Adjunct Immune Globulin for Vaccine-Induced Immune Thrombotic Thrombocytopenia.

The use of high-dose intravenous immune globulin (IVIG) plus anticoagulation is recommended for the treatment of vaccine-induced immune thrombotic thrombocytopenia (VITT), a rare side effect of adenoviral vector vaccines against coronavirus disease 2019 (Covid-19). We describe the response to IVIG therapy in three of the first patients in whom VITT was identified in Canada after the receipt of the ChAdOx1 nCoV-19 vaccine. The patients were between the ages of 63 and 72 years; one was female. At the time of this report, Canada had restricted the use of the ChAdOx1 nCoV-19 vaccine to persons who were 55 years of age or older on the basis of reports that VITT had occurred primarily in younger persons. Two of the patients in our study presented with limb-artery thrombosis; the third had cerebral venous and arterial thrombosis. Variable patterns of serum-induced platelet activation were observed in response to heparin and platelet factor 4 (PF4), indicating the heterogeneity of the manifestations of VITT in serum. After the initiation of IVIG, reduced antibody-induced platelet activation in serum was seen in all three patients. (Funded by the Canadian Institutes of Health Research.).

Development of a chemiluminescence assay for tissue plasminogen activator inhibitor complex and its applicability to gastric cancer.

BACKGROUND: Venous thromboembolism (VTE), is a noteworthy complication in individuals with gastric cancer, but the current diagnosis and treatment methods lack accuracy. In this study, we developed a t-PAIC chemiluminescence kit and employed chemiluminescence to detect the tissue plasminogen activator inhibitor complex (t-PAIC), thrombin-antithrombin III complex (TAT), plasmin-α2-plasmin inhibitor complex (PIC) and thrombomodulin (TM), combined with D-dimer and fibrin degradation products (FDP), to investigate their diagnostic potential for venous thrombosis in gastric cancer patients. The study assessed variations in six indicators among gastric cancer patients at different stages. RESULTS: The t-PAIC reagent showed LOD is 1.2 ng/mL and a linear factor R greater than 0.99. The reagents demonstrated accurate results, with all accuracy deviations being within 5%. The intra-batch and inter-batch CVs for the t-PAIC reagent were both within 8%. The correlation coefficient R between this method and Sysmex was 0.979. Gastric cancer patients exhibited elevated levels of TAT, PIC, TM, D-D, FDP compared to the healthy population, while no significant difference was observed in t-PAIC. In the staging of gastric cancer, patients in III-IV stages exhibit higher levels of the six markers compared to those in I-II stages. The ROC curve indicates an enhancement in sensitivity and specificity of the combined diagnosis of four or six indicators. CONCLUSION: Our chemiluminescence assay performs comparably to Sysmex's method and at a reduced cost. The use of multiple markers, including t-PAIC, TM, TAT, PIC, D-D, and FDP, is superior to the use of single markers for diagnosing VTE in patients with malignant tumors. Gastric cancer patients should be screened for the six markers to facilitate proactive prophylaxis, determine the most appropriate treatment timing, ameliorate their prognosis, decrease the occurrence of venous thrombosis and mortality, and extend their survival.

D-dimer and CoV-2 spike-immune complexes contribute to the production of PGE2 and proinflammatory cytokines in monocytes.

An overreactive inflammatory response and coagulopathy are observed in patients with severe form of COVID-19. Since increased levels of D-dimer (DD) are associated with coagulopathy in COVID-19, we explored whether DD contributes to the aberrant cytokine responses. Here we show that treatment of healthy human monocytes with DD induced a dose dependent increase in production of pyrogenic mediator, Prostaglandin E2 (PGE2) and inflammatory cytokines, IL-6 and IL-8. The DD-induced PGE2 and inflammatory cytokines were enhanced significantly by co-treatment with immune complexes (IC) of SARS CoV-2 recombinant S protein or of pseudovirus containing SARS CoV-2 S protein (PVCoV-2) coated with spike-specific chimeric monoclonal antibody (MAb) containing mouse variable and human Fc regions. The production of PGE2 and cytokines in monocytes activated with DD and ICs was sensitive to the inhibitors of ß2 integrin and FcγRIIa, and to the inhibitors of calcium signaling, Mitogen-Activated Protein Kinase (MAPK) pathway, and tyrosine-protein kinase. Importantly, strong increase in PGE2 and in IL-6/IL-8/IL-1ß cytokines was observed in monocytes activated with DD in the presence of IC of PVCoV-2 coated with plasma from hospitalized COVID-19 patients but not from healthy donors. The IC of PVCoV-2 with convalescent plasma induced much lower levels of PGE2 and cytokines compared with plasma from hospitalized COVID-19 patients. PGE2 and IL-6/IL-8 cytokines produced in monocytes activated with plasma-containing IC, correlated well with the levels of spike binding antibodies and not with neutralizing antibody titers. Our study suggests that a combination of high levels of DD and high titers of spike-binding antibodies that can form IC with SARS CoV-2 viral particles might accelerate the inflammatory status of lung infiltrating monocytes leading to increased lung pathology in patients with severe form of COVID-19.

