Emicizumab for the Treatment of Acquired Hemophilia A: Consensus Recommendations from the GTH-AHA Working Group

BACKGROUND

 Acquired hemophilia A (AHA) is a severe bleeding disorder caused by autoantibodies against coagulation factor VIII (FVIII). Standard treatment consists of bleeding control with bypassing agents and immunosuppressive therapy. Emicizumab is a bispecific antibody that mimics the function of activated FVIII irrespective of the presence of neutralizing antibodies. Recently, the GTH-AHA-EMI study demonstrated that emicizumab prevents bleeds and allows to postpone immunosuppression, which may influence future treatment strategies.

AIM

 To provide clinical practice recommendations on the use of emicizumab in AHA.

METHODS

 A Delphi procedure was conducted among 33 experts from 16 German and Austrian hemophilia care centers. Statements were scored on a scale of 1 to 9, and agreement was defined as a score of ≥7. Consensus was defined as ≥75% agreement among participants, and strong consensus as ≥95% agreement.

RESULTS

 Strong consensus was reached that emicizumab is effective for bleed prophylaxis and should be considered from the time of diagnosis (100% consensus). A fast-loading regimen of 6 mg/kg on day 1 and 3 mg/kg on day 2 should be used if rapid bleeding prophylaxis is required (94%). Maintenance doses of 1.5 mg/kg once weekly should be given (91%). Immunosuppression should be offered to patients on emicizumab if they are eligible based on physical status (97%). Emicizumab should be discontinued when remission of AHA is achieved (97%).

CONCLUSION

 These GTH consensus recommendations provide guidance to physicians on the use of emicizumab in AHA and follow the results of clinical trials that have shown emicizumab is effective in preventing bleeding in AHA.

Real-World Experience of People with Hemophilia A Receiving Turoctocog Alfa Pegol (N8-GP): Results from a Patient Experience Survey

Purpose

Turoctocog alfa pegol (N8-GP) is an extended half-life recombinant factor VIII molecule used for the treatment of hemophilia A (HA). The purpose of this study was to investigate real-world experiences of patients with HA treated with N8-GP.

Patients and Methods

A 25-minute online survey was completed by adults (≥18 years) and caregivers of adolescents (12-16 years) with HA receiving N8-GP across six countries (Germany, Italy, Portugal, Spain, UK and US). Patients were recruited using a multichannel approach through recruitment panels, referrals from healthcare professionals and patient associations. The survey comprised a questionnaire with metrics including satisfaction and preferences for N8-GP, quality of life (QoL) and long-term impact.

Results

A total of 62 participants (98% male [n=61], mean age 29 years) comprising 46 patients and 16 caregivers completed the survey. Patients (60% non-severe [n=37] and 40% severe [25]) were on N8-GP for a mean period of 1.4 years. Patients expressed satisfaction (95% vs 42%, p<0.001) and preference (91% vs 9%, p<0.001) for N8-GP vs their previous treatments. Most patients with severe HA (87%, p=0.038) and patients on prophylaxis (84%, p<0.001) stated lower frequency of injections as their main reason for satisfaction, while improved QoL drove satisfaction for non-severe patients (81%, p=0.053). Overall, patients perceived that QoL score improved (74.8 vs 65.9, p=0.01) with N8-GP treatment compared with previous treatments. Flexibility to store at room temperature was one of the key convenience factors driving satisfaction. Patients believed that N8-GP can offer a long-term impact in areas such as ability to perform day-to-day activities (68%), independence to live like a person without hemophilia (63%), ability to travel (60%) with a feeling of optimism and hopefulness (82%).

Conclusion

Lower frequency of injections, storage flexibility and improved QoL drove satisfaction and preference for N8-GP over previous treatments among patients with HA.

Activation of the Acute-Phase Response in Hemophilia

To identify recurrent inflammation in hemophilia, we assessed the acute-phase response in the blood of patients with hemophilia A and B. Compared to age- and weight-matched controls, blood levels of interleukin-6 (IL-6), C-reactive protein (CRP), and LPS-binding protein (LBP) were significantly elevated in the entire cohort of hemophilia patients but exhibited a particularly pronounced increase in obese hemophilia patients with a body mass index (BMI) ≥30. Subgroup analysis of the remaining nonobese hemophilia patients (BMI: 18-29.9) revealed a significant spike of IL-6, CRP, and LBP in connection with a de-novo increase of soluble IL-6 receptor α (sIL-6Rα) in patients with bleeding events within the last month. Hemophilia patients who did not experience recent bleeding had IL-6, CRP, and sIL-6Rα blood levels similar to healthy controls. We did not find increased IL-6 or acute-phase reactants in hemophilia patients with arthropathy or infectious disease. The role of IL-6 as a marker of bleeding in hemophilia was confirmed in hemophilia patients with acute bleeding events as well as in transgenic hemophilia mice after needle puncture of the knee, which exhibited an extensive hematoma and a 150-fold increase of IL-6 blood levels within 7 days of the injury compared to needle-punctured control mice. Notably, IL-6 blood levels shrunk to a fourfold elevation in hemophilia mice over controls after 28 days, when the hematoma was replaced by arthrofibrosis. These findings indicate that acute-phase reactants in combination with sIL-6Rα could be sensitive biomarkers for the detection of acute and recent bleeding events in hemophilia.

Big Data in Transfusion Medicine and Artificial Intelligence Analysis for Red Blood Cell Quality Control

Background

"Artificial intelligence" and "big data" increasingly take the step from just being interesting concepts to being relevant or even part of our lives. This general statement holds also true for transfusion medicine. Besides all advancements in transfusion medicine, there is not yet an established red blood cell quality measure, which is generally applied.

Summary

We highlight the usefulness of big data in transfusion medicine. Furthermore, we emphasize in the example of quality control of red blood cell units the application of artificial intelligence.

Key Messages

A variety of concepts making use of big data and artificial intelligence are readily available but still await to be implemented into any clinical routine. For the quality control of red blood cell units, clinical validation is still required.

Characteristics of BAY 2599023 in the Current Treatment Landscape of Hemophilia A Gene Therapy

Hemophilia A, a single gene disorder leading to deficient Factor VIII (FVIII), is a suitable candidate for gene therapy. The aspiration is for single administration of a genetic therapy that would allow the production of endogenous FVIII sufficient to restore hemostasis and other biological processes. This would potentially result in reliable protection from bleeding and its associated physical and emotional impacts. Gene therapy offers the possibility of a clinically relevant improvement in disease phenotype and transformational improvement in quality of life, including an opportunity to engage in physical activities more confidently. Gene therapy products for hemophilia A in advanced clinical development use adeno-associated viral (AAV) vectors and a codon-optimized B-domain deleted FVIII transgene. However, the different AAV-based gene therapies have distinct design features, such as choice of vector capsid, enhancer and promoter regions, FVIII transgene sequence and manufacturing processes. These, in turn, impact patient eligibility, safety and efficacy. Ideally, gene therapy technology for hemophilia A should offer bleed protection, durable FVIII expression, broad eligibility and limited response variability between patients, and long-term safety. However, several limitations and challenges must be overcome. Here, we introduce the characteristics of the BAY 2599023 (AAVhu37.hFVIIIco, DTX 201) gene therapy product, including the low prevalence in the general population of anti-AAV-hu37 antibodies, as well as other gene therapy AAV products and approaches. We will examine how these can potentially meet the challenges of gene therapy, with the ultimate aim of improving the lives of patients with hemophilia A.

