Annexin A2 autoantibodies in thrombosis and autoimmune diseases

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by arterial, venous or small-vessel thrombotic events, and recurrent miscarriages or fetal loss. APS diagnosis is based on the repeated detection of anti-phospholipid (PL) antibodies (Ab), typically associated with anti-β2 glycoprotein I (β2GPI)-Ab. Recent studies suggest that anti-β2GPI Ab activity involves a protein complex including β2GPI and annexin A2 (ANXA2). Anti-ANXA2 Ab recognizes this complex, and these Ab can effectively promote thrombosis by inhibiting plasmin generation, and by activating endothelial cells. Therefore, anti-ANXA2 Ab represent a new biomarker, which can be detected in up to 25% of APS patients. Moreover, anti-ANXA2 Ab have been detected, in thrombotic associated diseases including pre-eclampsia, in other autoimmune diseases, and in cancer.

Fibrinolysis for patients with intermediate-risk pulmonary embolism

BACKGROUND

The role of fibrinolytic therapy in patients with intermediate-risk pulmonary embolism is controversial.

METHODS

In a randomized, double-blind trial, we compared tenecteplase plus heparin with placebo plus heparin in normotensive patients with intermediate-risk pulmonary embolism. Eligible patients had right ventricular dysfunction on echocardiography or computed tomography, as well as myocardial injury as indicated by a positive test for cardiac troponin I or troponin T. The primary outcome was death or hemodynamic decompensation (or collapse) within 7 days after randomization. The main safety outcomes were major extracranial bleeding and ischemic or hemorrhagic stroke within 7 days after randomization.

RESULTS

Of 1006 patients who underwent randomization, 1005 were included in the intention-to-treat analysis. Death or hemodynamic decompensation occurred in 13 of 506 patients (2.6%) in the tenecteplase group as compared with 28 of 499 (5.6%) in the placebo group (odds ratio, 0.44; 95% confidence interval, 0.23 to 0.87; P=0.02). Between randomization and day 7, a total of 6 patients (1.2%) in the tenecteplase group and 9 (1.8%) in the placebo group died (P=0.42). Extracranial bleeding occurred in 32 patients (6.3%) in the tenecteplase group and 6 patients (1.2%) in the placebo group (P<0.001). Stroke occurred in 12 patients (2.4%) in the tenecteplase group and was hemorrhagic in 10 patients; 1 patient (0.2%) in the placebo group had a stroke, which was hemorrhagic (P=0.003). By day 30, a total of 12 patients (2.4%) in the tenecteplase group and 16 patients (3.2%) in the placebo group had died (P=0.42).

CONCLUSIONS

In patients with intermediate-risk pulmonary embolism, fibrinolytic therapy prevented hemodynamic decompensation but increased the risk of major hemorrhage and stroke. (Funded by the Programme Hospitalier de Recherche Clinique in France and others; PEITHO EudraCT number, 2006-005328-18; ClinicalTrials.gov number, NCT00639743.).

Pneumocystis jirovecii haplotypes at the internal transcribed spacers of the rRNA operon in French HIV-negative patients with diverse clinical presentations of Pneumocystis infections

Pneumocystis jirovecii, a transmissible fungus, is the causative agent of pulmonary infections. Its genomic diversity has appeared in reports from around the world but data on P. jirovecii genotypes in France are still limited. This study describes the typing of P. jirovecii isolates from 81 HIV-negative patients monitored at Brest University Hospital, Brittany, France, 40 of whom developed Pneumocystis pneumonia (PcP), and remaining 41 patients were colonized by the fungus. The isolates were assayed at the internal transcribed spacer (ITS)1 and ITS2 under improved amplification conditions to avoid in vitro ITS recombination. P. jirovecii ITS haplotypes were identified in 56/81 patients (31 PcP patients and 25 patients who were colonized) which revealed a high diversity in that 27 different haplotypes were identified. Eg was the most frequent haplotype (31/56, 55.3%), followed by Ec and Ai (5/56, 8.9% each). In contrast, Ne, usually the second most frequent haplotype in Europe and the USA, was observed in only 2/56 patients (3.6%). Mixed infections were detected in 18/56 patients (32.1%; 12 PcP patients and six who were colonized). No significant differences were observed in haplotype diversity, frequency of peculiar haplotypes, and mixed infection occurrence, between the two patient populations. The study, conducted with the largest HIV-negative patient population investigated so far, shows that ITS typing remains an efficient method for characterizing P. jirovecii among human populations, whatever their clinical presentation of Pneumocystis infections.

