COVID-19: A case for plasma derived natural anticoagulants?

Convalescent plasma was proposed for passive immunization against COVID-19; but so far there are conflicting results and still open questions. However, besides antibodies, other plasma proteins may be good candidates for further research and application. Thromboinflammation frequently complicates severe COVID-19, and classical anticoagulants like heparins seem to have limited effect. The natural protease inhibitors antithrombin III (ATIII), α1-antitrypsin (α1-AT) and α2-macroglobulin (α2-M), which are found decreased in severe COVD-19, play a crucial role in prothrombotic and inflammatory pathways. While ATIII and α1-AT are licensed as commercially prepared therapeutic concentrates, there is no preparation of α2-M available. The diagnostic, prognostic, and even therapeutic potential of plasma protease inhibitors should be further explored.

Kreuth V initiative: European consensus proposals for treatment of hemophilia using standard products, extended half-life coagulation factor concentrates and non-replacement therapies.

This report contains the updated consensus recommendations for optimal hemophilia care produced in 2019 by three Working Groups (WG) on behalf of the European Directorate for Quality of Medicines and Healthcare in the frame of the Kreuth V Initiative. WG1 recommended access to prophylaxis for all patients, the achievement of plasma factor trough levels of at least 3-5% when extended half-life factor VIII (FVIII) and FIX products are used, a personalized treatment regimen, and a choice of chromogenic assays for treatment monitoring. It was also emphasized that innovative therapies should be supervised by hemophilia comprehensive care centers. WG2 recommended mandatory collection of postmarketing data to assure the long-term safety and efficacy of new hemophilia therapies, the establishment of national patient registries including the core data recommended by the European Medicines Agency and the International Society on Thrombosis and Haemostasis, with adequate support under public control, and greater collaboration to facilitate a comprehensive data evaluation throughout Europe. WG3 discussed methodological aspects of hemophilia care in the context of access decisions, particularly for innovative therapies, and recommended that clinical studies should be designed to provide the quality of evidence needed by regulatory authorities, HTA bodies and healthcare providers. The dialogue between all stakeholders in hemophilia care and patient organizations should be fostered to implement these recommendations.

Evaluation of the in vitro Function of Platelet Concentrates from Pooled Buffy Coats or Apheresis.

BACKGROUND: Platelet concentrates play an important role in transfusion medicine. Their short lifespan and lack of robustness require efforts to ensure adequate product quality. In this study, we compared the in vitro quality of the main concentrate types, pooled platelet concentrate (PPC) from whole blood donations, and platelet concentrate from single-donor apheresis (APC). METHODS: Twenty PPCs and 20 APCs prepared in plasma were analyzed on days 2, 4, and 7 of storage. Variables related to metabolism, degranulation, platelet aggregation, P-selectin expression, and annexin V binding were analyzed. Morphology was assessed by transmission electron microscopy of ultrathin sections. A microfluidic device was applied to test the effects of shear stress on platelet function. RESULTS: The metabolic parameters indicated stable storage conditions throughout the 7-day period. The resting discoid form was the prevailing morphology on days 2 and 4 in the PPCs and APCs. Chemokine release and receptor shedding of soluble P-selectin and soluble CD40L equally increased in PPCs and APCs. Aggregation responses to ADP and collagen were heterogeneous, with marked losses in collagen responsiveness on day 4 in individual concentrates. Baseline expression of P-selectin in PPCs and APCs was low, and inducibility of P-selectin was well preserved until day 4. Under shear stress, equal adhesiveness and stability were found with platelets from PPCs and APCs. CONCLUSIONS: Platelets from PPCs and APCs showed similar in vitro function and stability parameters. However, platelet concentrates presented a high variability and individual concentrates an impaired functional capability. Identifying the factors contributing to this would help increase product reliability.

Free factor XIII activation peptide (fAP-FXIII) is a regulator of factor XIII activity via factor XIII-B.

