Monitoring of Therapy for Deep Vein Thrombosis Using Magnetic Resonance Imaging

Magnetic resonance imaging using limited-flip-angle, gradient refocused pulse sequences has been used to monitor the course of anticoagulant or fibrinolytic therapy for deep vein thrombosis in two patients. The findings demonstrate the capacity of this technique to delineate the extent of thrombosis and characterize changes in size in response to treatment. Advantages of this approach include high anatomic resolution, speed of examination and non-invasiveness, properties that make it well-suited to following the progress of therapy with potentially significant implications for improving treatment.

Young patients and gastrointestinal (GI) tract malignancies - are we addressing the unmet needs?

Background

Recent epidemiological studies indicate the rate of gastrointestinal (GI) malignancies among younger patients is increasing, mainly due to colorectal cancer. There is a paucity of data regarding the magnitude of treatment-related symptoms, psychosocial issues and potential unmet needs in this population. We aimed to characterize the needs of this population to evaluate whether unmet needs could be targeted by potential intervention.

Methods

Female and male patients diagnosed with cancer of the gastrointestinal tract <40y retrospectively completed a questionnaire to evaluate symptoms, daily function and unmet needs at pre-treatment, during and post-treatment. Comparisons were made by gender, disease stage and treatment modality. Multiple linear regression models evaluated effects of demographics, symptoms and needs on multiple domains of health-related-quality-of-life (using Short-Form Health Survey-12 and CARES).

Results

Fifty patients were enrolled (52 % female) to a pilot study. Median age at diagnosis was 35.5y (range, 21-40y). The symptoms that significantly increased from baseline to during and post-treatment were: diarrhea (37 %), sleeping disorder (32 %) and sexual dysfunction (40 %). Patients also reported significant deterioration in occupational activities and coping with children compared with baseline. Female patients reported significant unmet need for nutritional counseling and psychosocial support compared to male patients (p < 0.05). Patients treated with multimodality-treatment presented higher rates of unmet needs (p = 0.03).

Conclusions

Young patients with GI cancers represent a group with unique characteristics and needs compared with published evidence on other young-onset malignancies. The distinctive symptoms and areas of treatment-related functional impairments indicate there are unmet needs, especially in the area of psychosocial support and nutritional counseling.

[Exposure of Pupils to Recreational Noise from Portable Listening Devices and Possible Preventive Measures]

Background and Objectives: Exposure to recreational noise is becoming increasingly important due to a change in leisure behavior amongst children and adolescents. The aim of this pilot study was to assess exposure of 6^th grade pupils to recreational noise from portable listening devices (PLD). Furthermore, preventive measures to reduce recreational noise exposure should be identified. Methods: In "Ohrkan Kids", 38 Bavarian pupils aged 11 to 14 were interviewed regarding their music listening behavior using a standardized questionnaire. In addition, measurements of commonly used volume settings on the children's portable listening devices were carried out. Furthermore, the German Social Accident Insurance (DGUV), health insurance companies as well as health and education ministries of the German federal states were surveyed regarding their activities in the prevention of recreational noise exposure. Results: Based on the questionnaire data for weekly usage, 10 out of 31 children (32.3%) exceeded the upper exposure value of 85 dB recommended by labor protection law. Taking actually measured values, 9 out of 31 children (29%) exceeded this level. The DGUV and some federal states carry out specific projects for the prevention of recreational noise exposure. Conclusion: The large number of children with hazardous music consumption indicates that measures for the prevention of noise-induced hearing loss are already required for 11 to 14 year olds. To maximize the number of children addressed, age-appropriate and target-group-specific preventive measures are needed. As there are only few studies which examined the effectiveness of awareness campaigns for the prevention of recreational noise, any future prevention projects should be evaluated with an increased focus on estimating their effectiveness.

