Introduction of principles of blood management to healthy donor bone marrow harvesting.

BACKGROUND AND OBJECTIVES: Patient blood (more accurately: haemoglobin, Hb) management (PBM) aims to optimize endogenous Hb production and to minimize iatrogenic Hb loss while maintaining patient safety and optimal effectiveness of medical interventions. PBM was adopted as policy for patients by the World Health Organization (WHO), and, all the more, should be applied to healthy donors. MATERIALS AND METHODS: Observational data from 489 bone marrow (BM) donors were retrospectively analysed, and principles of patient blood management were applied to healthy volunteer BM donations. RESULTS AND CONCLUSION: We managed to render BM aspiration safe for donors, notably completely avoiding the collection of autologous blood units and blood transfusions through iron management, establishment and curation of high-yield aspiration technique, limitation of collection volume to 1·5% of donor body weight and development of volume prediction algorithms for the requested cell dose.

Erythrocyte depletion from bone marrow: performance evaluation after 50 clinical-scale depletions with Spectra Optia BMC.

BACKGROUND: Red blood cell (RBC) depletion is a standard graft manipulation technique for ABO-incompatible bone marrow (BM) transplants. The BM processing module for Spectra Optia, "BMC", was previously introduced. We here report the largest series to date of routine quality data after performing 50 clinical-scale RBC-depletions. METHODS: Fifty successive RBC-depletions from autologous (n = 5) and allogeneic (n = 45) BM transplants were performed with the Spectra Optia BMC apheresis suite. Product quality was assessed before and after processing for volume, RBC and leukocyte content; RBC-depletion and stem cell (CD34+ cells) recovery was calculated there from. Clinical engraftment data were collected from 26/45 allogeneic recipients. RESULTS: Median RBC removal was 98.2% (range 90.8-99.1%), median CD34+ cell recovery was 93.6%, minimum recovery being 72%, total product volume was reduced to 7.5% (range 4.7-23.0%). Products engrafted with expected probability and kinetics. Performance indicators were stable over time. DISCUSSION: Spectra Optia BMC is a robust and efficient technology for RBC-depletion and volume reduction of BM, providing near-complete RBC removal and excellent CD34+ cell recovery.

Spleen Size Is Significantly Influenced by Body Height and Sex: Establishment of Normal Values for Spleen Size at US with a Cohort of 1200 Healthy Individuals.

PURPOSE: To define height- and sex-corrected normal values for spleen length and volume determined with ultrasonography (US). MATERIALS AND METHODS: The authors performed a retrospective data review of stem cell donors who had provided written informed consent for stem cell donation and use of anonymized data and biologic materials for scientific and quality control purposes. Spleen length, spleen volume, and anthrophometric data were correlated in 1230 healthy volunteers to identify variables that affect spleen size. Multiple linear regression analysis was performed to weight effects of various variables on spleen size. Linear regression through the 95th percentile for men and women of different height cohorts generated the formula for the upper limit of normal for spleen length and volume. For validation, the upper limit of normal was calculated for each volunteer and compared with the observed value. Formulae to calculate the additional percentiles were similarly generated and validated. A cohort of 75 volunteers was analyzed twice to assess the stability of spleen length and volume over time. RESULTS: Spleen length and volume were significantly and independently associated with sex (length: P < .001; volume: P = .012), body height (P < .001 for both), and weight (P < .001 for both), with men and taller and heavier individuals having longer and larger spleens. The spleen length of 20 of 324 women (6%) and 234 of 906 men (26%) exceeded the previously reported upper limit of normal of 12 cm. Repeat measurements indicated that spleen length (median difference, 0.10 cm; range, -1.8 to 1.7 cm) and volume (median difference, 3 cm(3); range, -106 to 142 cm(3)) were quite stable. A mobile application that performs these calculations is available for download. CONCLUSION: The authors define height- and sex-corrected normal values for spleen length and volume for women with a body height of 155-179 cm and men with a body height of 165-199 cm and propose validated algorithms to gauge the percentile of an individual's spleen size.

Healthy donor hematopoietic stem cell mobilization with biosimilar granulocyte-colony-stimulating factor: safety, efficacy, and graft performance.

