Vascular endothelial growth factor-<em>D</em> (VEGF-<em>D</em>) binds and activates the endothelial cell tyrosine kinase receptors VEGF receptor-<em>2</em> (VEGFR-<em>2</em>) and VEGF receptor-3 (VEGFR-3), is mitogenic for endothelial cells, and shares structural homology and receptor specificity with VEGF-C. The primary translation product of VEGF-<em>D</em> has long N- and C-terminal polypeptide extensions in addition to a central VEGF homology domain (VH<em>D</em>). The VH<em>D</em> of VEGF-<em>D</em> is sufficient to bind and activate VEGFR-<em>2</em> and VEGFR-3. Here we report that VEGF-<em>D</em> is proteolytically processed to release the VH<em>D</em>. Studies in <em>2</em>93EBNA cells demonstrated that VEGF-<em>D</em> undergoes N- and C-terminal cleavage events to produce numerous secreted polypeptides including a fully processed form of M(r) approximately <em>2</em>1,000 consisting only of the VH<em>D</em>, which is predominantly a non-covalent <em>dimer</em>. Biosensor analysis demonstrated that the VH<em>D</em> has approximately <em>2</em>90- and approximately 40-fold greater affinity for VEGFR-<em>2</em> and VEGFR-3, respectively, compared with unprocessed VEGF-<em>D</em>. In situ hybridization demonstrated that embryonic lung is a major site of expression of the VEGF-<em>D</em> gene. Processed forms of VEGF-<em>D</em> were detected in embryonic lung indicating that VEGF-<em>D</em> is proteolytically processed in vivo.

Coagulopathy in corona virus infection has been shown to be associated with high mortality with high <em>D</em>-<em>dimers</em> being a particularly important marker for the coagulopathy.¹ In the latest paper from the same group, the use of anticoagulant therapy with heparin was shown to decrease mortality as well. ^<em>2</em> This is especially so in patients i) who have met the sepsis induced coagulopathy (SIC) criteria ≥4 (40.0% vs 64.<em>2</em>%, P=0.0<em>2</em>9) compared to those with SIC score <4 (<em>2</em>9.0% vs <em>2</em><em>2</em>.6%, P=0.419).or ii) with markedly elevated <em>D</em>-<em>dimer</em> (greater than six-fold at the upper limit of normal).

Kinetic and equilibrium properties are compared for a monomeric kinesin construct (K33<em>2</em>) and a <em>dimer</em>ic construct (K379). MtK379 has a low affinity (5 x 10(4) M(-1)) and a high affinity (5 x 10(6) M(-1)) binding site for mant A<em>D</em>P while MtK33<em>2</em> has a single low affinity site (5 x 10(4) M(-1)). Rate constants of dissociation of mant A<em>D</em>P are <1 s(-1) for the high affinity site and 75-100 s(-1) for the low affinity site for MtK379. For MtK33<em>2</em>, the effective rate constant is <em>2</em>00-300 s(-1). It is proposed that the two heads of the <em>dimer</em> are different through the interaction with the microtubule, a strongly bound head with low affinity for <em>2</em>'-(3')-O-(N-methylanthraniloyl) adenosine 5'-diphosphate (mant A<em>D</em>P), similar to the single strongly bound head of the monomer and a weakly bound or detached head with high affinity for mant A<em>D</em>P. Rate of binding of mant A<em>D</em>P gave an "S"-shaped dependence on concentration for MtK379 and a hyperbolic dependence for MtK33<em>2</em>. Binding of K379 x mant A<em>D</em>P <em>dimer</em> to microtubules releases only one mant A<em>D</em>P at a rate of 50 s(-1). The second strongly bound mant A<em>D</em>P is released by binding of nucleotides to the other head. Rates are 100 s(-1) for ATP, 30 s(-1) for AMPPNP or ATPgammaS, and <em>2</em> s(-1) for A<em>D</em>P. The rate of binding of mant ATP to MtK379 showed an "S"-shaped concentration dependence and limiting rate at zero concentration is <1 s(-1) while MtK33<em>2</em> gave a hyperbolic dependence and limiting rate of 100 s(-1). The limiting rate is determined by the rate of dissociation of mant A<em>D</em>P in the hydrolysis cycle. The evidence is consistent with an interacting site model in which binding of ATP to one head is required for release of A<em>D</em>P from the other head in the hydrolysis cycle. This model, in which the cycles are maintained partly out of phase, is an extension of the alternating site model of Hackney (Hackney, <em>D</em>. <em>D</em>. (1994) Proc. Nat. Acad. Sci. U.S.A. 91, 6865-6869). It provides a basis for a processive mechanism.

Yeast DNA polymerase <em>delta</em> (Pol<em>delta</em>) consists of three subunits encoded by the POL3, POL31, and POL3<em>2</em> genes. Each of these genes was cloned under control of the galactose-inducible GAL1-10 promoter and overexpressed in various combinations. Overexpression of all three genes resulted in a 30-fold overproduction of Pol<em>delta</em>, which was identical in enzymatic properties to Pol<em>delta</em> isolated from a wild-type yeast strain. Whereas overproduction of POL3 together with POL3<em>2</em> did not lead to an identifiable Pol3p.Pol3<em>2</em>p complex, a chromatographically distinct and novel complex was identified upon overproduction of POL3 and POL31. This two-subunit complex, designated Pol<em>delta</em>*, is structurally and functionally analogous to mammalian Pol<em>delta</em>. The properties of Pol<em>delta</em>* and Pol<em>delta</em> were compared. A gel filtration analysis showed that Pol<em>delta</em>* is a hetero<em>dimer</em> (Pol3p.Pol31p) and Pol<em>delta</em> a <em>dimer</em> of a heterotrimer, (Pol3p.Pol31p.Pol3<em>2</em>p)<em>2</em>. In the absence of proliferating cell nuclear antigen (PCNA), Pol<em>delta</em>* showed a processivity of <em>2</em>-3 on poly(dA). oligo(dT) compared with 5-10 for Pol<em>delta</em>. In the presence of PCNA, both enzymes were fully processive on this template. DNA replication by Pol<em>delta</em>* on a natural DNA template was dependent on PCNA and on replication factor C. However, Pol<em>delta</em>*-mediated DNA synthesis proceeded inefficiently and was characterized by frequent pause sites. Reconstitution of Pol<em>delta</em> was achieved upon addition of Pol3<em>2</em>p to Pol<em>delta</em>*.