In a factor XIIIa (FXIIIa) generation assay with recombinant FXIII-A2 (rFXIII-A2 ) free FXIII activation peptide (fAP-FXII) prolonged the time to peak (TTP) but did not affect the area under the curve (AUC) or concentration at peak (CP). Addition of recombinant factorXIII-B2 (rFXIII-B2 ) restored the characteristics of the FXIIIa generation parameters (AUC, TTP and CP) to those observed for plasma FXIII (FXIII-A2 B2 ). FXIII-A2 B2 reconstituted from rFXIII-A2 and rFXIII-B2 showed a similar effect on AUC, TTP and CP in the presence of fAP-FXII as observed for plasma FXIII-A2 B2 , indicating a role for FXIII-B in this observation. An effect of fAP-FXIII on thrombin, the proteolytic activator of FXIII, was excluded by thrombin generation assays and clotting experiments. In a purified system, fAP-FXIII did not interfere with the FXIIIa activity development of thrombin-cleaved rFXIII-A2 (rFXIII-A2 ') also excluding direct inhibition of FXIIIa. However, FXIIIa activity development of FXIII-A2 'B2 was inhibited in a concentration-dependent manner by fAP-FXIII, indicating that an interaction between AP-FXIII and FXIII-B2 contributes to the overall stability of FXIII-A2 'B2 . In addition to its well-known role, FXIII-B also contributes to FXIII-A2 B2 stability or dissociation depending on fAP-FXIII and calcium concentrations.

[Authorization of tissue and blood stem cell preparations for hematopoietic reconstitution: Documentation of clinical and nonclinical data in a central expert report]. / Genehmigungsverfahren für Gewebezubereitungen und Blutstammzellzubereitungen zur hämatopoetischen Rekonstitution: Dokumentation klinischer und nicht klinischer Daten mittels eines Zentralgutachtens.

In order to address the European Directive 2004/23 on human tissues and cells, the authorization obligation for tissue and blood stem cell preparations was introduced (§ 21a AMG) in the year 2007 in the German medicinal products act. Stem cell transplantation for hematopoietic reconstitution has been in use for decades and is well established for the treatment of many malignancies. The manufacture of stem cell preparations varies, but in terms of hematopoietic reconstitution, different products are intended for the same indication. Taking these aspects into account, it was considered inappropriate that every single applicant should provide their own documentation, including an expert report on clinical and nonclinical data. Consequently, the idea came up to create a central expert report, to which all applicants could refer and would include relevant clinical and nonclinical data according to current knowledge. A central expert report was therefore generated, called the "Gemeinsame Stellungnahme der Fachgesellschaften Deutsche Gesellschaft für Transfusionsmedizin und Immunhämatologie (DGTI), Deutsche Gesellschaft für Hämatologie und Onkologie (DGH) und Gesellschaft für Pädiatrische Onkologie und Hämatologie (GPOH)". Applicants are allowed to refer to this central expert report provided their stem cell product is comparable with the cell preparations included in the report. In order to represent current knowledge, the content of the central expert report was already reworked once, but should be updated regularly.

Factor XIIIa generation assay: a tool for studying factor XIII function in plasma.

Triggering the extrinsic coagulation pathway in plasma and using a fluorogenic factor XIIIa (FXIIIa) substrate for continuously monitoring FXIIIa activity, an FXIIIa generation curve is obtained. The parameters area under the curve (AUC), time to peak (TTP), and concentration at peak (CP) were calculated. In dilutions of normal plasma in FXIII-deficient plasma, AUC and CP showed linear dose-response relationships, whereas TTP increased from 9.9 min for 25% FXIII to 11.6 min for 100% FXIII. Three FXIII-A preparations (rFXIII, rFXIII(V34L), and cellular FXIII [cFXIII]) showed a linear dose response for AUC and CP. The TTP increased slightly for rFXIII from 13.5 to 15.0 min, but surprisingly for cFXIII TTP increased concentration dependently from 13.5 to 28.7 min. Adding 5 µg/ml FXIII-B at a concentration of 1U of FXIII-A increased the AUC for rFXIII(V34L) and cFXIII by approximately 20% and accelerated TTP from 27.3 to 20.8 min for cFVIII, indicating a supportive function of FXIII-B in orientating cFXIII-A for thrombin cleavage. A commercial assay quantifying FXIII after complete activation in a restricted time window did not reveal differences in the cFXIII preparation with or without FXIII-B. The FXIIIa generation assay provides additional information about activation and function of FXIII. This advantage was underlined in experiments with an irreversible FXIIIa inhibitor.

