 2018 to 2019, hospitals using the Roche Tina-quant assay ordered 21% fewer CTPA scans and had a 9% higher positivity rate compared with those using the Siemens INNOVANCE assay.

Conclusion

The findings highlight the necessity for assay-specific cutoff values or, ideally, the standardization of the D-dimer assay to optimize the accuracy and efficiency of PE diagnosis. This study demonstrates that the choice of D-dimer assay significantly influences the clinical management of suspected PE, affecting both the number of CTPA scans performed and the positivity rate of these scans. Implementing assay-specific cutoff values or standardization of the D-dimer assay could reduce unnecessary CTPA scans, minimize patient exposure to radiation, and lower healthcare costs. These results advocate enhanced collaboration between clinicians and laboratory specialists to accurately interpret D-dimer results within the context of the specific assay used. Future research should validate these findings in prospective studies and explore standardized protocols that account for interassay variability.

Psittacosis Pneumonia Features, Distinguishing Characteristics, and Outcomes: A Retrospective Study

Purpose

Psittacosis is an often-neglected cause of community acquired pneumonia (CAP). The limited diagnostic methods for psittacosis pneumonia invariably result in an unfavourable prognosis. Consequently, the early detection of psittacosis pneumonia is crucial. This study aimed to analyse the characteristics, clinical features and treatments of the patients to improve early diagnosis and outcomes.

Patients and Methods

We retrospectively analyzed the clinical features and outcomes of 52 cases of psittacosis pneumonia diagnosed with next-generation sequencing (NGS) from January 2022 to August 2024 in a local tertiary hospital in China.

Results

Of the 52 patients, 18 had a clear exposure to poultry or birds. The main clinical manifestations included fever (100%, 52/52), cough (75.0%, 39/52), fatigue (57.7%, 30/352), and dyspnea (36.5%, 19/52). Significant elevations in neutrophil counts (NEUT), C-reactive protein (CRP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), D-dimer, lactate dehydrogenase (LDH), creatine kinase (CK), interleukin-6 (IL-6) and interferon-γ (IFN-γ), as well as reductions in lymphocyte (LY) and albumin (ALB) were observed. The main chest computed tomography (CT) features were consolidated. Eight patients diagnosed with severe CAP (SCAP) exhibited higher NEUT, CRP, procalcitonin (PCT), blood urea nitrogen (BUN), creatinine, D-Dimer and IL-6 levels, as well as lower oxygen index. The interval between the onset of symptoms and diagnosis was 6-34 days. C. psittaci infection was identified by metagenomic NGS (mNGS) or targeted NGS (tNGS) in all cases, and the average length of hospital stay for these patients was 9.4 days. Following the identification of the aetiology, all patients were promptly initiated on tetracycline- or fluoroquinolone-based therapy, with complete recovery observed in all cases.

Conclusion

Patients exposed to poultry should be alert to Chlamydia psittaci pneumonia. The application of NGS has improved the diagnostic accuracy of C. psittaci pneumonia, reduced unnecessary use of antibiotics, and shortened the course of disease. Patients who received tetracycline-based therapy showed a good prognosis.

Characterisation of specific responses to three models of viral antigens in immunocompetent older adults

BACKGROUND

Memory responses to the antigens that an individual encounters throughout life may vary with the intensity and duration of antigen contacts or even with changes in immune status over time. This work aims to characterise specific responses to latent CMV, seasonal influenza and novel SARS-CoV-2 infections in immunocompetent individuals over 60 years of age. Specific cellular and humoral responses were identified by IFN-γ and granzyme B release by ELISpot and antibody level measurement. T lymphocyte subpopulation phenotypes were characterised by flow cytometry.

RESULTS

Cellular and humoral responses to these viruses were detected in almost all patients. Influenza and SARS-CoV-2 cellular responses were positively correlated. There was no significant correlation between CMV and influenza or SARS-CoV-2 responses although both were consistently lower in CMV-seropositive patients. CMV responses were negatively correlated with the levels of the least differentiated subsets of T lymphocytes, and positively correlated with the most differentiated ones, contrary to what happened with the influenza responses. Nevertheless, SARS-CoV-2 cellular responses were negatively correlated with the most differentiated CD8+ T lymphocytes, while humoral responses were negatively correlated with the least differentiated T lymphocytes. Responses to the three viruses were correlated with a Th1/Th2/Th17 balance in favour of Th1.

CONCLUSIONS

The results indicate that memory responses differ depending on the durability of the antigen stimulus. Cellular responses to novel pathogens resemble those generated by seasonal but not CMV infection. Subpopulation distribution and the level of specific T lymphocytes against previous pathogens could be used as immunocompetent status biomarkers in older adults reflecting their ability to generate memory responses to new pathogens.

Association Between Left Ventricular Diastolic Dysfunction, Systemic Inflammation, and Gastrointestinal Symptoms in HIV-Positive Patients on Antiretroviral Therapy

BACKGROUND/OBJECTIVES

Despite advancements in antiretroviral therapy (ART), HIV-positive individuals face heightened risks of cardiovascular and gastrointestinal (GI) complications, often linked to persistent systemic inflammation. Left ventricular diastolic dysfunction (LVDD), prevalent in HIV patients, exacerbates this inflammatory state and may contribute to worsened GI symptoms. This study aims to explore the association between LVDD, systemic inflammation, and gastrointestinal symptoms in HIV-positive patients undergoing ART. The primary objective is to analyze how LVDD contributes to the inflammatory burden and its impact on gastrointestinal health in this population.

METHODS

This cross-sectional study included 320 participants divided into three groups: HIV-positive with LVDD (n = 80), HIV-positive without LVDD (n = 120), and HIV-negative controls (n = 120). Levels of inflammatory biomarkers-CRP, IL-6, TNF-α, fibrinogen, IL-1β, IFN-γ, and D-dimer-were measured, and GI symptoms were assessed. Echocardiographic evaluations were performed to determine LVDD presence and severity, while multivariate logistic regression identified predictors of GI complications.

RESULTS

Patients in the HIV + LVDD group exhibited significantly elevated levels of TNF-α, CRP, and D-dimer compared to other groups, correlating with higher incidences of nausea, diarrhea, and abdominal pain. TNF-α emerged as the strongest predictor of GI symptoms, underscoring its role in the pathophysiology linking cardiovascular and GI distress in this population. Persistent inflammation and coagulation abnormalities in the ART + LVDD group suggest that ART alone may not fully mitigate these complications.

