D-dimer testing in laboratory practice

Serum levels of pentraxin-3 and other inflammatory biomarkers in migraine: Association with migraine characteristics

Background

Several studies have been conducted on the inflammatory aspects of migraine. Pentraxins are a novel and important part of innate immunity as a superfamily of acute phase proteins. In our study, we aimed to demonstrate the relationship between migraine and the serum levels of pentraxin-3 (PTX-3), C-reactive protein (CRP), fibrinogen and D-dimer.

Methods

We recruited 30 migraine patients (in both the attack and interictal period) and 30 healthy controls. Serum samples were obtained from all participants, and a brain MRI performed in the last six months was assessed regarding the presence of deep white matter lesions. Comparisons between the attack, interictal and control groups regarding the serum levels of PTX-3, CRP, fibrinogen and D-dimer were performed. The association between serum PTX-3 levels and migraine characteristics (disease duration, headache frequency, MRI findings, aura, family history, attack duration, and MIDAS score) was also assessed.

Results

We found higher serum levels of fibrinogen and PTX-3 in migraine attack patients compared with the interictal and control groups ( p = 0.03 and p < 0.001, respectively). Subgroup analysis also showed that patients with a disease duration of more than five years and with an attack duration of more than 12 hours have lower serum levels of PTX-3 than patients who have a relatively new diagnosis and have relatively short-lasting migraine attacks ( p = 0.042 and p = 0.038, respectively).

Conclusions

PTX-3 and fibrinogen exhibit different serum levels in patients undergoing a migraine attack compared with the interictal group and the controls. Participants with longer attacks and disease durations have lower serum levels of PTX-3, suggesting that inflammatory processes change along with disease progression.

D-Dimer Can Serve as a Prognostic and Predictive Biomarker for Metastatic Gastric Cancer Treated by Chemotherapy

Systemic activation of hemostasis and thrombosis has been implicated in tumor progression and metastasis. D-dimer has been used as an indicator for the thrombosis. Here, we investigated the role of the activation of coagulation in patients with metastatic gastric cancer by measuring D-dimer level.We conducted an observation study of 46 metastatic gastric cancer patients who received palliative chemotherapy (CTx). D-dimer levels were assessed before CTx and at the first response evaluation after CTx.The overall survival (OS) of patients with pretreatment D-dimer levels <1.5 μg/mL was significantly longer than that of patients with D-dimer levels ≥1.5 μg/mL (22.0 vs 7.9 months, P = 0.019). At the first response evaluation, the mean level of D-dimer was significantly decreased by 2.11 μg/mL in patients either with partial response or stable disease (P = 0.011) whereas the mean level of D-dimer, although the difference did not reach statistical significance, was increased by 2.46 μg/mL in patients with progressive disease. In addition, the OS of patients with D-dimer levels <1.0 μg/mL at the first response evaluation was significantly longer than that of patients with D-dimer levels ≥1.0 μg/mL (22.0 vs 7.0 months, P = 0.009). The lower D-dimer levels (<1.0 μg/mL) at the first response evaluation after CTx was independent predictive factor for better survival in multivariate analysis (P = 0.037).This study suggests that D-dimer levels may serve as a biomarker for response to CTx and OS in patients with metastatic gastric cancer.

Relationship of pericardial fat with biomarkers of inflammation and hemostasis, and cardiovascular disease: the Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

Pericardial fat may increase the risk of cardiovascular disease (CVD) by increasing circulating levels of inflammation and hemostasis biomarkers. We investigated the associations of pericardial fat with inflammation and hemostasis biomarkers, as well as incident CVD events, and whether there are any ethnic differences in these associations.

METHODS

We analyzed results from 6415 participants from the Multi-Ethnic Study of Atherosclerosis who had measurements of pericardial fat volume and circulating levels of C-reactive protein (CRP), fibrinogen, interleukin (IL)-6, factor VIII, D-dimer and plasmin-antiplasmin complex (PAP), and had a mean follow-up period of 9.5 years. Incident CVD event was defined as any adjudicated CVD event.