The Wildbad Kreuth initiative: European current practices and recommendations for optimal use of blood components.

With the aging population in Europe it is anticipated that the growing demand for blood products will not be met by the estimated supply. Therefore up-to-date recommendations for optimal administration of blood products in hemotherapy are needed. Ten years after the first meeting on optimal use of blood products at Wildbad Kreuth, Germany, a second symposium was organized to convene leading experts from the clinical, regulatory and economic perspective. The aim was to re-evaluate the existing state of hemotherapy, identify areas where further studies are needed, and to provide up-dated recommendations. A preparatory survey by questionnaire concerning guidelines, quality management in clinical use of blood products, provision of products in the individual countries and re-evaluation of the 1999 Wildbad Kreuth recommendations was completed in advance. The second Kreuth Meeting in April 2009 was attended by 110 experts in transfusion medicine, regulators and regulatory authorities from 38 countries. By consensus, 20 new recommendations were adopted. Most of the 1999 recommendations were found to still be valid 10 years later. But their realization and implementation on the levels of clinical practice, regulatory authorities and health policy decision makers is still lagging behind leaving an important task to accomplish. The Kreuth initiative toward optimal use of blood products should continue.

Report on Notifications Pursuant to §21 German Transfusion Act for 2008 and 2009.

SUMMARY: This report contains the data collected in 2008 and 2009, pursuant to Section 21 German Transfusion Act as well as an overview of the supply situation during the last 10 years. In 2009, blood donation services reported a total of 7.5 million donations - the largest amount since 2000. At the same time, more than 4.7 million red blood cell (RBC) concentrates and more than 500,000 platelet concentrates were available. The number of therapeutic single plasma units decreased to 1.1 million units in 2009. The loss rate for RBC concentrates is still between 3 and 4% for the users while for the manufacturers it has decreased slightly to 1.4%. The loss rate, for platelet concentrates, on the other hand, increased in 2009, especially-what is noteworthy-for manufacturers of pooled platelet concentrates. The loss rate for apheresis platelet concentrates accounted for 5.2% compared to 17.5% for pooled platelet concentrates. As far as the users were concerned, loss rates for platelet concentrates largely remained unchanged with rates between 5 and 6%. Based on the data collected, the supply with blood components for transfusion can be regarded as assured. Nearly 2.9 million 1 of plasma for fractionation were collected in Germany in 2009. According to reports from the pharmaceutical industry, out of these, 2.6 million 1 remained on the German market, out of which only 56% were fractionated in this country. Many plasma derivatives are not manufactured in Germany, despite the large amounts of plasma collected. The supply with these products, however, is assured by imports. Overall, 16,409 autologous and 9,435 allogeneic stem cell preparations were manufactured in 2009, out of which 3,382 allogeneic preparations were exported. 3,181 autologous and 2,374 allogeneic preparations were transplanted; 187 of these products from imports. The large number of exported stem cells and the small number of imported ones suggest that no serious shortages are to be expected for the supply with these products.

Thromboinflammation in COVID-19: Can α2 -macroglobulin help to control the fire?

The complex COVID-19-associated coagulopathy appears to impair prognosis. Recently, we presented the hypothesis that children are to some extent protected by higher α2 -macroglobulin (α2 -M) levels from severe COVID-19. In addition to endothelial cells, thrombin, and platelets, neutrophil granulocytes also appear to play an important role. Neutrophils extrude extracellular nets, which are histone- and protease-coated web-like DNA structures; activate coagulation and platelets; and release radicals and proteases such as elastase. The unique phylogenetically ancient and "versatile" inhibitor α2 -M contributes particularly during childhood to the antithrombin activity of plasma, binds a broad spectrum of proteases, and interacts with other mediators of inflammation such as cytokines. It is suggested that the scope of basic research and clinical studies would include the potential role of α2 -M in COVID-19.

Management of blood supplies during an influenza pandemic.