CONCLUSIONS

Our findings emphasize the compounded inflammatory burden in HIV patients with LVDD, highlighting the need for integrated approaches that address both cardiovascular and GI symptoms. Anti-inflammatory therapies targeting specific biomarkers like TNF-α could improve clinical outcomes, supporting a more comprehensive strategy to managing HIV-related comorbidities beyond viral suppression.

Risk factors and incidence of central venous access device-related thrombosis in hospitalized children: a systematic review and meta-analysis

BACKGROUND

The risk factors for central venous access device-related thrombosis (CRT) in children are not fully understood. We used evidence-based medicine to find the risk factors for CRT by pooling current studies reporting risk factors of CRT, aiming to guide clinical diagnosis and treatment.

METHODS

A systematic search of PubMed, Web of Science, Embase, Cochrane Library, Scopus, CNKI, Sinomed, and Wanfang databases was conducted. RevMan 5.4 was employed for data analysis.

RESULTS

The review included 47 studies evaluating 262,587 children with CVAD placement. Qualitative synthesis and quantitative meta-analysis identified D-dimer, location of insertion, type of catheter, number of lumens, catheter indwelling time, and central line-associated bloodstream infection as the most critical risk factors for CRT. Primarily due to observational design, the quality of evidence was regarded as low certainty for these risk factors according to the GRADE approach.

CONCLUSION

Because fewer high-quality studies are available, larger sample sizes and well-designed prospective studies are still needed to clarify the risk factors affecting CRT. In the future, developing pediatric-specific CRT risk assessment tools is important. Appropriate stratified preventive strategies for CRT according to risk assessment level will help improve clinical efficiency, avoid the occurrence of CRT, and alleviate unnecessary suffering of children.

IMPACT

This is the latest systematic review of risk factors and incidence of CRT in children. A total of 47 studies involving 262,587 patients were included in our meta-analysis, according to which the pooled prevalence of CRT was 9.1%. This study identified several of the most critical risk factors affecting CRT in children, including D-dimer, insertion location, type of catheter, number of lumens, catheter indwelling time, and central line-associated bloodstream infection (CLABSI).

Comparative Analysis of Coagulation Activation in Rheumatoid Arthritis Patients Treated With TNF Inhibitors Versus JAK Inhibitors: A Longitudinal Study

OBJECTIVES

This study aims to investigate the activation of the coagulation system of RA patients and assess changes during anti-inflammatory treatment with tumor necrosis factor blockers (anti-TNF) and Janus kinase inhibitors (JAKi).

METHODS

Biomarkers for the coagulation system, including D-dimer, fibrinogen, prothrombin time, activated partial thrombin time, prothrombin fragment 1 + 2, thrombin-antithrombin complex (TAT), activated factor IX, antithrombin complex, and von Willebrand factor (vWF), were longitudinally measured in 83 RA patients treated with anti-TNF and 38 RA patients with JAKi. Data were collected at baseline, after 1, 3, and 6 months.

RESULTS

The mean age was 57 (±14) years; 76% was female. The mean DAS28-CRP was 3.6 (±1.3) for anti-TNF users and 4.1 (±1.4) for JAKi users at baseline and declined in both groups. Baseline coagulation markers levels were comparable between groups. In anti-TNF users, D-dimer and fibrinogen levels significantly declined (-0.31 mg/L, p = 0.01 and -0.71 g/L, p < 0.001, respectively), whereas TAT significantly increased after 6 months follow-up (1.46 μg/L, p = 0.03) and no effect on vWF ( p = 0.98). In JAKi users, vWF declined significantly during the 6 months follow-up (-37.41%, p < 0.001); additionally, there were reductions of D-dimer, fibrinogen, and TAT that did not reach significance (-0.17 mg/L, p = 0.59; -0.49 g/L, p = 0.12; and 0.68 μg/L, p = 0.27, respectively).

CONCLUSIONS

The prothrombotic tendency in active RA declined during effective treatment with both anti-TNF and JAKi. Altogether, the biomarkers used in this study suggest that an increased VTE risk in the first 6 months due to either treatment with anti-TNF or JAKi is unlikely.

Enhanced Hypercoagulability Using Clot Waveform Analysis in Patients with Acute Myocardial Infarction and Acute Cerebral Infarction

Background: Routine activated partial thromboplastin time (APTT) and prothrombin time (PT) measurements do not indicate hypercoagulability in patients with acute myocardial infarction (AMI) and acute cerebral infarction (ACI). Methods: Hypercoagulability in patients with AMI or ACI was evaluated using a clot waveform analysis of the APTT or a small amount of tissue factor activation assay (sTF/FIXa). In the CWA, the derivative peak time (DPT), height (DPH), width (DPW), and area the under the curve (AUC) were evaluated. Results: The APTT did not indicate hypercoagulability, but the second DPT of CWA-sTF/FIXa was significantly shorter in patients with ACI than in healthy volunteers (HVs). The first DPH values of CWA-APTT and CWA-sTF/FIXa in patients with ACI and AMI were significantly higher than in HVs. In the receiver operating characteristic (ROC) analyses of ACI or AMI vs. non-thrombosis, the AUC was >0.800 in the DPHs of CWA-APTT and CWA-sTF/FIXa. The AUC of CWA-APTT and CWA-sTF/FIXa in patients with AMI and ACI was significantly higher than in HVs. The AUC/second DPT of CWA-APTT and CWA-sTF/FIXa in patients with AMI and ACI was significantly higher than in HVs. Regarding the ROC analyses of ACI or AMI vs. HVs, the AUC of ROC was higher than 0.800 in the AUC and AUC/second DPT of CWA-APTT and CWA-sTF/FIXa. Conclusions: The AUC/second DPT of CWA-APTT and CWA-sTF/FIXa may be a useful parameter for detecting a hypercoagulable state in patients with AMI and ACI.

Prevalence and Risk Factors of Thromboembolic Events in Dermatomyositis in China: A 10-Year Retrospective Analysis

Objective

Dermatomyositis (DM) is an autoimmune disease characterized by chronic muscle inflammation and weakness. Patients with DM are at an increased risk of thromboembolic events (TEs). This study aimed to investigate the prevalence of TEs in DM and to identify the independent predictors.

Methods

A total of 543 patients hospitalized for DM within the past 10 years were analyzed retrospectively and compared with patients with DM with and without TEs for demographic, clinical, and laboratory characteristics. The independent predictors were analyzed using multivariate logistic regression analysis. The diagnostic performance was calculated by a receiver operating curve (ROC).