RESULTS

After adjusting for confounding factors, pericardial fat volume was positively associated with natural log (ln) of IL-6 levels, but inversely associated with ln D-dimer and ln PAP levels (β = 0.067, -0.032, and -0.105 respectively, all P < 0.05). Although a larger pericardial fat volume was associated with a higher risk of incident CVD, the association was attenuated to borderline significance after adjusting for traditional cardiovascular risk factors (P = 0.050). There was a borderline significant ethnicity interaction (P = 0.080), whereby the association between pericardial fat volume and incident CVD was significant in Hispanic Americans, even after further adjusting for biomarkers of inflammation and hemostasis (hazard ratio = 1.31 per SD increase, 95% confidence interval 1.09-1.57, P = 0.004).

CONCLUSION

Pericardial fat was associated with several inflammation and hemostasis biomarkers. The association of pericardial fat with incident CVD events was independent of these biomarkers only among Hispanic Americans.

D-dimer: An Overview of Hemostasis and Fibrinolysis, Assays, and Clinical Applications

D-dimer is the smallest fibrinolysis-specific degradation product found in the circulation. The origins, assays, and clinical use of D-dimer will be addressed. Hemostasis (platelet and vascular function, coagulation, fibrinolysis, hemostasis) is briefly reviewed. D-dimer assays are reviewed. The D-dimer is very sensitive to intravascular thrombus and may be markedly elevated in disseminated intravascular coagulation, acute aortic dissection, and pulmonary embolus. Because of its exquisite sensitivity, negative tests are useful in the exclusion venous thromboembolism. Elevations occur in normal pregnancy, rising two- to fourfold by delivery. D-dimer also rises with age, limiting its use in those >80 years old. There is a variable rise in D-dimer in active malignancy and indicates increased thrombosis risk in active disease. Elevated D-dimer following anticoagulation for a thrombotic event indicates increased risk of recurrent thrombosis. These and other issues are addressed.

Management of a patient with small-area burns, severe sepsis and superficial vein thrombosis

Sepsis is frequently seen in severely burned patients, however it is not common in those with small-area burns. We present a case of a 22-year-old man suffering from a hot crush injury to his left hand dorsum covering 1% of his total body surface area. The patient developed severe sepsis and superficial vein thrombosis, probably due to wound infection. Culture of the wound secretion indicated Corynebacterium striatum. Following intensive topical and systemic treatment the severe sepsis was controlled. The local wound was repaired by the abdominal skin pedicle flap which had taken well by day 27 post admission. A topical superficial vein thrombosis, unintentionally found 42 days after admission, was partially excised. This case demonstrates that when treating severe sepsis in patients with small-area burns, the timely recognition and diagnosis along with active systemic support, play a vital role in successful management.

DECLARATION OF INTEREST

None of the authors have any financial interest to declare.

Quantification of D-dimer levels in human saliva

BACKGROUND

Plasma D-dimer tests are currently used to exclude deep vein thrombosis and pulmonary embolism. Human saliva has numerous advantages over blood as a diagnostic sample. The aims of our study were to develop a reliable immunoassay to detect D-dimer levels in saliva, and to determine the correlation between salivary and blood D-dimer levels. RESULTS/METHODOLOGY: Saliva and blood samples were collected from 40 healthy volunteers. We developed a AlphaLISA® immunoassay with acceptable analytical performances to quantify D-dimer levels in the samples. The median salivary D-dimer levels were 138.1 ng/ml (morning) and 140.7 ng/ml (afternoon), and the plasma levels were 75.0 ng/ml. Salivary D-dimer levels did not correlate with plasma levels (p = 0.61).

CONCLUSION

For the first time, we have quantified D-dimer levels and found twofold increase in saliva (p < 0.05) than in plasma. Further studies are required to demonstrate the clinical relevance/utility of salivary D-dimer in patients with confirmed deep vein thrombosis and/or pulmonary embolism.