The 2019 coronavirus disease (COVID-19) presents with a large variety of clinical manifestations ranging from asymptomatic carrier state to severe respiratory distress, multiple organ dysfunction and death. While it was initially considered primarily a respiratory illness, rapidly accumulating data suggests that COVID-19 results in a unique, profoundly prothrombotic milieu leading to both arterial and venous thrombosis. Consistently, elevated D-dimer level has emerged as an independent risk factor for poor outcomes, including death. Several other laboratory markers and blood counts have also been associated with poor prognosis, possibly due to their connection to thrombosis. At present, the pathophysiology underlying the hypercoagulable state is poorly understood. However, a growing body of data suggests that the initial events occur in the lung. A severe inflammatory response, originating in the alveoli, triggers a dysfunctional cascade of inflammatory thrombosis in the pulmonary vasculature, leading to a state of local coagulopathy. This is followed, in patients with more severe disease, by a generalized hypercoagulable state that results in macro- and microvascular thrombosis. Of concern, is the observation that anticoagulation may be inadequate in many circumstances, highlighting the need for alternative or additional therapies. Numerous ongoing studies investigating the pathophysiology of the COVID-19 associated coagulopathy may provide mechanistic insights that can direct appropriate interventional strategies.

Keywords: COVID-19; SARS-CoV-2; coagulopathy; inflammation; thrombosis.

Objectives: Recent studies have reported a high prevalence of thrombotic events in coronavirus disease 2019. However, the significance of thromboembolic complications has not been widely appreciated. The purpose of this review is to provide current knowledge of this serious problem.

Design: Narrative review.

Data sources: Online search of published medical literature through PubMed using the term "COVID-19," "SARS," "acute respiratory distress syndrome," "coronavirus," "coagulopathy," "thrombus," and "anticoagulants."

Study selection and data extraction: Articles were chosen for inclusion based on their relevance to coagulopathy and thrombosis in coronavirus disease 2019, and anticoagulant therapy. Reference lists were reviewed to identify additional relevant articles.

Data synthesis: Coronavirus disease 2019 is associated with a strikingly high prevalence of coagulopathy and venous thromboembolism that may contribute to respiratory deterioration. Monitoring coagulation variables is important, as abnormal coagulation tests are related to adverse outcomes and may necessitate adjuvant antithrombotic interventions. In the initial phase of the infection, D-dimer and fibrinogen levels are increased, while activated partial prothrombin time, prothrombin time, and platelet counts are often relatively normal. Increased D-dimer levels three times the upper limit of normal may trigger screening for venous thromboembolism. In all hospitalized patients, thromboprophylaxis using low-molecular-weight heparin is currently recommended. The etiology of the procoagulant responses is complex and thought to be a result of specific interactions between host defense mechanisms and the coagulation system. Although the coagulopathy is reminiscent of disseminated intravascular coagulation and thrombotic microangiopathy, it has features that are markedly distinct from these entities.

Conclusions: Severe acute respiratory syndrome coronavirus 2/coronavirus disease 2019 frequently induces hypercoagulability with both microangiopathy and local thrombus formation, and a systemic coagulation defect that leads to large vessel thrombosis and major thromboembolic complications, including pulmonary embolism in critically ill hospitalized patients. D-dimers and fibrinogen levels should be monitored, and all hospitalized patients should undergo thromboembolism prophylaxis with an increase in therapeutic anticoagulation in certain clinical situations.

A recently developed pneumonia caused by SARS-CoV-<em>2</em> bursting in Wuhan, China, has quickly spread across the world. We report the clinical characteristics of 8<em>2</em> cases of death from COVI<em>D</em>-19 in a single center. Clinical data on 8<em>2</em> death cases laboratory-confirmed as SARS-CoV-<em>2</em> infection were obtained from a Wuhan local hospital's electronic medical records according to previously designed standardized data collection forms. All patients were local residents of Wuhan, and a large proportion of them were diagnosed with severe illness when admitted. <em>D</em>ue to the overwhelming of our system, a total of 14 patients (17.1%) were treated in the ICU, 83% of deaths never received Critical Care Support, only 40% had mechanical ventilation support despite 100% needing oxygen and the leading cause of death being pulmonary. Most of the patients who died were male (65.9%). More than half of the patients who died were older than 60 years (80.5%), and the median age was 7<em>2</em>.5 years. The bulk of the patients who died had comorbidities (76.8%), including hypertension (56.1%), heart disease (<em>2</em>0.7%), diabetes (18.3%), cerebrovascular disease (1<em>2</em>.<em>2</em>%), and cancer (7.3%). Respiratory failure remained the leading cause of death (69.5%), followed by sepsis/MOF (<em>2</em>8.0%), cardiac failure (14.6%), hemorrhage (6.1%), and renal failure (3.7%). Furthermore, respiratory, cardiac, hemorrhagic, hepatic, and renal damage were found in 100%, 89%, 80.5%, 78.0%, and 31.7% of patients, respectively. On admission, lymphopenia (89.<em>2</em>%), neutrophilia (74.3%), and thrombocytopenia (<em>2</em>4.3%) were usually observed. Most patients had a high neutrophil-to-lymphocyte ratio of >5 (94.5%), high systemic immune-inflammation index of >500 (89.<em>2</em>%), and increased C-reactive protein (100%), lactate dehydrogenase (93.<em>2</em>%), and <em>D</em>-<em>dimer</em> (97.1%) levels. A high level of IL-6 (>10 pg/ml) was observed in all detected patients. The median time from initial symptoms to death was 15 days (IQR 11-<em>2</em>0), and a significant association between aspartate aminotransferase (p = 0.00<em>2</em>), alanine aminotransferase (p = 0.037) and time from initial symptoms to death was remarkably observed. Older males with comorbidities are more likely to develop severe disease and even die from SARS-CoV-<em>2</em> infection. Respiratory failure is the main cause of COVI<em>D</em>-19, but the virus itself and cytokine release syndrome-mediated damage to other organs, including cardiac, renal, hepatic, and hemorrhagic damage, should be taken seriously as well.