[Taking Care of Asylum Seekers: Occupational Health Aspects with a Special Focus on Vaccination]

Employees and volunteers often feel insecure about the potential transmission of infectious diseases when taking care of asylum seekers. It could be shown that overall only a minor risk of infection emanates from asylum seekers. However, aspects of occupational health and vaccination should be kept in mind.Besides the standard vaccination the Standing Committee on Vaccination (STIKO) recommends for occupational indication, which is given for employees and volunteers in asylum facilities, vaccination against hepatitis A, hepatitis B, polio (if the last vaccination was more than 10 years before) as well as influenza (seasonal).According to the German Occupational Safety and Health Act taking care of the employer has to determine which exposures might occur at the workplace (risk assessment) and define necessary protection measures. Depending on task and exposure when taking care of asylum seekers different acts (e. g. biological agents regulation) and technical guidelines for the handling biological agents (e. g. TRBA 250 or TRBA 500) have to be applied.The Bavarian Health and Food Safety Authority (LGL) has published several information sheets regarding "asylum seekers and health management" for employees and volunteers from the non-medical as well as the medical area (www.lgl.bayern.de search term "Asylbewerber"). With theses publications insecurities in taking care of asylum seekers should be prevented. Furthermore the employer gets support in the implementation of legal obligations to ensure occupational safety for the employees.

PO-45 - The role of microvesicles in multiple myeloma progression

INTRODUCTION

Multiple myeloma (MM) is an incurable, genetically heterogeneous malignancy of plasma cells that secrete non-functioning immunoglobulins and present high proteasome activity. MM is characterized by bone marrow infiltration leading to multiple lytic bone lesions, cytopenia and increased rate of thrombotic events. Microvesicles (MVs) include exosomes (30-100 nm) and microparticles (0.1-1 micron) shed from various cells and expressing antigens reflecting their cellular origin. MVs are involved in thrombosis, inflammation and cancer.However, the effect of MM-MVs on disease progression and their mechanism of action are unclear. We assume that MVs play a role in the interaction between malignant plasma cells and mesenchymal and endothelial cells (EC).

AIM

To characterize MM-MVs and investigate their effects on microenvironment cells.

MATERIALS AND METHODS

MVs were isolated from MM cell line RPMI 8226 untreated or treated with bortezomib and from peripheral blood (PB) and bone marrow (BM) of MM patients (n=13) and healthy controls (n=14). MM-MV size, concentration and cell origin were measured by Nanosite and FACS. Protein content was evaluated by protein arrays and ELISA. Coagulation and proteasome activity were assessed using chromogenic assays. Migratory capacity (migration assay), proliferative rate (XTT assay) and cell-signaling effects (Western blot analysis) of MVs on BM-mesenchymal and ECs were analyzed.

RESULTS

MM cells exhibited high MV shedding rate, which further increased with the exposure to bortezomib. Significant elevation in MV production was found in MM patients compared to controls. MM-MVs expressed membrane MM markers (syndecan-1/ CD138, CD38), coagulation factor (TF, TFPI, EPCR, TM) and angiogenic factors (VEGFR1, VEGFR2, and CD31). MM-MVs contained high levels of growth factors (Angiogenin, PDGF-BB and VEGF) and displayed procoagulant and proteasome activity. MM-MVs penetrated cells and affected their function. MVs of untreated cells and patient MVs increased EC and mesenchymal cell migration and EC proliferation, while MVs obtained from bortezomib-treated cells decreased these effects. MVs of untreated cells increased ERK1/2 and c-Jun phosphorylation in ECs (by 6.15 and 1.84 fold) but did not affect MAPKAPK-2. MVs of bortezomib-treated cells reduced c-Jun phosphorylation in ECs.

CONCLUSIONS

MM cells are characterized by high shedding rate of MVs. They are pro-coagulants and increase EC thrombogenicity, suggesting their involvement in MM-related thrombosis. MVs contain high levels of angiogenic factors that affect mesenchymal and EC, induce cell migration and proliferation via specific signal transductions. MVs exposed to bortezomib display lower levels of angiogenic factors, which limits proliferation and migration of MVs, reflecting the efficacy of therapy and MM dynamics.