Serum D-dimer levels to evaluate the risk for arterial thromboembolism after intravitreal injection of bevacizumab and ranibizumab

PURPOSE

There are concerns about arterial thromboembolic event after intravitreal injection of bevacizumab or ranibizumab. Motivated by the fact that D-dimer was a sensitive biomarker for thromboembolism, we evaluated serum D-dimer levels in patients with age-related macular degeneration (AMD) after intravitreal injection of bevacizumab and ranibizumab.

METHODS

In this prospective, nonrandomized, uncontrolled study, 122 patients (122 eyes) with AMD were enrolled. Sixty-two eyes received intravitreal injections of bevacizumab and 60 eyes received intravitreal injections of ranibizumab monthly for 3 months. Serum D-dimer levels were measured in patients before intravitreal injection and 1 day, 1 week, 1 month, and 3 months thereafter.

RESULTS

Serum D-dimer levels were not significantly altered following injection of either bevacizumab or ranibizumab. Subgroup analysis for patients at risk for thromboembolic events revealed that serum D-dimer levels showed no significant change after injection of ranibizumab. However, D-dimer levels significantly increased at 1 day (P=0.041) and 1 week (P=0.022) after injection of bevacizumab.

CONCLUSIONS

Serum D-dimer levels were not changed after injection with either bevacizumab or ranibizumab. In subgroup analysis, bevacizumab injection in patients at risk of thromboembolism increased serum D-dimer levels.

Progression of plasma D-dimer concentration and coagulopathies during hospitalization in horses with colic

OBJECTIVE

To assess the progression of plasma D-dimer concentrations and coagulation status in horses with different types of colic.

DESIGN

Prospective clinical observational study performed between March 2004 and September 2008.

SETTING

Veterinary university teaching hospital.

ANIMALS

Horses admitted and treated for colic and hospitalized for >48 hours were considered. Animals were classified by diagnosis into medical obstructive conditions (MO), surgical obstructive conditions (SO), inflammatory conditions, and ischemic lesions (IS).

INTERVENTIONS

Three blood samples were obtained from each horse (admission, at 24-48 h [or after surgery] and upon discharge). For each sample, plasma D-dimer concentration, prothrombin time, activated partial thromboplastin time, antithrombin activity, and the presence of subclinical disseminated intravascular coagulation were determined.

MEASUREMENTS AND MAIN RESULTS

When median plasma D-dimer concentration values at admission and after 24-48 hours were compared, they were different but stable in horses with MO (1.29-1.95 nmol/L) and inflammatory conditions (5.70-6.69 nmol/L). However, 10-fold and 5-fold increases were observed, respectively, in SO (2.08 to 16.38 nmol/L) and IS (3.08 to 15.91 nmol/L) in the postoperative period. By 24-48 hours, the percentage of horses with coagulopathy increased in most groups (MO, 43 to 58%; SO, 50 to 96%, IS, 53 to 90%). By the time of discharge, 87% of horses with SO problems and 89% of horses with IS still had some form of coagulopathy documented.

CONCLUSIONS

Throughout hospitalization, horses with MO problems had less severe coagulopathy and lower plasmatic D-dimer concentrations compared to other groups of horses. On admission, most horses with inflammatory conditions presented with coagulopathy. At 24-48 hours of hospitalization and following surgery, the hemostatic profile can differ markedly when compared to admission values.

D-dimer level predicts in-hospital mortality in patients with infective endocarditis: a prospective single-centre study

BACKGROUND

Increased circulating D-dimer levels have been correlated with adverse outcomes in various clinical conditions. To our knowledge, the association of on-admission D-dimer and in-hospital mortality in infective endocarditis (IE) has not been investigated. We hypothesized that increased on-admission D-dimer levels would correlate with adverse outcomes when prospectively studied in patients with IE.

METHODS

In this prospective study, a total of 157 consecutive patients with the definite IE diagnosis met the inclusion criteria and underwent testing for on-admission D-dimer and CRP assays. The outcome measure was in-hospital death from any cause.