Results

Twenty-two (4.1%) patients with DM had TEs, including 12 (54.5%) with venous thromboembolism and 10 (45.5%) with arterial thromboembolism. Multivariate logistic regression analysis demonstrated that glucocorticoid therapy (odds ratio (OR)=0.003, 95% confidence interval (CI) 0.00-0.03, P<0.001) was a protective factor for the patients with DM developing TEs, whereas increased D-Dimer (OR=1.885, 95% CI 1.21-2.95, P=0.006) was a risk factor. The combined ROC analysis of glucocorticoid therapy and D-Dimer indicated high diagnostic values in distinguishing patients with both DM and TEs from patients without TEs, with 86.4% sensitivity, 98.9% specificity, and 0.983 area under the ROC curve (95% CI 0.962-1.000, P<0.001).

Conclusion

Patients with DM who have never received glucocorticoid therapy and have increased D-Dimer (>1.3 mg/L fibrinogen equivalent units) should be screened for TEs.

Ultrasonographic assessment of the risk of free-floating thrombus detachment in the lower extremity deep veins in patients with fracture

OBJECTIVE

To explore the ultrasonographic features and influencing factors of free-floating thrombus (FFT) detachment in the lower extremity deep veins (LEDVs) of patients with fractures.

METHODS

Clinical data of patients diagnosed with FFT in the LEDVs and implanted with an inferior vena cava filter (IVCF) in our hospital between July 2021 and August 2023 were retrospectively analysed. The patients were divided into the thrombus detachment group (the experimental group, n = 92) and the non-thrombus detachment group (the control group, n = 103) based on the presence of detached thrombus in the IVCF. The effects of thrombus echogenicity, floating degree, thrombus location, thrombin time, D-dimer and fibrinogen on thrombus shedding were analysed. The nomogram method was used to establish the model and predict the probability of delayed postoperative recovery.

RESULTS

The proportions of patients with extremely hypoechoic thrombus and medium and high floating degrees increased in the experimental group compared with those in the control group, and the differences between the two groups were statistically significant (P < 0.05). Extremely hypoechoic thrombus (P = 0.021, 95 % CI: 1.109-13.748) and high (P = 0.001, 95 % CI: 3.854-28.573) and medium floating degrees (P = 0.004, 95 % CI: 1.792-13.453) were risk factors for deep veins FFT (DV FFT) detachment. The results of receiver operating characteristic curve analysis showed that the area under the curve of the model was 0.893, with a 95 % CI of 0.856-0.937, indicating a high prediction accuracy.

CONCLUSION

Ultrasonographic parameters, including thrombus echogenicity and floating degree, are valuable in predicting DV FFT detachment in patients with traumatic fractures, providing references for IVCF implantation.

D-dimers in advanced liver cirrhosis: Useful biomarker or not?

In clinical practice, the d-dimer levels rule out venous thromboembolism and diagnose disseminated intravascular coagulation. d-dimers increase in both physiological and pathological conditions. Liver cirrhosis, especially in the final stages, is characterized by complex coagulation and fibrinolysis factor disorders. Multiple mechanisms tried to explain the increased d-dimer levels in patients with liver cirrhosis and ascites. The d-dimer cut-off level used to rule out venous thromboembolism in cirrhosis is higher than that used to confirm the diagnosis of VTE or DIC in noncirrhotic patients. The cut-off d-dimer level used for the prognosis of thrombotic events is not standardized in advanced liver cirrhosis. Thus, it is necessary to update the clinical guidelines regarding the usefulness of d-dimer testing in advanced liver cirrhosis and the cut-off d-dimer levels, which should vary based on the detection method.

D-dimer-An International Assessment of the Quality of Laboratory Testing: Implications for D-dimer Use in the Real World

D-dimer assessment has several established roles in venous thromboembolism (VTE) and disseminated intravascular coagulation diagnosis, and recently the risk stratification of coronavirus disease 2019 (COVID-19). D-dimer assays are neither standardized nor harmonized, use varying methodologies, and use different reporting units, all resulting in a lack of interchangeability and generalizability of assays. Using large multiyear datasets from an international laboratory quality assurance program, we assessed (1) common D-dimer assays in use worldwide, (2) differences in analytical performance between different methods, and (3) interlaboratory variability between positive samples. External proficiency testing results from laboratories participating in the External Quality Control for Assays and Tests (ECAT) Foundation were analyzed from 2017 to 2023. Annually, between 578 and 690 laboratories participated in the D-dimer sample surveys with response rates ranging from 88 to 97%. The three most common assays in use in 2023 were the Siemens Innovance D-dimer (42%), the IL HemosIL D-dimer HS 500 (20%), and the Diagnostica Stago (Stago) Liatest D-dimer Plus (10%)-all these are automated, quantitative, latex immunoassays expressed in fibrinogen equivalent units (FEU). The highest interlaboratory variability was observed around the typical VTE exclusion threshold of 0.5 mg/L FEU. Lower interlaboratory variability was observed at values above 0.8 mg/L FEU. Our study provides recent, international performance data on currently used D-dimer assays and describes the significant variability between assays and across D-dimer concentrations. We demonstrate that assays are not interchangeable and that using them interchangeably has the potential to result in clinically important errors. There is an urgent need to educate users about these issues and to work towards harmonizing D-dimer units and reporting.

Association Between NOX2-Mediated Oxidative Stress, Low-Grade Endotoxemia, Hypoalbuminemia, and Clotting Activation in COVID-19

Low-grade endotoxemia by lipopolysaccharide (LPS) has been detected in COVID-19 and could favor thrombosis via eliciting a pro-inflammatory and pro-coagulant state. The aim of this study was to analyze the mechanism accounting for low-grade endotoxemia and its relationship with oxidative stress and clotting activation thrombosis in COVID-19. We measured serum levels of sNOX2-dp, zonulin, LPS, D-dimer, and albumin in 175 patients with COVID-19, classified as having or not acute respiratory distress syndrome (ARDS), and 50 healthy subjects. Baseline levels of sNOX2-dp, LPS, zonulin, D-dimer, albumin, and hs-CRP were significantly higher in COVID-19 compared to controls. In COVID-19 patients with ARDS, sNOX2-dp, LPS, zonulin, D-dimer, and hs-CRP were significantly higher compared to COVID-19 patients without ARDS. Conversely, concentration of albumin was lower in patients with ARDS compared with those without ARDS and inversely associated with LPS. In the COVID-19 cohort, the number of patients with ARDS progressively increased according to sNOX2-dp and LPS quartiles; a significant correlation between LPS and sNOX2-dp and LPS and D-dimer was detected in COVID-19. In a multivariable logistic regression model, LPS/albumin levels and D-dimer predicted thrombotic events. In COVID-19 patients, LPS is significantly associated with a hypercoagulation state and disease severity. In vitro, LPS can increase endothelial oxidative stress and coagulation biomarkers that were reduced by the treatment with albumin. In conclusion, impaired gut barrier permeability, increased NOX2 activation, and low serum albumin may account for low-grade endotoxemia and may be implicated in thrombotic events in COVID-19.