Gene therapy of Hemophilia: Recommendations from the German, Austrian, and Swiss Society for Thrombosis and Haemostasis Research (GTH)

Gene therapy has recently become a realistic treatment perspective for patients with hemophilia. Reviewing the literature and our personal experience from clinical trials, we discuss key aspects of hemophilia A and B gene therapy with vectors derived from adeno-associated virus, including predictable results, risks, adverse events, and patient-reported outcomes. Patient selection, informed consent, administration, and monitoring of gene therapy as well as data collection are explained. We also discuss the need for interdisciplinary cooperation with hepatology and other specialties. We emphasize structural and organizational requirements for treatment centers according to the hub-and-spoke model and recommend the use of electronic diaries to ensure safe and timely collection and exchange of data. Electronic diaries will play a key role as a primary source of data for pharmacovigilance, postmarketing clinical studies, national and international registries, as well as health technology and benefit assessment. Reimbursement aspects and the future of gene therapy in adolescents and children are also considered. In a rapidly evolving scientific environment, these recommendations aim to support treatment providers and payers to prepare for the implementation of gene therapy following marketing authorization.

Erysense, a Lab-on-a-Chip-Based Point-of-Care Device to Evaluate Red Blood Cell Flow Properties With Multiple Clinical Applications

In many medical disciplines, red blood cells are discovered to be biomarkers since they "experience" various conditions in basically all organs of the body. Classical examples are diabetes and hypercholesterolemia. However, recently the red blood cell distribution width (RDW), is often referred to, as an unspecific parameter/marker (e.g., for cardiac events or in oncological studies). The measurement of RDW requires venous blood samples to perform the complete blood cell count (CBC). Here, we introduce Erysense, a lab-on-a-chip-based point-of-care device, to evaluate red blood cell flow properties. The capillary chip technology in combination with algorithms based on artificial neural networks allows the detection of very subtle changes in the red blood cell morphology. This flow-based method closely resembles in vivo conditions and blood sample volumes in the sub-microliter range are sufficient. We provide clinical examples for potential applications of Erysense as a diagnostic tool [here: neuroacanthocytosis syndromes (NAS)] and as cellular quality control for red blood cells [here: hemodiafiltration (HDF) and erythrocyte concentrate (EC) storage]. Due to the wide range of the applicable flow velocities (0.1-10 mm/s) different mechanical properties of the red blood cells can be addressed with Erysense providing the opportunity for differential diagnosis/judgments. Due to these versatile properties, we anticipate the value of Erysense for further diagnostic, prognostic, and theragnostic applications including but not limited to diabetes, iron deficiency, COVID-19, rheumatism, various red blood cell disorders and anemia, as well as inflammation-based diseases including sepsis.

Preparing for tomorrow: Defining a future agenda

Gene therapy will be the first long-term therapy with potential to produce a functional cure for haemophilia. As a single dose ('once-and-done') therapy with significant uncertainties regarding impact and duration of factor expression, flexibility and adaptability of (1) value framework, (2) health technology assessment (HTA) methodology, and (3) development of alternative payment models will be needed for adoption of this new technology and to facilitate transparent decision-making to support its implementation. The responsibility for each of these currently lies with distinct entities, underscoring a need for enhanced collaboration between all stakeholders, as expanded engagement by key stakeholders will be critical to optimizing the assessment of value, enabling an optimised approach to HTA, and opening receptivity to new and innovative payment models. This supplement issue describes important considerations for a gene therapy 'toolkit', highlighting key considerations for each of the aforementioned tools, which will be useful for guiding decision-making regarding gene therapy as a novel treatment modality. In this article, we outline how the tools presented in this supplement can be applied as part of a framework to address the requirements of the relevant stakeholders, including payers, manufacturers, treaters, and patients. The paper also provides an illustrative example of how to understand the features of alternative payment models depending on the organization of and payment for healthcare.

A preliminary application of a haemophilia value framework to emerging therapies in haemophilia

INTRODUCTION

Emergence of new therapies are anticipated to improve clinical outcomes and quality of life of persons with haemophilia. Challenges in conducting randomized clinical trials in rare diseases have resulted in a lack of direct head-to-head comparisons to support value-based decision-making between different treatments.

METHODS

We conducted a literature review for new and emerging haemophilia A and B therapies (extended half-life [EHL] replacement factor, non-replacement therapies [NRT], and gene therapies [GT]) to identify differentiating patient-centred outcomes defined previously in a haemophilia value framework. Since the literature included all publication types (e.g., surveys, modelling studies, commentaries/reviews), collected data were assigned level of evidence scores.

RESULTS

Across different classes of therapies, bleeding was determined as the most frequently reported differentiating outcome, with EHL, NRT, and GT each demonstrating an advantage over comparator replacement therapies. EHL therapies for haemophilia A and B and NRT for haemophilia A showed good representation across Tier 1 outcomes (health status achieved/retained), while more publications were identified with Tier 2 (process of recovery) outcomes for NRT than EHL or GT. In Tier 3 (sustainability of health), frequency of breakthrough bleeds represented a differentiating outcome for EHL (both haemophilia A and B), NRT (haemophilia A only), and GT (haemophilia B only), whereas sustained good health was differentiating for most comparisons.

CONCLUSIONS

We demonstrate the utility of the haemophilia value framework as a common core outcome set for effectively comparing therapies. Application of this framework will serve as a useful decision-making tool for patients, clinicians, and within health technology assessments.

KEY POINTS OF CONSIDERATION

With the emergence of high-cost, paradigm changing treatments across multiple areas of medicine, we, the haemophilia community, need to be equipped to meet the growing demands for more rigorous evidence-based value assessments using the tools expected by assessors. The traditional access toolbox needs to evolve to meet the paradigm shift in treatment options. Value can no longer be defined by annualized bleed rates alone. To realize the full impact of new therapies, we need to utilize tools, such as a value framework, to organize evidence, identify data gaps, and assess patient-defined, meaningful outcomes across a multi-faceted dimension. The haemophilia value framework is an effective tool for organizing the available evidence and identifying gaps in the evidence. This can be used for assessing the value of emerging therapies in haemophilia utilizing data generated through randomized clinical trials and real world evidence generation. This is a call for incorporating the Value Framework into official submissions to authorities, as it captures a broader range of outcomes, including patient meaningful outcomes, in ways that better assess the potential benefits of new therapies.

Electronic diaries in the management of haemophilia gene therapy: Perspective of an expert group from the German, Austrian and Swiss Society on Thrombosis and Haemostasis (GTH)

INTRODUCTION

Gene therapy (GT) is becoming a realistic treatment option for patients with haemophilia. Outside clinical trials, the complexity and potential complications of GT will pose unprecedented challenges to haemophilia care centres.

AIM

To explore the potential use of electronic tools to improve the delivery of GT under real-world conditions.

METHODS

Considering the hub-and-spoke model, the GTH working group on GT considered the entire patient pathway and reached consensus on requirements for an integrative software tool to secure documenting and sharing information between treaters, pharmacies and patients.

RESULTS

Six steps of the gene therapy process were identified, each requiring completion of the previous step as a prerequisite for entry. The responsibilities of GT dosing and follow-up treatment centres, read/write access rules, and the minimum data set were outlined. Data contributed by patients through mobile devices was also considered.

CONCLUSION

Important information needs to be shared between patients and treatment centres in a real-world GT hub-and-spoke model. Collecting and sharing this information in well-organised electronic applications will not only improve patient care but also enable national and international data collection in clinical registries.