RESULTS

In-hospital mortality occurred in 40 (26%) patients. Increased levels of plasma D-dimer (5.1 ± 1.7 vs 1.9 ± 0.8, p<0.001), CRP [45(13-98) vs 12(5-28), p<0.001] were found in dead patients compared with those survived. In addition to S. aureus infection, increased leukocyte count, end-stage renal disease, LVEF<50%, vegetation size of >10mm, perivalvular abscess, on-admission D-dimer (HR: 1.32; 95% CI: 1.24-1.40; p<0.001) and CRP (HR: 1.18; 95% CI: 1.09-1.36; p=0.001) levels were significantly associated with in-hospital mortality. Furthermore, the sensitivity and specificity of D-dimer ≥ 4.2mg/L in predicting in-hospital death in IE were 86% and 85%, respectively. Moreover, the sensitivity and specificity of CRP levels ≥ 13.6 mg/L were 72% and 69%, respectively.

CONCLUSION

Our findings suggest that on-admission D-dimer level may be a simple, available and valuable biomarker that allows us to identify high-risk IE patients for in-hospital mortality. D-dimer ≥ 4.2mg/L, CRP ≥ 13.6 mg/L were independently associated with IE related in-hospital death.

Predictive value of plasma (D)-dimer levels for cancer-related stroke: a 3-year retrospective study

BACKGROUND

Cerebrovascular disease is the second leading cause of central nervous system pathology in cancer patients. Cancer-associated hypercoagulation plays an important role in cancer-related stroke. The present study aims to test whether plasma d-dimer levels could predict comorbid malignancy in patients with ischemic stroke.

METHODS

Five hundred sixteen stroke patients with measured d-dimer levels and who were consecutively admitted to our stroke center from 2009 to 2012 were included. Cancer status was determined by medical chart, and 59 patients were identified to have active cancer. An additional 48 cancer patients with stroke were identified from the hospital database. Several d-dimer cutoff levels were used to predict cancer-related stroke.

RESULTS

Stroke patients with active cancer had significantly higher d-dimer levels than those without cancer (P < .001). The average d-dimer level in stroke patients without cancer was .66 ± 1.83 mg/L, whereas the levels for active cancer patients from the stroke center and hospital database were 5.70 ± 9.63 mg/L and 10.47 ± 12.31 mg/L, respectively. When using d-dimer of .55 mg/L or more and multiple territory infarctions as criteria, the specificity and positive predictive value (PPV) for cancer-related stroke were 99.7% and 92.9%, respectively. When using d-dimer of 5.5 mg/L or more as the cutoff value, the test had a high specificity and PPV regardless the brain magnetic resonance imaging (MRI) findings. Six stroke patients fitting our criteria were confirmed to have occult malignancy after comprehensive cancer survey.

CONCLUSIONS

Extraordinary high d-dimer levels or combining d-dimer and MRI findings may be used as a screening tool to detect malignancy in stroke patients.

The Utility of Platelet and Coagulation Testing of Antithrombotics: Fusing Science with Patient Care

[Table: see text] There is an increasing need for the standardization of platelet function and coagulation testing for the assessment of antithrombotic therapies. Investigators continue to strive to identify ideal laboratory testing and monitoring procedures for acquired and inherited platelet function defects as well as for evaluating patient status when treated with existing or emerging antithrombotics. These therapies are used primarily in the treatment of ischemic complications. In patients receiving antithrombotic therapy, the balance between hemostasis and thrombosis is a challenge as there is an ongoing risk for bleeding when patients are receiving antiplatelet agents or anticoagulants to lessen their risk for secondary thrombotic events. There are several diverse tests for monitoring anticoagulant therapy; however, as new agents are developed, more specific tests will be required to directly assess these agents in relationship to overall coagulation status. Research in the platelet biology field is ongoing to provide point-of-care methodologies for the assessment of platelet reactivity in terms of both bleeding and thrombosis risk. Currently there are no instruments that reliably assess the risk of bleeding. The challenges that routinely faced are the complexity of physiology, the need for standardization of platelet testing methodology, and the necessity for appropriate interpretation of the test results.