D-dimer assay interference detected by the discrepancy in D-dimer concentrations at different dilutions: a case report

This case report describes interference from heterophilic antibodies in D-dimer assay. The interference was suspected due to discrepancies between D-dimer concentrations in the original sample and diluted samples, as well as inconsistent clinical findings. The patient's medical history, laboratory results, and imaging studies were considered in the investigation. Heterophilic antibodies, likely developed during the SARS-CoV-2 infection, were identified as the probable cause of interference. The interference was confirmed through various methods, including dilution studies, blocking heterophilic antibodies, and comparing results with an alternative D-dimer method. This case highlights the importance of recognizing and addressing interference in D-dimer testing, emphasizing the need for collaboration between clinicians and laboratory specialists.

Diagnosis and treatment of 2 cases with cryptogenic stroke due to patent foramen ovale in children: A case report

RATIONALE

Arterial ischemic stroke is a general term for necrosis of brain tissue due to insufficient blood supply to the brain from various causes. About 30% of these cases are of unknown origin and are known as cryptogenic strokes (CS).

PATIENT CONCERNS

We report 2 female patients, one 5 years and 5 months old and the other 6 years old. Both children had clinical manifestations of CS, and after ruling out other possible etiologies, we finally suspected that CS was associated with patent foramen ovale (PFO).

DIAGNOSES

Case 1 was diagnosed with PFO, paradoxical embolism, and third-degree atrioventricular block, and case 2 was diagnosed with PFO, paradoxical embolism, and refractory mycoplasma pneumonia.

INTERVENTIONS

Case 1 underwent permanent pacemaker placement at the same time as PFO closure. Case 2 underwent conservative anticoagulation with poor therapeutic results and subsequently underwent PFO closure.

OUTCOMES

Patient 1 underwent PFO closure, which resulted in relief of neurologic symptoms and no recurrence of neurologic symptoms after 10 months of follow-up. In case 2, the child's neurologic symptoms improved after PFO closure.

LESSONS

Although most children with PFO do not require targeted interventions, a few cases involving PFO and CS may benefit from closure of the foramen ovale.

Comparison of four D-dimer assays in the context of venous thromboembolism in the emergency department

INTRODUCTION

This observational study conducted across seven emergency care units compares the efficacy of four D-dimer detection methods, namely HemosIL D-dimer HS (HS), HemosIL D-dimer HS-500 (HS-500), VIDAS D-dimer (VIDAS), and HemosIL AcuStar D-dimer (ACUSTAR). The primary focus is on patients with a clinical suspicion of deep venous thrombosis (DVT) or pulmonary embolism (PE).

METHODS

A total of 149 samples were collected from patients with suspected DVT or PE. The confirmation of DVT/PE was based on calf ultrasound or computed tomography-Angiography. Direct comparisons were made between the different detection methods, considering both their analytical performance and clinical utility. Additionally, the impact of an age-adjusted cut-off on the diagnostic accuracy of each method was assessed.

RESULTS

The results revealed comparable negative predictive value, sensitivity, and specificity across the methods, with a notable exception of increased specificity for HS compared with HS-500 (50.8% vs. 41.5%, p = 0.03). Further analysis incorporating an age-adjusted cut-off demonstrated a significant improvement in specificity for HS. When using the age-adjusted cut-off, HS exhibited a substantial increase in specificity compared with HS-500 (63.1% vs. 49.2%, p = 0.004) and demonstrated significantly higher specificity compared with VIDAS (63.1% vs. 53.8%, p = 0.04).

CONCLUSION

The study emphasizes the nonuniversal effect of an age-adjusted cut-off and discusses the potential necessity for different cut-off values, particularly in the case of HS-500. These findings contribute to the understanding of D-dimer detection methods in the context of DVT and PE, providing insights into their relative performances and the potential optimization through age-adjusted cut-offs.

Assessment of accuracy of laboratory testing results, relative to peer group consensus values in external quality control, by bivariate z-score analysis: the example of D-Dimer

OBJECTIVES

The aim of this study is to develop a practical method for bivariate z-score analysis which can be applied to the survey of an external quality assessment programme.

METHODS

To develop the bivariate z-score analysis, the results of four surveys of the international D-Dimer external quality assessment programme of 2022 of the ECAT Foundation were used. The proposed methodology starts by identifying the bivariate outliers, using a Supervised Sequential Hotelling T2 control chart. The outlying data are removed, and all the remaining data are used to provide robust estimates of the parameters of the assumed underlying bivariate normal distribution. Based on these estimates two nested homocentric ellipses are drawn, corresponding to confidence levels of 95 and 99.7 %. The bivariate z-score plot described provides the laboratory with an indication of both systematic and random deviations from zero z-score values. The bivariate z-score analysis was examined within survey 2022-D4 across the three most frequently used methods.

RESULTS

The number of z-score pairs included varied between 830 and 857 and the number of bivariate outliers varied between 20 and 28. The correlation between the z-score pairs varied between 0.431 and 0.647. The correlation between the z-score pairs for the three most frequently used varied between 0.208 and 0.636.

CONCLUSIONS

The use of the bivariate z-score analysis is of major importance when multiple samples are distributed around in the same survey and dependency of the results is likely. Important lessons can be drawn from the shape of the ellipse with respect to random and systematic deviations, while individual laboratories have been informed about their position in the state-of-the-art distribution and whether they have to deal with systematic and/or random deviations.