The History of Diagnosing Venous Thromboembolism.

An accurate and prompt diagnosis of deep vein thrombosis and/or pulmonary embolism is important to prevent serious complications and mortality. Because the clinical presentation of venous thromboembolism (VTE) is often nonspecific, objective testing by means of radiological imaging is required to confirm the diagnosis. Historically, a diagnosis of VTE involved invasive imaging techniques like contrast venography or conventional pulmonary angiography. Technological developments toward more accurate and less invasive diagnostics have driven the implementation of a variety of newer technologies over the past decades, as well as the derivation and validation of clinical decision rules (CDRs) that can be used to rule out VTE in combination with D-dimer blood tests. In this narrative review, we provide a historical overview of the most notable developments in the imaging techniques and CDRs for VTE diagnosis.

Understanding COVID-19 outcome: Exploring the prognostic value of soluble biomarkers indicative of endothelial impairment.

Host proteins released by the activated endothelial cells during SARS-CoV-2 infection are implicated to be involved in coagulation and endothelial dysfunction. However, the underlying mechanism that governs the vascular dysfunction and disease severity in COVID-19 remains obscure. The study evaluated the serum levels of Bradykinin, Kallikrein, SERPIN A, and IL-18 in COVID-19 (N-42 with 20 moderate and 22 severe) patients compared to healthy controls (HC: N-10) using ELISA at the day of admission (DOA) and day 7 post-admission. The efficacy of the protein levels in predicting disease severity was further determined using machine learning models. The levels of bradykinins and SERPIN A were higher (P ≤ 0.001) in both severe and moderate cases on day 7 post-admission compared to DOA. All the soluble proteins studied were found to elevated (P ≤ 0.01) in severe compared to moderate in day 7 and were positively correlated (P ≤ 0.001) with D-dimer, a marker for coagulation. ROC analysis identified that SERPIN A, IL-18, and bradykinin could predict the clinical condition of COVID-19 with AUC values of 1, 0.979, and 1, respectively. Among the models trained using univariate model analysis, SERPIN A emerged as a strong prognostic biomarker for COVID-19 disease severity. The serum levels of SERPIN A in conjunction with the coagulation marker D-dimer, serve as a predictive indicator for COVID-19 clinical outcomes. However, studies are required to ascertain the role of these markers in disease virulence.

How we manage a high D-dimer.

D-dimer, a soluble fibrin degradation product that originates from plasmin-induced degradation of cross-linked fibrin, is an important biomarker of coagulation activation and secondary fibrinolysis that is routinely used to rule out venous thromboembolism (VTE), and to evaluate the risk of VTE recurrence, as well as the optimal duration of anticoagulant therapy. Besides VTE, D-dimer may be high due to physiologic conditions, including aging, pregnancy, and strenuous physical activity. In addition, several disorders have been associated with increased D-dimer levels, ranging from disseminated intravascular coagulation to infectious diseases and cancers. Thus, it is far from unusual for hematologists to have to deal with ambulatory individuals with increased D-dimer without signs or symptoms of thrombus formation. This narrative review is dedicated to the management of these cases by the hematologist.

Programmable DARPin-based receptors for the detection of thrombotic markers.

