bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunosuppression (IST) Can Be Safely Ceased During Chemotherapy For Post-Transplant Lymphoproliferative Disorders (PTLD) In Renal Transplant Patients
Authors: Taylor Emma , Jones Mark , Hourigan Matthew J , Johnson David W , Gill Devinder S , Isbel Nicole , Hawley Carmel M , Marlton Paula , Gandhi Maher K , Campbell Scott B , Mollee Peter 
Published: October 2019

Abstract

Introduction
The optimal reduction of IST in renal transplant patients with PTLD is uncertain. As chemotherapy used to treat PTLD is inherently immunosuppressive, IST may be able to be stopped during this time without compromising graft function. Subsequent long-term reduction of IST is important to reduce PTLD relapse, but may increase long-term risk of graft rejection.

Methods
We performed a retrospective matched cohort study of adult renal transplant patients where IST was ceased during chemotherapy and then resumed at lower dose (calcineurin inhibitor at 50%, prednisolone <6mg daily, no third agent). Outcomes were compared to renal transplant patients without PTLD, matched for creatinine at the equivalent time post-transplant that PTLD was diagnosed in the cases, as well as age, gender, year of transplant and age at transplant. The primary endpoint of time to renal deterioration, defined as the time from PTLD diagnosis (cases) or study entry (controls) to a 25% increase in creatinine, was analysed using competing risk survival analyses. Additional endpoints were time to renal allograft failure requiring dialysis or re-transplant and overall survival.

Results
24 cases were identified: median age at PTLD diagnosis 45yrs; 75% male; median time to onset of PTLD post-transplant was 9 years. 22 cases received CHOP-like chemotherapy and 2 received primary CNS lymphoma protocols, 7 received concurrent rituximab and 4 had consolidation radiation therapy. 88% attained complete remission. Five patients have relapsed. The 5 yr overall survival for the cases was 71% with a median follow-up of survivors of 11.9 years.
The 24 PTLD cases were compared to 84 well matched controls. There were 11 deaths in the cases and 5 in the controls. Three cases recommenced dialysis, compared to 3 controls (HR 2.5, p=0.27). The 5 yr rate of 25% increase in creatinine was 36% in cases and 20% in controls (HR 1.8, p=0.098). Of the 11 cases with ≥25% increase in creatinine, only 1 of these occurred within 6 months of IST cessation in the setting of rapidly progressive PTLD and early death. Only 2 of these 11 cases received rituximab. In contrast 5 of the 7 patients given rituximab did not develop a ≥25% deterioration in renal function.

Conclusions
IST can be safely ceased during chemotherapy for PTLD in renal transplant patients. Whilst long-term reduction in IST is necessary to reduce PTLD relapse, this is associated with a trend to increased risk of chronic allograft nephropathy. Prospective trials are needed to address the ideal reduction of IST in PTLD.

Disclosures:
No relevant conflicts of interest to declare.
Pregnancy Does Not Affect The Thrombotic Thrombocytopenic Purpura (TTP) phenotype Of ADAMTS13-Deficient Mice
Authors: Hayon Yael , Varon David , Kalish Yosef 
Published: October 2019