BACKGROUND: Biosimilar granulocyte-colony-stimulating factors (G-CSFs) have been available in the European Union since 2008, and Sandoz' biosimilar filgrastim was approved in the United States in March 2015 for all of the reference product's indications except acute radiation syndrome. Biosimilar G-CSFs have been largely embraced by the medical community, except for some reservations about healthy-donor stem cell mobilization, for which use outside of clinical studies was cautioned against by some members of the scientific community. STUDY DESIGN AND METHODS: In a two-center safety surveillance study (National Clinical Trial NCT01766934), 245 healthy volunteer stem cell donors were enrolled. Of 244 donors who began mobilization with twice-daily Sandoz biosimilar filgrastim, 242 received a full (n = 241) or partial (n = 1) course of G-CSF and underwent apheresis. Efficacy and safety were assessed and are reported here. RESULTS: Biosimilar filgrastim was accompanied by the typical G-CSF class-related adverse effects of expected frequency and severity. Median mobilization for CD34-positive stem cells was 97/µL (range, 20-347/µL); after one apheresis (91%) or two aphereses (9%) from all but three donors (1.2%), cell doses in excess of the typical 4 × 106 CD34-positive cells/kg of the recipient had been collected (range, 3-52 × 106 /kg). Biochemical and hematologic alterations were consistent with previous reports; all had normalized by the first follow-up 1 month after mobilization. Stem cell products engrafted with typical probability and kinetics for G-CSF-mobilized stem cell products. CONCLUSION: These data support the use of biosimilar filgrastim for healthy-donor stem cell mobilization as safe and effective.

Granulocyte collections: comparison of two apheresis systems.

BACKGROUND: Donor granulocyte concentrates are routinely administered to patients with granulocyte function defects or transient neutropenia and (risk of) bacterial or fungal exacerbations, despite lack of definitive clinical proof for patient-relevant outcome improvement. Granulocytes are collected by apheresis from healthy donors treated with granulocyte-colony-stimulating factor and/or steroids for neutrophil mobilization the evening before apheresis, as well as with hydroxyethyl starch during apheresis, to enhance sedimentation of red blood cells (RBCs) and thus to facilitate accessibility of neutrophils for collection. STUDY DESIGN AND METHODS: Granulocyte apheresis procedures are performed with standard apheresis equipment, including with the frequently used apheresis system for peripheral blood "stem cell" collection, COBE Spectra MNC (Terumo BCT), using the same tubing set as for MNC collection, but a different software protocol, PMN. An automated apheresis system for granulocyte collection, Spectra Optia IDL (Terumo BCT), became available in October 2011. Since then, 70 granulocyte apheresis procedures have been performed at our site, 35 each with the new and old systems. RESULTS: Apheresis procedures were well tolerated throughout. The target dose of 1 × 10(10) neutrophils was achieved in all but one collection with Spectra Optia IDL. Spectra Optia IDL collections were approximately 20% more efficient. Products contained more nontarget white blood cells (mononuclear cells), but fewer RBCs and platelets. Although less blood had to be processed with Spectra Optia IDL to achieve the same granulocyte dose, clinically relevant differences between the two apheresis devices were not apparent. CONCLUSION: Both apheresis systems are similarly capable of generating granulocyte concentrates.

Cytomegalovirus infection is associated with venous thromboembolism of immunocompetent adults--a case-control study.

Cytomegalovirus (CMV) seems to contribute to the development of venous thromboembolism (VTE) in immunocompromised patients whereas literature data on the role in immunocompetent individuals are mainly limited to case reports. This study aimed to investigate if cytomegalovirus infection contributes to the development of VTE in immunocompetent individuals. CMV-IgG and CMV-IgM antibody titres, CMV-IgG avidity and CMV-DNA were identified in samples from 166 VTE patients and from 166 healthy blood donors matched for gender and age. CMV-IgG antibodies were found more frequently in VTE patients compared to controls [57.8% vs. 44.0%; adjusted OR 1.75 (95% CI 1.13-2.70); p = 0.016]. Accordingly, median CMV-IgG titres were significantly higher in the case group (89.4 vs. 1.8 AU/ml; p = 0.002). Although the overall rate was low, CMV-IgM antibodies were detected more often among cases than controls. The difference was significant in patients with an unprovoked VTE event [7.4% vs. 0.6%; adjusted OR 5.26 (95% CI 1.35-20.8); p = 0.017]. CMV-IgG antibodies of almost all VTE patients (98.9%) and controls (98.6%) were found to be of high avidity. The rate of positive CMV-DNA samples was low and not different between cases and controls. With the exception of age, no association was found between CMV seropositivity and established VTE risk factors within the VTE group. CMV infection seems to play a role in the development of VTE in immunocompetent patients. Recurrent infection might be more important than acute CMV infection.

