The diagnostic yield of D-Dimer in relation to time from symptom onset in patients evaluated for venous thromboembolism in the emergency medicine department.

D-Dimer concentrations increase following the thrombotic event and decrease thereafter. Timing of D-Dimer evaluation in relation to the onset of the disease might have a diagnostic impact. We have presently performed a retrospective analysis of diagnostic procedures performed in individuals who presented to the Emergency department and evaluated for acute venous thromboembolism (VTE) following a single quantitative D-Dimer testing. Individuals who had a negative objective test served as controls to those who had a positive one (Doppler ultrasonography, high probability lung scan or a CT angiography). Seven hundred thirty-four individuals presented to the Emergency department, performed a single D-Dimer test as well as an objective test during their evaluation for an eventual event of acute VTE. One hundred ninety-seven patients had a positive objective test for either deep vein thrombosis (DVT) or pulmonary embolus. They were divided into seven tiles of times from symptoms onset. Highly significant differences between patients and controls regarding D-Dimer concentrations were noted mainly during the early days from symptom onset and turned less significant thereafter. Taking into consideration the time from symptoms onset in patients with acute VTE might have an effect on the diagnostic yield of quantitative D-Dimer in the Emergency department. We suggest not to exclude the eventual presence of acute VTE if quantitative D-Dimer is obtained later than 1 week following the onset of symptoms.

Correlated expression of D-dimer concentrations with thrombotic burden in acute pulmonary embolism.

Thrombotic burden might have an influence upon the concentration of D-dimer in patients with acute pulmonary embolism. Patients with small pulmonary embolisms may thus present with relatively low concentrations of D-dimer. The objective of this study was to assess the correlation of the concentrations of D-dimer with the pulmonary artery occlusion score (PAOS) in a cohort of patients with acute pulmonary embolism. We have presently studied the correlation between the concentrations of D-dimer and the PAOS in a group of 75 patients who presented to the Department of Emergency Medicine with a clinical picture suggestive for acute pulmonary embolism and whose pulmonary computerized tomography (CT) angiography was positive for pulmonary embolism. A significant (P < 0.001) correlation (r = 0.42) was noted between the concentration of D-dimer and the PAOS in this group of 75 patients with acute pulmonary embolism. We further divided the cohort into those patients who had a score below the median of 18 (n = 37) and those who had a score above the median (n = 38), the corresponding mean concentrations of D-dimer being 364 and 814 ng/ml, respectively, in contrast to a mean concentration of 285 ng/ml that was observed in the group of controls (n = 73). In addition, from the receiver-operated characteristic (ROC) curves that were produced for the purpose of differentiating between the presence or absence of pulmonary embolism, for those who had a low score it was not possible to differentiate between those who had or did not have a pulmonary embolism [area under the curve 0.595 as opposed to 0.835 (P < 0.001) for the group with the high score]. Patients with acute small pulmonary embolism might present with relatively low concentrations of D-dimer. These findings might have implications regarding the diagnostic yield of D-dimer in patients who are suspected of having an acute pulmonary embolism.

Acute phase response detection and quantitation at the point of care in older adults with acute bacterial infections.

BACKGROUND: We investigated the reliability of a slide test in determining the presence of acute bacterial infections in a group of older adults to determine the usefulness of this test at the point of care. METHODS: The study group included older adults with an acute bacterial infection and matched controls. We examined the white blood cell count (WBCC), the erythrocyte sedimentation, fibrinogen concentration, and high sensitivity C-reactive protein (hs-CRP), in addition to the slide test that reveals the number of leukocytes and degree of erythrocyte aggregation. RESULTS: There were 144 patients and 144 controls at a respective mean +/- standard deviation age of 71.3 +/- 20.7 and 70.6 +/- 20.2 years. A highly significant difference was noted between patients and controls in all laboratory markers, both conventional and those obtained by the slide test. By using hs-CRP, we correctly predicted the individual group as control or bacterial infection. When analyzed by means of a receiver-operated characteristic (ROC) curve, hs-CRP was again most reliable, with the slide leukocyte test being superior to the WBCC. CONCLUSION: The slide leukocyte count provided a similar diagnostic yield to that of the WBCC. The availability of this slide test at the point of care will provide the clinician with a useful biomarker when faced with clinical decisions in the care of older adults.