Abstract
Thrombotic thrombocytopenic purpura (TTP) is a life threatening disease, characterized by sudden onset of the pentad of fever, hemolytic anemia, thrombocytopenia, renal dysfunction and neurological findings. Previous studies in ADAMTS13-deficient mice demonstrated a dependence on both genetic and environmental factors for the expression of the disease. Though homozygous Adamts13-/- mice on a C57BL6/J (B6) background are indistinguishable from wild-type controls, introduction of the CAST/EiJ genetic background results in a spontaneous TTP-like syndrome in a subset of mice.
The aim of this study was to evaluate the effect of pregnancy on TTP expression in this mouse model of TTP.
Adamts13 +/- mice were backcrossed for 20 generations to C57BL/6J to generate N20 B6 Adamts13+/- progeny. These mice were backcrossed for 2 generations into the CAST/EiJ mouse strain to generate N2F1 Adamts13-/- female mice that were tested and compared to N20F1 B6 Adamts13-/- female mice.
Two groups of 20 Adamts13-/- female mice from each strain were tested. Mice from one group were mated with wild type males, and mice from the second group were housed separately from male mice. Pregnant Adamts13-/- mice were compared to control non-pregnant Adamts13-/- female mice. Mice were monitored for a full profile of blood parameters and peripheral blood smears weekly for 10 weeks. Data was collected for mortality, pregnancy outcome and litter size. Von Willebrand factor (VWF) levels were also measured.
All Adamts13-/- mice in the B6 non-pregnant group appeared healthy and exhibited normal blood count parameters, without microangiopathic changes on peripheral blood smears. None of Adamts13-/- mice in the B6 pregnant group developed TTP. Mean platelet count in this group was 844,000±127,000 cells/µl compared to 666,000±56,000 cells/µl in the B6 non-pregnant group (p<0.01)
In contrast to the B6 results, Adamts13-/- CAST/EiJ non-pregnant mice exhibited lower platelet counts 369,000±89,000 cells/µl with spontaneous TTP-like disease in 54% of mice, as expected from previous studies.
Pregnancy did not worsen TTP expression in Adamts13-/- CAST/EiJ mice. Only 45% of mice in the CAST/EiJ pregnant group developed low platelet counts with a higher mean platelet count of 511,000±160,000 cells/µl, compared to non-pregnant group(p<0.01).
The physiological rise in VWF levels of pregnancy had no effect on TTP susceptibility in this model. VWF antigen levels were 167%, 203%, 197% and 245% in B6 non-pregnant, B6 pregnant, CAST/EiJ non-pregnant and pregnant respectively, compared to wild-type B6 levels. Four mice died during follow-up, 2 in the B6 pregnant and 2 in the CAST/EiJ non-pregnant groups.
In summary, TTP expression was unique to Adamts13-/- CAST/EiJ mice. Pregnancy and elevated VWF levels had no deleterious effect on TTP susceptibility in this mouse model.

Disclosures:
No relevant conflicts of interest to declare.
Efficacy, Immunogenicity, Pharmacokinetics, and Safety Of Human-cl rhFVIII – a GCP Study In Children With Severe Haemophilia A
Authors: Liesner Raina , Jansen Martina , Klukowska Anna , Vdovin Vladimir , Szczepanski Tomasz , Knaub Sigurd 
Published: October 2019

Abstract

Introduction
Human-cl rhFVIIIis the first recombinant factor VIII concentrate expressed in a human cell line (Human Embryonic Kidney 293F cells). Studies in adolescent and adult pre-treated patients with severe haemophilia A showed a favorable PK profile with a median half-life of 17.1 hours (one stage assay) and indicated safety and efficacy in preventing and treating bleeding episodes (BE).

Aims
The objectives of this international GCP study were to evaluate the efficacy, safety, immunogenicity and pharmacokinetic (PK) properties of Human-cl rhFVIIIin previously treated children between 2 and 12 years of age.

Methods
All patients started with an in-vivo recovery (IVR) investigation and in a subset of patients, the PK of Human-cl rhFVIII was assessed in comparison to the patient’s previously used FVIII product. After an injection of 50 IU/kg, blood samples were collected up to 48 hours for PK analysis and up to 2 hours for IVR. IVR was repeated in all patients after 3 and 6 months. FVIII plasma levels were measured by chromogenic and one-stage assay in a central laboratory. Patients were treated prophylactically with Human-cl rhFVIII every other day or 3x weekly, injecting 30-40 IU Human-cl rhFVIIIper kg for at least 6 months and > 50 exposure days. Inhibitors were measured before, during and at the end of the study by modified Nijmegen Bethesda assay in a central laboratory. Adverse events were recorded throughout the study.

Results
59 patients (29: 2-5 years; 30: 6-12 years) were enrolled from 15 specialized sites in Europe. 13 children of each age group participated in the comparative PK investigation. Mean PK parameters of Human-cl rhFVIII were similar in both age groups for both the chromogenic and the one-stage assay: AUCnorm 0.23 vs. 0.24 h*IU/mL/[IU/kg]); IVR 1.88 vs. 1.61% per IU/kg; T1/2 9.7 vs. 12.5 h. IVR remained stable throughout the study. A total of 108 BEs in 32/59 patients were treated with Human-cl rhFVIII. The majority of treated BEs were traumatic (60.2%) and minor (56.5%). The mean ± SD monthly bleeding rate of all types of BEs/patient was 0.34±0.43 (spontaneous BEs: 0.12±0.27; traumatic BEs: 0.19±0.29). No inhibitor development was reported; no patient discontinued the study because of an AE.

Conclusion
The data indicate that Human-cl rhFVIII is efficacious and safe in preventing and treating BEs in previously treated children. The PK of Human-cl rhFVIII was comparable in both studied age groups.