Antipsychotic drugs and venous thromboembolism

Since preliminary case reports suggesting a possible association between first generation of antipsychotics and venous thromboembolism (VTE), consistent epidemiological data is now available suggesting a moderate association between antipsychotics and VTE. However, despite several hypotheses, the underlying mechanisms remain unknown or uncertain. In addition, if the association between antipsychotics and VTE is plausible, the intensity of this risk and the dose effect relationship do not have yet been determined. Prospective data is therefore needed in order to confirm and to quantify this association. Because of the level of uncertainty, the clinical impact on the prevention and the treatment of VTE in patients with a psychiatric illness appears to be low.

V/Q SPECT interpretation for pulmonary embolism diagnosis: which criteria to use?

Ventilation-perfusion (V/Q) SPECT has been reported to improve the diagnostic performance of V/Q imaging for the diagnosis of pulmonary embolism (PE). However, only sparse data based on an objective reference test are available, and the criteria used for interpretation have varied widely. Therefore, the aim of our study was to assess the performance of V/Q SPECT using various criteria for interpretation, in comparison with a validated independent diagnostic strategy.

METHODS

The SPECT study included patients for whom V/Q SPECT data were compared with the results of an independent and validated diagnostic algorithm for PE. V/Q SPECT scans were performed after intravenous injection of (99m)Tc-macroaggregated albumin and simultaneous ventilation with (81m)Kr gas. Interpretation was performed independently by 2 nuclear medicine physicians who were not aware of the clinical history, diagnostic strategy conclusion, or patient's outcome. Sensitivity, specificity, and likelihood ratios were evaluated for various combinations of mismatched defect numbers and sizes (segmental or subsegmental). Generation of receiver-operating-characteristic curves was based on the number of mismatch defects and the number of subsegmental mismatch defects or equivalent.

RESULTS

Of the 249 patients who were analyzed, the diagnosis of PE was confirmed in 49 and ruled out in 200 according to the previously validated independent strategy. Of all the tested criteria, the best performance was achieved using a diagnostic cutoff of at least 1 segmental or 2 subsegmental mismatches, with sensitivity and specificity of 0.92 (95% confidence interval, 0.84-1) and 0.91 (95% confidence interval, 0.87-0.95), respectively. With a negative V/Q SPECT result, the posttest probability of PE was 0.010, 0.037, and 0.119 for a low, intermediate, and high clinical probability. With a positive V/Q SPECT result, the posttest probability of PE was 0.531, 0.814, and 0.939 for a low, intermediate, and high probability.

CONCLUSION

For V/Q SPECT interpretation, a diagnostic cutoff of 1 segmental or 2 subsegmental mismatches seems best for confirming or excluding acute PE.

The prognostic value of pro-B-Type natriuretic peptide in acute pulmonary embolism

AIMS

To assess the clinical performance of pro-B-type natriuretic peptide 1-108 (proBNP) for the prognosis of acute pulmonary embolism.

METHODS

This study was ancillary to a recently published multicentre study including 570 patients with acute pulmonary embolism. ProBNP values were analysed using a new sandwich immunoassay proBNP1-108, Bioplex2200 (Bio-Rade Laboratories). Data was compared with BNP and N-terminal (NT) proBNP values. Adverse outcomes at 30 days were defined as death, secondary cardiogenic shock, or recurrent venous thromboembolism.

RESULTS

ProBNP values were analysed in 549 patients, with 39 (7.1%) presenting adverse outcomes. All three natriuretic peptides were significantly elevated in these 39 patients compared with the group without adverse outcomes (BNP: p < 0.001; NT-proBNP: p < 0.001; proBNP: 0.044), with median proBNP values being 605 pg/ml (113-1437) and 109 pg/ml (30-444), respectively. Multivariate analyses revealed that proBNP significantly depended on patient age (p < 0.001) and renal failure (p=0.001), with proBNP values increasing with both factors. The areas under the receiver operating curve were 0.74 (95% CI 0.69-0.79) for BNP, 0.76 (95% CI 0.72-0.80) for NT-proBNP, and 0.70 (95% CI 0.65-0.75) for proBNP, meaning that the performance of proBNP was significantly lower than that of the two other peptides (p = 0.017).