An observational study investigating soluble immune checkpoints as indicators of severe COVID-19

This study aimed to investigate the immunomodulatory behavior of soluble immune checkpoints (sICPs) and other biomarkers in the pathophysiology of SARS-CoV-2 infection. The study included 59 adult participants, 43 of whom tested positive for SARS-CoV-2. Patients were divided into three cohorts: those with moderate disease (n = 16), recovered patients with severe disease (n = 13), and deceased patients with severe disease (n = 16). In addition, 16 participants were pre-pandemic subjects negative for SARS-CoV-2. The relative activity of neutralizing antibodies (rNAbs) against SARS-CoV-2 and the values of 14 sICPs in peripheral blood were compared between the four groups. Because the increase of markers values of inflammation [NLR > 12; CRP > 150 mg/L] and venous thromboembolism [D-dimer > 0.5 mg/L] has been associated with mortality from COVID-19, the total and differential leukocyte counts, the NLR, and CRP and D-dimer values were obtained in patients with severe disease. No differences in rNAbs were observed between the cohorts. Only the levels of five sICPs, sCD27, sHVEM sTIM-3, sPD-1, and sPDL-1, were significantly higher in patients with severe rather than moderate disease. The sPDL-2 level and NLR were higher in deceased patients than in recovered patients. However, there was no difference in CRP and D-dimer values between the two groups. Of the five soluble biomarkers compared among patients with severe disease, only sPDL-2 was higher in deceased patients than in recovered patients. This suggests that immuno-inhibitory sICPs might be used as indicators for severe COVID-19, with sPDL-2 used to assess individual risk for fatality.IMPORTANCECOVID-19, the disease caused by a SARS-CoV-2 infection, generates a broad spectrum of clinical symptoms, progressing to multiorgan failure in the most severe cases. As activation of the immune system is pivotal to eradicating the virus, future research should focus on identifying reliable biomarkers to efficiently predict the outcome in severe COVID-19 cases. Soluble immune checkpoints represent the function of the immune system and are easily determined in peripheral blood. This research could lead to implementing more effective severity biomarkers for COVID-19, which could increase patients' survival rate and quality of life.

A systematic review and meta-analysis of the association between the D-dimer and rheumatic diseases

INTRODUCTION

There is good evidence that specific autoimmune rheumatic diseases (RDs), for example, rheumatoid arthritis and systemic lupus erythematosus (SLE), are associated with a state of hypercoagulability and an increased risk of venous thromboembolism (VTE). However, limited information regarding this association is available for other autoimmune or autoinflammatory RDs. We sought to address this issue by conducting a systematic review and meta-analysis of the association between the d-dimer, an established marker of hypercoagulability and VTE, and RDs and the possible clinical and demographic factors mediating this association.

METHODS

We searched the electronic databases PubMed, Web of Science, and Scopus from inception to January 31, 2024. The risk of bias and the certainty of evidence were assessed using the Joanna Briggs Institute Critical Appraisal Checklist and GRADE, respectively.

RESULTS

In 31 studies selected for analysis (2724 RD patients and 3437 healthy controls), RD patients had overall significantly higher d-dimer concentrations when compared to controls (standard mean difference = 0.93, 95% CI 0.76-1.10, p < .001; I2 = 86.1%, p < .001; moderate certainty of evidence). The results were stable in a sensitivity analysis. Significant associations were observed between the effect size of the between-group differences in d-dimer concentration and age, specific RD and RD category, RD duration, fibrinogen, plasminogen activator inhibitor, C-reactive protein, and erythrocyte sedimentation rate.

CONCLUSIONS

Overall, patients with RDs have significantly higher d-dimer concentrations when compared with healthy controls, indicating a state of hypercoagulability. The alterations in d-dimer concentrations are mediated by age, specific RD and RD category, RD duration, and markers of anticoagulation and inflammation. Further research is warranted to investigate d-dimer concentrations across the spectrum of RDs and their utility in predicting and managing VTE in these patients (PROSPERO registration number: CRD42024517712).

Effects of dabigatran, rivaroxaban, and apixaban on fibrin network permeability, thrombin generation, and fibrinolysis

INTRODUCTION

There are important pharmacological differences between direct oral anticoagulants (DOAC) and a deeper knowledge of how they influence different aspects of hemostasis in patients on treatment is desirable.

MATERIALS AND METHODS

Blood samples from patients on dabigatran (n = 23), rivaroxaban (n = 26), or apixaban (n = 20) were analyzed with a fibrin network permeability assay, a turbidimetric clotting and lysis assay, the calibrated automated thrombogram (CAT), plasma levels of thrombin-antithrombin complex (TAT) and D-dimer, as well as DOAC concentrations, PT-INR and aPTT. As a comparison, we also analyzed samples from 27 patients on treatment with warfarin.

RESULTS

Patients on dabigatran had a more permeable fibrin network, longer lag time (CAT and turbidimetric assay), and lower levels of D-dimer in plasma, compared with patients on rivaroxaban- and apixaban treatment, and a more permeable fibrin network than patients on warfarin. Clot lysis time was slightly longer in patients on dabigatran than in patients on rivaroxaban. Warfarin patients formed a more permeable fibrin network than patients on apixaban, had longer lag time than patients on rivaroxaban (CAT assay), and lower peak thrombin and ETP compared to patients on treatment with both FXa-inhibitors.

CONCLUSIONS

Results from this study indicate dabigatran treatment is a more potent anticoagulant than apixaban and rivaroxaban. However, as these results are not supported by clinical data, they are probably more related to the assays used and highlight the difficulty of measuring and comparing the effect of anticoagulants.

D-dimer as a Useful Biomarker in Early Diagnosis of Neonatal Sepsis: A Single-Center Study From Romania

BACKGROUND

This study evaluates the role of D-dimer in identifying neonatal sepsis and their potential value in clinical decision-making due to challenges in early detection.

METHODOLOGY

A case-control study was conducted on 102 neonates at the Children's Clinical Hospital "Louis Turcanu" in Timisoara, Romania, from October 2018 to July 2023. The participants were divided into two groups: those with neonatal sepsis and those without sepsis.

RESULTS

The study found that neonates with sepsis were more likely to be delivered by cesarean section and had higher rates of premature ruptured membranes compared to those without sepsis. The D-dimer biomarker's predictive value for sepsis was assessed using a receiver operating characteristic (ROC) curve, with an area under the curve (AUC) exceeding 0.982 and an optimum cutoff value of 342 ng/mL. An increase in neonatal D-dimer significantly increases the likelihood of sepsis by 2.7% per unit increase. A value above 250 ng/mL indicates a 127-fold increased likelihood of sepsis. The D-dimer's ability to predict mortality in newborns with sepsis is unsatisfactory, with an AUC of 0.528.

CONCLUSIONS

D-dimer, a potential biomarker of neonatal sepsis, warrants further clinical investigation to enhance diagnostic sensitivity and specificity, demonstrating its potential in conjunction with other sepsis markers.