BACKGROUND: Blood supplies are delicate resources, particularly vulnerable to incidents affecting the health of donors. The critical impact of a pandemic on the availability of red blood cells (RBCs) has been demonstrated in previous research; however, a detailed estimate of the expected deficit is missing. This has become a priority issue in the face of the current influenza pandemic. STUDY DESIGN AND METHODS: Data from several major blood donation services were used to analyze management of blood supplies in Germany. Routine management of RBCs was extrapolated to epidemic and pandemic situations using computer simulations with a mathematical model that allows for analysis of deficits in blood supplies. RESULTS: Routine management and distribution of RBCs are driven by supply, which has marked fluctuations but does not appear to have seasonality. There seems to be a remarkable elasticity in the demand for RBCs that helps to mitigate minor crises in supply, but this is likely to be overstretched during a severe pandemic. CONCLUSION: The supply-driven management of RBCs in Germany implies that assessment of severity of shortages due to a pandemic depends on detailed knowledge about the fraction of transfusions that do not allow for postponement. Pandemic preparedness should include criteria for prioritization of transfusions.

Quality and Safety in Blood Supply in 2010.

The past two decades saw tremendous achievements in blood safety, which are due to the commitment of blood establishments and industry, progress in technology such as the improvement of serological and NAT screening tests, and stringent regulatory control. Milestones in the legislation were the inclusion of plasma derivatives in the pharmaceutical legislation of the European Community (EC) in the year 1989 and special laws for the blood sector in EC and in member states, such as the Transfusionsgesetz (Transfusion Law) in Germany. The legal frame has to be supplemented by scientific and technical guidance, which is provided on the European level by the European Directorate for the Quality of Medicines and Health Care and by the European Medicines Agency. In the member states, guidelines taking into account the national peculiarities can be elaborated, such as the German hemotherapy guidelines issued by the German Medical Association (Bundesärztekammer) in agreement with the Paul-Ehrlich-Institut. The regulatory control of screening tests, and the introduction of NAT testing lead to a remarkably high degree of safety concerning the most relevant viruses HIV, HBV and HCV. Issues needing further attention are bacterial contamination and transfusion-associated acute lung injury (TRALI). Measures aiming at minimizing risks have to be balanced against their impact on supply. In order to ensure the assured supply with safe blood products, sustained efforts and research are needed as well as a continuous dialogue among blood services, industry, physicians, patients and regulatory authorities.

Report on Notifications Pursuant to section sign21 German Transfusion Act for 2007.

The present report contains the data collected in 2007, pursuant to Section 21 German Transfusion Act, and an analysis of the supply situation over the past 8 years. As in previous years, all blood donation centres located in Germany transmitted data on the collection, manufacture, import and export of blood components for transfusion. According to these data, a total of 6.7 million blood collections were performed in 2007. With 4.7 million, the portion of whole blood donations was at the level of previous years, whereas the number of apheresis donations rose again, to 1.9 million. The portion of autologous blood collections accounts for only 1.1% and thus continues to decline. Since 2003, the number of red blood cell concentrates prepared has been a constant 4.5 million transfusion units. The decay of red blood cell concentrates on the user side in 2000 accounted for 5% while in 2007 it was just above 3%, referred to the total quantity of data reported as transfused and decayed. The manufacture of platelet concentrates rose from 366,000 to 480,000 transfusion units between 2003 and 2007. The production of therapeutic single plasmas, too, markedly increased in 2007 (to 1.2 million transfusion units). In 2007, 2.2 million I of plasma for fractionation were collected in Germany. In addition, 1.0 million I were imported, and 1.8 million I were exported. The quantity available in Germany from a pure arithmetic point of view of 1.4 million I was almost entirely allocated to basic fractionation so that a sufficient plasma supply can be assumed. Due to the fact that manufacturing capacities are still lacking in Germany, recombinant factors need to be imported in their entirety. Since 2003, Germany has by far been the leader in Europe with more than 20 I of fractionation plasma collected per 1,000 inhabitants. Furthermore, regarding the manufacturing figures of red blood cell concentrates, platelet concentrates, and therapeutic single plasma, Germany is in the top third for all these products compared with other European countries. The manufacture of allogeneic stem cell products for haematopoietic reconstitution, obtained by apheresis, has continuously risen to 4,700. A large portion of this (1,810 transplants) could be exported while only a small number (179 preparations) had to be imported. The manufacture of autologous stem cell preparations from cord blood has risen drastically to more than 10,000 in 2007. The interest in the figures collected in compliance with Section 21, German Transfusion Act remains high both in Germany and at an international level. Meanwhile reliable data are available.