CONCLUSION

ProBNP, BNP, and NT-proBNP values were significantly increased in patients with adverse outcomes after acute pulmonary embolism. However, the prognostic performance of proBNP for predicting adverse versus favourable outcomes was lower than that of the other natriuretic peptides, thus limiting the clinical relevance of proBNP as a prognostic marker in pulmonary embolism.

Echocardiography and pulmonary embolism severity index have independent prognostic roles in pulmonary embolism

We analysed a cohort of patients with normotensive pulmonary embolism (PE) in order to assess whether combining echocardiography and biomarkers with the pulmonary embolism severity index (PESI) improves the risk stratification in comparison to the PESI alone. The PESI was calculated in normotensive patients with PE who also underwent echocardiography and assays of cardiac troponin I and brain natriuretic peptide. 30-day adverse outcome was defined as death, recurrent PE or shock. 529 patients were included, 25 (4.7%, 95% CI 3.2-6.9%) had at least one outcome event. The proportion of patients with adverse events increased from 2.1% in PESI class I-II to 8.4% in PESI class III-IV, and to 14.3% in PESI class V (p<0.001). In PESI class I-II, the rate of outcome events was significantly higher in patients with abnormal values of biomarkers or right ventricular dilatation. In multivariate analysis, the PESI (class III-IV versus I-II, OR 3.1, 95% CI 1.2-8.3; class V versus I-II, OR 5.5, 95% CI 1.5-25.5 and echocardiography (right ventricular/left ventricular ratio, OR (for an increase of 0.1) 1.3, 95% CI 1.1-1.5) were independent predictors of an adverse outcome. In patients with normotensive PE, biomarkers and echocardiography provided additional prognostic information to the PESI.

[Optimal duration of anticoagulation of venous thromboembolism]

The optimal duration of anticoagulation after venous thromboembolism (VTE) is determined according to the risk of recurrent VTE after stopping anticoagulant therapy and the risk of anticoagulant-related bleeding while on antivitamin K. Clinical risk factors appears to be determinant to predict the risk of recurrence whereas the influence of biochemical and morphological tests is uncertain. The risk of recurrent venous thromboembolism is low when the initial episode was provoked by a reversible major risk factor (surgery): 3 months of anticoagulation is optimal. Conversely, this risk is high when venous thromboembolism was unprovoked or associated with persistent risk factor (cancer): 6 months or more prolonged anticoagulation is warranted. After this first estimation, the duration of anticoagulation may be modulated according to the presence of additional minor risk factors (major thrombophilia, chronic pulmonary hypertension, massive pulmonary embolism): 6 months if VTE was provoked and 12 to 24 months if VTE was unprovoked. If the risk of anticoagulant related bleeding is high, the duration of anticoagulation should be shortened (3 months if VTE was provoked and 6 or 3 months if it was unprovoked). Lastly, if VTE occurred in the setting of a cancer, anticoagulation should be conducted for 6 months or more while cancer is active or on ongoing treatment. Despite an increasing knowledge of the risk factors of recurrent VTE, a number of issues remain unresolved; randomised trial comparing different duration of anticoagulation are needed.

[Acute chest syndrome of adults suffering from sickle cell disease]

Sickle cell disease is a common but often poorly understood by chest physicians. The acute chest syndrome represents its main respiratory complication.

STATE OF ART

Sickle cell disease is an autosomal recessive disorder inducing, in certain circumstances, sickling of red cells. Natives from western or central Africa and from the Caribbean islands are mainly affected. Acute chest syndrome is defined by the association of chest pain or fever and recent radiographic infiltrates, in patients suffering from sickle cell disease. Determination of etiology, infection, fat embolism or hypoventilation, is difficult, as a self-perpetuating vicious circle is ongoing. Support, largely undervalued, is based on etiological treatment and measures to avoid worsening linked to complications, especially microcirculatory disease.

CONCLUSIONS

Acute chest syndrome is a severe respiratory complication of sickle cell disease. Therapeutic measures are simple but undervalued.