Advances in D-dimer testing: progress in harmonization of clinical assays and innovative detection methods

The D-dimer is a sensitive indicator of coagulation and fibrinolysis activation, especially valuable as a biomarker of intravascular thrombosis. Measurement of plasma D-dimer levels plays a crucial role in the diagnosis and monitoring of conditions such as deep vein thrombosis, pulmonary embolism, and disseminated intravascular coagulation. A variety of immunoassays, including enzyme-linked immunosorbent assays, latex-enhanced immunoturbidimetric assays, whole-blood aggregation analysis, and immunochromatography assays, are widely used in clinical settings to determine D-dimer levels. However, the results obtained from different D-dimer assays vary significantly. These assays exhibit intra-method coefficients of variation ranging from 6.4% to 17.7%, and the measurement discrepancies among different assays can be as high as 20-fold. The accuracy and reliability of D-dimer testing cannot be guaranteed due to the lack of an internationally endorsed reference measurement system (including reference materials and reference measurement procedures), which may lead to misdiagnosis and underdiagnosis, limiting its full clinical application. In this review, we present an in-depth analysis of clinical D-dimer testing, summarizing the existing challenges, the current state of metrology, and progress towards harmonization. We also review the latest advancements in D-dimer detection techniques, which include mass spectrometry and electrochemical and optical immunoassays. By comparing the basic principles, the definition of the measurand, and analytical performance of these methods, we provide an outlook on the potential improvements in D-dimer clinical testing.

Roles of spectral dual-layer CT, D-dimer concentration, and COVID-19 pneumonia in diagnosis of pulmonary embolism

Purpose

To demonstrate advantages of spectral dual-layer computed tomography (CT) in diagnosing pulmonary embolism (PE). To compare D-dimer values in patients with PE and concomitant COVID-19 pneumonia to those in patients without PE and COVID-19 pneumonia. To compare D-dimer values in cases of minor versus extensive PE.

Methods

A monocentric retrospective study of 1500 CT pulmonary angiographies (CTPAs). Three groups of 500 consecutive examinations: 1) using conventional multidetector CT (CTC), 2) using spectral dual-layer CT (CTS), and 3) of COVID-19 pneumonia patients using spectral dual-layer CT (COV). Only patients with known D-dimer levels were enrolled in the study.

Results

Prevalence of inconclusive PE findings differed significantly between CTS and CTC (0.8 % vs. 5.4 %, p < 0.001). In all groups, D-dimer levels were significantly higher in PE positive patients than in patients without PE (CTC, 8.04 vs. 3.05 mg/L; CTS, 6.92 vs. 2.57 mg/L; COV, 10.26 vs. 2.72 mg/L, p < 0.001). There were also statistically significant differences in D-dimer values between minor and extensive PE in the groups negative for COVID-19 (CTC, 5.16 vs. 8.98 mg/L; CTS 3.52 vs. 9.27 mg/L, p < 0.001). The lowest recorded D-dimer value for proven PE in patients with COVID-19 pneumonia was 1.19 mg/L.

Conclusion

CTPAs using spectral dual-layer CT reduce the number of inconclusive PE findings. Plasma D-dimer concentration increases with extent of PE. Cut-off value of D-dimer with 100 % sensitivity for patients with COVID-19 pneumonia could be doubled to 1.0 mg/L. This threshold would have saved 110 (22 %) examinations in our cohort.

Combining KRAS gene status with preoperative D‑dimer levels as a predictive marker of venous thromboembolism risk in patients with resectable colorectal cancer: A prospective cohort study

Colorectal cancer (CRC), one of the most prevalent types of cancer, is accompanied by a notably high incidence of thrombotic complications. The present study aimed to elucidate the association between KRAS mutations and hypercoagulability in operable CRC. The prognostic value of preoperative D-dimer levels was also investigated, thus providing novel insights into the development of therapeutic strategies to enhance patient survival and diminish morbidity. Therefore, a prospective analysis of 333 CRC cases post-surgery at Yan'an Hospital Affiliated to Kunming Medical University, between May 2019 and October 2022 was performed. Data on demographics, tumor characteristics and D-dimer levels were compiled from the electronic health records. Venous thromboembolism (VTE) was diagnosed by doppler or computed tomography angiography, with D-dimer thresholds set at 550 and 1,650 µg/l. KRAS mutations at codons 12 and 13 were assessed in a subset of 56 cases. Subsequently, the factors affecting the hypercoagulable state in these patients were prospectively analyzed, focusing on the pivotal role of KRAS. The results showed that KRAS mutations were associated with elevated preoperative D-dimer levels, with 1,076 µg/l compared with 485 µg/l in the wild-type cohort, indicative of a hypercoagulable state. Increased D-dimer levels were also associated with vascular invasion, distant metastases and a heightened risk of postoperative VTE. Furthermore, multivariate analyses identified KRAS mutations, distant metastases and vascular invasion as independent predictors of elevated D-dimer levels, with relative risk values of 2.912, 1.884 and 1.525, respectively. Conversely, sex, age, tumor location, differentiation grade, Ki67 index and tumor stage could not significantly affect D-dimer levels, thus indicating a complex interplay between tumor genetics and coagulation dysfunction in CRC. The current study suggested that the KRAS mutation status, distant metastasis and vascular invasion could be considered as independent risk factors of blood hypercoagulability in patients with CRC, potentially serving as prognostic factors for VTE risk.

The Curious Role of PAI-1 in Severe Obstructive Sleep Apnea

Plasminogen activator inhibitor-1 (PAI-1) has a significant role in fibrinolysis, atherogenesis, cellular senescence, and chronic inflammation. OSA (obstructive sleep apnea) leads to increased PAI-1 levels and the development of cardiovascular disease (CVD). The aim of this study was to determine the effects of CPAP therapy on coagulation parameters and PAI-1 in patients with severe OSA. This prospective, controlled study enrolled 57 patients who were newly diagnosed with severe OSA, 37 of whom had had good CPAP adherence after 6 months of therapy (usage of the device for at least 4 h per night), and their data were analyzed. The analysis showed a statistically significant increase in D-dimer values before CPAP therapy (415 (316.5-537.5)) vs. after therapy (499 (327-652)), p = 0.0282, and a decrease in fibrinogen values (3.665 ± 0.752 before CPAP therapy vs. 3.365 ± 0.771 after therapy, p = 0.0075)). PAI-1 concentration values before and after CPAP therapy did not differ significantly (17.35 ± 7.01 ng/mL before CPAP therapy vs. 17.42 ± 6.99 ng/mL after therapy, p = 0.9367). This study shows a tendency for fibrinolytic capacity to improve in patients with OSA after CPAP therapy, although PAI-1 levels did not differ significantly.