Cellular therapies remain constrained by the limited availability of sensors for disease markers. Here we present an integrated target-to-receptor pipeline for constructing a customizable advanced modular bispecific extracellular receptor (AMBER) that combines our generalized extracellular molecule sensor (GEMS) system with a high-throughput platform for generating designed ankyrin repeat proteins (DARPins). For proof of concept, we chose human fibrin degradation products (FDPs) as markers with high clinical relevance and screened a DARPin library for FDP binders. We built AMBERs equipped with 19 different DARPins selected from 160 hits, and found 4 of them to be functional as heterodimers with a known single-chain variable fragments binder. Tandem receptors consisting of combinations of the validated DARPins are also functional. We demonstrate applications of these AMBER receptors in vitro and in vivo by constructing designer cell lines that detect pathological concentrations of FDPs and respond with the production of a reporter and a therapeutic anti-thrombotic protein.

Fibrinolysis as a Causative Mechanism for Bleeding Complications on Extracorporeal Membrane Oxygenation: A Pilot Observational Prospective Study.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is associated with a high risk of bleeding complications. The specific impact of ECMO on fibrinolysis remains unexplored. The objective of the current pilot observational prospective study was to investigate the longitudinal dynamics of fibrinolytic markers-i.e., changes over time-in the context of bleeding events in patients on ECMO. METHODS: Longitudinal dynamics of contact phase components (kininogen and bradykinin) and fibrinolysis markers (tissue plasminogen activator [tPA], plasminogen activator inhibitor-1 [PAI-1], their complexes [tPA•PAI-1], plasmin-antiplasmin complexes, plasminogen, and D-dimer) were measured in patients undergoing venovenous and venoarterial ECMO, before implantation, at 0, 6, and 12 h after implantation, and daily thereafter. RESULTS: The cohort consisted of 30 patients (214 ECMO days). The concentrations of tPA, D-dimer, plasmin-antiplasmin complexes, PAI-1, and tPA•PAI-1 complexes were increased, whereas plasminogen decreased compared to normal values. A noteworthy divergence was observed between hemorrhagic and nonhemorrhagic patients: in bleeding patients, D-dimer, plasmin-antiplasmin, tPA, PAI-1, and tPA•PAI-1 followed an increasing kinetics before hemorrhage and then decreased to their baseline level; conversely, nonbleeding patients showed a decreasing kinetics in these markers. Also, D-dimer and tPA followed an increasing kinetics in bleeding patients compared to nonbleeding patients (median values for D-dimer dynamics: 1,080 vs. -440 ng/ml, P = 0.05; tPA dynamics: 0.130 vs. 0.100 nM, P = 0.038), and both markers significantly increased the day before hemorrhage. A tPA concentration above 0.304 nM was associated with bleeding events (odds ratio, 4.92; 95% CI, 1.01 to 24.08; P = 0.049). CONCLUSIONS: Contact activation induces fibrinolysis in ECMO patients, especially in patients experiencing bleeding. This finding supports the role of this mechanism as a possible causal factor for hemorrhages during ECMO and open new avenues for novel therapeutic perspectives.

D-dimer and sinusoidal obstructive syndrome-novel poor prognostic features of thrombotic microangiopathy in children after hematopoietic cellular therapy in a single institution prospective cohort study.

Transplant-associated thrombotic microangiopathy (TA-TMA) is a common, severe complication of allogeneic hematopoietic cellular therapy (HCT). Even when treated in many studies, morbidity and mortality rates are high. This prospective single-institution cohort study serially enrolled all allogeneic HCT recipients from August 2019-August 2022. Patients were universally screened for TA-TMA and intermediate and high-risk patients were immediately treated with eculizumab. Sub-distribution cox-proportional hazards models were used to identify sub-distribution hazard ratios (sHR)  for multi-organ dysfunction (MOD) and non-relapse-related mortality (NRM). Of 136 patients, 36 (26%) were diagnosed with TA-TMA and 21/36 (58%) developed MOD, significantly more than those without TA-TMA, (p < .0001). Of those with TA-TMA, 18 (50%) had high-risk TA-TMA (HR-TA-TMA), 11 (31%) had intermediate-risk TA-TMA (IR-TA-TMA), and 8 (22%) had standard risk (SR-TA-TMA). Twenty-six were treated with eculizumab (1/8 SR, 7/11 IR, and 18/18 HR). Elevated D-dimer predicted the development of MOD (sHR 7.6, 95% confidence interval [CI] 1.8-32.3). Children with concurrent sinusoidal obstructive syndrome (SOS) and TA-TMA had an excess risk of MOD of 34% and data supported a biologic interaction. The adjusted NRM risk was significantly higher in the TA-TMA patients (sHR 10.54, 95% CI 3.8-29.2, p < .0001), despite prompt treatment with eculizumab. Significant RF for NRM in TA-TMA patients included SOS (HR 2.89, 95% 1.07-7.80) and elevated D-dimer (HR 3.82, 95% CI 1.14-12.84). An unrelated donor source and random urine protein to creatine ratio ≥2 mg/mg were significantly associated with no response to eculizumab (odds ratio 15, 95% CI 2.0-113.6 and OR 6.5, 95% CI 1.1-38.6 respectively). TA-TMA was independently associated with NRM despite early diagnosis and treatment with eculizumab in this large pediatric transplant cohort. Prognostic implications of D-dimer in TA-TMA merit further investigation as this is a readily accessible biomarker. Concurrent SOS is an exclusion criterion of many ongoing clinical trials, but these data highlight these patients could benefit from novel therapeutic approaches. Multi-institutional clinical trials are needed to understand the impact of TA-TMA-targeted therapies.