Disclosures:
Liesner: Octapharma AG: Consultancy, Investigator Other. Jansen:Octapharma AG: Employment. Klukowska:Octapharma AG: Investigator Other. Vdovin:Octapharma AG: Investigator Other. Szczepanski:Octapharma AG: Investigator Other. Knaub:Octapharma AG: Employment.
A Simple Genetic Thrombosis Score Of Five Single Nucleotide Polymorphisms Is Associated With Risk Of First Venous Thrombosis In Pregnant Women
Authors: Bare Lance A. , de Haan Hugoline G. , Arellano Andre R. , Tong Carmen H. , Devlin James J. , Rosendaal Frits R. 
Published: October 2019

Abstract

Background
Venous thrombosis (VT), a major cause of maternal morbidity and mortality, is increased 4- to 5- fold during pregnancy. A thrombosis score comprising 5 single nucleotide polymorphisms (SNPs) [rs6025 (Factor V Leiden), rs1799963 (Prothrombin 20210 G>A), rs8176719 (ABO 261G>deletion), rs2066865 (FGG 10034 C>T) and rs2036914 (F11 10364T>C)] was previously shown to be associated with VT events in the general population. We asked whether this thrombosis score could predict VT in pregnant and postpartum women in a case-control study on the etiology of thrombosis.

Methods
We studied women during pregnancy and up to three months postpartum (55 controls, 144 cases) selected from over 5000 female cases and controls of the MEGA (the Multiple Environmental and Genetic Assessment of risk factors for venous thrombosis) study. The thrombosis score was calculated for each individual as a sum of risk alleles weighted by the log of the published odds ratio (de Haan et al, Blood 2012). The VT risk per unit of thrombosis score was calculated as a continuous variable in a logistic regression model that adjusted for age, smoking history and family history of VT. The thrombosis scores ranged from 0 to 1.8 in female participants in MEGA with genotypes for the 5 SNPs (n=3,464).

Results
In pregnant and postpartum women, the odds ratio per unit increase in thrombosis score was 10.7 (95%CI 3.2 to 36.2). When the thrombosis score was evaluated in a sub study of pregnant and postpartum women who do not carry factor V Leiden—an important contributant to the risk score— the remaining 4-SNP thrombosis score was also associated with VT: the odds ratio per unit increase in thrombosis score was 10.6 (95%CI 2.3-48.3).The American College of Obstetricians and Gynecologists recommends thromboprophylaxis during pregnancy and postpartum periods in women who are compound carriers of both factor V Leiden and prothrombin 20210 G>A; these compound carriers who do not carry other risk variants would have a thrombosis score of 1.02. Compared with women in the bottom quintile of thrombosis scores, women with thrombosis scores equal to or greater than 1.02 had an odds ratio for VT of 12.3 (95%CI 1.5 to 99.9). About 2% of female controls in MEGA had thrombosis scores equal to or greater than 1.02.

Conclusions
A 5-SNP thrombosis score that combines the VT risk of 5 genetic variants is associated with VT in pregnant women.

Disclosures:
Bare: Celera: Employment. Arellano:Celera: Employment. Tong:Celera: Employment. Devlin:Celera: Employment.
Influence Of Antithrombin Deficiency On Symptomatic Recurrent Venous Thromboembolism (VTE) In Children: A Multicenter Cohort Study
Authors: Kenet Gili , Limperger Verena , Goldenberg Neil A , Heller Christine , Holzhauer Susanne , Vilk Shoshana Revel- , Young Guy , Nowak- Gottl Ulrike 
Published: October 2019

Abstract

Objective
To determine the importance of antithrombin [AT] deficiency as risk factor or predictor for fatal/non-fatal recurrent venous thromboembolism (VTE) in children.

Methods
In the present cohort of 874 consecutively enrolled pediatric patients with VTE aged newborn to <18 years the rate of VTE recurrence and the time to recurrence in relation to AT-deficiency [confirmed by underlying gene mutations; type 1 deficiency n=17; type 2 deficiency n=3], age and sex was determined. Twenty of 874 patients [2.4%] suffered from AT-deficiency. From the same cohort 150 VTE children carrying the heterozygous F5 G1691A mutation [F5: 17.7%] served as controls. Patients were prospectively followed for a median of 84 months. Data were pooled across participating sites to increase power and to enhance the generalisability of the data. Incidence rates were given as events per 1000 person-years.