Noninvasive diagnosis of pulmonary embolism

BACKGROUND

We designed a simple and integrated diagnostic algorithm for acute pulmonary embolism (PE). Diagnosis was based on clinical probability assessment, plasma D-dimer testing, then sequential testing to include lower limb venous compression ultrasonography, ventilation perfusion lung scan, and chest multidetector CT (MDCT) imaging.

METHODS

We included 321 consecutive patients presenting at Brest University Hospital in Brest, France, with clinically suspected PE and positive d-dimer or high clinical probability. Patients in whom VTE was deemed absent were not given anticoagulants and were followed up for 3 months.

RESULTS

Detection of DVT by ultrasonography established the diagnosis of PE in 43 (13%). Lung scan associated with clinical probability was diagnostic in 243 (76%) of the remaining patients. MDCT scan was required in only 35 (11%) of the patients. The 3-month thromboembolic risk in patients not given anticoagulants, based on the results of the diagnostic protocol, was 0.53% (95% CI, 0.09-2.94).

CONCLUSIONS

A diagnostic strategy combining clinical assessment, d-dimer, ultrasonography, and lung scan gave a noninvasive diagnosis in the majority of outpatients with suspected PE and appeared to be safe.

Fatal congenital tuberculosis due to a Beijing strain in a premature neonate

Congenital tuberculosis (TB) remains a rare disease but is fatal if untreated. Early detection is difficult because of the non-specific nature of the symptoms in TB during pregnancy and infancy. This report summarizes a case of congenital TB in a very premature infant, born at 25 weeks gestation. Miliary TB was diagnosed in the mother when the neonate was 20 days old. Antituberculous therapy allowed a rapid improvement in the mother. The infant died at 27 days old. A Beijing genotype strain of Mycobacterium tuberculosis was isolated both in the mother, from pulmonary and urine specimens, and in the infant, from peritoneal fluid.

Differences in clinical presentation of pulmonary embolism in women and men

BACKGROUND

The risk of recurrence of pulmonary embolism (PE) is higher in men than in women. Differences in clinical presentation of deep vein thrombosis (DVT) have been reported between the two genders but comparative data on PE are lacking.

OBJECTIVES

To compare clinical characteristics between women and men with suspected and confirmed PE and their impact on clinical probability prediction scores and on diagnostic work-up of PE, and to assess whether differences at presentation could account for the increased recurrence rate in men.

METHODS

Combined data from three prospective cohort studies including a total of 3414 outpatients with suspected PE were analyzed retrospectively. Clinical characteristics, pretest probability of PE, diagnostic yield of non-invasive tests and VTE recurrence rate were compared between genders.

RESULTS

The overall prevalence of PE was similar among women and men (22.3% vs. 23.1%; P = 0.55). The clinical probability prediction scores (Geneva score and Wells score) performed equally well in both genders. A non-invasive diagnostic work-up was possible more often in men than in women. The proportion of PE-associated proximal DVT was higher in men than in women (43% vs. 33%; P = 0.009). VTE recurrence rate was also higher in men than women with PE (5.0% vs. 2.3%; P = 0.045).

CONCLUSION

In spite of some differences in the clinical presentation of PE between women and men, clinical probability prediction scores perform equally in both genders. A higher prevalence of PE-associated proximal DVT in men could possibly indicate greater severity of PE episodes and partly account for the higher VTE recurrence rate in men.

[Prolongation of anti vitamin K treatment for 18 months versus placebo after 6 months treatment of a first episode of ideopathic pulmonary embolism: a mutlicentre, randomised double blind trail. The PADIS-EP Trial]

BACKGROUND

After stopping a 3 to 6 months course of oral anticoagulation for a first episode of idiopathic venous thromboembolism (VTE), the risk of recurrent VTE is high (10% per year). In this setting, international guidelines recommend at least 6 months treatment. However, this recommendation is not satisfactory for the following reasons: (1) no randomized trial has compared 6 months to extended duration (2 years) anticoagulation; and (2), even though the frequency of recurrent VTE is similar after pulmonary embolism (PE) and deep vein thrombosis (DVT), the fatality rate of recurrent VTE after PE is higher than that after DVT.