Direct oral anticoagulants in patients with antiphospholipid syndrome: a retrospective study in a real-life patient cohort.

The current mainstay for the treatment of thrombotic antiphospholipid syndrome (APS) is anticoagulation with vitamin K antagonists (VKAs). The use of direct oral anticoagulants (DOACs) is under debate. We aimed to assess whether DOACs would be safe in APS patients presenting to the thrombosis clinic. A retrospective cohort study was conducted. All patients presenting to our thrombosis clinic between 2010 and 2017 with a diagnosis of APS taking either VKAs or DOACs were included. APS diagnosis was based on the revised Sapporo criteria. Clinical and laboratory data were collected from the electronic and physical patient files. Out of 200 patients, 81 received VKAs, and 119 DOACs. The two cohorts did not differ with regard to their initial clinical manifestation or additional prothrombotic risk factors. Only a small minority of patients was antiphospholipid antibody triple positive (VKA, 7.0% vs. DOAC, 4.2%). Numberofon-treatment events was low (3 vs. 2). The hazard ratio for any thromboembolic event for patients taking DOACs was 0.78 (95% confidence interval, 0.12-5.19). Treatment with DOACs was not associated with an increased risk of recurrent thromboembolism in comparison with VKAs in this retrospective study. Our observation supports the assumption that in nontriple positive (low risk) APS patients, DOACs might be safe. Prospective data are urgently needed.

Prediction of phenprocoumon maintenance dose and phenprocoumon plasma concentration by genetic and non-genetic parameters.

PURPOSE: The anticoagulation response to vitamin K antagonists is characterised by high inter-individual variability. The impact of single nucleotide polymorphisms (SNPs) in several genes of enzymes involved in the vitamin K cycle on phenprocoumon dose variability and phenprocoumon plasma concentrations is still under investigation. METHODS: We assessed the influence of VKORC1 c.-1639G>A, CYP2C9*2, CYP2C9*3, CYP4F2 c.1297G>A, CALU c.*4A>G, EPHX1 c.337T>C, GGCX c.214+597G>A, F7 c.-402G>A, F7 c.-401G>T, PROC c.-228C>T and PROC c.-215G>A along with clinical and demographic parameters on steady-state phenprocoumon therapy in 75 patients. A prediction model was developed for total phenprocoumon plasma concentrations and daily phenprocoumon doses required for therapeutic anticoagulation. RESULTS: The VKORC1 c.-1639 genotype was the main predictor of the phenprocoumon daily dose (adjusted R(2) = 37.6%) and the total phenprocoumon concentration (adjusted R(2) = 38.3%). CYP2C9 affected the phenprocoumon concentration, but not the dose requirements. SNPs in the other genes of the vitamin K cycle, concomitant medication, nicotine use and alcohol consumption did not predict phenprocoumon concentrations and phenprocoumon dose requirements in a multiple linear regression model. Phenprocoumon concentrations were predicted by VKORC1 c.-1639, CYP2C9 genotype, age and BMI. The final prediction model for the daily phenprocoumon dose requirements comprised VKORC1 c.-1639 genotype, age and height accounting for 48.6% of the inter-individual variability. CONCLUSIONS: A rough prediction of phenprocoumon maintenance doses can be achieved by a limited set of parameters (VKORC1, age, height). The investigated SNPs in CYP4F2, CALU, EPHX1, GGCX, F7, and PROC did not improve the predictive value of a pharmacogenetic-based dosing equation for phenprocoumon.

Impact of double heterozygosity for Factor V Leiden and Prothrombin G20210A on the thrombotic phenotype.