Novel Tissue Factor Inhibition for Thromboprophylaxis in COVID-19: Primary Results of the ASPEN-COVID-19 Trial.

BACKGROUND: Thrombo-inflammation is central to COVID-19-associated coagulopathy. TF (tissue factor), a driver of disordered coagulation and inflammation in viral infections, may be a therapeutic target in COVID-19. The safety and efficacy of the novel TF inhibitor rNAPc2 (recombinant nematode anticoagulation protein c2) in COVID-19 are unknown. METHODS: ASPEN-COVID-19 was an international, randomized, open-label, active comparator clinical trial with blinded end point adjudication. Hospitalized patients with COVID-19 and elevated D-dimer levels were randomized 1:1:2 to lower or higher dose rNAPc2 on days 1, 3, and 5 followed by heparin on day 8 or to heparin per local standard of care. In comparisons of the pooled rNAPc2 versus heparin groups, the primary safety end point was major or nonmajor clinically relevant International Society of Thrombosis and Haemostasis bleeding through day 8. The primary efficacy end point was proportional change in D-dimer concentration from baseline to day 8, or discharge if before day 8. Patients were followed for 30 days. RESULTS: Among 160 randomized patients, median age was 54 years, 43.1% were female, and 38.8% had severe baseline COVID-19. There were no significant differences between rNAPc2 and heparin in bleeding or other safety events. Overall, median change in D-dimer was -16.8% (interquartile range, -45.7 to 36.8; P=0.41) with rNAPc2 treatment and -11.2% (-36.0 to 34.4; P=0.91) with heparin (Pintergroup=0.47). In prespecified analyses, in severely ill patients, D-dimer levels tended to increase more within the heparin (median, 29.0% [-14.9 to 145.2]; P=0.02) than the rNAPc2 group (median, 25.9% [-49.1 to 136.4]; P=0.14; Pintergroup=0.96); in mildly ill patients, D-dimer levels were reduced within each group with a numerically greater reduction with rNAPc2 versus heparin (rNAPc2 median, -32.7% [-44.7 to 4.3]; P=0.007 and heparin median, -16.8% [-36.0 to 0.5]; P=0.008, Pintergroup=0.34). CONCLUSIONS: rNAPc2 treatment in hospitalized patients with COVID-19 was well tolerated without excess bleeding or serious adverse events but did not significantly reduce D-dimer more than heparin at day 8. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT04655586.

Prostaglandin E2/Leukotriene B4 balance and viral load in distinct clinical stages of COVID-19: A cross-sectional study.