METHODS

A French multicentre double blind randomized trial. The main objective is to demonstrate, after a first episode of symptomatic idiopathic PE treated for 6 months using a vitamin K antagonist, that extended anticoagulation for 18 months (INR between 2 and 3) is associated with an increased benefit / risk ratio (recurrent VTE and severe anticoagulant-related bleeding) compared to placebo. The double blind evaluation is ensured using by active warfarin and placebo, and blinded INR. The protocol was approved by the ethics board of the Brest Hospital on the 7th of March 2006. For an alpha risk of 5% and a beta risk of 20%, the estimated sample size is 374 patients.

EXPECTED RESULTS

This study has the potential to: (1) demonstrate that the benefit / risk ratio of extended anticoagulation for 18 months is higher than that observed with placebo in patients with a first episode of idiopathic PE initially treated for 6 months, during and after the treatment period; and (2) to validate or invalidate the contribution of isotope lung scans, lower limb Doppler ultrasound and D-Dimer at 6 months of treatment as predictors of recurrent VTE (medico-economic analysis included).

[Care of acute pulmonary embolism]

Pulmonary embolism (PE) is common and potentially serious. Three stages are described: mild PE, moderate PE (associated with an ultrasound right ventricular dysfunction) and severe PE (associated with a shock). In the first category, the prognosis is highly favourable (mortality under 5%) and the initial phase of anticoagulant treatment is well documented and codified: the treatment is based on heparin therapy (non fractionated or derivatives) and oral anticoagulants. In the severe forms, fibrinolysis is indicated in addition to the heparin therapy, given the very high mortality (up to 50%). However, the optimum care of moderate PE (intermediate mortality between 10 and 15%) remains uncertain, due to the inability to demonstrate a benefits-risk ratio in favour of fibrinolysis. In addition, this entity is still poorly defined. Although cardiac ultrasound data is useful, other parameters, such as pro-BNP, provide a better identification of these forms of intermediate prognosis. Although the evaluation of the new oral and injectable anticoagulants is promising, it mainly concerns mild PE. In addition, trials are currently under way in patients with a gloomier prognosis. The purpose is to validate or invalidate the indication of classic treatments (fibrinolysis) or new treatments (optional caval filters).

[Pulmonary embolism: the extent of computerized tomography]

The use of computerised tomography in the diagnosis of pulmonary embolism has been the subject of clinical research while, at the same time, technical progress has provided the current multidetector-row spiral equipment. Computerised tomography has been assessed both with respect to reference strategies as well as in extensive pragmatic trials. The preliminary evaluation of the clinical probability and the assay of d-dimers has progressively become imperative. The value of the venous doppler ultrasound of the legs, in particular in the elderly, is limited by the variable accessibility according to the centre. In rare cases, uncertainty persists, for example with a good quality negative multidetector-row spiral computerised tomography associated with a high clinical probability, leaving room for complementary explorations. The confrontation between clinicians and radiologists is then all the more pertinent.

[Venous thromboembolism and cancer]

Cancer and venous thromboembolism (VTE), VTE and cancer: there is a close bond between these two diseases. On the one hand, a cancer patient runs a high risk of developing VTE. Certain cancer-specific factors, such as its metastatic nature increase this risk. The means involved in the care of cancer (insertion of a venous catheter, chemotherapy, etc.) also increase the probability of a thromboembolism. On the other hand, VTE, especially if it is idiopathic, may be the harbinger of a neoplasm. The present paper involves the dual nature of this relationship, first dealing with several points specific to the occurrence of VTE in a cancer patient, before dealing with the specific care in a curative and prophylactic situation. VTE is then considered as a clinical manifestation prior to a cancer. Several characteristics evoking an underlying neoplasm are known. However, the benefits of the screening for cancer when confronted with an episode of VTE remains to be debated.

[Optimum duration of anticoagulant treatment after an episode of venous thromboembolism]

Vitamin K antagonists are the mainstay for the treatment for venous thromboembolism. The optimum (VTE) course of oral anticoagulant therapy is determined according to the risk of recurrent VTE after stopping anticoagulant therapy and the risk of anticoagulant-related bleeding while on antivitamin K. The risk of recurrent VTE is low when the initial episode is provoked by a reversible major-risk factor (surgery), whereas this risk is high when VTE is not provoked or associated with a persistent-risk factor (cancer). Conversely, the influence of biochemical and morphological tests is uncertain. The optimum balance of the benefits and the risks of oral anticoagulant therapy is based on the frequency as well as the consequences of the risk of recurrent VTE and anticoagulant-related bleeding. After VTE provoked by a major reversible-risk factor, three months of anticoagulation is optimal, whereas after unprovoked VTE, anticoagulation should be extended. However, given the number of unresolved issues, a randomised trial comparing different durations of anticoagulation is needed.

