Diagnosis of deep venous thrombosis by use of soluble necrosis factor receptor

Diagnostic biomarkers in venous thromboembolic disease

OBJECTIVE

Venous thromboembolism (VTE) is a common disease with serious, often fatal sequelae. The optimal strategy for diagnosis of VTE remains unclear, although considerable progress has been made in this area. Several new biomarkers have showed promise for diagnosis of VTE, and more are under active investigation. We reviewed the literature for studies evaluating these diagnostic biomarkers.

METHODS

We reviewed the English literature between 1990 and 2015, searching for papers evaluating diagnostic performance of biomarkers in VTE.

RESULTS

D-dimer, a fibrin degradation product, has been thoroughly investigated, and performs well in select populations, although it is best as a rule-out test because of its generally low specificity. Soluble P-selectin, a marker of endothelial activation, has shown good diagnostic performance in several studies but has not yet been adopted widely. Others, including cellular adhesion molecules, tissue factor, circulating microparticles, and C-reactive protein, are under investigation, with varying results in a few studies.

CONCLUSIONS

At this time, D-dimer and P-selectin remain the most clinically valuable. New biomarkers are needed for clinical use in VTE.

Heparin and low-molecular weight heparins in thrombosis and beyond

Heparin and its improved version, low-molecular weight heparin (LMWH), are known to exert polypharmacological effects at various levels. Early studies focused on the plasma anti-Xa and anti-IIa pharmacodynamics of different LMWHs. Other important pharmacodynamic parameters for heparin and LMWH, including effects on vascular tissue factor pathway inhibitor (TFPI) release, inhibition of inflammation through NFkappaB, inhibition of key matrix-degrading enzymes, selectin modulation, inhibition of platelet-cancer cell interactions, and inflammatory cell adhesion, help explain the diverse clinical impact of this class of agents in thrombosis and beyond.

Low molecular weight heparin suppresses tumor necrosis factor expression from deep vein thrombosis

Prior investigations have shown that low molecular weight heparin (LMWH) possesses anti-inflammatory properties in addition to its anticoagulant effects. The physiology of this anti-inflammatory mechanism is poorly understood. Experiments were performed to assess the in vivo anti-inflammatory effects of LMWH in a rat model of deep vein thrombosis (DVT). Sprague-Dawley rats were divided into three groups and underwent laparotomy and inferior vena cava (IVC) ligation directly below the renal veins to induce thrombosis. Twenty-four hours later, intraluminal clot was confirmed at repeat laparotomy using an electromagnetic flowmeter and visual inspection. An intravenous infusion of LMWH or urokinase or no infusion (control) was then performed. Subcutaneous LMWH was given postoperatively to the heparin group. Twenty-four hours after the second operation, the animals were killed, the IVC harvested, the cells from the IVC purified, and cytokine measurements done. The LMWH group showed an overall statistically significant decrease in tumor necrosis factor-alpha (TNF-alpha) levels compared to both the control and urokinase groups by analysis of variance (918 pg/mL vs. 1,345 and 1,623, respectively; P = 0.001). To ensure accuracy, individual pairwise comparisons were performed, which also showed statistically significant TNF-alpha suppression by LMWH compared to control (P = 0.015) and urokinase (P = 0.0009). Treatment of DVT with LMWH causes suppression of TNF-alpha expression. This may, in part, explain its anti-inflammatory effects.

Diagnosis of pulmonary embolism by use of urinary TNF alpha and its soluble TNF receptor I

The purpose of this clinical study was to determine the concentration of soluble tumor necrosis factor in urine of patients with pulmonary embolism (PE), verses voluntary control individuals. Sixteen patients (ages 24 to 74 years) with diagnosis of PE, documented by ventilation perfusion scan or pulmonary angiogram, were the subjects of this study. Ten cc of urine was obtained from each patient and subjected to a solid-phase enzyme-linked immunosorbent assay thus determining the soluble tumor necrosis factor (TNF) receptor I (R I) and TNF alpha levels in these samples. In this pilot study of PE cases, a statistically significant elevation in urinary levels of TNF alpha and soluble TNF R I was demonstrated in PE patients. The average urinary soluble TNF R I in normal subjects was 1,029 pg/mL and in PE patients the average TNF R I was 3,734.4 pg/mL. The clinical diagnosis of PE is a challenging problem for the physician. Late diagnosis and delayed management of this condition could be associated with massive PE. Although pulmonary angiography is the gold standard for diagnosis of PE, it requires expensive equipment, trained radiologists, and the patient could be at risk of sensitivity to contrast agents.