BACKGROUND: Prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) are eicosanoids involved in modulation of the antiviral immune response. Recent studies have identified increased levels of several eicosanoids in the plasma and bronchoalveolar lavage of patients with coronavirus disease (COVID-19). This study investigated correlations between plasma levels of PGE2 and LTB4 and clinical severity of COVID-19. METHODS: This cross-sectional study involved non-infected (n = 10) individuals and COVID-19 patients classified as cured (n = 13), oligosymptomatic (n = 29), severe (n = 15) or deceased (n = 11). Levels of D-dimer a, known COVID-19 severity marker, PGE2 and LTB4 were measured by ELISAs and data were analysed with respect to viral load. RESULTS: PGE2 plasma levels were decreased in COVID-19 patients compared to the non-infected group. Changes in PGE2 and LTB4 levels did not correlate with any particular clinical presentations of COVID-19. However, LTB4 was related to decreased SARS-CoV-2 burden in patients, suggesting that only LTB4 is associated with control of viral load. CONCLUSIONS: Our data indicate that PGE2/LTB4 plasma levels are not associated with COVID-19 clinical severity. Hospitalized patients with COVID-19 are treated with corticosteroids, which may influence the observed eicosanoid imbalance. Additional analyses are required to fully understand the participation of PGE2 receptors in the pathophysiology of COVID-19.

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.

Asymmetric Dimethylarginine Is Associated with the Phenomenon of Coronary Slow Flow in Patients with Nonvalvular Atrial Fibrillation.

INTRODUCTION: Coronary slow flow phenomena (CSFP) are associated with endothelial and blood component abnormalities in coronary arteries. Asymmetric dimethylarginine (ADMA) can damage the endothelium of the heart or blood vessels in patients with non-valvular atrial fibrillation (NVAF), causing changes in levels of biological indicators. Our aim was to analyze the relationship between ADMA and CSFP in NVAF patients. METHODS: We consecutively enrolled 134 patients diagnosed with NVAF and underwent coronary angiography, 50 control patients without a history of atrial fibrillation and with normal coronary angiographic flow were included at the same time. Based on the corrected TIMI frame count (CTFC), the NVAF patients were categorized into two groups, CTFC ≤27 frames and CTFC >27 frames. Plasma ADMA, P-selectin (p-sel), von Willebrand factor (vWF), D-dimer (D-Di), plasminogen activator inhibitor 1 (PAI-1), and nitric oxide (NO) were detected by ELISA in the different groups. RESULTS: We found that plasma ADMA levels were significantly higher among NVAF patients in the CTFC >27 grade group compared with the control or CTFC ≤27 group. In addition, the levels of blood cells and endothelium-related biomarkers (NO, P-selectin, vWF, D-Di, and PAI-1) were significantly altered and correlated with ADMA levels. Multifactorial analysis showed that plasma ADMA (odd ratio [OR; 95% CI]: 1.65 [1.21-2.43], p < 0.001) and left atrial internal diameter (OR [95% CI]: 1.04 [1.02, 1.1], p < 0.001) could be used as independent risk factors for the development of CSFP in patients with NVAF. The ROC curves of ADMA can predict the development of CSFP in NVAF patients. The minimum diagnostic concentration for the development of CSFP in patients was 2.31 µmol/L. CONCLUSION: Our study demonstrated that CSFP in NVAF patients was associated with high levels of ADMA and left atrial internal diameter. Therefore, aggressive preoperative detection and evaluation of ADMA and left atrial internal diameter can help deal with the intraoperative presence of CSFP.

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.

The relationship between Nuclear Factor-Kappa B and Inhibitor-Kappa B parameters with clinical course in COVID-19 patients.

BACKGROUND: We aimed to investigate the serum Nuclear Factor Kappa B (NF-κB) p105, NF-κB p65 and Inhibitor Kappa B Alpha (IκBα) levels in patients with mild/moderate Coronavirus Disease 2019 (COVID-19) and their association with the course of the disease. MATERIALS AND METHODS: Blood was drawn from 35 COVID-19 patients who applied to the Department of Emergency Medicine of Istanbul University-Cerrahpasa at the time of diagnosis and from 35 healthy individuals. The patients were evaluated to have mild/moderate degree of disease according to National Early Warning Score 2 (NEWS2) scoring and computed tomography (CT) findings. The markers were studied in the obtained serum samples, using enzyme-linked immunoassay (ELISA). Receiver Operating Characteristic (ROC) analysis was performed. Statistical significance was evaluated to be p < 0.05. RESULTS: NF-κB p105 levels were significantly higher in the COVID-19 group compared to the control group. C-reactive protein (CRP), D-dimer, ferritin levels of the patients were significantly higher (p < 0.001) compared to the control group, while the lymphocyte count was found lower (p = 0.001). IκBα and NF-κB p65 levels are similar in both groups. Threshold value for NF-κB p105 was above 0.78 ng/mL, sensitivity was 71.4% and specificity was 97.1% (p < 0.05). NF-κB p105 levels at the time of diagnosis of the patients who required supplemental oxygen (O2), were significantly higher (p < 0.01). CONCLUSIONS: The rise in serum NF-κB p105 levels during the early stages of infection holds diagnostic value. Besides its relation with severity might have a prognostic feature to foresee the requirement for supplemental O2 that occurs during hospitalization.