[A bilateral diaphragmatic paralysis due to Parsonage and Turner syndrome--its evolution over eight years]

The diaphragmatic paralysis is a rare disease whose causes and evolving forms are numerous. We report the development to eight years of paralysis diaphragmatic bilateral attributed to a Parsonage-Turner syndrome: the lack of recovery is proved by respiratory functional follow-up. The therapeutic possibilities, limited, are discussed.

Association between antipsychotic drugs, antidepressant drugs and venous thromboembolism: results from the EDITH case-control study

Cohort studies suggest that exposure to antipsychotic agents may be associated with an increased risk of venous thromboembolism (VTE). Few data concerning antidepressant drugs are available. Using a different methodological approach, the aim of this study was to estimate the association between neuroleptic and antidepressant drug use and the risk of VTE. We report the results of a case-control study designed to evaluate interactions between acquired and inherited risk factors of VTE. We included 677 cases hospitalized with deep vein thrombosis and or pulmonary embolism with no major acquired risk factor for VTE, and 677 controls matched for gender and age. Drug exposure was defined as current use of drugs at admission. Neuroleptic exposure was associated with an increased risk of VTE (OR = 2.1, 95% CI 1.4-3.2). Among neuroleptics, antipsychotic agent use was associated with a 3.5-fold increased risk of VTE (OR = 3.5, 95% CI 2.0-6.2). No association was found between antidepressant drug exposure and the risk of VTE (OR = 1.1, 95% CI 0.9-1.5). In this hospital-based case-control study, exposure to antipsychotic drugs was associated with an increased risk of VTE. These results, added to previous results, suggest that clinicians should consider antipsychotic drug exposure as a potential risk factor of VTE. More studies are needed in order to further elucidate this adverse effect, and to determine the possible predisposing factors and the biological mechanisms involved.

High frequency of factor V Leiden in surgical patients with symptomatic venous thromboembolism despite prophylaxis

Among candidate risk factors associated with postoperative venous thromboembolism (VTE), the role of factorV Leiden (FVL) mutation remains unclear. We performed a case-control study to assess the potential significance of FVL mutation in postoperative VTE cases despite prophylaxis. We used data from the ongoing case-control "EDITH" study. We extracted 133VTE cases and 144 controls who had undergone either surgery or had plaster cast in the previous three months. Prophylaxis adequacy with regard to the recommendations published by the American College of Chest Physicians was retrospectively assessed. FVL mutation was present in 20VTE cases and four controls (OR 5.9, 95% CI 2-18). Prophylaxis was judged as adequate in 116 cases (88.5%) and in 129 controls (87.2%) (p=0.66). The frequency of FVL mutation was not different in VTE cases occurring while on adequate prophylaxis and in VTE cases occurring after the end of adequate prophylaxis (p=0.27). FVL mutation was closely associated with postoperative VTE in patients classified as having received an adequate prophylaxis (8.4; 95% CI, 2.4 to 29). This study shows a close association between the presence of factorV Leiden mutation in symptomatic VTE occurring after surgery despite prophylaxis.

Fibrinogen Aα-Thr312Ala and factor XIII-A Val34Leu polymorphisms in idiopathic venous thromboembolism

INTRODUCTION

Fibrinogen Aalpha-Thr312Ala and Factor XIII Val34Leu polymorphisms have been shown to modify fibrin clot structure and function. However, clinical studies have yielded conflicting results on their possible association with venous thromboembolism (VTE).

METHODS

We studied the association between these two polymorphisms and VTE in a hospital-based case-control study. We also assessed whether an independent or interactive association exists between Aalpha-fibrinogen Thr312Ala and FXIII Val34Leu polymorphisms and VTE. Fibrinogen Aalpha-Thr312Ala and FXIII Val34Leu polymorphisms were determined after PCR and restriction endonuclease digestion in 286 patients with idiopathic VTE and 286 age- and gender-matched controls. Results were analysed using a conditional logistic regression model for matched series.