Hemophilia treatment in 2021: Choosing the"optimal" treatment using an integrative, patient-oriented approach to shared decision-making between patients and clinicians

The mainstay of hemophilia treatment is to prevent bleeding through regular long-term prophylaxis and to control acute breakthrough bleeds. Various treatment options are currently available for prophylaxis, and treatment decision-making is a challenging and multifaceted process of identifying the most appropriate option for each patient. A multidisciplinary expert panel convened to develop a practical, patient-oriented algorithm to facilitate shared treatment decision-making between clinicians and patients. Key variables were identified, and an algorithm proposed based on five variables: bleeding phenotype, musculoskeletal status, treatment adherence, venous access, and lifestyle. A complementary, patient-focused preference tool was also hypothesized, with the aim of exploring individual patients' priorities, preferences, and goals. It is hoped that the proposed algorithm and the hypothesized patient preference tool will assist in selecting a treatment for each patient that is as efficient as possible in preventing bleeds while also accounting for the patient's expectations and priorities.

Donors for SARS-CoV-2 Convalescent Plasma for a Controlled Clinical Trial: Donor Characteristics, Content and Time Course of SARS-CoV-2 Neutralizing Antibodies

Background

Convalescent plasma is one of the treatment options for COVID-19 which is currently being investigated in many clinical trials. Understanding of donor and product characteristics is important for optimization of convalescent plasma.

Methods

Patients who had recovered from CO­VID-19 were recruited as donors for COVID-19 convalescent plasma (CCP) for a randomized clinical trial of CCP for treatment of severe COVID-19 (CAPSID Trial). Titers of neutralizing antibodies were measured by a plaque-reduction neutralization test (PRNT). Correlation of antibody titers with host factors and evolution of neutralizing antibody titers over time in repeat donors were analysed.

Results

A series of 144 donors (41% females, 59% males; median age 40 years) underwent 319 plasmapheresis procedures providing a median collection volume of 850 mL and a mean number of 2.7 therapeutic units per plasmapheresis. The majority of donors had a mild or moderate course of COVID-19. The titers of neutralizing antibodies varied greatly between CCP donors (from <1:20 to >1:640). Donor factors (gender, age, ABO type, body weight) did not correlate significantly with the titer of neutralizing antibodies. We observed a significant positive correlation of neutralization titers with the number of reported COVID-19 symptoms and with the time from SARS-CoV-2 diagnosis to plasmapheresis. Neutralizing antibody levels were stable or increased over time in 58% of repeat CCP donors. Mean titers of neutralizing antibodies of first donation and last donation of repeat CCP donors did not differ significantly (1:86 at first compared to 1:87 at the last donation). There was a significant correlation of neutralizing antibodies measured by PRNT and anti-SARS-CoV-2 IgG and IgA antibodies which were measured by ELISA. CCP donations with an anti-SARS-CoV-2 IgG antibody content above the 25th percentile were substantially enriched for CCP donations with higher neutralizing antibody levels.

Conclusion

We demonstrate the feasibility of collection of a large number of CCP products under a harmonized protocol for a randomized clinical trial. Titers of neutralizing antibodies were stable or increased over time in a subgroup of repeat donors. A history of higher number of COVID-19 symptoms and higher levels of anti-SARS-CoV-2 IgG and IgA antibodies in immunoassays can preselect donations with higher neutralizing capacity.

Principles of care for acquired hemophilia

Objective

To establish clear priorities for the care of patients with acquired hemophilia A (AHA) by proposing 10 key principles of practical, holistic AHA management.

Method

These principles were developed by the Zürich Haemophilia Forum, an expert panel of European hemophilia specialists comprising physicians and nursing and laboratory specialists.

Results

The 10 proposed principles for AHA care are as follows: (a) Improving initial diagnosis of AHA; (b) Differential diagnosis of AHA: laboratory assessment of patients with unusual bleeding; (c) Effective communication between laboratories, physicians, and specialists; (d) Improving clinical care: networking between healthcare professionals in the treating hospital and specialist hemophilia centers; (e) Comprehensive assessment of bleeding; (f) Appropriate use of bypassing agents; (g) Long‐term follow‐up and monitoring for efficacy and safety of immunosuppressive treatment; (h) Inpatient/outpatient settings; (i) Access to innovative and disruptive treatments; (j) Promotion of international collaborative research.

Conclusion

The proposed principles for holistic AHA care aim to ensure swift diagnosis and optimal patient management. Key to achieving this goal is training for healthcare personnel in non‐specialist hospitals and collaboration between different specialists. We hope these principles will increase awareness of AHA in the wider medical community and catalyze efforts toward improving its practical, multidisciplinary management.

Recombinant FVIII Products (Turoctocog Alfa and Turoctocog Alfa Pegol) Stable Up to 40°C

PURPOSE

The stability under high-temperature conditions of factor VIII (FVIII) concentrates for replacement therapy is of critical importance to patients, particularly those who reside in, or travel to, regions with high ambient temperatures. Concerns about product stability may limit or prevent access to treatment for patients and may limit their ability to live a close-to-normal life. This study evaluated the effect of hot and humid storage conditions on the long-term stability of the recombinant FVIII products, turoctocog alfa and turoctocog alfa pegol.

METHODS

Turoctocog alfa samples were assessed for stability at 30°C for 9 months or 40°C for 3 months following storage at 5°C for 21 or 27 months, respectively, while turoctocog alfa pegol samples were assessed at 30°C for 12 months or 40°C for 3 months following storage at 5°C for 18 or 27 months, respectively. In addition, turoctocog alfa and turoctocog alfa pegol dry powders were evaluated for stability at 5°C/ambient humidity (AH) for 30 months, 30°C/75% relative humidity (RH) for 12 months and 40°C/75% RH for 6 months. Both studies utilized a range of product strengths. Key stability assessments included oxidized forms, potency, water content and high molecular weight protein (HMWP).

RESULTS

Both turoctocog alfa and turoctocog alfa pegol remained stable following storage at 40°C/75% RH for 3 months, and at single temperatures (5°C/AH, 30 and 40°C/75% RH), without any major increase in HMWP or any impairment of potency or water content.

CONCLUSION

Turoctocog alfa and turoctocog alfa pegol offer stability at 40°C for up to 3 months without jeopardizing the quality of each product. These stability characteristics may offer patients flexibility with product storage and daily use.

Population-Based Analysis of the Impact of Demographics on the Current and Future Blood Supply in the Saarland

Background

The federal state of Saarland (SL) is experiencing the fastest demographic change in the western part of Germany. In this study, we analyzed retrospective data on the current and future supply of red blood cell concentrates (RBC) in this region and compared it to the current and future RBC demand in SL hospitals.

Methods

The projection of the SL blood supply in 2030 was modeled based on SL demographics for age distribution and donation frequency of donors, and the RBC transfusion data for in-house patients. These results were compared to published data on the transfusion demand from the state of Mecklenburg-Western Pomerania (MV).

Results

For the period January 1 to December 31, 2017, a total of 43,205 whole blood donations were collected. The donation frequency in SL never exceeded 80 per 1,000 inhabitants and was well below the numbers in MV. Thirty-one percent of the donors were responsible for 53.5% of the donations, and donors older than 45 years of age contributed highly to the total blood supply. In addition, 40,614 RBC transfusions at 10 SL hospitals were analyzed representing nearly all RBC transfusions for in-house patients in this region. RBC transfusions per 1,000 inhabitants increased with age from 24 (50-54) to 140 (80-84) years. Facing an already existing structural deficit of nearly 8,200 RBC in 2017, the projection predicts a dramatic increase in the regional deficit to >18,300 RBC in 2030.