Background: Patients with COVID-19 can develop acute respiratory distress syndrome (ARDS), which is associated with high mortality. The aim of this study was to examine the functional and morphological features of COVID-19-associated ARDS and to compare these with the characteristics of ARDS unrelated to COVID-19.

Methods: This prospective observational study was done at seven hospitals in Italy. We enrolled consecutive, mechanically ventilated patients with laboratory-confirmed COVID-19 and who met Berlin criteria for ARDS, who were admitted to the intensive care unit (ICU) between March 9 and March 22, 2020. All patients were sedated, paralysed, and ventilated in volume-control mode with standard ICU ventilators. Static respiratory system compliance, the ratio of partial pressure of arterial oxygen to fractional concentration of oxygen in inspired air, ventilatory ratio (a surrogate of dead space), and D-dimer concentrations were measured within 24 h of ICU admission. Lung CT scans and CT angiograms were done when clinically indicated. A dataset for ARDS unrelated to COVID-19 was created from previous ARDS studies. Survival to day 28 was assessed.

Findings: Between March 9 and March 22, 2020, 301 patients with COVID-19 met the Berlin criteria for ARDS at participating hospitals. Median static compliance was 41 mL/cm H₂O (33-52), which was 28% higher than in the cohort of patients with ARDS unrelated to COVID-19 (32 mL/cm H₂O [25-43]; p<0·0001). 17 (6%) of 297 patients with COVID-19-associated ARDS had compliances greater than the 95th percentile of the classical ARDS cohort. Total lung weight did not differ between the two cohorts. CT pulmonary angiograms (obtained in 23 [8%] patients with COVID-19-related ARDS) showed that 15 (94%) of 16 patients with D-dimer concentrations greater than the median had bilateral areas of hypoperfusion, consistent with thromboembolic disease. Patients with D-dimer concentrations equal to or less than the median had ventilatory ratios lower than those of patients with D-dimer concentrations greater than the median (1·66 [1·32-1·95] vs 1·90 [1·50-2·33]; p=0·0001). Patients with static compliance equal to or less than the median and D-dimer concentrations greater than the median had markedly increased 28-day mortality compared with other patient subgroups (40 [56%] of 71 with high D-dimers and low compliance vs 18 [27%] of 67 with low D-dimers and high compliance, 13 [22%] of 60 with low D-dimers and low compliance, and 22 [35%] of 63 with high D-dimers and high compliance, all p=0·0001).

Interpretation: Patients with COVID-19-associated ARDS have a form of injury that, in many aspects, is similar to that of those with ARDS unrelated to COVID-19. Notably, patients with COVID-19-related ARDS who have a reduction in respiratory system compliance together with increased D-dimer concentrations have high mortality rates.

Funding: None.

The recent emergence of SARS-CoV-<em>2</em> and the ensuing global pandemic has presented a health emergency of unprecedented magnitude. Recent clinical data has highlighted that COVI<em>D</em>-19 is associated with a significant risk of thrombotic complications ranging from microvascular thrombosis, venous thromboembolic disease and stroke. Importantly, thrombotic complications are markers of severe COVI<em>D</em>-19 and are associated with multi-organ failure and increased mortality. The evidence to date supports the concept that the thrombotic manifestations of severe COVI<em>D</em>-19 is due to the ability of SARS-CoV-<em>2</em> to invade endo¬thelial cells via angiotensin-converting enzyme <em>2</em> (ACE<em>2</em>), which is expressed on the endothelial cell surface. However, in patients with COVI<em>D</em>-19 the subsequent endothelial inflammation, complement activation, thrombin generation, platelet and leukocyte recruitment, and the initiation of innate and adaptive immune responses culminate in immunothrombosis, ultimately causing (micro)thrombotic compli¬cations such as deep vein thrombosis, pulmonary embolism and stroke. Accordingly, the activation of coagulation (e.g. as measured with plasma <em>D</em>-<em>dimer</em>) and thrombocytopenia have emerged as prognostic markers in COVI<em>D</em>-19. Given thrombotic complications are central determinants of the high mortality rate in COVI<em>D</em>-19, strategies to prevent thrombosis are of critical importance. A number of antithrombotic drugs have been proposed as potential therapies to prevent COVI<em>D</em>-19-associated thrombosis, including, heparin, FXII inhibitors, fibrinolytic drugs, nafamostat and dipyridamole, many of which also possess pleiotropic anti-inflammatory or anti-viral effects. The growing awareness and mechanistic understanding of the prothrombotic state of COVI<em>D</em>-19 patients is driving efforts to more stringent diagnostic screening for thrombotic compli¬cations and to the early institution of antithrombotic drugs, for both the prevention and therapy of thrombotic complications. The shifting paradigm of diagnostic and treatment strategies holds significant promise to reduce the burden of thrombotic complications and ultimately improve the prognosis for patients with COVI<em>D</em>-19.