INTRODUCTION: Because of the rarity of double heterozygosity for Factor V Leiden (FVL) and Prothrombin (FII) G20210A, little is known about the thrombotic phenotype in double heterozygotes. MATERIAL AND METHODS: In a retrospective cohort study of patients referred for a thrombophilia work-up, we investigated whether double heterozygotes (n = 138) exhibit a more severe thrombotic phenotype compared with single FVL or FIIG20210A heterozygotes, single FVL homozygotes, or wildtype carriers. RESULTS: The risk of venous thromboembolism (VTE) was higher for female but not male double heterozygotes compared with single heterozygotes (FVL: 2.51, 95%CI 1.55-4.08, FIIG20210A: 1.75, 95%CI 1.14-2.68) and wildtype carriers (HR 2.53, 95%CI 1.58-4.05) but not compared with FVL homozygotes (HR 1.31, 95%CI 0.94-1.83). Female double heterozygotes developed VTE nearly a decade earlier than wildtype carriers and FVL heterozygotes (mean 44.2 vs. 52.6 and 52.2 years), most often in association with oral contraceptives. Spontaneous VTE and arterial thromboembolic events were not more frequent in double heterozygotes compared with the other genotype groups. Deep vein thrombosis (DVT) of the lower limb was the predominant VTE location in double heterozygotes, atypical vein thrombosis was rare. A phenomenon that has been described as the FVL paradox, a higher proportion of isolated DVT than pulmonary embolism, was also found for double heterozygotes. CONCLUSION: The thrombotic phenotype in double heterozygotes resembles the appearance of the thrombotic phenotype in FVL carriers but the thrombotic risk is aggravated by women-specific risk factors.

Incidence, clinical characteristics, and long-term prognosis of travel-associated pulmonary embolism.

AIMS: Prolonged air travel is considered a risk factor for pulmonary embolism (PE). The clinical characteristics as well as the long-term prognosis of patients suffering from travel-associated PE ('economy-class syndrome', ECS) remain largely unknown. Owing to its proximity, our hospital is the primary referral centre for Frankfurt Airport, Europe's third-largest airport. The goal of our study was to follow-up all patients with ECS, who were admitted to our hospital between 1997 and 2006. METHODS AND RESULTS: We systematically reviewed all medical charts from patients presenting with acute PE to our emergency room or intensive care unit (ICU) and performed a telephone follow-up on patients discharged alive. Together with the data provided from the statistics department of Fraport Inc., the operating company of the Frankfurt International Airport, we were also able to put the medical data in context with the corresponding number of passengers and flight distances. A total of 257 patients with acute PE were admitted to our emergency and ICU between 1997 and 2006. Out of these, 62 patients suffered from ECS (45 flight-associated PE and 17 from other travel-associated PE). ECS patients were prone to more haemodynamic relevant acute events, reflected by a higher rate of initial cardiopulmonary resuscitation (4.8% vs. 1.5%; P = 0.153) and higher percentage of massive PE (8% vs. 3%; P = 0.064). Nevertheless, intrahospital mortality was similar in both groups (ECS 4.8%, others 4.1%; P = 0.730). Interestingly, the long-term outcome of ECS patients was excellent (Kaplan-Meier analysis; P log-rank: 0.008 vs. other entities). In general, ECS was a rare event (one event/5 million passengers), where long-haul flights over 5000 km lead to a 17-fold risk increase compared with shorter flights. CONCLUSIONS: Travel-associated PE was a common cause of PE in our hospital, with patients showing excellent long-term prognosis after discharge. The risk of ECS is rather low and strictly dependent on the flight distance.

Cardiovascular risk factors in idiopathic compared to risk-associated venous thromboembolism: A focus on fibrinogen, factor VIII, and high-sensitivity C-reactive protein (hs-CRP).