Asymmetric dimethylarginine correlates with indicators of prethrombotic state in patients with nonvalvular atrial fibrillation.

OBJECTIVE: The mechanism of asymmetric dimethylarginine (ADMA) in thrombosis in patients with nonvalvular atrial fibrillation (NVAF) is still unclear. Our aim was to investigate the relationship between ADMA and indicators of prethrombotic state in NVAF patients and to analyze the predictive role of ADMA in NVAF thrombosis. METHODS: A total of 192 NVAF patients were continuously selected from January 2023 to October 2023. Plasma ADMA levels were measured by high-performance liquid chromatography. P-selectin (P-sel), von Willebrand factor (vWF), D-dimer (D-D), and plasminogen activator inhibitor-1 (PAI-1) levels were measured by enzyme-linked immunosorbent assay (ELISA). Nitric oxide (NO) levels were measured by the nitrate reductase assay for plasma nitrite/nitrate, then the Griess method (Shanghai Hailian Biotechnology Co., Shanghai, China) was used to calculate plasma NO levels. RESULTS: In our study, ADMA levels were significantly elevated and positively correlated with P-sel, vWF, D-D, and PAI-1, whereas NO levels were significantly negatively correlated with these prethrombotic factors in NVAF. Furthermore, multifactorial logistic regression analysis showed that ADMA and LA diameter were independent predictors of high thrombosis risk (CHA2DS2-VASc ≥2 score) in patients with NVAF. CONCLUSIONS: Our findings suggested that ADMA correlated with the prethrombotic state in NVAF and that reduction of ADMA levels in NVAF patients may be a novel therapeutic strategy for thrombosis risk reduction.

Investigation of coagulation and proteomics profiles in symptomatic feline hypertrophic cardiomyopathy and healthy control cats.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a crucial heart disease in cats. The clinical manifestations of HCM comprise pulmonary edema, dyspnea, syncope, arterial thromboembolism (ATE), and sudden cardiac death. D-dimer and prothrombin time (PT) are powerful biomarkers used to assess coagulation function. Dysregulation in these two biomarkers may be associated with HCM in cats. This study aims to assess D-dimer levels, PT, and proteomic profiling in healthy cats in comparison to cats with symptomatic HCM. RESULTS: Twenty-nine client-owned cats with HCM were enrolled, including 15 healthy control and 14 symptomatic HCM cats. The D-dimer concentration and PT were examined. Proteomic analysis was conducted by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry and liquid chromatography-tandem mass spectrometry (LC-MS/MS). In symptomatic cats, D-dimer levels were statistically significantly higher (mean ± SEM: 372.19 ng/ml ± 58.28) than in healthy cats (mean ± SEM: 208.54 ng/ml ± 10.92) with P-value of less than 0.01, while PT was statistically significantly lower in symptomatic cats (mean ± SEM: 9.8 s ± 0.15) compared to healthy cats (mean ± SEM: 11.08 s ± 0.23) with P-value of less than 0.0001. The proteomics analysis revealed upregulation of integrin subunit alpha M (ITGAM), elongin B (ELOB), and fibrillin 2 (FBN2) and downregulation of zinc finger protein 316 (ZNF316) and ectonucleoside triphosphate diphosphohydrolase 8 (ENTPD8) in symptomatic HCM cats. In addition, protein-drug interaction analysis identified the Ras signaling pathway and PI3K-Akt signaling pathway. CONCLUSIONS: Cats with symptomatic HCM have higher D-dimer and lower PT than healthy cats. Proteomic profiles may be used as potential biomarkers for the detection and management of HCM in cats. The use of D-dimer as a biomarker for HCM detection and the use of proteomic profiling for a better understanding of disease mechanisms remain to be further studied in cats.