PO-46 - Influence of extracellular vesicles derived from AML patients on stem cells and their microenvironment

INTRODUCTION

Acute myeloid leukemia (AML) is characterized by rapid growth of leukemic blast cells. Extracellular vesicles (EVs) are shed from normal and pathologic cells and express membrane proteins and antigens, reflecting their cellular origin.

AIM

To explore whether bone marrow EVs of AML patients originate from blast cells and are capable of influencing hematopoietic stem cells (HSC) in a pseudo-natural microenvironment obtained by co-culture of HSC with mesenchymal stem cells (MSC).

MATERIALS AND METHODS

Bone marrow (BM) samples were collected from healthy controls and patients with newly diagnosed AML at three time points: diagnosis, nadir and remission. EV concentration, cell origin and expression of coagulation proteins were characterized by FACS. Stem cells were obtained from Ficoll gradient of cord blood (CB) followed by CD34+ isolation. Cord blood stem cells with or without MSC were co-incubated with AML EVs. EV internalization was demonstrated by FACS-AMNIS and confocal microscopy. Mir-125b and -155 expressions in the cells were analyzed by RT-PCR.

RESULTS

AML patients were enrolled in the study. The total BM-EVs number was higher in patients at first remission compared to controls, while blast EV counts (labeled with anti-CD34, CD33, CD117) were higher in patients at diagnosis compared to controls and to patients in remission. Internalization of CD117+/CD33+ BM-EVs to cord blood stem cells in the presence or absence of MSC was evaluated by FACS-AMNIS. Confocal microscopy of CD33+ stained EVs strengthens the findings and shows presence of EVs even in the cytoplasm and the nucleus. Quantitative analysis of mir-125b and mir-155 expression in cord blood stem cells incubated with AML EVs revealed a clear tendency of increased expression in case of cell exposure to AML EVs in comparison to healthy control EVs. This tendency was emphasized in the presence of MSC.

CONCLUSIONS

EVs of AML patients are generated from blast cells. By internalization into naïve stem cells they can influence their differentiation. Moreover, the presence of mesenchymal stem cells is likely to be essential to the process.

A prognostic score to identify low-risk outpatients with acute deep vein thrombosis in the lower limbs

BACKGROUND

No prior studies have identified which patients with deep vein thrombosis in the lower limbs are at a low risk for adverse events within the first week of therapy.

METHODS

We used data from the Registro Informatizado de la Enfermedad TromboEmbólica (RIETE) to identify patients at low risk for the composite outcome of pulmonary embolism, major bleeding, or death within the first week. We built a prognostic score and compared it with the decision to treat patients at home.

RESULTS

As of December 2013, 15,280 outpatients with deep vein thrombosis had been enrolled. Overall, 5164 patients (34%) were treated at home. Of these, 12 (0.23%) had pulmonary embolism, 8 (0.15%) bled, and 4 (0.08%) died. On multivariable analysis, chronic heart failure, recent immobility, recent bleeding, cancer, renal insufficiency, and abnormal platelet count independently predicted the risk for the composite outcome. Among 11,430 patients (75%) considered to be at low risk, 15 (0.13%) suffered pulmonary embolism, 22 (0.19%) bled, and 8 (0.07%) died. The C-statistic was 0.61 (95% confidence interval [CI], 0.57-0.65) for the decision to treat patients at home and 0.76 (95% CI, 0.72-0.79) for the score (P = .003). Net reclassification improvement was 41% (P < .001). Integrated discrimination improvement was 0.034 for the score and 0.015 for the clinical decision (P < .001).

CONCLUSIONS

Using 6 easily available variables, we identified outpatients with deep vein thrombosis at low risk for adverse events within the first week. These data may help to safely treat more patients at home. This score, however, should be validated.

A significant reduction in the frequency of HIV-1 drug resistance in Québec from 2001 to 2011 is associated with a decrease in the monitored viral load

Background

HIV drug resistance represents a major threat for effective treatment. We assessed the trends in the frequency of drug resistance mutations and the monitored viral load (VL) in treatment-naïve (TN) and treatment-experienced (TE) individuals infected with HIV-1 in Québec, Canada, between 2001 and 2011.