Conclusion

Our results on RBC demand in SL are comparable but not identical to those projected for the region of MV in eastern Germany. Due to the ongoing demographic changes in Germany as a whole, regular regional monitoring of RBC demand and the age structure of blood recipients and donors should be implemented to allow for better strategic planning in blood transfusion services and hospitals.

Health-Related Quality of Life, Treatment Satisfaction and Adherence Outcomes of Haemophilia Patients Living in a German Rural Region

In the context of the ‘Mobile Haemophilia Outpatient Care (MHOC)’ project we aimed to gather insights into the health-related quality of life (HRQoL), treatment satisfaction (TS) and adherence of persons with haemophilia (PWHs) who get treated at the Saarland University Hospital Haemophilia Treatment Centre (HTC). PWHs were visited at home at least twice (baseline, follow-up) by trained medical staff. Individual interviews were performed to measure patients' HRQoL and TS with validated questionnaires (Haem-A-QoL/Haemo-QoL and Hemo-SatA/Hemo-SatP). Socio-demographic and clinical data were collected. In total, 79 PWHs were enrolled; 56 adults with a mean age of 37.4 ± 16.4 years (17–78) and 23 children [mean age of 9.8 ± 4.2 years (3–16)]. In total, 62% were severely affected; 48.1% received prophylaxis. Patients reported good HRQoL (adults: 23.1 ± 17.1; kids: 24.3 ± 11.1). Patients (M = 11.2 ± 9.5) and parents (M = 14.3 ± 7.4) were very satisfied with their provided treatment. The majority of study participants were evaluated to have a good treatment adherence. After 1-year follow-up of the MHOC, a significant improvement in HRQoL was seen in adults (p < 0.033) and in proxy ratings of parents (p < 0.0001); TS remained high with no change by MHOC intervention. Patients reported good HRQoL and TS. Most of them were evaluated as having a good treatment adherence. After implementation of the MHOC, adult patients reported a better HRQoL. Such a mobile medical care service is considered beneficial for patients, especially with limited access to a HTC.

High levels of SARS-CoV-2-specific T cells with restricted functionality in severe courses of COVID-19

BACKGROUND

Patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) differ in the severity of disease. We hypothesized that characteristics of SARS-CoV-2–specific immunity correlate with disease severity.

METHODS

In this study, SARS-CoV-2–specific T cells and antibodies were characterized in uninfected controls and patients with different coronavirus disease 2019 (COVID-19) disease severity. SARS-CoV-2–specific T cells were flow cytometrically quantified after stimulation with SARS-CoV-2 peptide pools and analyzed for expression of cytokines (IFN-γ, IL-2, and TNF-α) and markers for activation, proliferation, and functional anergy. SARS-CoV-2–specific IgG and IgA antibodies were quantified using ELISA. Moreover, global characteristics of lymphocyte subpopulations were compared between patient groups and uninfected controls.

RESULTS

Despite severe lymphopenia affecting all major lymphocyte subpopulations, patients with severe disease mounted significantly higher levels of SARS-CoV-2–specific T cells as compared with convalescent individuals. SARS-CoV-2–specific CD4⁺ T cells dominated over CD8⁺ T cells and closely correlated with the number of plasmablasts and SARS-CoV-2–specific IgA and IgG levels. Unlike in convalescent patients, SARS-CoV-2–specific T cells in patients with severe disease showed marked alterations in phenotypical and functional properties, which also extended to CD4⁺ and CD8⁺ T cells in general.

CONCLUSION

Given the strong induction of specific immunity to control viral replication in patients with severe disease, the functionally altered characteristics may result from the need for contraction of specific and general immunity to counteract excessive immunopathology in the lung.

FUNDING

The study was supported by institutional funds to MS and in part by grants of Saarland University, the State of Saarland, and the Rolf M. Schwiete Stiftung.

COVID-19 patients with severe disease have higher levels of SARS-CoV-2 specific T-cells as compared to convalescent individuals.

Cross-reacting inhibitors against recombinant porcine factor VIII in acquired hemophilia A: Data from the GTH-AH 01/2010 Study

BACKGROUND

Recombinant porcine factor VIII (rpFVIII, OBI-1, susoctocog alfa) is used for the treatment of acute bleeds in patients with acquired hemophilia A (AHA). Inhibitors in AHA can sometimes cross-react with rpFVIII.

OBJECTIVES

To assess the frequency, strength, and determinants of cross-reactivity.

PATIENTS/METHODS

Baseline samples from 70 patients of the prospective, observational cohort study GTH-AH 01/2010 were assessed for anti-human FVIII and anti-rpFVIII inhibitors using modified Nijmegen-Bethesda assays, as well as anti-human FVIII domain reactivity using enzyme-linked immunoassay (ELISA).

RESULTS

Anti-human FVIII inhibitors were present in all samples ranging between 0.7 and 3891 Bethesda Units (BU)/mL. Inhibitors from 31 of 70 patients (44%) partially inhibited rpFVIII with anti-rpFVIII titers ranging between 0.5 and 471 BU/mL. Anti-rpFVIII titers were ≤5 BU in most patients. Patients with cross-reacting inhibitors, as compared to patients without, had significantly higher anti-human FVIII titers (27.8 versus 5.4 BU/mL) and lower baseline FVIII activity (<1 versus 2.6 IU/dL). The ratio between anti-rpFVIII to anti-human titers was highest for inhibitors involving the C1 domain. Cross-reactivity was very rare, if inhibitors reacted only with the C2 domain of FVIII (6%). An anti-human FVIII titer of >100 BU/mL predicted cross-reactivity with 97% likelihood, whereas an anti-human FVIII titer of <3.8 BU/mL predicted absent cross-reactivity with 90% likelihood.

CONCLUSION

Cross-reacting inhibitors should be considered when choosing a treatment for bleeding patients with AHA. Cross-reactivity is frequent in patients with anti-human FVIII titers of >100 BU/mL.

PTFEP-Al2O3 hybrid nanowires reducing thrombosis and biofouling

Thrombosis and bacterial infection are major problems in cardiovascular implants. Here we demonstrated that a superhydrophobic surface composed of poly(bis(2,2,2-trifluoroethoxy)phosphazene) (PTFEP)-Al₂O₃ hybrid nanowires (NWs) is effective to reduce both platelet adhesion/activation and bacterial adherence/colonization. The proposed approach allows surface modification of cardiovascular implants which have 3D complex geometries.

Macrophage Polarization is Deregulated in Haemophilia

Macrophages make important contributions to inflammation and wound healing. We show here that macrophage polarization is deregulated in haemophilia in response to macrophage colony-stimulating factor (M-CSF) and partially in response to granulocyte-macrophage colony-stimulating factor (GM-CSF). As a result, haemophilia macrophages exhibit a specific impairment of M-CSF-mediated functions involved in wound healing such as clot invasion and phagocytosis. Haemophilia monocytes express reduced amounts of the receptors for M-CSF and GM-CSF, which correlates with a failure to express tumour necrosis factor α (TNFα) and CD163 in M-CSF-treated haemophilia macrophages and reduced expression of TNFα and CD206 after treatment with GM-CSF. Protein expression in response to M-CSF was regained with respect to CD163 and CD206 after embedding haemophilia monocytes in clotted plasma suggesting that a functioning coagulation system has positive effects on macrophage M2 polarization. Mimicking the functional deficits of haemophilia macrophages in normal macrophages was possible by adding leptin, which we found to be elevated in the blood of haemophilia patients, to a monocyte cell line. The increase of leptin occurred in conjunction with C-reactive protein in a body mass index-controlled cohort suggesting that haemophilia patients harbour chronic low-grade inflammation. Together, our data indicate that impaired clotting in haemophilia patients leads to increased inflammation and a deregulation in macrophage differentiation, which may explain the commonly observed deficits in wound healing and tissue regeneration.