<strong class="sub-title"> Keywords: </strong> COVI<em>D</em>-19; SARS-CoV-<em>2</em>; coagulopathy; deep vein thrombosis; stroke.

The metallochromic indicator 4-(<em>2</em>-pyridylazo)resorcinol (PAR) has been used at pH 7.0 to monitor the mercurial-promoted Zn<em>2</em>+ release from Escherichia coli aspartate transcarbamoylase and Zn<em>2</em>+ uptake by regulatory <em>dimers</em> upon displacement of the mercurial reagent with <em>2</em>-mercaptoethanol. The release of Zn<em>2</em>+ (as reflected by a yellow to orange color change in PAR solutions) is linked to dissociation of the enzyme since the six Zn<em>2</em>+ bonding domains stabilize catalytic and regulatory chain contacts; the rebinding of Zn<em>2</em>+ produces enzyme assembly and a corresponding decrease in the amount of PAR-Zn<em>2</em>+ complex. Using greater than 10-fold PAR to free Zn<em>2</em>+ at pH 7.0, <em>delta</em> epsilon = 6.6 +/- 0.<em>2</em> X 10(4) M-1 cm-1 at 500 nm (<em>2</em>0 degrees C) for (PAR)<em>2</em>Zn<em>2</em>+ complex formation (beta'<em>2</em> approximately equal to 10(1<em>2</em>) M-1). In kinetic studies at pH 7.0, PAR (10(-4) M) has been used to measure the instantaneous concentration of Zn<em>2</em>+ released from micromolar quantities of protein; second-order k = <em>2</em> X 10(7) M-1 s-1 for forming the 1:1 PAR:Zn<em>2</em>+ complex. These properties of PAR-Zn<em>2</em>+ interactions make PAR a generally useful reagent for studying Zn<em>2</em>+ release from proteins.

BACKGROUND

Single-detector-row computed tomography (CT) has a low sensitivity for pulmonary embolism and must be combined with venous-compression ultrasonography of the lower limbs. We evaluated whether the use of D-dimer measurement and multidetector-row CT, without lower-limb ultrasonography, might safely rule out pulmonary embolism.

METHODS

We included 756 consecutive patients with clinically suspected pulmonary embolism from the emergency departments of three teaching hospitals and managed their cases according to a standardized sequential diagnostic strategy. All patients were followed for three months.

RESULTS

Pulmonary embolism was detected in 194 of the 756 patients (26 percent). Among the 82 patients with a high clinical probability of pulmonary embolism, multidetector-row CT showed pulmonary embolism in 78, and 1 patient had proximal deep venous thrombosis and a CT scan that was negative for pulmonary embolism. Of the 674 patients without a high probability of pulmonary embolism, 232 (34 percent) had a negative D-dimer assay and an uneventful follow-up; CT showed pulmonary embolism in 109 patients. CT and ultrasonography were negative in 318 patients, of whom 3 had a definite thromboembolic event and 2 died of possible pulmonary embolism during follow-up (three-month risk of thromboembolism, 1.7 percent; 95 percent confidence interval, 0.7 to 3.9). Two patients had proximal deep venous thrombosis and a negative CT scan (risk, 0.6 percent; 95 percent confidence interval, 0.2 to 2.2). The overall three-month risk of thromboembolism in patients without pulmonary embolism would have been 1.5 percent (95 percent confidence interval, 0.8 to 3.0) if the D-dimer assay and multidetector-row CT had been the only tests used to rule out pulmonary embolism and ultrasonography had not been performed.

CONCLUSIONS

Our data indicate the potential clinical use of a diagnostic strategy for ruling out pulmonary embolism on the basis of D-dimer testing and multidetector-row CT without lower-limb ultrasonography. A larger outcome study is needed before this approach can be adopted.

Antibody responses generated by mice to the dengue-<em>2</em> virus NS1 protein (<em>D</em>-<em>2</em>V NS1) were influenced by MHC class II (I-A) haplotype but each antiserum cross-reacted with human fibrinogen, thrombocytes and endothelial cells. To investigate these findings, a highly avid subclone (MAb 1G5.4-A1-C3) was selected from a parent hybridoma that secreted a monoclonal antibody (MAb) specific for the native <em>dimer</em>ic form of <em>D</em>-<em>2</em>V NS1. When MAb reactions were compared using a panel of overlapping synthetic peptides covering the entire protein sequence, <em>dimer</em> specificity was found to be a weak reaction with multiple ELK-type motifs present in either the positive (E/<em>D</em>-hydrophobic-K/R) or negative (K/R-hydrophobic-<em>D</em>/E) orientations. MAb 1G5.4-A1-C3 and highly avid anti-NS1 polyclonal antisera reacted with the NS1 proteins of the four dengue virus serotypes, but only weakly reacted with the NS1 proteins of the other flaviviruses. MAb 1G5.4-A1-C3 and several other anti-NS1 MAbs produced haemorrhage in mice, cross-reacted with human fibrinogen, thrombocytes and endothelial cells, with known epitopes or active sites on human clotting factors and integrin/adhesin proteins present on these cells. <em>D</em>-<em>2</em>V NS1 bound to human endothelial cells via a site within its N-terminal region, which led to significantly increased binding of avid anti-NS1 antibodies. These results identified a potential role of both 'antigenic' and 'biochemical' mimicry in dengue haemorrhagic fever pathogenesis, consistent with clinical data.

BACKGROUND

Activation and coagulation biomarkers were measured within the Strategies for Management of Antiretroviral Therapy (SMART) trial. Their associations with opportunistic disease (OD) in human immunodeficiency virus (HIV)-positive patients were examined.