Results
Of the 170 children enrolled 26 [AT n=9; F5 n=17] had recurrent VTE at a median of 15 months [95%CI: 12-36] following VTE onset: two of nine [AT] and two of 17 [F5] children suffered recurrent VTE while on anticoagulation with warfarin. The overall incidence rate of recurrence was 61.5 in patients with AT-deficiency compared to 23.5 for pediatric F5 carriers [p=0.02]. The recurrent-free survival probability is shown in the figure [logrank p-value: p=0.001]. When comparing AT patients and F5 children multivariate analysis [Cox regression] adjusted for age, sex and duration of anticoagulation treatment showed that AT deficiency [HR/95%CI: 4.1/1.8-9.4] significantly influenced the hazard for recurrent VTE.

Conclusions
Based on multivariate analysis, the presence of AT deficiency was associated with an increased risk of VTE recurrence. AT-deficiency in pediatric patients should be identified at VTE onset and the possible influence of intensified treatment protocols on recurrence should be studied in future prospective international studies.

Condensed abstract
To determine the relative importance of antithrombin deficiency or factor V (FV) mutations as risk factors for fatal/non-fatal recurrence in pediatric thromboembolism (VTE). Antithrombin deficiency influenced the hazard for recurrent VTE.

Disclosures:
No relevant conflicts of interest to declare.
Thrombin Generationand Fibrinolytic Activity in Microparticles In Acute Promyelocytic Leukemia
Authors: Kwaan Hau C. , Rego Eduardo M. , McMachon Brandon , Weiss Ivy 
Published: October 2019

Abstract

Introduction
The coagulopathy in acute promyelocytic leukemia (APL) is unique among the leukemias and accounts for the major complications of hemorrhage and thrombosis. The pathogenesis is in large part the result of increased expression by the APL promyelocytes of the procoagulant TF, and the fibrinolytic components of tPA , PAI-1 and Annexin A2. Recently, microparticles derived from plasma of APL patients and from culture medium of the human APL cell line NB4 have been shown to contain antigens of procoagulant tissue factor (TF), and the fibrinolytic components of tPA , Annexin A2 and PAI-1 (Kwaan HC, Rego EM. Role of microparticles in the hemostatic dysfunction in acute promyelocytic leukemia. Seminars in thrombosis and hemostasis 2010;36:917-24;Kwaan et al:Microparticles in acute promyelocytic leukemia. 53rdASH Annual Meeting; Blood 2011 Abstract No.3346). Results of functional activities of these components and thrombin generation in the microparticles are presented in the present study.

Material and Methods
Blood samples were collected in citrate vacutainers from 23 patients at the time of diagnosis and after induction therapy with ATRA at one month when there was molecular remission, under the approval of the respective institutional review boards. Control samples were collected from 37 healthy subjects.

Preparation of Microparticles
sodium citrated blood is centrifuged at 1500g for 20 minutes. The plasma portion is collected and centrifuged a second time at 3000g for 3 minutes to eliminate any extraneous platelets. 250µl of plasma is then centrifuged at 20,000g for 15 minutes at 4C. The resultant pellet contains the microparticles. [Standardization of platelet-derived microparticle enumeration by flow cytometry with calibrated beads: results of the International Society on Thrombosis and Haemostasis SSC Collaborative workshop. Lacroix R. Robert S. Poncelet P. Kasthuri RS. Key NS. Dignat-George F. ISTH SSC Workshop. Journal of Thrombosis & Haemostasis. 8(11):2571-4, 2010 Nov.

Results

Conclusion
Microparticles bearing TF have been shown to play a thrombogenic role in cancer. We had previously shown that there is an increase of microparticles containing procoagulants and fibrinolytic factors in APL and that these microparticles are mostly derived from CD33 positive (myeloid) cells. Present findings show that procoagulant and fibrinolytic factors are functional. The TF activity, thrombin generation are increased in the APL microparticles. It is noteworthy that thrombin generation is increased in the APL microparticles. In contrast, there is a complete absence of thrombin generation in the control microparticles. This suggests that the TF in microparticles, which are components of cell membranes, are not activated in healthy subjects but in APL.

Disclosures:
No relevant conflicts of interest to declare.
Differential Expression Of Platelet Proteins In Stable Unstable Coronary Artery Disease and Acute Coronary Syndromes
Authors: McRedmond James P , Holohan Brid , Roy Andrew K , Inzitari Rosanna , Alghamdi Kawthar Saad , Quinn Martin , Fitzgerald Desmond J 
Published: October 2019

Abstract

Background
In coronary artery disease (CAD), the risk of platelet-mediated coronary thrombosis varies over time, with the risk of events falling in the months following an episode of acute coronary syndrome (ACS). This study aims to characterize the platelet protein signature that differentiates stable CAD and ACS so as to identify when a patient with stable CAD is at risk for ACS.