Smart Medication ™, an Electronic Diary for Surveillance of Haemophilia Home Care and Optimization of Resource Distribution

This report describes the technical features and potential advantages of the application of electronic haemophilia treatment diary smart medication ^™ and an evaluation of real-life electronic treatment data collected from haemophilia patients. Since 2012, a total of 663 patients from 30 German haemophilia treatment centres (HTCs) have used the device. Data of nine HTCs were merged for real-life data analysis. Patients were divided into four subgroups according to above versus below mean values for annual factor consumption (AFC) and annual joint bleeds (AJB), respectively. The largest subgroup comprised patients with low mean AFC and AJB less than 2.25 (group A: 42%). Second largest was the group with low mean AJB but high AFC (group B: 32%), suggesting that resources could be saved in some patients. The group with low AFC but high AJB may need increased factor dosing (group D: 13%). Patients who showed a high mean AJB despite high AFC (group C: 13%) may require special medical attention, such as pharmacokinetic-adapted treatment modification or orthopaedic measures. Smart medication ^™ enables the HTC to quickly identify patients in need of treatment changes and, thus, to plan individualized therapy modifications prior to patient visits. The growing pool of real-life data facilitates data analysis and may play an important role in the optimization of resource distribution.

Concizumab restores thrombin generation potential in patients with haemophilia: Pharmacokinetic/pharmacodynamic modelling results of concizumab phase 1/1b data

Introduction

Concizumab enhances thrombin generation (TG) potential in haemophilia patients by inhibiting tissue factor pathway inhibitor (TFPI). In EXPLORER3 (phase 1b), a dose‐dependent pharmacokinetic/pharmacodynamic (PK/PD) relationship was confirmed between concizumab dose, free TFPI and TG potential.

Aim

Determine the association between concizumab exposure, PD markers (free TFPI; peak TG) and bleeding episodes to establish the minimum concizumab concentration for achieving sufficient efficacy.

Methods

Free TFPI predictions were generated using an estimated concizumab‐free TFPI exposure‐response (E_max) model based on concizumab phase 1/1b data for which simultaneously collected concizumab and free TFPI samples were available. Concizumab concentration at the time of a bleed was predicted using a PK model, based on available data for concizumab doses >50 μg/kg to ≤9 mg/kg. Peak TG vs concizumab concentration analyses and an E_max model were constructed based on EXPLORER3 observations.

Results

The E_max model showed a tight PK/PD relationship between concizumab exposure and free TFPI; free TFPI decreased with increasing concizumab concentration. A strong correlation between concizumab concentration and peak TG was observed; concizumab >100 ng/mL re‐established TG potential to within the normal reference range. Estimated EC₅₀ values for the identified concizumab‐free TFPI and concizumab‐TG potential models were very similar, supporting free TFPI as an important biomarker. A correlation between bleeding episode frequency and concizumab concentration was indicated; patients with a concizumab concentration >100 ng/mL experienced less frequent bleeding. The PK model predicted that once‐daily dosing would minimize within‐patient concizumab PK variability.

Conclusion

Concizumab phase 2 trials will target an exposure ≥100 ng/mL, with a once‐daily regimen.

A randomized trial of safety, pharmacokinetics and pharmacodynamics of concizumab in people with hemophilia A

Essentials explorer™3 was a double-blinded, multiple-dose escalation trial of subcutaneous concizumab. A pharmacodynamic relationship for unbound TFPI and thrombin generation was confirmed. No serious adverse events and no anti-drug antibodies were observed. explorer™3 data support further clinical development of concizumab in people with hemophilia. SUMMARY: Background Concizumab is a humanized mAb targeting tissue factor pathway inhibitor (TFPI), leading to enhanced thrombin generation (TG) potential. explorer™3 (NCT02490787) was a phase 1b, double-blind, multiple-dose escalation trial of subcutaneous concizumab in people with severe hemophilia A without inhibitors. Objectives The primary objective was to evaluate safety. Assessments of pharmacokinetics, pharmacodynamics and subcutaneous concizumab immunogenicity were secondary objectives. Patients/Methods Adverse events (AEs), clinical assessments and bleeding episodes were recorded. Plasma concizumab levels and unbound TFPI levels were measured with ELISAs; residual TFPI activity was measured with a chromogenic assay. Standardized assays were used to assess TG, D-dimer and prothrombin fragment 1 + 2 (F1 + 2 ) levels. explorer™3 was completed after investigation of three dose cohorts (0.25, 0.5 and 0.8 mg kg-1 , once every 4 days) had been completed. Twenty-four patients received 12 doses of concizumab or placebo in a 3 : 1 randomization over a 42-day period. Results No serious AEs and no anti-drug antibodies were observed. Fifty-four mild and two moderate AEs were observed in 19 patients. Concizumab exposure increased with dose in a non-linear manner, confirming target-mediated drug disposition. D-dimer and F1 + 2 levels were increased mostly in the highest dose cohort, in line with previous observations. The level of unbound TFPI decreased in a dose-dependent manner, and was accompanied by a residual TFPI activity decrease and an increase in peak TG. Although the trial was not powered to evaluate efficacy, a trend towards lower bleeding rates was observed in patients in the highest dose cohort. Conclusion explorer™3 data support further clinical development of concizumab for use in people with hemophilia, with or without inhibitors.

Feasibility and Results of a Mobile Haemophilia Outpatient Care Pilot Project

Introduction Regular visits at haemophilia treatment centres (HTCs) in rural regions are often dependent on the access to a private car due to lack of or limited availability of public means. Therefore, a mobile haemophilia outpatient care (MHOC) concept providing home visits to haemophilia patients has been developed by the Saarland HTC, which is located in a rural German region.

Methods Haemophilia patients and their parents were home visited at least twice (baseline, follow-up) by trained medical staff. Socio-demographic and clinical data were collected and interviews were performed asking the patients and parents about their needs and expectations towards such a MHOC.

Results Seventy-nine patients were enrolled (56 adults, 23 children), 62.0% severely affected, 48.1% on prophylaxis, with a mean age of 37.4 ± 16.4 years (17–78) and 9.8 ± 4.2 years (3–16), respectively. Median travel distance to the HTC was 43.5 km (3–200). Note that 92.4% considered an intense binding to the HTC and a MHOC concept as ‘rather/very important’ (88.6%). They expected from a MHOC to provide consulting and educating activities, support in elderhood issues and treatment. For 35.4%, a MHOC could currently provide additional support, mainly due to patient's immobility and need of consultancy. They mainly used services in terms of consultancy in social–legal affairs and support in contacting authorities.

Conclusion The results of this study support the hypothesis that a MHOC concept is a needful supplement in haemophilia comprehensive care and will improve the challenging haemophilia treatment, especially for those with limited access to HTCs or with disabilities.

[The use of Idarucizumab in intracerebral bleeding - a case report]

HISTORY AND CLINICAL FINDINGS

 82-year old male patient suspected of having cerebral hemorrhage under anticoagulation therapy with Dabigatran due to atrial fibrillation.

INVESTIGATIONS

 CT scan showed bilateral chronic subdural hematomas with fresh blood in left-subdural hematoma and midline shift. Laboratory analysis shows only a moderately high Dabigatran level but thrombin time was high out of range.

DIAGNOSIS

 Fall-related intracerebral haemorrhage and subdural hematoma under anticoagulation therapy.