Methods and Findings

Resistance data were obtained from 4,105 and 5,086 genotypic tests performed on TN and TE patients, respectively. Concomitantly, 274,161 VL tests were carried out in the Province. Changes over time in drug resistance frequency and in different categories of VL were assessed using univariate logistic regression. Multiple logistic regression was used to evaluate associations between the rates of certain mutations and antiretroviral prescriptions. From 2001 to 2011, the proportion of undetectable VL test results continually increased, from 42.1% to 75.9%, while a significant decrease in the frequency of resistance mutations associated with protease inhibitors [PI (from 54% to 16%)], nucleoside [NRTI (from 78% to 37%) and non-nucleoside reverse transcriptase inhibitors [NNRTI (from 44% to 31%)] was observed in TE patients. In TN individuals, the overall frequency of transmitted drug resistance was 13.1%. A multiple logistic regression analysis indicated that the introduction of co-formulated emtricitabine/tenofovir or emtricitabine/tenofovir/efavirenz was positively associated with the decrease of the frequency of the M184I/V mutations observed overtime (p = 0.0004).

Conclusions

We observed a significant decrease in the frequency of drug resistance mutations in TE patients, concomitant with a decrease in the proportion of patients with detectable viremia. These findings may be related to both the increased potencies and adherence to therapy associated with newer antiretroviral regimens. Nevertheless, our data demonstrate that broad use of antiretrovirals does not increase the level of circulating drug resistant variants.

Evolution of a novel pathway leading to dolutegravir resistance in a patient harbouring N155H and multiclass drug resistance

OBJECTIVES

Dolutegravir has been recently approved for treatment-naive and -experienced HIV-infected subjects, including integrase inhibitor (INI)-experienced patients. Dolutegravir is a second-generation INI that can overcome many prior raltegravir and elvitegravir failures. Here, we report the evolution of resistance to dolutegravir in a highly treatment-experienced patient harbouring the major N155H mutation consequent to raltegravir treatment failure.

METHODS

Genotypic and phenotypic analyses were done on longitudinal samples to determine viral resistance to INIs. Integrase amino acid sequence interactions with raltegravir and dolutegravir were assessed by molecular modelling and docking simulations.

RESULTS

Five mutations (A49P, L68FL, T97A, E138K and L234V) were implicated in emergent dolutegravir resistance, with a concomitant severe compromise in viral replicative capacity. Molecular modelling and docking simulations revealed that dolutegravir binding to integrase was affected by these acquired dolutegravir mutations.

CONCLUSIONS

Our findings identify a novel mutational pathway involving integrase mutations A49P and L234V, leading to dolutegravir resistance in a patient with the N155H raltegravir mutation.

Novel peptides that inhibit heparanase activation of the coagulation system

Heparanase is implicated in cell invasion, tumour metastasis and angiogenesis. It forms a complex and enhances the activity of the blood coagulation initiator - tissue factor (TF). We describe new peptides derived from the solvent accessible surface of TF pathway inhibitor 2 (TFPI-2) that inhibit the heparanase procoagulant activity. Peptides were evaluated in vitro by measuring activated coagulation factor X levels and co-immunoprecipitation. Heparanase protein and/or lipopolysaccharide (LPS) were injected intra-peritoneally and inhibitory peptides were injected subcutaneously in mouse models. Plasma was analysed by ELISA for thrombin-antithrombin complex (TAT), D-dimer as markers of coagulation activation, and interleukin 6 as marker of sepsis severity. Peptides 5, 6, 7, 21 and 22, at the length of 11-14 amino acids, inhibited heparanase procoagulant activity but did not affect TF activity. Injection of newly identified peptides 5, 6 and 7 significantly decreased or abolished TAT plasma levels when heparanase or LPS were pre-injected, and inhibited clot formation in an inferior vena cava thrombosis model. To conclude, the solvent accessible surface of TFPI-2 first Kunitz domain is involved in TF/heparanase complex inhibition. The newly identified peptides potentially attenuate activation of the coagulation system induced by heparanase or LPS without predisposing to significant bleeding tendency.