RESULTS

The Fg-Aalpha 312Ala allele was associated with higher risk of VTE (OR 1.5; 95% CI: 1.1 to 2.2, p=0.01) while the FXIII 34Leu allele appeared protective (OR 0.7; 95% CI: 0.6 to 0.9, p=0.02). Both alleles demonstrated an independent association with idiopathic VTE after adjustment for Factor V Leiden and G20210A prothrombin polymorphisms. There was no interaction between the fibrinogen Aalpha-Thr312Ala and FXIII Val34Leu polymorphisms for the risk of VTE.

CONCLUSION

In this case-control study, the fibrinogen Fg-Aalpha 312Ala allele was associated with an increased risk of VTE. The FXIII 34Leu allele was also significantly associated with a lower risk of VTE without any interaction between the two polymorphisms studied.

Incidence of venous thromboembolism in first-degree relatives of patients with venous thromboembolism who have factor V Leiden

The factor V Leiden (FVL) mutation, a genetic abnormality with an autosomal mode of inheritance, is associated with an increased risk of venous thromboembolism (VTE). We aimed to determine the annual incidence of VTE in first-degree relatives of patients with VTE and FVL and to identify factors in patients and the relatives that influence this incidence. In this retrospective and prospective cohort study, the incidence of objectively diagnosed first episodes of VTE was assessed in 553 first-degree relatives of 161 patients with acute VTE and FVL. The annual incidence of VTE was 0.43% (95% CI, 0.3 to 0.56) with FVL and 0.17% (95% CI, 0.07 to 0.27) without FVL (relative risk of 2.5,95% CI, 1.3 to 4.7). A majority (70%) of episodes of VTE were provoked, and this proportion was similar with and without FVL. A larger proportion of VTE was provoked in women (83%) that in men (33%), with the difference accounted for by pregnancy and use of oral contraceptives. The proportion of pregnancies complicated by VTE was 3.9% (95% CI, 2.0-5.8) with FVL and 1.4% (95% CI, 0.04-2.7) without FVL. FVL is associated with a two- to threefold increase in VTE in first-degree relatives of patients with VTE. No subgroup of relatives was identified who require more than routine prophylaxis because of a particularly high risk of VTE.

Interrelation of hyperhomocysteinemia and inherited risk factors for venous thromboembolism. Results from the E.D.I.TH. study: a hospital-based case-control study

BACKGROUND

Moderate hyperhomocysteinemia and factor V Leiden mutation are among the most prevalent risk factors for venous thromboembolism (VTE). The hypothesis of an interaction between those risks has been raised and conflicting results were reported.

METHODS

We designed a hospital-based case-control study to test the interaction between Factor V Leiden and fasting serum total homocysteine (tHcy). We have also analysed the G20210A prothrombin gene variant. This study enrolled 904 hospitalised patients who had an objectively proven deep vein thrombosis and/or pulmonary embolism as well as 904 hospitalised control patients matched for gender, age and major acquired risk factor for VTE.

RESULTS

Our data did not detect any multiplicative interaction between hyperhomocysteinemia (>15 mumol/L) and factor V Leiden mutation or G20210A prothrombin gene variant. Odds ratios (95% CI) were 4.0 (1.5-11) and 6.0 (1.3-27) for the combined effect of hyperhomocysteinemia with either factor V Leiden mutation or G20210A prothrombin gene variant, respectively.

CONCLUSIONS

Current data provide further knowledge in relationship between hyperhomocysteinemia and inherited risk factors, such as factor V Leiden mutation and G20210A prothrombin gene variant. As those risk factors are not so rare among Caucasians, a better estimate of the risk related to double exposure might help to optimise venous thromboembolism prevention.

Diagnostic value of D-dimer in patients with suspected pulmonary embolism: results from a multicentre outcome study

BACKGROUND

D-dimer tests are used in various diagnostic strategies to exclude pulmonary embolism (PE). However, their role as an exclusionary first-line test is still uncertain, mainly because accuracy of the test varies according to the assay and the studied population.