Prospective analysis of pre and postoperative laboratory parameters associated with thrombosis in patients with ovarian cancer.

Patients with ovarian cancer have a high risk of developing thrombosis. We aimed to investigate pre and post operative biomarkers associated with thrombosis including deep vein thrombosis and pulmonary thromboembolism in patients treated for ovarian cancer. We collected pre and post operative blood samples from 133 patients undergoing surgery for ovarian cancer between December 2021 and August 2022. The measured parameters were white blood cell count, hemoglobin, platelets, monocytes, serum glucose, CA125, D-dimer, fibrinogen, prothrombin time, activated partial thromboplastin time, fibrinogen degradation products, antithrombin III, protein C, protein S, plasminogen, plasminogen activator inhibitor 1, homocysteine, N-terminal pro-brain natriuretic peptide, interleukin 6, thrombopoietin, soluble P-selectin and granulocyte stimulating factor. Body mass index of patients were collected. Differences between patients who developed thrombosis and those without were compared with Wilcoxon rank-sum test and we analyzed the continuous variables using logistic regression. Twenty-one (15.8%) patients developed thrombosis ranging from 6 to 146 days (median 15 days) after surgery. Pre operative values of homocysteine (p = 0.033) and IL-6 (p = 0.043) were significantly increased and post operative aPTT (p = 0.022) was prolonged and plasminogen (p = 0.041) was decreased in patients with thrombosis. It is important to find novel biomarkers for thrombosis to carefully manage patients who are prone to develop thrombosis despite preventive measures were applied.

External validation of the CHEDDAR score for suspected pulmonary embolism in patients with SARS-CoV-2 infection in an independent cohort.

The accuracy of the classic scores that help stratify the pretest clinical probability of pulmonary embolism (PE) in SARS-CoV-2 infection (COVID-19) is low. Therefore, to estimate the risk of PE in these patients, a new set of guidelines must be established. The recently published CHEDDAR score proposes a new diagnostic strategy to reduce the use of computed tomography pulmonary angiography (CTPA) in non-critically ill SARS-COV-2 patients with suspected PE. According to the nomogram, patients are segregated into low-risk (< 182 points) or high-risk (≥ 182 points) based on the best cut-off value to discard PE in the original cohort. We aimed to externally validate this diagnostic strategy in an independent cohort. We analyzed data from two retrospective cohorts of hospitalized non-critically ill COVID-19 patients who underwent a CTPA due to suspicion for PE. CHEDDAR score was applied. As per the CHEDDAR nomogram, patients were classified as having a low or high clinical pre-test probability. Of the 270 patients included, 69 (25.5%) had PE. Applying the CHEDDAR score, 182 (67.4%) patients could have had PE excluded without imaging. Among 58 patients classified as having high clinical pre-test probability, 39 (67.2%) had PE. Sensitivity, specificity, positive and negative predictive values, and AUC were 56%, 90%, 67%, 85%, and 0.783 (95% CI 0.71-0.85), respectively. We provide external validation of the CHEDDAR score in an independent cohort. Even though the CHEDDAR score showed good discrimination capacity, caution is required in patients classified as having low clinical pre-test probability with a D-dimer value > 3000 ng/mL, and a RALE score ≥ 4.

A Case of False Elevation of D-Dimer and Elimination Methods.

BACKGROUND: There are many methods for the detection of D-dimer in clinical laboratories. Immunoturbidimetric assays are widely used because of its high sensitivity and specificity [1-3]. However, this method may be affected by the interference of rheumatoid factor (RF), heterophilic antibodies, and other unknown proteins, and its falsity will increase, thus affecting clinical diagnosis. METHODS: This paper reports the cause analysis of a case of spurious D-dimer increase and four corresponding elimination methods: double dilution of the original specimen, detection of fibrin degradation product (FDP) level, addition of heterophilic blocking reagent, and comparison between different instruments. RESULTS: It was confirmed that there were special antibodies in the patient's body by four methods, which had non-specific reactions with D-dimer reagents, resulting in false increases of results. CONCLUSIONS: When the coagulation function results of patients show isolated increases in D-dimer, or the results are inconsistent with clinical symptoms, laboratory personnel should consider the possibility of interference factors, and conduct effective treatment to obtain correct test results, and thus reduce the occurrence of medical adverse events caused by inaccurate test results.