Absolute protein quantification based on calibrated particle counting using electrospray-differential mobility analysis

The traceability of in vitro diagnostics or drug products is based on the accurate quantification of proteins. In this study, we developed an absolute quantification approach for proteins. This method is based on calibrated particle counting using electrospray-differential mobility analysis (ES-DMA) coupled with a condensation particle counter (CPC). The absolute concentration of proteins was quantified with the observed protein particle number measured with ES-DMA-CPC, and the detection efficiency was determined by calibrators. The measurement performance and quantitative level were verified using two certificated reference materials, BSA and NIMCmAb. The linear regression fit for the detection efficiency values of three reference materials and one highly purified protein (myoglobin, BSA, NIMCmAb and fibrinogen) indicated that the detection efficiency and the particle size distribution of these proteins exhibited a linear relationship. Moreover, to explore the suitability of the detection efficiency-particle size curve for protein quantification, the concentrations of three typical proteinaceous particles, including two high molecular weight proteins (NIST reference material 8671 and D-dimer) and one protein complex (glutathione S-transferase dimer), were determined. This work suggests that this calibrated particle counting method is an efficient approach for nondestructive, rapid and accurate quantification of proteins, especially for measuring proteinaceous particles with tremendous size and without reference standards.

Elevation of D-dimer in eosinophilic gastrointestinal diseases in the absence of venous thrombosis: A case series and literature review

Introduction

Eosinophilic gastrointestinal diseases (EGIDs) are rare and heterogeneous diseases characterized by excessive eosinophilic infiltration of the digestive system. D-dimer levels and its possible association with disease course were not reported.

Case series

We reported a series of three EGID cases presenting with high levels of D-dimer. No evidence for potential venous thromboembolism was found through computed tomography pulmonary angiogram and vascular ultrasounds. Moreover, D-dimer levels decreased after short-time systemic prednisolone administration, accompanied by remission of clinical symptoms and decrease of peripheral eosinophil counts and IgE levels.

Conclusion

Elevation of D-dimer in EGID may not represent thrombotic events but is possibly associated with disease severity. More population-based studies are needed to delineate the potential relationship among D-dimer, thrombosis, and inflammation in EGID.

Cancer-Associated Stroke: Thrombosis Mechanism, Diagnosis, Outcome, and Therapeutic Strategies

Cancer can induce hypercoagulability, which may lead to stroke. This occurs when tumor cells activate platelets as part of their growth and metastasis. Tumor cells activate platelets by generating thrombin and expressing tissue factor, resulting in tumor cell-induced platelet aggregation. Histopathological studies of thrombi obtained during endovascular thrombectomy in patients with acute stroke and active cancer have shown a high proportion of platelets and thrombin. This underscores the crucial roles of platelets and thrombin in cancer-associated thrombosis. Cancer-associated stroke typically occurs in patients with active cancer and is characterized by distinctive features. These features include multiple infarctions across multiple vascular territories, markedly elevated blood D-dimer levels, and metastasis. The presence of cardiac vegetations on echocardiography is a robust indicator of cancer-associated stroke. Suspicion of cancer-associated stroke during endovascular thrombectomy arises when white thrombi are detected, particularly in patients with active cancer. Cancer-associated stroke is almost certain when histopathological examination of thrombi shows a very high platelet and a very low erythrocyte composition. Patients with cancer-associated stroke have high risks of mortality and recurrent stroke. However, limited data are available on the optimal treatment regimen for stroke prevention in these patients. Thrombosis mechanism in cancer is well understood, and distinct therapeutic targets involving thrombin and platelets have been identified. Therefore, direct thrombin inhibitors and/or antiplatelet agents may effectively prevent stroke recurrence. Additionally, this strategy has potential benefits in cancer treatment as accumulating evidence suggests that aspirin use reduces cancer progression, metastasis, and cancer-related mortality. However, clinical trials are necessary to assess the efficacy of this strategy involving the use of direct thrombin inhibitors and/or antiplatelet therapies.

Intermediate-Risk and High-Risk Pulmonary Embolism: Recognition and Management: Cardiology Clinics: Cardiac Emergencies

Pulmonary embolism (PE) is the third most common cause of cardiovascular death. Every specialty of medical practitioner will encounter PE in their patients, and should be prepared to employ contemporary strategies for diagnosis and initial risk-stratification. Treatment of PE is based on risk-stratification, with anticoagulation for all patients, and advanced modalities including systemic thrombolysis, catheter-directed therapies, and mechanical circulatory supports utilized in a manner paralleling PE severity and clinical context.

A real-world study of different doses of rivaroxaban in patients with nonvalvular atrial fibrillation

To explore the anticoagulant effect and safety of utilizing different doses of rivaroxaban for the treatment of patients with atrial fibrillation (AF) in the real world. A retrospective case-control analysis was performed by applying the hospital database, and 3595 patients with non-valvular atrial fibrillation (NVAF) who were hospitalized and taking rivaroxaban at Wuhan Asia Heart Hospital and Wuhan Asia General Hospital from March 2018 to December 2021 were included in the study, and were divided into the rivaroxaban 10 mg and 15 mg groups according to the daily prescribed dose, of which 443 cases were in the 10 mg group and 3152 cases were in the 15 mg group. The patients were followed up regularly, and the incidence of thrombotic events, bleeding events and all-cause deaths were recorded and compared between the 2 groups, and logistic regression was applied to analyze the influencing factors for the occurrence of adverse events. Comparison of the incidence of thrombosis, bleeding and all-cause death between the 2 groups of patients showed that the 10 mg group was higher than the 15 mg group, but the difference was not statistically significant (χ2 = 0.36, 3.26, 1.99, all P > .05); the incidence of total adverse events between the 2 groups of patients was higher in the 10 mg group than in the 15 mg group, with a statistically significant difference (χ2 = 4.53, P = .033); multifactorial logistic regression results showed that age [OR (95% CI) = 1.02 (1.00-1.04)], diabetes mellitus [OR (95% CI) = 1.69 (1.09-2.62)], D-dimer level [OR (95% CI) = 1.06 (1.00-1.11)] and persistent AF [OR (95% CI) = 1.54 (1.03-2.31)] were risk factors for adverse events (P < .05). In the real world, Asian clinicians recommend rivaroxaban 10 mg once daily for NVAF patients for a variety of reasons; however, this dose is not superior or even inferior to the 15 mg group in terms of effectiveness and safety. Advanced age, elevated D-dimer levels, history of diabetes mellitus, and persistent AF are risk factors for adverse events, and the optimal dosage of rivaroxaban or optimal anticoagulation strategy for Asian patients with nonvalvular AF requires further study.