METHODS

The aim of this multicentre study was to evaluate the accuracy of D-dimer testing in patients with suspected PE. Diagnosis of PE was based on pre-test clinical probability (PCP) evaluation and both single-detector spiral CT (CT) and lower limbs compression ultrasonography (CUS). Lung scanning and/or pulmonary angiography was mandatory when CT or CUS was inconclusive and when both CT and CUS were normal in a patient with a high PCP. All patients were followed-up for 3 months, looking for VTE recurrence. D-dimers were collected within 24 h of inclusion and stored in each local hematology unit, to be analyzed at the end of all inclusions; physicians in charge of the patient were blinded to D-dimer results.

RESULTS

Three hundred and fifty two patients were included in 4 centres. Prevalence of PE was 38.6%. PCP was low in 82 (23.3%), intermediate in 176 (50%) and high in 94 (26.7%) patients. Sensitivity of D-dimer was 96.3% (95% CI: 93-99) and negative predictive value reached 94.4% (95% CI: 90-99). Five patients with a confirmed PE had a D-dimer level below 500 ng/ml (two patients with a high PCP). Among 258 patients with low or intermediate PCP, 80 (31%) had a negative D-dimer test result; three of them had a false negative result and the number needed to test was 3.3. Among 94 patients with a high PCP, 9 had a negative D-dimer test result; two of them had a false negative result and the number needed to test was 13.5.

CONCLUSION

These results confirm that rapid assays used in this study can safely exclude PE in first-line testing only in non-high CP patients.

Hyperhomocysteinemia and low B vitamin levels are independently associated with venous thromboembolism: results from the EDITH study: a hospital-based case-control study

BACKGROUND

Moderate hyperhomocysteinemia and B vitamins deficiency are thought to be risk factors for venous thromboembolism (VTE). The causality and independence of those associations are still questioned.

METHODS

We measured fasting serum total homocysteine, folates, and vitamin B12 levels as well as 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T genotypes in 467 patients hospitalized with a first well-documented deep vein thrombosis and/or pulmonary embolism not related to a major acquired risk factor and 467 controls matched for gender and age.

RESULTS

Mild hyperhomocysteinemia, low serum folates, and vitamin B12 were associated with VTE independently of each other. In multivariate analysis, odds ratios (OR) (95% CI) for VTE associated with mild hyperhomocysteinemia (>15 micromol L(-1)), low serum folates (< or = 4.9 nmol L(-1)), and vitamin B12 (< or = 253 pmol L(-1)) were 1.48 (1.05-2.08), 3.14 (1.35-7.32) and 1.42 (1.03-1.98), respectively. An MTHFRC677T genotype was not significantly associated with VTE; OR (95% CI): 1.13 (0.70-1.81)

CONCLUSIONS

The current data provides further knowledge in the complex relationship between hyperhomocysteinemia, low vitamin levels, and VTE.

Diagnosis and management of subsegmental pulmonary embolism

INTRODUCTION

Although the advent of multi-detector row computed tomography (CT) has enabled better visualization of subsegmental pulmonary (SSP) arteries, SSP embolism is of uncertain clinical significance. We aimed at answering the following questions: Is spiral CT an accurate method to detect SSP embolism? How are subsegmental perfusion defects managed in outcome studies including spiral CT? What are the main characteristics and outcomes of patients in whom CT detects isolated subsegmental defects?

METHODS

We performed a Medline search on July 1, 2004, using the keywords 'pulmonary embolism' and 'computed tomography'. We limited our search to English language prospective studies comparing CT to pulmonary angiography, and to prospective outcome studies including CT in a diagnostic strategy, with at least a 3-month follow-up.

RESULTS

Fourteen studies comparing CT to pulmonary angiography, and five prospective management studies using CT were retrieved. The sensitivity of single-detector CT for detecting subsegmental defects compared with pulmonary angiography was low (25%). The proportion of isolated SSP images was significantly higher in management studies using multi-detector CT (17 of 770 scans, 2.2%) compared with those using single-detector CT (22 of 2232, 1.0%; P = 0.01). No straightforward attitude regarding anticoagulation therapy for isolated subsegmental defects emerged from the available literature. Finally, important clinical differences were found between patients having subsegmental and segmental or more proximal defects.

CONCLUSIONS

These findings underline the uncertainty regarding the clinical significance of SSP embolism, and the management of patients with such findings.