THERAPY AND COURSE

 Neurosurgical hematoma evacuation and trepanation after preoperative use of Idarucizumab as an antidote for Dabigatran to stop anticoagulative effects and secure normal bleeding conditions, led to reduced midline shift. We started heparin-based anticoagulation first followed by Dabigatran again in clinical steady state and after rehabilitation with neurologically low-grade residuals.

Quantity, quality, and functionality of peripheral blood cells derived from residual blood of different apheresis kits

BACKGROUND

Research with primary human white blood cell (WBC) subpopulations requires high quantity, quality, and functionality of peripheral blood mononuclear cells (PBMCs) as a source to further characterize cellular subpopulations such as T and B lymphocytes, monocytes, or natural killer cells. Apart from buffy coats derived from whole blood, residual blood from preparative hemapheresis kits are used as a source for PBMCs, but knowledge on the yield and functionality of cells from different devices is limited.

STUDY DESIGN AND METHODS

We evaluated quantity and quality of PBMCs isolated from apheresis kits of two apheresis devices (AMICUS, Fenwal; and Trima Accel, Terumo BCT), the latter being our standard source for many years. PBMCs derived from Trima or AMICUS were tested for yield and subtype composition by flow cytometry. Functionality was assessed by cytokine induction of CD4⁺ and CD8⁺ T cells and by degranulation. Moreover, cytotoxic activity of natural killer cells was quantified by a real-time killing assay.

RESULTS

Mean numbers of isolated cells were 5.5 ± 2.4 × 10⁸ for AMICUS, and 10.3 ± 6.4 × 10⁸ for Trima Accel, respectively. The proportion of WBC subtypes corresponded to well-known numbers from whole blood, with minor differences between the two apheresis systems. Likewise, minor differences in cytokine induction were found in stimulated CD4⁺ or CD8⁺ T cells. Finally, PBMCs derived from the two systems showed comparable cytotoxic activity.

CONCLUSION

PBMC derived from residual blood of the AMICUS and Trima Accel apheresis devices serve as an economic and easily accessible source for functional PBMCs with comparable quantity and quality to PBMCs derived from whole blood.

Messenger RNA profiling of human platelets by microarray hybridization

Platelets are generally believed to be inactive in terms of de novo protein synthesis. On the other hand, the presence of ribosomes and mRNA molecules is well established. Many studies have used reverse transcriptase (RT) -PCR for detection of gene transcripts in platelets. As RT-PCR is a very sensitive method, any leukocyte contamination of platelet preparations can lead to false results. We performed three filtration procedures to minimize leukocyte contamination of pooled buffy-coat platelet concentrates prior to RNA isolation. Furthermore, by applying a genomic PCR approach with 50 amplification cycles we demonstrated that nucleated cells were not detectable. Microarray hybridization was used to analyze 9,850 individual human genes in RNA from purified platelets. In total we identified 1,526 (15.5%) positive genes. The data were confirmed in six individual experiments each performed on a PC pooled from four individual blood donations. Genes specific for nucleated blood cells such as CD4, CD83 and others were negative and verified the purity of PC. Overrepresentation of positive genes was found in the functional categories of glycoproteins/integrins (22.6% vs. 15.5%, p=0.029) and receptors (20.7% vs. 15.5%, p<0.001). Gene transcripts encoding RANTES, GRO-α, MIP-1α, MIP-1β, and others were found at high levels of signal intensity and confirmed literature data. This work provides a mRNA profile of human platelets and a complete list of results can be downloaded from the website of our institute www.ma.uni-heidelberg.de/inst/iti/plt_array.xls. The knowledge about gene transcripts may have an impact on the characterization of novel proteins and their functions in platelets.

A Case of Immune Thrombocytopenia as a Rare Side Effect of an Immunotherapy with PD1-Blocking Agents for Metastatic Melanoma

Background

Checkpoint blocking agents such as pembrolizumab or nivolumab may induce a diversity of mostly autoimmune-mediated side effects. These autoimmune phenomena mainly affect ductless glands such as the pituitary gland (hypophysitis), the thyroid gland (thyreoiditis), the skin (vitiligo and rash), the colon (colitis), and the lung (pneumonitis). Furthermore, many other organs or organ systems may be affected.

Case Report

This work describes a case of an immune thrombocytopenia that developed or rather became clinically significant shortly after initiation of a systemic therapy with first nivolumab and later pembrolizumab given due to metastatic melanoma. Platelet counts before this systemic therapy were slightly decreased with values around 110/nl (normal value 140-400/nl). Thrombocytopenia developed or became apparent rapidly within 10 days after the first intravenous application of nivolumab and worsened after changeover to pembrolizumab. Therapy had to be stopped due to disease progression and steady aggravation of thrombocytopenia. Immune hematology assays could prove an autoimmune mediated genesis of thrombocytopenia.

Conclusion

Checkpoint inhibitors may induce a multiplicity of mostly autoimmune-mediated side effects. In contrast to chemotherapy-induced cytopenia that results from bone marrow toxicity, thrombocytopenia in melanoma patients treated with checkpoint inhibiting substances seems to result from autoimmune-mediated side effects in the majority of the cases. Thorough laboratory controls during these therapies are therefore required. In case of thrombocytopenia, immune hematology testing to diagnose or rule out immune thrombocytopenia is indispensable.

Pathogen reduction/inactivation of products for the treatment of bleeding disorders: what are the processes and what should we say to patients?

Patients with blood disorders (including leukaemia, platelet function disorders and coagulation factor deficiencies) or acute bleeding receive blood-derived products, such as red blood cells, platelet concentrates and plasma-derived products. Although the risk of pathogen contamination of blood products has fallen considerably over the past three decades, contamination is still a topic of concern. In order to counsel patients and obtain informed consent before transfusion, physicians are required to keep up to date with current knowledge on residual risk of pathogen transmission and methods of pathogen removal/inactivation. Here, we describe pathogens relevant to transfusion of blood products and discuss contemporary pathogen removal/inactivation procedures, as well as the potential risks associated with these products: the risk of contamination by infectious agents varies according to blood product/region, and there is a fine line between adequate inactivation and functional impairment of the product. The cost implications of implementing pathogen inactivation technology are also considered.

Dual inhibition of PI3K and mTOR by VS-5584 suppresses thrombus formation

VS-5584 is a highly selective dual kinase inhibitor which suppresses phosphatidylinositol 3-kinase (PI3K) and mammalian target of rapamycin (mTOR) activity. Because these kinases are crucially involved in primary hemostasis, we herein investigated the effect of this compound on thrombus formation in vitro and in vivo. Pretreatment of washed platelets (WP) or platelet-rich plasma (PRP) with VS-5584 inhibited the agonist-induced activation of surface glycoprotein complex (GP)IIb/IIIa and the upregulation of P-selectin. This was associated with a significantly reduced formation of platelet-leukocyte aggregates (PLA). VS-5584 further attenuated platelet aggregation and adhesion after agonist stimulation. In contrast, endothelial expression of intercellular adhesion molecule (ICAM)-1 and vascular cellular adhesion molecule (VCAM)-1 and secretion of von Willebrand Factor (vWF) were not affected by the dual kinase inhibitor. In vivo, VS-5584 inhibited photochemically induced thrombus formation as shown by a significantly prolonged time to complete vessel occlusion when compared to vehicle-treated controls. This was associated with an elevated tail vein bleeding time, indicating a potential hemorrhagic risk in VS-5584-treated mice. Taken together, these novel findings demonstrate that VS-5584 is a potent inhibitor of primary hemostasis targeting multiple platelet functions.