METHODS

Inflammatory (high-sensitivity C-reactive protein [hsCRP], interleukin-6 [IL-6], amyloid-A, and amyloid-P) and coagulation (<em>D</em>-<em>dimer</em> and prothrombin-fragment 1+<em>2</em>) markers were determined. Conditional logistic regression analyses were used to assess associations between these biomarkers and risk of O<em>D</em>.

RESULTS

The 91 patients who developed an O<em>D</em> were matched to 18<em>2</em> control subjects. Patients with an hsCRP level>> or =5 microg/mL at baseline had a 3.5 higher odds of O<em>D</em> (95% confidence interval [CI], 1.5-8.1) than did those with an hsCRP level <1 microg/mL (P=.003, by test for trend) and patients with an IL-6 level>> or =3 pg/mL at baseline had a <em>2</em>.4 higher odds of O<em>D</em> (95% CI, 1.0-5.4) than did those with an IL-6 level <1.5 pg/mL (P=.0<em>2</em>, by test for trend). No other baseline biomarkers predicted development of an O<em>D</em>. Latest follow-up hsCRP level for those with an hsCRP level>> or =5 microg/mL (compared with a level <1 microg/mL; odds ratio [OR], 7.6; 95% CI, <em>2</em>.0-<em>2</em>8.5; [P=.00<em>2</em>, by test for trend), latest amyloid-A level for those with an amyloid-A level>> or =6 mg/L (compared with a level (<em>2</em> mg/L; OR, 3.8; 95% CI, 1.1-13.4; P=.03, by test for trend), and latest IL-6 level for those with an IL-6 level>> or =3 pg/mL (compared with a level <1.5 pg/mL; OR <em>2</em>.4; 95% CI, 0.7-8.8; P=.04, by test for trend) were also associated with development of an O<em>D</em>.

CONCLUSIONS

Higher IL-6 and hsCRP levels independently predicted development of OD. These biomarkers could provide additional prognostic information for predicting the risk of OD.

BACKGROUND

Systemic activation of hemostasis is frequently observed in cancer patients, even in the absence of thrombosis. Moreover, this activation has been implicated in tumor progression, angiogenesis and metastatic spread. Increased levels of D-dimer, which is a degradation product of cross-linked fibrin, indicate a global activation of hemostasis and fibrinolysis.

METHODS

In a prospective and observational cohort study, we assessed the prognostic value of D-dimer levels for overall survival and mortality risk in 1178 cancer patients included in the Vienna Cancer and Thrombosis Study (CATS). Patients were followed over 2 years at regular intervals until occurrence of symptomatic venous thromboembolism or death. D-dimer levels were measured with a quantitative D-dimer latex agglutination assay

RESULTS

The main solid tumors were malignancies of the lung (n=182), breast (n=157), lower gastrointestinal tract (n=133), pancreas (n=74), stomach (n=50), kidney (n=37), prostate (n=133), and brain (n=148); 201 of the patients had hematologic malignancies; 63 had other tumors. During a median follow-up of 731 days, 460 (39.0%) patients died. The overall survival probabilities for patients with D-dimer levels categorized into four groups based on the 1(st), 2(nd) and 3(rd) quartiles of the D-dimer distribution in the total study population were 88%, 82%, 66% and 53% after 1 year, and 78%, 66%, 50% and 30% after 2 years, respectively (P<0.001). The univariate hazard ratio of D-dimer (per double increase) for mortality was 1.5 (95% confidence interval: 1.4-1.6, P<0.001) and remained increased in multivariable analysis including tumor subgroups, age, sex and venous thromboembolism.

CONCLUSIONS

High D-dimer levels were associated with poor overall survival and increased mortality risk in cancer patients.

In normal pregnancy, there is a marked increase in the procoagulant activity in maternal blood characterized by elevation of factors VII, X, VIII, fibrinogen and von Willebrand factor, which is maximal around term. This is associated with an increase in prothrombin fragments (PF1+<em>2</em>) and thrombin-antithrombin complexes. There is a decrease in physiological anticoagulants manifested by a significant reduction in protein S activity and by acquired activated protein C (APC) resistance. The overall fibrinolytic activity is impaired during pregnancy, but returns rapidly to normal following delivery. This is largely due to placental derived plasminogen activator inhibitor type <em>2</em> (PAI-<em>2</em>), which is present in substantial quantities during pregnancy. <em>D</em>-<em>dimer</em>, a specific marker of fibrinolysis resulting from breakdown of cross-linked fibrin polymer by plasmin, increases as pregnancy progresses. Overall, there is a 4- to 10-fold increased thrombotic risk throughout gestation and the postpartum period. Local haemostasis at the placental throphoblast level is characterized by increased tissue factor (TF) expression and low expression of the inhibitor TFPI. Microparticles derived from maternal endothelial cells and platelets, and from placental throphoblasts may contribute to the procoagulant effect. Local anticoagulant mechanisms on placental throphoblasts are important for counterbalance of the procoagulant milieu. <em>D</em>isruption of anticoagulant mechanisms, for example, autoantibodies, to annexin V may increase pregnancy complications in patients with antiphospholipid antibodies (APLA).

<strong class="sub-title">Objectives:</strong> To determine mortality rates among adults with critical illness from coronavirus disease <em>2</em>019.

<strong class="sub-title">Design:</strong> Observational cohort study of patients admitted from March 6, <em>2</em>0<em>2</em>0, to April 17, <em>2</em>0<em>2</em>0.

<strong class="sub-title">Setting:</strong> Six coronavirus disease <em>2</em>019 designated ICUs at three hospitals within an academic health center network in Atlanta, Georgia, United States.

<strong class="sub-title">Patients:</strong> Adults greater than or equal to 18 years old with confirmed severe acute respiratory syndrome-CoV-<em>2</em> disease who were admitted to an ICU during the study period.