There have recently been reports of an increased incidence of arterial cardiovascular events in patients with idiopathic venous thromboembolism (VTE) compared to patients with risk-associated VTE. The aim of our study was to evaluate whether elevated clotting factors, which have been linked to chronic sub-clinical inflammation and arterial thromboembolic disease, have a higher prevalence in idiopathic VTE compared to secondary VTE. Plasma fibrinogen, factor VIII, and high-sensitivity C-reactive protein (hs-CRP) levels were determined in a cohort of sex- and age-matched patients with unprovoked VTE (n=101), patients with secondary VTE (n=101), and controls (n=202). Fibrinogen and hs-CRP levels were higher in patients with idiopathic VTE (fibrinogen: median/range: 331/214-524 mg/dl; hs-CRP: median/interquartile range: 1.8/0.8-3.7 mg/l) than in those with risk-associated VTE (299/162-458 mg/dl, p=0.004; 1.5/0.8-2.2 mg/l, p=0.05) and controls (302/185-644 mg/dl, p=0.001; 1.2/0.5-2.2 mg/l, p=0.02). Fibrinogen levels in the upper tertile of the controls were seen in 53% of patients with unprovoked VTE, compared to 35% of patients with secondary VTE. According to their hs-CRP levels (>3 mg/l), 26% of patients with idiopathic VTE were categorised as being at high risk for cardiovascular disease, as opposed to just 9% of those with risk-associated VTE. Factor VIII activity was significantly higher in patients with both idiopathic and secondary VTE than in controls, with the highest median value in patients with idiopathic VTE. Our data show that markers of inflammation, such as hs-CRP, fibrinogen, and factor VIII, are at higher levels in patients with idiopathic compared to secondary VTE, supporting the hypothesis that idiopathic VTE and arterial thromboembolism share common risk factors.

Association of ADAMDEC1 haplotype with high factor VIII levels in venous thromboembolism.

A suggestive locus on chromosome 8 could be shown to be associated with familial high factor VIII (FVIII) levels in venous thromboembolism. The ADAMDEC 1 gene is a candidate expressing an ectodomain sheddase. However, the ectodomain of the clearance receptor for FVIII, the low-density lipoprotein receptor-related protein (LRP), is subject to proteolysis by metalloproteases like ADAMDEC1. Other LRP-interacting proteins are lipoprotein lipase (LPL) and t-PA. For an association study, 165 thrombotic patients with high FVIII levels (from the MAISTHRO, i.e. Main-Isar-thrombosis register) were included. All patients with known causes for high FVIII levels had been previously excluded. The patients were compared with 214 healthy blood donors. Polymorphisms with usually a minor allele frequency >5%, i.e. 24 SNPs and two insertion/deletion polymorphisms of LPL gene, eight SNPs of the t-PA gene, and five SNPs of the ADAMDEC1 gene, were analyzed. Haplotype differences were calculated using PHASE. A new polymorphism in intron 7 of the t-PA gene with a minor allele frequency of 2.2% was identified. Analysis of each SNP by the Cochrane-Armitage trend test did not show any significant association between genotype and disease status. Interestingly, the ADAMDEC1 haplotype (rs12674766, rs10087305, rs2291577, rs2291578, rs3765124) differed between cases and controls (p = 0.04). In particular, the TGTGG haplotype showed a difference. In conclusion, the ADAMDEC 1 haplotype may indicate an underlying mechanism for high FVIII levels. The only moderate linkage disequilibrium may be due to a possible causal polymorphism in distant introns or the promoter region against a polygenic background.

A prospective analysis of heparin-platelet factor 4 antibodies in pregnant women treated with the low-molecular-weight heparin, dalteparin.

Indications for heparin during pregnancy are expanding. Heparin-induced thrombocytopenia caused by heparin-platelet factor 4 antibodies (HPF4-As), however, remains a serious concern. While up to 50% of cardiovascular surgical patients develop HPF4-As while receiving heparin, the rate of seroconversion is lower in medical patients, suggesting an impact of the patient population on the underlying immune response. We therefore prospectively analyzed HPF4-As development in 31 pregnant women (32 +/- 5 years) receiving thromboprophylaxis with dalteparin for more than 4 weeks. According to their individual risk, study individuals were stratified to receive subcutaneous dosages of 2500-10 000 IU/day. The median treatment duration was 33 weeks (6-45 weeks). HPF4-As isotypes (IgG, IgM, IgA) were measured at baseline, on days 6-9, days 19-21 and subsequently every month until the end of therapy. Platelet counts and clinical examinations were carried out routinely or earlier if indicated. Throughout the study no thromboembolic event occurred, and in none of the patients was HPF4-As seroconversion noted. A prolonged drop in platelets to less than 50% from baseline was observed in one case (3%) after 35 weeks of treatment, which spontaneously resolved after child delivery. These findings suggest that long-term thromboprophylaxis with low-molecular-weight heparin is associated with a low rate of HPF4-As seroconversion in pregnancy.

Detection of heterozygous large deletions in the antithrombin gene using multiplex polymerase chain reaction and denatured high performance liquid chromatography.