microRNA-496 - A new, potentially aging-relevant regulator of mTOR

Recent findings strongly support a role for small regulatory RNAs in the regulation of human lifespan yet little information exists about the precise underlying mechanisms. Although extensive studies on model organisms have indicated that reduced activity of the nutrient response pathway, for example as a result of dietary restriction, can extend lifespan through the suppression of the protein kinase mechanistic target of rapamycin (mTOR), it still is subject of debate whether this mechanism is operative in humans as well. Here, we present findings indicating that human microRNA (miR)-496 targets 2 sites within the human mTOR 3'UTR. Coexpression of miR-496 with different fusion transcripts, consisting of the luciferase transcript and either wild-type mTOR 3'UTR or mTOR 3'UTR transcript with the miR-496 binding sites singly or combined mutated, confirmed this prediction and revealed cooperativity between the 2 binding sites. miR-496 reduced the mTOR protein level in HeLa-K cells, and the levels of miR-496 and mTOR protein were inversely correlated in Peripheral Blood Mononuclear Cells (PBMC), with old individuals (n = 40) harbouring high levels of miR-496 relative to young individuals (n = 40). Together, these findings point to the possibility that miR-496 is involved in the regulation of human aging through the control of mTOR.

[Coagulation management in geriatric surgery]

BACKGROUND

Elderly patients often suffer from cardiovascular diseases and are treated with anticoagulation medications, which must be taken into consideration when planning elective surgery.

OBJECTIVE

The etiology, diagnostic work-up and clinical management of selected inherited and acquired hemophilic and thrombophilic coagulation disorders are described.

METHODS

Data from clinical studies, current guidelines and expert opinions are discussed.

RESULTS

Beside inherited hemophilic coagulation defects, elderly patients very frequently show an acquired bleeding tendency caused by the intake of analgesic drugs or long-term medication due to cardiovascular diseases. In rare cases, elderly patients can develop acquired hemophilia caused by autoantibodies to coagulation factors resulting in a severe bleeding disorder. Moreover, elderly patients have an increased risk to develop venous or arterial thrombotic events. Prior to surgery a relevant bleeding tendency should be excluded by the combination of medical history, clinical investigation and screening of laboratory parameters. If laboratory parameters are outside the normal range, e.g. a prolonged activated partial thromboplastin time (aPTT), the reasons must be clarified prior to an elective surgery.

CONCLUSION

The clinical management of elderly patients under anticoagulation treatment should start early and must also cover the post-surgery period. When planning treatment for patients at risk, a physician qualified in clinical hemostaseology should be consulted. For the management of thrombosis prophylaxis, the implementation of clinical guidelines is a valuable measure.

Impedance aggregometric analysis of platelet function of apheresis platelet concentrates as a function of storage time

Multiple electrode (impedance) aggregometry (MEA) allows reliable monitoring of platelet function in whole blood. The aims of the present study were to implement MEA for analyzing aggregation in platelet concentrates and to correlate results with storage time and blood gas analysis (BGA). We investigated the influence of platelet counts, calcium concentrations and agonists on platelet aggregation. Samples of apheresis concentrates up to an age of 12 days were investigated by MEA and BGA. For ASPI- and TRAPtest MEA was reproducible for a platelet count of 400 per 10^-9L and a calcium concentration of 5 mmol L^-1. Platelets at the age of 2-4 days yielded steady aggregation. Platelet concentrates exceeding the storage time for transfusion showed steady aggregation up to 10 days, but a significant decline on day 12. Weak correlation was found regarding pCO₂ and MEA as well as regarding glucose concentration and MEA. Our results indicate that MEA is applicable for evaluation of aggregation in stored apheresis concentrates. Prolonged storage seems not to be prejudicial regarding platelet aggregation. Platelet concentrates showed acceptable BGA throughout storage time. Further studies are required to evaluate the application of MEA for quality controls in platelet concentrates.

Deep characterization of blood cell miRNomes by NGS

A systematic understanding of different factors influencing cell type specific microRNA profiles is essential for state-of-the art biomarker research. We carried out a comprehensive analysis of the biological variability and changes in cell type pattern over time for different cell types and different isolation approaches in technical replicates. All combinations of the parameters mentioned above have been measured, resulting in 108 miRNA profiles that were evaluated by next-generation-sequencing. The largest miRNA variability was due to inter-individual differences (34 %), followed by the cell types (23.4 %) and the isolation technique (17.2 %). The change over time in cell miRNA composition was moderate (<3 %) being close to the technical variations (<1 %). Largest variability (including technical and biological variance) was observed for CD8 cells while CD3 and CD4 cells showed significantly lower variations. ANOVA highlighted that 51.5 % of all miRNAs were significantly influenced by the purification technique. While CD4 cells were least affected, especially miRNA profiles of CD8 cells were fluctuating depending on the cell purification approach. To provide researchers access to the profiles and to allow further analyses of the tested conditions we implemented a dynamic web resource.

Red Cell Properties after Different Modes of Blood Transportation

Transportation of blood samples is unavoidable for assessment of specific parameters in blood of patients with rare anemias, blood doping testing, or for research purposes. Despite the awareness that shipment may substantially alter multiple parameters, no study of that extent has been performed to assess these changes and optimize shipment conditions to reduce transportation-related artifacts. Here we investigate the changes in multiple parameters in blood of healthy donors over 72 h of simulated shipment conditions. Three different anticoagulants (K3EDTA, Sodium Heparin, and citrate-based CPDA) for two temperatures (4°C and room temperature) were tested to define the optimal transportation conditions. Parameters measured cover common cytology and biochemistry parameters (complete blood count, hematocrit, morphological examination), red blood cell (RBC) volume, ion content and density, membrane properties and stability (hemolysis, osmotic fragility, membrane heat stability, patch-clamp investigations, and formation of micro vesicles), Ca(2+) handling, RBC metabolism, activity of numerous enzymes, and O2 transport capacity. Our findings indicate that individual sets of parameters may require different shipment settings (anticoagulants, temperature). Most of the parameters except for ion (Na(+), K(+), Ca(2+)) handling and, possibly, reticulocytes counts, tend to favor transportation at 4°C. Whereas plasma and intraerythrocytic Ca(2+) cannot be accurately measured in the presence of chelators such as citrate and EDTA, the majority of Ca(2+)-dependent parameters are stabilized in CPDA samples. Even in blood samples from healthy donors transported using an optimized shipment protocol, the majority of parameters were stable within 24 h, a condition that may not hold for the samples of patients with rare anemias. This implies for as short as possible shipping using fast courier services to the closest expert laboratory at reach. Mobile laboratories or the travel of the patients to the specialized laboratories may be the only option for some groups of patients with highly unstable RBCs.

Tumor antigen-specific T cells for immune monitoring of dendritic cell-treated glioblastoma patients

BACKGROUND AIMS

CD8(+) T cells are part of the adaptive immune system and, as such, are responsible for the elimination of tumor cells. Dendritic cells (DC) are professional antigen-presenting cells (APC) that activate CD8(+) T cells. Effector CD8(+) T cells in turn mediate the active immunotherapeutic response of DC vaccination against the aggressive glioblastoma (GBM). The lack of tumor response assays complicates the assessment of treatment success in GBM patients.