Interventions: None.

<strong class="sub-title">Measurements and main results:</strong> Among <em>2</em>17 critically ill patients, mortality for those who required mechanical ventilation was 35.7% (59/165), with 4.8% of patients (8/165) still on the ventilator at the time of this report. Overall mortality to date in this critically ill cohort is 30.9% (67/<em>2</em>17) and 60.4% (131/<em>2</em>17) patients have survived to hospital discharge. Mortality was significantly associated with older age, lower body mass index, chronic renal disease, higher Sequential Organ Failure Assessment score, lower PaO<em>2</em>/FIO<em>2</em> ratio, higher D-dimer, higher C-reactive protein, and receipt of mechanical ventilation, vasopressors, renal replacement therapy, or vasodilator therapy.

<strong class="sub-title">Conclusions:</strong> Despite multiple reports of mortality rates exceeding 50% among critically ill adults with coronavirus disease <em>2</em>019, particularly among those requiring mechanical ventilation, our early experience indicates that many patients survive their critical illness.

CG7870 is a replication-selective oncolytic a<em>d</em>enovirus genetically engineere<em>d</em> to replicate preferentially in prostate tissue. In a previous phase I/II clinical trial of intraprostatic <em>d</em>elivery of CG7870 for locally recurrent prostate cancer this virus was well tolerate<em>d</em>. In this phase I stu<em>d</em>y CG7870 was a<em>d</em>ministere<em>d</em> as a single intravenous infusion in a group-sequential <em>d</em>ose escalation <em>d</em>esign (1 x 10(10) to 6 x 10(1<em>2</em>) viral particles (vp)) to <em>2</em>3 patients with hormone-refractory metastatic prostate cancer. Flulike symptoms (fever, fatigue, rigors, nausea, an<em>d</em>/or vomiting) were the most common a<em>d</em>verse events. Three therapy-relate<em>d</em> gra<em>d</em>e 3 a<em>d</em>verse events were reporte<em>d</em>, one of which (fatigue) was serious. At <em>d</em>oses greater than 10(1<em>2</em>) vp all five patients experience<em>d</em> asymptomatic gra<em>d</em>e 1 to <em>2</em> transaminitis an<em>d</em>/or isolate<em>d</em> <em>d</em>-<em>dimer</em> elevations starting on <em>d</em>ay <em>2</em> through 8; <em>d</em>ose escalation was therefore halte<em>d</em> at 6 x 10(1<em>2</em>) vp. All teste<em>d</em> patients ha<em>d</em> CG7870 genomes present in the peripheral bloo<em>d</em> for at least 90 minutes after infusion; patients in the highest <em>d</em>ose group ha<em>d</em> persistence of genomes through <em>2</em>9 <em>d</em>ays. A "secon<em>d</em>ary" or "<em>d</em>elaye<em>d</em>" peak in plasma CG7870 genome copies (<em>d</em>efine<em>d</em> as a >10-fol<em>d</em> increase in CG7870 genomes from na<em>d</em>ir concentration) suggestive of active viral replication an<em>d</em> she<em>d</em><em>d</em>ing into the bloo<em>d</em>stream was <em>d</em>etecte<em>d</em> in 16/<em>2</em>3 (70%) patients. CG7870 was <em>d</em>etecte<em>d</em> in the saliva of 3 patients, whereas all urine samples teste<em>d</em> negative. All patients <em>d</em>evelope<em>d</em> antibo<em>d</em>ies to CG7870. Dose-relate<em>d</em> increases in interleukins 6 an<em>d</em> 10 (IL-6, IL-10) bloo<em>d</em> levels were <em>d</em>etecte<em>d</em>. The peak IL-6 concentration after CG7870 treatment was associate<em>d</em> with a transient, asymptomatic <em>d</em>ecrease in bloo<em>d</em> pressure. No partial or complete prostate-specific antigen (PSA) responses were observe<em>d</em>; however, 5 patients ha<em>d</em> a <em>d</em>ecrease in serum PSA of <em>2</em>5% to 49% following a single treatment, inclu<em>d</em>ing 3 of 8 patients at the highest <em>d</em>ose levels.

Objectives: To correlate a CT-based semi-quantitative score of pulmonary involvement in COVID-19 pneumonia with clinical staging of disease and laboratory findings. We also aimed to investigate whether CT findings may be predictive of patients' outcome.

<strong class="sub-title"> Methods: </strong> From March 6 to March <em>2</em><em>2</em>, <em>2</em>0<em>2</em>0, 130 symptomatic SARS-CoV-<em>2</em> patients were enrolled for this single-center analysis and chest CT examinations were retrospectively evaluated. A semi-quantitative CT score was calculated based on the extent of lobar involvement (0:0%; 1, < 5%; <em>2</em>:5-<em>2</em>5%; 3:<em>2</em>6-50%; 4:51-75%; 5, > 75%; range 0-5; global score 0-<em>2</em>5). Data were matched with clinical stages and laboratory findings. Survival curves and univariate and multivariate analyses were performed to evaluate the role of CT score as a predictor of patients' outcome.

<strong class="sub-title"> Results: </strong> Ground glass opacities were predominant in early-phase (≤ 7 days since symptoms' onset), while crazy-paving pattern, consolidation, and fibrosis characterized late-phase disease (> 7 days). CT score was significantly higher in critical and severe than in mild stage (p < 0.0001), and among late-phase than early-phase patients (p < 0.0001). CT score was significantly correlated with CRP (p < 0.0001, r = 0.6<em>2</em>04) and D-dimer (p < 0.0001, r = 0.66<em>2</em>5) levels. A CT score of ≥ 18 was associated with an increased mortality risk and was found to be predictive of death both in univariate (HR, 8.33; 95% CI, 3.19-<em>2</em>1.73; p < 0.0001) and multivariate analysis (HR, 3.74; 95% CI, 1.10-1<em>2</em>.77; p = 0.0348).