Providing accurate information to patients who develop deep vein thrombosis

Venous thromboembolism is an increasingly recognised complication in the community and in hospital in-patients. Nowadays, most physicians are familiar with the algorithmic approach to the management of suspected deep vein thrombosis. However, a lack of understanding remains with regard to certain aspects of the diagnostic and treatment pathways, which has resulted in the wrong information being imparted to patients. Some of these issues are discussed in this paper, with considerations for changes in management.

Evaluation of the utility of the Wells score in predicting pulmonary embolism in patients admitted to a spine surgery service

STUDY DESIGN

A retrospective medical chart review of 4179 patients admitted to the spine surgery service.

OBJECTIVE

To evaluate the utility of the Wells score in predicting pulmonary embolism (PE) in patients admitted to a spine surgery service.

SUMMARY OF BACKGROUND DATA

The decision to perform computed tomography pulmonary angiography (CTPA) to diagnose PE in patients who have undergone spine surgery requires consideration of multiple factors: false-positive CTPA results may lead to unnecessary anticoagulation treatment, and computed tomography scans are costly and expose patients to ionizing radiation. The Wells score was developed to assign risk categories to patients with suspected PE and thereby indicate the need for CTPA. However, the utility of the Wells score in predicting the likelihood of PE, specifically in spine surgery patients, has not been described to date. We identified all patients who were admitted to the spine surgery service at our institution from January 1, 2001 to December 31, 2011 and underwent CTPA. Each patient's CTPA result was classified as positive or negative for PE, and the reason for ordering the CTPA was recorded. The Wells score was calculated retrospectively for each patient, and risk categories were assigned by using the traditional and alternative interpretations of the Wells score. The reason for the CTPA, the Wells score, and Wells risk category were compared for patients who were classified as being positive or negative for PE.

RESULTS

Sixty-six of the 4179 patients who were admitted to the spine surgery service underwent CTPA for suspected PE. Nineteen of the 66 patients (28.8%) were diagnosed with acute PE, and the overall PE rate was 0.45% (19 of 4179 patients). The mean Wells score for patients diagnosed with PE was 5.3, whereas the mean score for the remaining patients was 4.9 (P = 0.793). Neither the traditional nor the alternative interpretation of the Wells score was predictive of PE (P = 0.394 and P = 0.178, respectively). Our study examined the utility of the Wells score in predicting PE in spine surgery patients.

CONCLUSION

The results of the CTPA did not show a significant correlation with the Wells score or the reason for the test. Our findings indicate the need to develop a predictive scoring system that assesses the risk of PE and assists in the decision-making process for ordering CTPA in spine surgery patients.

Predicting pulmonary embolus in orthopedic trauma patients using the Wells score

The decision to perform computed tomography pulmonary angiography (CTPA) to rule out pulmonary embolism (PE) in orthopedic trauma patients is challenging. The Wells score is a commonly used clinical probability tool developed to determine the likelihood of PE and assist in determining the need for CTPA examination. This study evaluated the usefulness of the Wells score for predicting PE in patients admitted to the orthopedic trauma service. All patients who were admitted to the orthopedic trauma service at the authors' institution between 2001 and 2011 who underwent CTPA were identified. The Wells score was calculated retrospectively for each patient, and risk categories using the traditional and alternative interpretations of the Wells score were assigned. Pulmonary embolism was diagnosed in 27 (16%) of 169 patients who underwent CTPA. In total, 27 (0.39%) of 6854 patients admitted to the orthopedic trauma service were diagnosed with PE during initial hospitalization. Mean Wells score was 3.31 (95% confidence interval, ±.28) for the entire population, 3.32 for those without PE (95% confidence interval, ±.31), and 3.28 for those with PE (95% confidence interval, ±.72) (P=.91). Average times from admission to CTPA examination for those with and without PE were 6.18 and 5.7 days, respectively (P=.94). No significant correlation existed between the Wells score and CTPA results, indicating that the Wells score is limited in predicting PE risk in orthopedic trauma patients.