METHODS

A novel assay to identify specific cytotoxicity of activated T cells by APC was evaluated. Tumor antigen-pulsed DCs from HLA-A*02-positive GBM patients were cultivated to stimulate autologous cytotoxic T lymphocytes (CTL) over a 12-day culture period. To directly correlate antigen specificity and cytotoxic capacity, intracellular interferon (IFN)-γ fluorescence flow cytometry-based measurements were combined with anti-GBM tumor peptide dextramer staining. IFN-γ response was quantified by real-time polymerase chain reaction (PCR), and selected GBM genes were compared with healthy human brain cDNA by single specific primer PCR characterization.

RESULTS

Using CTL of GBM patients stimulated with GBM lysate-pulsed DCs increased IFN-γ messenger RNA levels, and intracellular IFN-γ protein expression was positively correlated with specificity against GBM antigens. Moreover, the GBM peptide-specific CD8(+) T-cell response correlated with specific GBM gene expression. Following DC vaccination, GBM patients showed 10-fold higher tumor-specific signals compared with unvaccinated GBM patients.

DISCUSSION

These data indicate that GBM tumor peptide-dextramer staining of CTL in combination with intracellular IFN-γ staining may be a useful tool to acquire information on whether a specific tumor antigen has the potential to induce an immune response in vivo.

Diagnostic and prognostic value of factor VIII binding antibodies in acquired hemophilia A: data from the GTH-AH 01/2010 study

Essentials Factor VIII (FVIII) binding IgG detected by ELISA could be an alternative to the Bethesda assay. We studied the performance of anti-FVIII IgG ELISA in patients with acquired hemophilia and controls. Anti-FVIII IgG > 99th percentile of controls was highly sensitive and specific. Patients with high anti-FVIII IgG have a lower chance of achieving remission.

SUMMARY

Background Acquired hemophilia A is a severe bleeding disorder that requires fast and accurate diagnosis as it occurs often unexpectedly in previously healthy men and women of every age. The Nijmegen-modified Bethesda assay is the diagnostic reference standard for detecting neutralizing autoantibodies against factor VIII (FVIII), but is not widely available, not ideal for quantifying the complex type 2 inhibitors seen in acquired hemophilia, and suffers from high inter-laboratory variability. Objectives To assess the diagnostic and prognostic value of FVIII-binding antibodies as detected by ELISA compared with the Nijmegen Bethesda assay. Methods Samples from the time of first diagnosis and clinical data were available from 102 patients with acquired hemophilia enrolled in the prospective GTH-AH 01/2010 study. Controls (n = 102) were matched for gender and age. Diagnostic cut-offs were determined by receiver-operator curve analysis. The prognostic value was assessed in 92 of the 102 patients by Cox regression analysis of time to partial remission. Results Anti-FVIII IgG above the 99th percentile (> 15 arbitrary units per mL) revealed high sensitivity and specificity (both 0.99; 95% confidence interval, 0.95-1.0) for diagnosing acquired hemophilia. The likelihood of achieving partial remission was related to anti-FVIII IgG concentration (< 300 arbitrary units, 1.0; 300-1050, 0.65; > 1050, 0.39). The Bethesda titer was only associated with the likelihood of partial remission when analyzed in the central laboratory, but not when data from local GTH study sites were used. Conclusion Although the Nijmegen-modified Bethesda assay is the reference standard for demonstrating neutralizing antibodies, the detection of FVIII-binding antibodies by ELISA is similarly sensitive and specific for diagnosing acquired hemophilia. In addition, anti-FVIII IgG may provide prognostic information.

The Marine-Derived Kinase Inhibitor Fascaplysin Exerts Anti-Thrombotic Activity

Background: The marine-derived kinase inhibitor fascaplysin down-regulates the PI3K pathway in cancer cells. Since this pathway also plays an essential role in platelet signaling, we herein investigated the effect of fascaplysin on thrombosis. Methods: Fascaplysin effects on platelet activation, platelet aggregation and platelet-leukocyte aggregates (PLA) formation were analyzed by flow cytometry. Mouse dorsal skinfold chambers were used to determine in vivo the effect of fascaplysin on photochemically induced thrombus formation and tail-vein bleeding time. Results: Pre-treatment of platelets with fascaplysin reduced the activation of glycoprotein (GP)IIb/IIIa after protease-activated receptor-1-activating peptide (PAR-1-AP), adenosine diphosphate (ADP) and phorbol-12-myristate-13-acetate (PMA) stimulation, but did not markedly affect the expression of P-selectin. This was associated with a decreased platelet aggregation. Fascaplysin also decreased PLA formation after PMA but not PAR-1-AP and ADP stimulation. This may be explained by an increased expression of CD11b on leukocytes in PAR-1-AP- and ADP-treated whole blood. In the dorsal skinfold chamber model of photochemically induced thrombus formation, fascaplysin-treated mice revealed a significantly extended complete vessel occlusion time when compared to controls. Furthermore, fascaplysin increased the tail-vein bleeding time. Conclusion: Fascaplysin exerts anti-thrombotic activity, which represents a novel mode of action in the pleiotropic activity spectrum of this compound.

Static image analysis as new approach for the characterization of tumor cell lysate used in dendritic cell vaccine preparation

BACKGROUND

Safety is an important consideration for the clinical application of dendritic cells (DC) loaded with autologous tumor lysate (TL). Thus, avitalization of TL from living autologous tumor tissue has to be guaranteed.

METHODS

Composition of TL was investigated by static image analysis (SIA) with the Morphologi G3 device, which simultaneously measures size and shape of up to 100,000 particles within one sample run. This approach was compared with sample characterization by high-resolution automated cell counting, trypan blue staining, and ATP quantification.

RESULTS

Using SIA, we only detected fragmented, non-cellular structures in completely avitalized TL, indicating complete destruction of living cells. Analysis of particle size distribution by SIA as well as CASY cell counter showed that 95% of particles had a diameter of <10 µm as a sign of cell fragmentation. Complete avitalization of TL was confirmed with trypan blue staining and ATP analysis.

CONCLUSION

Regarding generation of DC vaccines, the proof of avitality of TL from living tumor tissue can clearly be achieved by SIA alone or in combination with standard assays. Our data show that SIA is a highly precise method for TL characterization. The SIA device complies with FDA regulation and, therefore, might be suitable for characterization of cellular therapy medicinal products.

Internal medicine resident knowledge of transfusion medicine: results from the BEST-TEST international education needs assessment

BACKGROUND

Blood transfusion is the most common hospital procedure performed in the United States. While inadequate physician transfusion medicine knowledge may lead to inappropriate practice, such an educational deficit has not been investigated on an international scale using a validated assessment tool. Identifying specific deficiencies is critical for developing curricula to improve patient care.

STUDY DESIGN AND METHODS

Rasch analysis, a method used in high-stakes testing, was used to validate an assessment tool consisting of a 23-question survey and a 20-question examination. The assessment tool was administered to internal medicine residents to determine prior training, attitudes, perceived ability, and actual knowledge related to transfusion medicine.

RESULTS

A total of 474 residents at 23 programs in nine countries completed the examination. The overall mean score of correct responses was 45.7% (site range, 32%-56%). The mean score for Postgraduate Year (PGY)1 (43.9%) was significantly lower than for PGY3 (47.1%) and PGY4 (50.6%) residents. Although 89% of residents had participated in obtaining informed consent from a patient for transfusion, residents scored poorly (<25% correct) on questions related to transfusion reactions. The majority of residents (65%) would find additional transfusion medicine training "very" or "extremely" helpful.

CONCLUSION

Internationally, internal medicine residents have poor transfusion medicine knowledge and would welcome additional training. The especially limited knowledge of transfusion reactions suggests an initial area for focused training. This study not only represents the largest international assessment of transfusion medicine knowledge, but also serves as a model for rigorous, collaborative research in medical education.