<strong class="sub-title"> Conclusions: </strong> Our preliminary data suggest the potential role of CT score for predicting the outcome of SARS-CoV-<em>2</em> patients. CT score is highly correlated with laboratory findings and disease severity and might be beneficial to speed-up diagnostic workflow in symptomatic cases.

Key points: • CT score is positively correlated with age, inflammatory biomarkers, severity of clinical categories, and disease phases. • A CT score ≥ 18 has shown to be highly predictive of patient's mortality in short-term follow-up. • Our multivariate analysis demonstrated that CT parenchymal assessment may more accurately reflect short-term outcome, providing a direct visualization of anatomic injury compared with non-specific inflammatory biomarkers.

<strong class="sub-title"> Keywords: </strong> COVID-19; Pneumonia; Severe acute respiratory syndrome coronavirus <em>2</em>; Tomography, X-ray computed.

<AbstractText>The Coronavirus <em>D</em>isease-<em>2</em>019 (COVI<em>D</em>-19), infected by severe acute respiratory syndrome coronavirus <em>2</em> (SARS-CoV-<em>2</em>), has caused a severe outbreak in China. The host immunity of COVI<em>D</em>-19 patients is unknown.</AbstractText><AbstractText>The routine laboratory tests and host immunity in COVI<em>D</em>-19 patients with different severity of illness were compared after patient admission.</AbstractText><AbstractText>A total of 65 SARS-CoV-<em>2</em>-positive patients were classified as mild (n=30), severe (n=<em>2</em>0), and extremely severe (n=15) illness. Many routine laboratory tests such as ferritin, lactate dehydrogenase and <em>D</em>-<em>dimer</em> were increased in severe and extremely severe patients. The absolute numbers of C<em>D</em>4+ T cells, C<em>D</em>8+ T cells and B cells were all gradually decreased with increased severity of illness. The activation markers such as HLA-<em>D</em>R and C<em>D</em>45RO expressed on C<em>D</em>4+ and C<em>D</em>8+ T cells were increased in severe and extremely severe patients compared with mild patients. The co-stimulatory molecule C<em>D</em><em>2</em>8 had opposite results. The percentage of natural regulatory T cells was decreased in extremely severe patients. The percentage of IFN-γ producing C<em>D</em>8+ T cells was increased in both severe and extremely severe patients compared with mild patients. The percentage of IFN-γ producing C<em>D</em>4+ T cells was increased in extremely severe patients. The IL-<em>2</em>R, IL-6, and IL-10 were all increased in extremely severe patients. The activation of <em>D</em>C and B cells was decreased in extremely severe patients.</AbstractText><AbstractText>The number and function of T cells are inconsistent in COVI<em>D</em>-19 patients. The hyperfunction of C<em>D</em>4+ and C<em>D</em>8+ T cells is associated with the pathogenesis of extremely severe SARS-CoV-<em>2</em> infection.</AbstractText>

The coronavirus disease <em>2</em>019 (COVI<em>D</em>-19) pandemic is a scientific, medical, and social challenge. The complexity of the severe acute respiratory syndrome coronavirus <em>2</em> (SARS-CoV-<em>2</em>) is centered on the unpredictable clinical course of the disease that can rapidly develop, causing severe and deadly complications. The identification of effective laboratory biomarkers able to classify patients based on their risk is imperative in being able to guarantee prompt treatment. The analysis of recently published studies highlights the role of systemic vasculitis and cytokine mediated coagulation disorders as the principal actors of multi organ failure in patients with severe COVI<em>D</em>-19 complications. The following biomarkers have been identified: hematological (lymphocyte count, neutrophil count, neutrophil-lymphocyte ratio (NLR)), inflammatory (C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), procalcitonin (PCT)), immunological (interleukin (IL)-6 and biochemical (<em>D</em>-<em>dimer</em>, troponin, creatine kinase (CK), aspartate aminotransferase (AST)), especially those related to coagulation cascades in disseminated intravascular coagulation (<em>D</em>IC) and acute respiratory distress syndrome (AR<em>D</em>S). New laboratory biomarkers could be identified through the accurate analysis of multicentric case series; in particular, homocysteine and angiotensin II could play a significant role.

Keywords: COVID-19; biochemical biomarkers; biomarkers of disease progression; hematological biomarkers; immunological biomarkers; inflammatory biomarkers; neutrophil–lymphocyte ratio (NLR).

The extracellular homophilic-binding domain of the cadherins consists of 5 cadherin repeats (EC1-EC5). Studies on cadherin specificity have implicated the NH(<em>2</em>)-terminal EC1 domain in the homophilic binding interaction, but the roles of the other extracellular cadherin (EC) domains have not been evaluated. We have undertaken a systematic analysis of the binding properties of the entire cadherin extracellular domain and the contributions of the other EC domains to homophilic binding. Lateral (cis) <em>dimer</em>ization of the extracellular domain is thought to be required for adhesive function. Sedimentation analysis of the soluble extracellular segment of C-cadherin revealed that it exists in a monomer-<em>dimer</em> equilibrium with an affinity constant of approximately 64 microm. No higher order oligomers were detected, indicating that homophilic binding between cis-<em>dimers</em> is of significantly lower affinity. The homophilic binding properties of a series of deletion constructs, lacking successive or individual EC domains fused at the COOH terminus to an Fc domain, were analyzed using a bead aggregation assay and a cell attachment-based adhesion assay. A protein with only the first two NH(<em>2</em>)-terminal EC domains (CEC1-<em>2</em>Fc) exhibited very low activity compared with the entire extracellular domain (CEC1-5Fc), demonstrating that EC1 alone is not sufficient for effective homophilic binding. CEC1-3Fc exhibited high activity, but not as much as CEC1-4Fc or CEC1-5Fc. EC3 is not required for homophilic binding, however, since CEC1-<em>2</em>-4Fc and CEC1-<em>2</em>-4-5Fc exhibited high activity in both assays. These and experiments using additional EC combinations show that many, if not all, the EC domains contribute to the formation of the cadherin homophilic bond, and specific one-to-one interaction between particular EC domains may not be required. These conclusions are consistent with a previous study on direct molecular force measurements between cadherin ectodomains demonstrating multiple adhesive interactions (Sivasankar, S., W. Brieher, N. Lavrik, B. Gumbiner, and <em>D</em>. Leckband. 1999. PROC: Natl. Acad. Sci. USA. 96:118<em>2</em>0-118<em>2</em>4; Sivasankar, S., B. Gumbiner, and <em>D</em>. Leckband. <em>2</em>001. Biophys J. 80:1758-68). We propose new models for how the cadherin extracellular repeats may contribute to adhesive specificity and function.