Changes in d-dimer levels in pregnant women according to gestational week

We performed a retrospective review of medical charts regarding blood d-dimer levels determined cross-sectionally by the latex agglutination assay in 1952 samples from 1185 women to determine changes in d-dimer levels according to the stage of pregnancy. Three of 17 women in whom further investigations were performed were found to have clinical venous thromboembolism (VTE). The median and 95th percentile values of d-dimer (μg/mL) in the 1182 women without clinical VTE, 0.54 and 2.41 at gestational week (GW) 4-13, increased gradually to 1.22 and 5.03 at GW 14-27, 1.81 and 6.18 at GW 28-35, and 2.13 and 5.85 at GW 36-42, respectively. A total of nine women (0.76%), including three women with clinical VTE, exhibited a d-dimer level >14.0μg/mL, which was well above the 99th percentile for any stage of pregnancy. Thus, 3 (33%) of the nine with a d-dimer level >14μg/mL developed clinical VTE, while none of the remaining 1176 women with a d-dimer level ⩽14μg/mL developed clinical VTE. Although further prospective studies are required, our results suggested that there is a certain cut-off d-dimer value that would allow us to differentiate between pregnant women with and without clinical VTE.

Postintervention duration of anticoagulation in venous surgery

For a substantial proportion of patients with deep venous thrombosis (DVT), current treatment strategies are suboptimal and new treatment options are needed. Especially for the group of patients who are at the highest risk for post-thrombotic syndrome, new treatment modalities such as catheter-directed thrombolysis and additional stenting are being investigated. With current clinical studies addressing new technical options, the medical management of patients following these interventions deserves attention. The duration of anticoagulant treatment following surgical or radiological interventions for DVT seems not to be influenced by the presence of a venous stent. According to recent ACCP 2012 guidelines the anticoagulant management in patients who have had any method of thrombus removal performed, the same intensity and duration of anticoagulant therapy as in comparable patients who do not undergo thrombosis removal is recommended (Grade 1B). In the acute phase of thrombosis, irrespective of the technique and whether or not stenting is applied, immediate anticoagulation following the procedure is pertinent to reduce the risk of recurrent thrombosis and thrombus propagation. The long-term treatment duration after venous interventions therefore may be tailored based on common risk factors for recurrent thrombosis and the individual risk for bleeding. Selected thrombophilia factors, d-dimer assessment and residual venous thrombosis provide markers for recurrent DVT. Currently, vitamin K antagonists) provide the main anticoagulants for (prolonged) anticoagulation, while the new oral anticoagulants emerge as promising alternatives. In case prolonged anticoagulation after unprovoked DVT is not indicated, cardiovascular risk management is warranted because of an increased rate of arterial thrombotic events after DVT; aspirin may be indicated as secondary prevention against recurrent thrombosis (while providing primary prevention against arterial thrombosis).

Relationship between plasma (D)-dimer level and cerebral infarction volume in patients with nonvalvular atrial fibrillation

BACKGROUND

Plasma D-dimer level may reflect the activity of thrombus formation in the left atrium of patients with nonvalvular atrial fibrillation (NVAF). Proper anticoagulation with warfarin dramatically decreases the rate of cerebral embolism, reduces stroke severity and subsequent risk of death, as well as the level of D-dimer in NVAF patients. However, the predictive value of D-dimer level on cerebral embolism severity has not been examined. Thus, the purpose of this study was to investigate the association between plasma D-dimer level at admission and infarct size in NVAF patients.

METHODS

We identified 124 patients with consecutive ischemic stroke and NVAF who were admitted within 48 h of symptom onset. We measured infarction volume from CT taken after 3 ± 1 days from the onset. Plasma D-dimer levels were measured at the time of admission. Relationships were analyzed between infarction volume and plasma D-dimer levels, cardiovascular risk factors, preadmission medications and admission conditions. We also assessed the influence of D-dimer level on functional outcome in patients with preadmission modified Rankin Scale (mRS) score of 0-1 and patients by tertile of D-dimer level (≤0.83, 0.83-2.16 and ≥2.16 µg/ml).