Impact of Sample Type on D-Dimer Screening

Background

The quality of laboratory test results depends on various factors, including sample type selection. Blood samples, such as whole blood, plasma and serum are commonly used for most clinical laboratory examinations. D-dimer parameters are frequently analysed in haematology laboratories and serve as biomarkers for coagulation activation and fibrinolysis. This study aimed to assess the impact of using different sample types on the quality of D-dimer test results.

Method

An observational analytical method was used. D-dimer examination was performed using the fluorescent lateral flow immunoassay method. The study sample consisted of 26 participants aged between 18 years old and 22 years old who had no blood disorders. Whole blood and ethylenediaminetetraacetic acid (EDTA) plasma samples were used for the examination of D-dimer levels.

Results

D-dimer levels in 26 participants using whole blood samples had a mean value of 0.23 mg/L (230 ng/mL), while plasma samples yielded a mean value of 0.14 mg/L (140 ng/mL). D-dimer levels obtained from whole blood samples were higher than plasma samples but remained within the normal range of 0 mg/L-0.5 mg/L (0 ng/mL-500 ng/mL).

Conclusion

The results showed that whole blood samples were more practical than plasma samples. Nevertheless, plasma samples gave results within the normal range of D-dimer values.

Fast screening using attenuated total reflectance- fourier transform infrared (ATR-FTIR) spectroscopy of patients based on D-dimer threshold value

Attenuated Total Reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy is an emerging technology in the medical field. Blood D-dimer was initially studied as a marker of the activation of coagulation and fibrinolysis. It is mainly used as a potential diagnosis screening test for pulmonary embolism or deep vein thrombosis but was recently associated with COVID-19 severity. This study aimed to evaluate the use of ATR-FTIR spectroscopy with machine learning to classify plasma D-dimer concentrations. The plasma ATR-FTIR spectra from 100 patients were studied through principal component analysis (PCA) and two supervised approaches: genetic algorithm with linear discriminant analysis (GA-LDA) and partial least squares with linear discriminant (PLS-DA). The spectra were truncated to the fingerprint region (1800-1000 cm-1). The GA-LDA method effectively classified patients according to D-dimer cutoff (≤0.5 μg/mL and >0.5 μg/mL) with 87.5 % specificity and 100 % sensitivity on the training set, and 85.7 % specificity, and 95.6 % sensitivity on the test set. Thus, we demonstrate that ATR-FTIR spectroscopy might be an important additional tool for classifying patients according to D-dimer values. ATR-FTIR spectral analyses associated with clinical evidence can contribute to a faster and more accurate medical diagnosis, reduce patient morbidity, and save resources and demand for professionals.

Fibrinogen contribution to clot strength in patients with sepsis and hematologic malignancies and thrombocytopenia-a prospective, single-center, analytical, cross-sectional study

Background

Patients with hematological malignancies (HM) frequently present thrombocytopenia and higher risk of bleeding. Although transfusion is associated with higher risk of adverse events and poor outcomes, prophylactic transfusion of platelets is a common practice to prevent hemorrhagic complications. Thromboelastometry has been considered a better predictor for bleeding than isolated platelet counts in different settings. In early stages of sepsis, hypercoagulability may occur due to higher fibrinogen levels.

Objectives

To evaluate the behavior of coagulation in patients with HM who develop sepsis and to verify whether a higher concentration of fibrinogen is associated with a proportional increase in maximum clot firmness (MCF) even in the presence of severe thrombocytopenia.

Methods

We performed a unicentric analytical cross-sectional study with 60 adult patients with HM and severe thrombocytopenia, of whom 30 had sepsis (sepsis group) and 30 had no infections (control group). Coagulation conventional tests and specific coagulation tests, including thromboelastometry, were performed. The main outcome evaluated was MCF.

Results

Higher levels of fibrinogen and MCF were found in sepsis group. Both fibrinogen and platelets contributed to MCF. The relative contribution of fibrin was significantly higher (60.5 ± 12.8% vs 43.6 ± 9.7%; P < .001) and that of platelets was significantly lower (39.5 ± 12.8% vs 56.4 ± 9.7%; P < .001) in the sepsis group compared with the control group.

Conclusion

Patients with sepsis and HM presented higher concentrations of fibrinogen than uninfected patients, resulting in greater MCF amplitudes even in the presence of thrombocytopenia.

Development and validation of a risk model for intracardiac thrombosis in patients with dilated cardiomyopathy: a retrospective study

Intracardiac thrombosis is a severe complication in patients with non-ischemic dilated cardiomyopathy. This study aims to develop and validate an individualized nomogram to evaluate the risk of intracardiac thrombosis in patients with non-ischemic dilated cardiomyopathy. This retrospective study included patients diagnosed with dilated cardiomyopathy at first admission. Clinical baseline characteristics were acquired from electronic medical record systems. Multiple methods were applied to screen the key variables and generate multiple different variable combinations. Multivariable logistic regression was used to build the models, and the optimal model was chosen by comparing the discrimination. Then we checked the performance of the model in different thrombus subgroups. Finally, the model was presented using a nomogram and evaluated from the perspectives of discrimination, calibration, and clinical usefulness. Internal validation was performed by extracting different proportions of data for Bootstrapping. Ultimately, 564 eligible patients were enrolled, 67 of whom developed an intracardiac thrombosis. Risk factors included d-dimer, white blood cell count, high-sensitivity C-reactive protein, pulse pressure, history of stroke, hematocrit, and NT-proBNP in the optimal model. The model had good discrimination and calibration, and the area under the curve (AUC) was 0.833 (0.782-0.884), and the model's performance in each subgroup was stable. Clinical decision curve analysis showed that the model had clinical application value when the high-risk threshold was between 2% and 78%. The AUC of interval validation (30% and 70% data resampling) was 0.844 (0.765-0.924) and 0.833 (0.775-0.891), respectively. This novel intracardiac thrombosis nomogram could be conveniently applied to facilitate the individual intracardiac thrombosis risk assessment in patients with non-ischemic dilated cardiomyopathy.