The present study reports a method for the easy, rapid and cost effective detection of heterozygous large deletions. As a model gene all exons of the antithrombin gene were amplified in a one tube multiplex polymerase chain reaction (PCR) and the products separated according to their size by reverse-phase ion-pair high performance liquid chromatography. A significant reduction in the height of a peak in the probandOs sample compared to in the control indicates the presence of a large deletion of the corresponding allele. Using this approach we identified heterozygous deletions in four patients: the deletions affected exons 1 and 2, exon 7 and the whole antithrombin gene.

Prediction of the pathogenicity of antithrombin sequence variations by in silico methods.

Computational prediction tools have been developed to aid in the interpretation of novel sequence variations, but their utility within the diagnostic setting of antithrombin (AT) deficiency has not been evaluated to date. The aim of our study was to test the performance of different bioinformatic tools (Meta-SNP, MutPred, nsSNPAnalyzer, PANTHER, PhD-SNP, PMut, SIFT, SNAP, SNPs&Go, PolyPhen-2, PON-P2, and PredictSNP) in predicting the pathogenicity of AT sequence variations. We analysed all naturally occurring SERPINC1 missense mutations that have been previously characterised to be damaging with regard to the secretion or function of the AT molecule. Additionally, we analysed all reported non-synonymous exonic polymorphisms within SERPINC1 with a population allele frequency >1.0%. The in silico tools had accuracies of 62-96%, sensitivities of 59-98%, and specificities of 33-100% for the prediction of the pathogenicity of AT sequence variations; receiver operating characteristic analysis had area under the curves between 0.54-0.97. When mutations were grouped according to their effect on the phenotype of AT deficiency [type I or type II with a thrombin (IIRS) or heparin (IIHBS) binding defect or pleiotropic effects (IIPE)], we observed the lowest performance characteristics of the tools for mutations causing AT deficiency type IIHBS. Only three tools (MutPred, PhD-SNP, PolyPhen-2) detected mutants causing type IIHBS AT deficiency with high sensitivity (93%), the sensitivities of the other tools ranged between 36% and 79%. This study demonstrates that bioinformatic tools are useful for pathogenicity prediction for AT sequence variations, but they have substantially different performance characteristics, particularly for type IIHBS AT deficiency.

Impact of the type of SERPINC1 mutation and subtype of antithrombin deficiency on the thrombotic phenotype in hereditary antithrombin deficiency.

Mutations in the antithrombin (AT) gene can impair the capacity of AT to bind heparin (AT deficiency type IIHBS), its target proteases such as thrombin (type IIRS), or both (type IIPE). Type II AT deficiencies are almost exclusively caused by missense mutations, whereas type I AT deficiency can originate from missense or null mutations. In a retrospective cohort study, we investigated the impact of the type of mutation and type of AT deficiency on the manifestation of thromboembolic events in 377 patients with hereditary AT deficiencies (133 from our own cohort, 244 reported in the literature). Carriers of missense mutations showed a lower risk of venous thromboembolism (VTE) than those of null mutations (adjusted hazard ratio [HR] 0.39, 95% confidence interval [CI] 0.27-0.58, p<0.001), and the risk of VTE was significantly decreased among patients with type IIHBS AT deficiency compared to patients with other types of AT deficiency (HR 0.23, 95%CI 0.13-0.41, p<0.001). The risk of pulmonary embolism complicating deep-vein thrombosis was lower in all type II AT deficiencies compared to type I AT deficiency (relative risk 0.69, 95%CI 0.56-0.84). By contrast, the risk of arterial thromboembolism tended to be higher in carriers of missense mutations than in those with null mutations (HR 6.08-fold, 95%CI 0.74-49.81, p=0.093) and was 5.9-fold increased (95%CI 1.22-28.62, p=0.028) in type IIHBS versus other types of AT deficiency. Our data indicate that the type of inherited AT defect modulates not only the risk of thromboembolism but also the localisation and encourage further studies to unravel this phenomenon.

Travel habits and complications in patients treated with vitamin K antagonists: a cross sectional analysis.