RESULTS

Infarction volume significantly correlated with D-dimer level (r = 0.309, p < 0.001), systolic blood pressure (r = 0.201, p = 0.026), diastolic blood pressure (r = 0.283, p = 0.002), National Institutes of Health Stroke Scale (NIHSS) score on admission (r = 0.546, p < 0.001) and mRS score at discharge (r = 0.557, p < 0.001). Multivariate regression analyses showed that the D-dimer level was significantly associated with infarction volume after adjusting for age, sex, current smoker or not, prothrombin time-international normalized ratio ≥1.6, diastolic blood pressure, CHADS(2) score and NIHSS score on admission. In patients with a preadmission mRS score of 0-1 (n = 108), D-dimer level was significantly associated with NIHSS score at admission (r = 0.318, p < 0.001) and mRS score at discharge (r = 0.310, p = 0.001). Patients in the highest D-dimer tertile group showed worse outcome than those in the middle (p = 0.041) and lowest (p < 0.001) tertiles.

CONCLUSIONS

Plasma D-dimer level on admission is significantly related to infarction volume and functional outcome, following cardioembolic stroke in NVAF patients.

Stroke and cancer: the importance of cancer-associated hypercoagulation as a possible stroke etiology

BACKGROUND AND PURPOSE

The importance of cancer-associated hypercoagulability as a possible stroke etiology in patients with cancer has received relatively little attention to date. A recent study has suggested that cancer-associated hypercoagulation may be of special importance in the absence of conventional stroke mechanisms.

METHODS

We identified patients with ischemic stroke sequentially admitted to our stroke center with the additional diagnosis of active and malignant cancer from 2002 to 2011. By using our prospectively collected stroke, MRI, and laboratory data banks, the etiology and risk factors of stroke, types of cancer, deep vein thrombosis/pulmonary embolism, d-dimer levels, and diffusion-weighted imaging lesion patterns were compared to an age- and sex-matched control group. Patients with cancer with a conventional stroke etiology and patients with an unidentified and/or cancer-associated stroke etiology were analyzed separately.

RESULTS

One hundred forty patients with cancer and 140 control subjects were included. Unidentified stroke (P<0.001) and infarction in multiple vascular territories (P<0.001) were significantly more frequent and d-dimer levels significantly higher (P<0.05) in patients with cancer. Vice versa, risk factors such as hypertension (P<0.05) and hyperlipidemia (P<0.01) were more prevalent in control subjects. Deep vein thrombosis and pulmonary embolism were more frequent (P<0.01) and d-dimer levels higher (P<0.01) in the patients with unidentified and/or cancer-associated stroke etiology compared to the patients with cancer with a conventional stroke etiology. Lung and pancreatic cancer were significantly overrepresented and d-dimer levels higher in these patients compared with other patients with cancer (P<0.01).

CONCLUSIONS

Our data confirm the concept of cancer-associated hypercoagulation as a widely underestimated important stroke risk factor in patients with cancer, especially in those with severely elevated d-dimer levels and in the absence of conventional risk factors.

Heparin infusion to prevent umbilical venous catheter related thrombosis in neonates

OBJECTIVE

To investigate umbilical venous catheter (UVC) related thrombosis by Doppler echocardiographic evaluation of neonates infused with heparin or placebo.

METHODS

We conducted a prospective study to determine UVC-related thrombosis in term and nearterm neonates. Heparin or placebo (0.5 IU/mL) was infused at a rate of 1 mL/hr to the study and control group. Doppler echocardiography was performed at 1, 3, and 5 days after UVC insertion.

RESULTS

Forty-six neonates (63% males) with a mean gestational age of 38.2 ± 1.8 weeks, and a mean birth-weight of 2993 ± 563 grams were included. No UVC-related thrombosis was observed in the study group, which included 19 neonates. Among the 27 neonates in the control group, one neonate developed UVC-related thrombosis. There were no statistical differences between the groups for gestational age, birth weight, postnatal age, UVC duration, mortality, mechanical ventilation, and inotrope requirement, and hemagram or coagulation profile. The complications were as follows, mild pulmonary hemorrhage, 6.5% (3); leak-out, 4.3% (2); peritoneal leakage, 2.2% (1); occlusion, 2.2% (1); gastrointestinal findings, 6.5% (3); sepsis, 10.9% (5); and catheter-related thrombosis, 2.2% (1).