Methods
We studied 2 groups of patients (N=10) undergoing PCI for CAD; patients with ACS (NSTEMI, STEMI), and patients with stable CAD undergoing PCI. All patients received a standard antiplatelet regimen of clopidogrel or prasugrel and aspirin. Samples were obtained immediately following PCI (days 1-3) and at follow-up (30-60 days). Total platelet lysate and secreted proteins following TRAP-induced platelet activation were extracted and the proteins trypsin-digested prior to analysis by liquid chromatography coupled to high resolution, high mass accuracy Orbitrap mass spectrometry. Protein identities and relative quantitation were determined in a label-free approach, using the MaxQuant suite of programs.

Results
Lysates: In total 1585 proteins were identified in platelet lysates. Comparing the 2 groups at PCI, there were 266 proteins differentially expressed between stable CAD and ACS; these are enriched in several ontology categories including coagulation and platelet activation. At follow up, 167 proteins were differentially expressed between groups -up, including a cluster of proteins involved in signal transduction.
Secreted proteins
In total 258 proteins were detected in TRAP-induced platelet secretion samples. Clustering analysis of samples from ACS (both PCI and follow up) showed that these patients largely clustered together in that they exhibited a consistent pattern of protein expression. Interestingly, a subgroup of samples from patients with stable CAD was closely related to ACS samples (Figure).

Discussion
Clustering of secreted platelet protein profiles indicates a common pattern of expression in patients with ACS. A subset of stable CAD patients has a similar pattern, and these patients may be at increased risk of thrombosis. Replication of this signature of protein expression in other patient populations and prospective analysis of risk will be required to address its applicability in the assessment of patients with CAD.

Disclosures:
No relevant conflicts of interest to declare.
The Concentration and Separation Of Blood Components Using Acoustic Radiation Force
Authors: Kennedy Daniel R , Gerhardson Tyler , Sporbert Brianna , Mealey Dane , Rust Michael J , Lipkens Bart 
Published: October 2019

Abstract
The concentration of whole blood has a wide spectrum of medical uses, especially in blood transfusions for patients suffering acute blood loss from trauma or surgery. However, current methods rely on centrifugation, which has a tendency to cause fragmentation and deformation of cells. Acoustic standing waves are considered to be a gentler means to concentrate blood cells, but generally suffer from flow rate limitations of >103fold, functioning only on the microscale. To address this issue, we have developed a novel ultrasound technology that works at the macroscale, enabling it to process flow rates that would typically be required to handle medically relevant volumes.
In this study, we have applied the principles of acoustic radiation at the macroscale to re-concentrate 10X diluted porcine blood by trapping the blood cells within a standing wave, resulting in the clumping of cells and platelets, ultimately leading to enhanced gravitational settling. Complete blood counts were measured with a VetScan HM5 hematology analyzer. Using an acoustic force generated by power levels up to 25 Watts, no lysing was observed in any of the experiments. The inlet flow rate through the device was 16 ml/min, and the concentrate flow rate of the blood components was typically 1 ml/min. The transducer was a 2 MHz PZT-8 operating at 10 W, and it was oriented to create an acoustic standing wave perpendicular to the flow direction. Results indicate successful capture of red blood cells, white blood cells, and platelets with separation efficiencies in excess of 90% in a single pass. Furthermore, the blood components were all reconcentrated back to levels similar to those in whole blood.
Subsequent experiments and conditions have allowed for the separation of blood components, suggesting that the future development of acoustic methods to perform blood re-concentration procedures such as erythropheresis, leukapheresis and plateletpheresis in a gentler manner than current methods holds great promise. With almost 15 million transfusions performed each year in the United States, this technology has the potential to make a significant impact on the medical community, particularly for treatment of critically ill patients. Additionally, the novel technology has also demonstrated performance in separating lipid particles from blood, thus indicating its utility for reducing the occurrence of lipid microemboli during re-transfusion of shed blood in cardiopulmonary bypass surgeries, which have been linked with post-operative neurocognitive complications. As a result, the novel acoustophoretic technology may become a general purpose platform for achieving separation in a variety of biomedical applications.

Disclosures:
Mealey: Flo Design Sonics: Employment. Lipkens:Flo Design Sonics: Equity Ownership.