BACKGROUND: Travel-related conditions have impact on the quality of oral anticoagulation therapy (OAT) with vitamin K-antagonists. No predictors for travel activity and for travel-associated haemorrhage or thromboembolic complications of patients on OAT are known. METHODS: A standardised questionnaire was sent to 2500 patients on long-term OAT in Austria, Switzerland and Germany. 997 questionnaires were received (responder rate 39.9%). Ordinal or logistic regression models with travel activity before and after onset of OAT or travel-associated haemorrhages and thromboembolic complications as outcome measures were applied. RESULTS: 43.4% changed travel habits since onset of OAT with 24.9% and 18.5% reporting decreased or increased travel activity, respectively. Long-distance worldwide before OAT or having suffered from thromboembolic complications was associated with reduced travel activity. Increased travel activity was associated with more intensive travel experience, increased duration of OAT, higher education, or performing patient self-management (PSM). Travel-associated haemorrhages or thromboembolic complications were reported by 6.5% and 0.9% of the patients, respectively. Former thromboembolic complications, former bleedings and PSM were significant predictors of travel-associated complications. CONCLUSIONS: OAT also increases travel intensity. Specific medical advice prior travelling to prevent complications should be given especially to patients with former bleedings or thromboembolic complications and to those performing PSM.

Performance of five D-dimer assays for the exclusion of symptomatic distal leg vein thrombosis.

The diagnostic value of D-dimer (DD) in the exclusion of proximal deep-vein thrombosis (DVT) is well-established but is less well-known in the exclusion of distal (infrapopliteal) DVT. Therefore, we evaluated the diagnostic abilities of five DD assays (Vidas-DD, Liatest-DD, HemosIL-DD, HemosIL-DDHS, Innovance-DD) for excluding symptomatic proximal and distal leg DVT. A total of 243 outpatients whose symptoms were suggestive of DVT received complete compression ultrasonography (cCUS) of the symptomatic leg(s). The clinical probability of DVT (PTP) was assessed by Wells score. Thirty-eight proximal and 31 distal DVTs (17 tibial/fibular DVTs, 14 muscle DVTs) were diagnosed by cCUS. Although all assays showed high sensitivity for proximal DVT (range 97-100%), the sensitivity was poor for distal DVT (range 78-93%). None of the assays were individually able to rule out all DVTs as a stand-alone test (negative predictive value [NPV] 91-96%). However, a negative DD test result combined with a low PTP exhibited a NPV of 100% for all DVTs (including proximal, tibial/fibular, and muscle DVTs) with the HemosIL-DDHS and Innovance-DD. All proximal and tibial/fibular DVTs, but not all muscle DVTs, could be ruled out with this strategy using the Liatest-DD and Vidas-DD. The HemosIL-DD could not exclude distal leg DVT, even in combination with a low PTP. The combination of a negative DD with a low PTP showed a specificity of 32-35% for all DVTs. In conclusion, our study shows that when used in conjunction with a low PTP some DD assays are useful tools for the exclusion of distal leg DVT.

Validation of a rapid and inexpensive allele-specific amplification (ASA)-PCR genotyping assay for vitamin K antagonist pharmacogenomics.

BACKGROUND: Variant alleles of vitamin K epoxide reductase complex subunit 1 gene (VKORC1), the target molecule of vitamin K antagonists, and of cytochrome P450 (CYP) 2C9, an enzyme involved in coumarin metabolism, affect the anticoagulant response of coumarins, which have a narrow therapeutic window. Genotyping for these variants allows for prediction of therapeutic drug doses. The discussion of the clinical role of genotype-guided coumarin dosing is ongoing. For pharmacogenetic information to be useful, results must be available quickly. METHODS: Here we report on the establishment of an allele-specific amplification (ASA)-PCR assay for the three most relevant polymorphisms for coumarin pharmacogenetics. The assay was validated against sequencing data on 100 random samples from Caucasian blood donors, incorporating all genotypes. Divergent results were confirmed by repeating the analysis with both methods. One hundred percent congruence with DNA sequencing was determined as the 'pass' criterion for the assay. RESULTS: The ASA-PCR assay reproducibly identified the three informative single nucleotide polymorphisms. Discrepancies between ASA-PCR and sequencing were clarified by retrospective analysis as being due to erroneous analysis or documentation. In summary, the congruence of sequencing and duplex ASA-PCR was 100%. CONCLUSION: ASA-PCR is significantly faster and less expensive than sequencing. We expect that pharmacogenetics-based dosing decisions may reduce the frequency of over- and undertreatment with vitamin K antagonists, especially during drug initiation, and thus improve patient safety.