The erythrosense as a real-time biomarker to reveal the presence of enhanced red blood cell aggregability in atherothrombosis.

Both anemia and inflammation might be present in individuals with atherothrombosis. We have evaluated the eventual influence of these 2 variables on the degree of erythrocyte adhesiveness/aggregation in the peripheral blood of 583 women and 402 men with various atherothrombotic risk factors and vascular events. It turned out that both anemia and inflammation (highly sensitive C-reactive protein concentrations) influence the degree of cell adhesiveness/aggregation and that there is no interaction between them. Thus, the degree of erythrocyte adhesiveness/aggregation might have the diagnostic advantage of being enhanced in individuals with atherothrombosis who have inflammation and no anemia as well as those who have anemia and no inflammation. These findings might help to turn a phenomenon of hemorheological relevance into a diagnostic tool for the detection of individuals at risk of an acute ischemic event.

Erythrocyte adhesiveness/aggregation: a novel biomarker for the detection of low-grade internal inflammation in individuals with atherothrombotic risk factors and proven vascular disease.

BACKGROUND: We have introduced a concept of using the erythrocyte as a sensor for the detection of enhanced inflammation-sensitive protein concentrations. We presently evaluated the capability of this new biomarker to detect the presence of inflammation in individuals with a history of a vascular disease as opposed to individuals with atherothrombotic risk factors but no clinically evident vascular disease. METHODS: The degree of erythrocyte adhesiveness/aggregation was determined in the peripheral venous blood by using a simple blood test. Blood was drawn into a syringe containing sodium citrate and trickled onto a slide at an angle of 30 degrees. The slides were than scanned by a blinded technician by using an image analyzer to determine the area that is covered by the erythrocytes. RESULTS: One hundred fifty-six subjects (61 women and 95 men) of 2586 (1238 women and 1348 men) met the criteria of a definite vascular disease (history of stroke, myocardial infarction, coronary artery bypass grafting, or peripheral vascular disease). The degree of erythrocyte aggregation was significantly (P = .008) higher in men, but not in women, with vascular disease as opposed to these without a vascular disease. The results of receiver operating characteristic curve analysis confirmed the diagnostic superiority of the erythrocyte aggregation biomarker over other commonly used markers of the acute phase in men. Similar results were obtained by using discriminant analysis. Finally, a significant correlation was found between the degree of erythrocyte aggregation and other markers of the acute phase suggesting its relevance for the detection and quantitation of low-grade inflammation in individuals with atherothrombosis. CONCLUSION: Erythrocyte adhesiveness/aggregation may be a useful biomarker to detect internal inflammation in individuals with atherothrombosis.

Gender difference in C-reactive protein concentrations in individuals with atherothrombotic risk factors and apparently healthy ones.

Recent studies have shown that C-reactive proteins have a pathogenetic role in atherothrombosis and concentrations of these substances could be used as a marker for future vascular events. The objective of this study was to determine gender differences in highly sensitive C-reactive protein (hs-CRP) in individuals with atherothrombotic risk factors and apparently healthy ones. We have presently matched 469 females and 469 males having the same age and body mass index (BMI). Of these, 210 men and 210 women had no atherothrombotic risk factors. In this group the hs-CRP concentrations were 1.6+/-3.4 mg l(-1) in women and 1.0+/-2.7 mg l(-1) in men (p<0.0005). These values were 2.1+/-3.4 mg l(-1) and 1.5+/-2.8 mg l(-1), respectively, in the entire cohort (p<0.0005), which included also individuals with atherothrombotic risk factors. We conclude that significant gender differences exist in hs-CRP concentrations despite perfect matching for age and BMI. These differences should be reflected in guidelines that suggest hs-CRP cut-off points for the stratification of vascular risk.

Inflammation at a glance: erythrocyte adhesiveness/aggregation test to reveal the presence of inflammation in people with atherothrombosis.

The erythrocyte adhesiveness/aggregation test is a new biomarker to detect low-grade inflammation in patients with atherothrombosis. In a group of 30 individuals with an acute ischemic event, the variability of EAAT during a follow-up period was similar to those obtained for other commonly used markers of the acute phase response, suggesting the potential clinical use of this novel marker.