BACKGROUND

Postpartum hemorrhage (PPH) is a major source of maternal morbidity.

OBJECTIVE

This study's objective was to determine whether changes in hemostasis markers during the course of PPH are predictive of its severity.

METHODS

We enrolled 1<em>2</em>8 women with PPH requiring uterotonic prostaglandin E<em>2</em> (sulprostone) infusion. Two groups were defined (severe and non-severe PPH) according to the outcome during the first <em>2</em>4 hours. According to our criteria, 50 of the 1<em>2</em>8 women had severe PPH. Serial coagulation tests were performed at enrollment (H0), and 1, <em>2</em>, 4 and <em>2</em>4 hours thereafter.

RESULTS

At H0, and through H4, women with severe PPH had significantly lower fibrinogen, factor V, antithrombin activity, protein C antigen, prolonged prothrombin time, and higher D-dimer and TAT complexes than women with non-severe PPH. In multivariate analysis, from H0 to H4, fibrinogen was the only marker associated with the occurrence of severe PPH. At H0, the risk for severe PPH was <em>2</em>.63-fold higher for each 1 gL(-1) decrease of fibrinogen. The negative predictive value of a fibrinogen concentration >4 gL(-1) was 79% and the positive predictive value of a concentration <or=<em>2</em> gL(-1) was 100%.

CONCLUSIONS

These findings indicate that a simple fibrinogen measurement can anticipate the risk of severe bleeding in PPH.

Aims: As of the 28th April 2020, the COVID-19 pandemic has infiltrated over 200 countries and affected over three million confirmed people. We review different biomarkers to evaluate if they are able to predict clinical outcomes and correlate with the severity of COVID-19 disease.

Methods: A systematic review of the literature was carried out to identify relevant articles using six different databases. Keywords to refine the search included 'COVID-19', 'SARS-CoV2', 'Biomarkers', among others. Only studies which reported data on pre-defined outcomes were included.

Key findings: Thirty-four relevant articles were identified which reviewed the following biomarkers: C-reactive protein, serum amyloid A, interleukin-6, lactate dehydrogenase, neutrophil-to-lymphocyte ratio, D-dimer, cardiac troponin, renal biomarkers, lymphocytes and platelet count. Of these, all but two, showed significantly higher levels in patients with severe complications of COVID-19 infection compared to their non-severe counterparts. Lymphocytes and platelet count showed significantly lower levels in severe patients compared to non-severe patients.

Significance: Although research is still in its early stages, the discovery of how different biomarkers behave during the course of the disease could help clinicians in identifying severe disease earlier and subsequently improve prognosis. Nevertheless, we urge for more research across the globe to corroborate these findings.

Keywords: Biomarkers; Blood tests; COVID-19; SARS-CoV-2.

The human herpesvirus entry mediator C (HveC/PRR1) is a member of the immunoglobulin family used as a cellular receptor by the alphaherpesviruses herpes simplex virus (HSV), pseudorabies virus, and bovine herpesvirus type 1. We previously demonstrated direct binding of the purified HveC ectodomain to purified HSV type 1 (HSV-1) and HSV-<em>2</em> glycoprotein <em>D</em> (g<em>D</em>). Here, using a baculovirus expression system, we constructed and purified truncated forms of the receptor containing one [HveC(143t)], two [HveC(<em>2</em>45t)], or all three immunoglobulin-like domains [HveC(346t)] of the extracellular region. All three constructs were equally able to compete with HveC(346t) for g<em>D</em> binding. The variable domain bound to virions and blocked HSV infection as well as HveC(346t). Thus, all of the binding to the receptor occurs within the first immunoglobulin-like domain, or V-domain, of HveC. These data confirm and extend those of Cocchi et al. (F. Cocchi, M. Lopez, L. Menotti, M. Aoubala, P. <em>D</em>ubreuil, and G. Campadelli-Fiume, Proc. Natl. Acad. Sci. USA 95:15700, 1998). Using biosensor analysis, we measured the affinity of binding of g<em>D</em> from HSV strains KOS and rid1 to two forms of HveC. Soluble g<em>D</em>s from the KOS strain of HSV-1 had the same affinity for HveC(346t) and HveC(143t). The mutant g<em>D</em>(rid1t) had an increased affinity for HveC(346t) and HveC(143t) due to a faster rate of complex formation. Interestingly, we found that HveC(346t) was a tetramer in solution, whereas HveC(143t) and HveC(<em>2</em>45t) formed <em>dimers</em>, suggesting a role for the third immunoglobulin-like domain of HveC in oligomerization. In addition, the stoichiometry between g<em>D</em> and HveC appeared to be influenced by the level of HveC oligomerization.