CONCLUSION

This study demonstrated that heparin infusion of 0.5 IU/mL through the UVC had no effect on catheter-related thrombosis in term and near-term neonates. Randomized controlled trials are necessary to conclusively evaluate the effect of heparin on UVC-related thrombosis.

Novel high-sensitive D-dimer determination predicts chemotherapy-associated venous thromboembolism in intermediate risk lung cancer patients

INTRODUCTION

We hypothesized that the use of a novel high sensitivity (HS) assay for D-dimer determination might ameliorate venous thromboembolism (VTE) risk prediction in intermediate risk lung cancer patients in whom chemotherapy could act as a trigger for VTE onset.

PATIENTS AND METHODS

Pretreatment HS D-dimer levels were retrospectively evaluated in 108 lung cancer outpatients using a novel automated latex enhanced turbidimetric immunoassay. All patients were at the start of a new platinum-based chemotherapy regimen and were classified as intermediate risk according to Khorana's assessment model. Patients were followed-up for a median period of 6.9 months.

RESULTS

Receiver operating characteristic (ROC) curves and corresponding Bayesian analysis showed that the best performance was obtained at a cutoff level of 1500 ng/mL, which resulted in a sensitivity of 81%, a specificity of 69%, a positive predictive value (PPV) of 31%, a negative predictive value (NPV) of 96%, and an accuracy of 70%. Patients with HS D-dimer levels above the cutoff had a worse VTE-free survival (60%) compared with those with levels below the cutoff (95%; P = .0001). Multivariate Cox proportional hazards survival analysis confirmed that pretreatment HS D-dimer levels were able to significantly predict VTE with a hazard ratio of 11 (95% confidence interval, 2.62-46.2; P = .001), independently of classic VTE risk factors.

CONCLUSIONS

The use of HS D-dimer determination prior to chemotherapy might allow for VTE risk stratification of intermediate risk cancer patients, helping in identifying those individuals who could benefit from thromboprophylaxis.

Characterization of the yeast tricalbins: membrane-bound multi-C2-domain proteins that form complexes involved in membrane trafficking

In a survey of yeast genomic sequences encoding calcium- and phospholipid-binding C2 domains, three homologous genes were identified that encode proteins that each have three C2 domains and an apparent transmembrane domain near the N terminus. The name tricalbins is suggested for these proteins, corresponding to the open reading frames YOR086c (TCB1), YNL087w (TCB2), and YML072c (TCB3). An antiserum was raised against the C-terminal portion of tricalbin 2 and used on Western blots to demonstrate that the corresponding protein is expressed in yeast and appears as a high-molecular-weight band at 130 kDa with smaller fragments at 39 kDa and 46 kDa. A fusion protein consisting of full length tricalbin 2 fused to the green fluorescent protein was expressed in cells and found to traffic from the cell surface to intracellular vesicles near the vacuole. A two-hybrid interaction screen with the C-terminal portion of tricalbin 2 indicated that tricalbin 2 binds the C-terminal portions of tricalbins 1 and 3 suggesting that the tricalbins may form heterodimers in vivo. Tricalbin 2 also interacted with the activation domain of the pleiotropic drug resistance transcription factor Pdr1p. Combinatorial disruptions of the tricalbin genes revealed that tcb2 single mutants or tcb1, tcb3 double mutants have an altered vacuole morphology and are hypersensitive to cycloheximide. A screen for single-copy suppressors of the cycloheximide sensitivity of tricalbin mutants yielded RSP5, which encodes a C2-domain-containing, ubiquitin-conjugating ligase essential for receptor-mediated and fluid phase endocytosis. The results suggest that the tricalbins function as multimers in membrane-trafficking events and may provide insights into the roles of multi-C2-domain proteins, such as the synaptotagmins, in other organisms.