Experience of mandatory nucleic acid test (NAT) screening across all blood organizations in Germany: NAT yield versus breakthrough transmissions.

BACKGROUND: Mandatory nucleic acid test (NAT) blood screening was introduced in Germany in 1999 for hepatitis C virus (HCV) RNA and in 2004 for human immunodeficiency virus Type 1 (HIV-1) RNA. Minimal sensitivity limits of 5000 IU HCV RNA/mL and 10,000 IU HIV-1 RNA/mL were defined for the individual donation facilitating testing of minipools (MPs). The NAT yield obtained from all blood organizations is summarized. Transfusion-associated virus transmissions despite NAT screening ("breakthrough transmissions") are analyzed. STUDY DESIGN AND METHODS: In Germany, a variety of NAT assays is applied for NAT screening pool sizes of up to 96 donations. Subsets of NAT yield cases were characterized with regard to viral loads by quantitative NAT and with regard to viral genotypes. Confirmed breakthrough transmissions were analyzed using different molecular and serologic assays. RESULTS: Ninety-two HCV NAT yield cases among 40.8 million and 11 HIV-1 NAT yield cases among 17.1 million donations were identified. During this period, one transmission case was confirmed for HCV and one for HIV-1. The two incidents escaped NAT detection because of low-level viremia and/or suboptimal amplification efficiency. Evidence was obtained for a case of HIV-1 nontransmission by a low-level HIV-1 contaminated red blood cell unit. CONCLUSION: NAT screening of MPs identified the vast majority of window-phase donations. A significant number of transmission cases was interdicted; breakthrough transmissions may still occur as rare events, even with individual-donation NAT in place. Sensitivity limits might be adapted to the current "state of the art" taking account of viral dynamics during early infection, incidence rates, and costs.

Role of regulatory agencies.

In this paper the authors discuss the role of regulation in assuring blood safety. After an overview of the subject by a leading expert, examples are provided of regulatory systems for blood transfusion services in several countries and regions. Additionally, the perspective of WHO is given on the essential role of national regulatory authorities in assuring the quality of national blood programmes. Collectively, the sections of this paper afford an opportunity for readers to make comparisons among different regulatory frameworks and to "benchmark" among the existing systems. Despite many differences in approach, a clear pattern emerges of worldwide efforts to strengthen blood regulatory systems.

Evaluation of Quality Parameters for Cord Blood Donations.

SUMMARY: BACKGROUND: Umbilical cord blood (CB) is widely used for hematopoietic stem cell transplantation and holds promise for the development of innovative medicinal products. In order to find out whether the conditions for collection and storage before processing might have an impact on the quality of CB preparations, viability and the clonogenic potential were assessed. METHODS: CB was collected under field conditions. Flow cytometry was used to determine leukocytes, CD34/CD45+ cells, viability, and nucleated red blood cells (NRBC). Clonogenic activity was determined using isolated mononuclear cells (MNC). RESULTS: Neither plasma citrate concentrations nor storage temperature (within 24 h) affected cell viability or colony formation. After storage for 49-80 h, leukocyte viability declined by about 16% compared to CB stored up to 24 h. In contrast, the clonogenic activity and CD34/CD45+ cell content were not affected. A higher gestational age was associated with a lower yield of clonogenic activity compared to midterm deliveries. NRBC varied widely (median 7.3%; range 0.63-17.3%) without relation to gestational age or colony formation. There was a close correlation between the percentage of viable CD34/CD45+ cells and colony formation (r = 0.77 for CFU-GM; r = 0.75 for CFU-C). CONCLUSIONS: The content of viable CD34/CD45+ cells represents the clonogenic activity of CB preparations. Therefore, determination of viable CD34/CD45+ cells should be generally performed as a routine quality control assay.