Properties of a highly purified human plasma factor IX:c therapeutic concentrate prepared by conventional chromatography

Two-Step Size-Exclusion Nanofiltration of Prothrombin Complex Concentrate Using Nanocellulose-Based Filter Paper

Coagulation Factor IX-rich protrhombin complex concentrate (FIX-PCC) is a therapeutic biologic product that consists of a mixture of several human plasma-derived proteins, useful for treating hemophilia B. Due to its complex composition, FIX-PCC is very challenging to bioprocess through virus removing nanofilters in order to ensure its biosafety. This article describes a two-step filtration process of FIX-PCC using a nanocellulose-based filter paper with tailored porosity. The filters were characterized with scanning electron microscopy (SEM), cryoporometry with differential scanning calorimetry, and nitrogen gas sorption. Furthermore, in order to probe the filter's cut-off size rejection threshold, removal of small- and large-size model viruses, i.e., ΦX174 (28 nm) and PR772 (70 nm), was evaluated. The feed, pre-filtrate, and permeate solutions were characterized with mass-spectrometric proteomic analysis, dynamic light scattering (DLS), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and analytical size-exclusion high-performance liquid chromatography (SEHPLC). By sequential filtration through 11 μm pre-filter and 33 μm virus removal filter paper, it was possible to achieve high product throughput and high virus removal capacity. The presented approach could potentially be applied for bioprocessing other protein-based drugs.

Blood derived products in pediatrics: New laboratory tools for optimizing potency assignment and reducing side effects

Neonates and children can develop rare bleeding disorders due to congenital/acquired coagulation Factor deficiencies, or allo-immune/autoimmune complications, or can undergo surgeries at high haemorrhagic risk. They then need specialized transfusion of blood components/products, or purified blood extracted products or recombinant proteins. Blood-derived therapies conventionally used for management of affected infants with genetic/acquired deficiencies, bleeding problems (coagulation Factor reduced or missing) or thrombotic disorders (reduced or missing anticoagulant proteins) pose some additional risks. These remedial therapies can cause tolerance when used very early in life and, sometimes needed, repeatedly. The introduction of recombinant proteins has allowed manufacturers to produce large amounts of the proteins usually present at very low concentration in blood. This has also changed the risk pattern of plasma-extracted products, especially in terms of continual reduction of viral transmission. Many efforts have been made over these past decades to reduce the risks associated with the use of all these products in terms of viral and bacterial safety, as well as immune disorders but they are not the objective of this article. Other associated side effects are the presence of undesired activities in blood products, which can produce thrombotic events or adverse reactions. The progressive introduction of blood derived products has greatly improved the prognosis and quality of life of affected patients. This concerns whole blood, but also blood cell concentrates, mainly platelets and red blood cells, plasma, while the blood extracted products are increasingly replaced by recombinant proteins. All these therapeutic products, i.e. blood extracted drugs, improve health and quality of life for hemophiliac's A or B, or patients with auto/allo-immune thrombocytopenias or with rare bleeding disorders, and those with thrombotic events occurring in childhood, which are mainly due to Protein C or Protein S deficiencies (congenital or acquired). Progress in analytical methods and biotechnology allow better control of the manufacturing processes for all blood derived or plasma extracted products and recombinant proteins, and contribute to improved manufacturing processes to minimize the occurrence of side effects. These adverse events can be due to the aging of the blood cell concentrate with release of their granule content, and generation of EVs, which can produce anaphylactic reactions and risk of thrombosis, but also to the presence of activated coagulation Factors in purified products, such as Factor Xia as recently identified in immunoglobulin concentrates. Characterization and measurement of contaminant products is of special usefulness during product preparation and for optimization of manufacturing processes for purified extracted products, but also for recombinant proteins. The pharmaceutical industry introduces these new methods for validating manufacturing processes, or for quality control assessments. The objective is first to warrant the full quality and safety of the lots produced, and assure the highest efficacy with the lowest risks when used in patients. For cell concentrates and fresh blood, storage conditions are critical and measurement of analytes such as EVs or Annexin V allows evaluation of quality of each individual transfused pouch. In addition to all the rules around viral and bacterial transmission risk, and immune tolerance, our available laboratory methods contribute to reducing the side effects of blood cell concentrates and derived plasma products, as well as those of the therapeutic recombinant proteins.

Influence of washing conditions on effective components of prothrombin complex concentrates

In order to increase the yield of prothrombin complex concentrates (PCCs) and to reduce their associated thrombotic risks, the influence of washing conditions on the yield, purity, and balance of coagulation factors (FII, FVII, FIX, and FX), and inhibitor proteins (PC, PS, PZ, and AT [antithrombin]) in PCCs was investigated by orthogonal testing, in which three variables (sodium citrate, NaCl, and pH) and their three levels were selected. It was found that AT yield and purity were extraordinarily low, and at lower NaCl content, the general yield, purity, and balance were higher, lower, and better, respectively; however, the results became contrary at higher NaCl. Moreover, within the investigated levels, NaCl was the first determinant for the yield except AT and the purity except FVII, PC, PS, and AT. Sodium citrate was the first determinant for AT yield and FVII, PS, and AT purity. The yield except FII, PS, and AT decreased and the purity except PC increased with increase of sodium citrate content. Just for PC purity, pH was the first determinant. The effect with pH fluctuation on the yield and purity was characteristically unobvious. The outcome undoubtedly supplies the guidance to further improve PCCs.

Therapeutic plasma proteins--application of proteomics in process optimization, validation, and analysis of the final product

An overview is given on the application of proteomic technology in the monitoring of different steps during the production of therapeutic proteins from human plasma. Recent advances in this technology enable the use of proteomics as an advantageous tool for the validation of already existing processes, the development and fine tuning of new production steps, the characterization and quality control of final products, the detection of both harmful impurities and modifications of the therapeutic protein and the auditing of batch-to-batch variations. Further, use of proteomics for preclinical testing of new products, which can be either recombinant or plasma-derived, is also discussed.

Use of proteomics for validation of the isolation process of clotting factor IX from human plasma

The use of proteomic techniques in the monitoring of different production steps of plasma-derived clotting factor IX (pd F IX) was demonstrated. The first step, solid-phase extraction with a weak anion-exchange resin, fractionates the bulk of human serum albumin (HSA), immunoglobulin G, and other non-binding proteins from F IX. The proteins that strongly bind to the anion-exchange resin are eluted by higher salt concentrations. In the second step, anion-exchange chromatography, residual HSA, some proteases and other contaminating proteins are separated. In the last chromatographic step, affinity chromatography with immobilized heparin, the majority of the residual impurities are removed. However, some contaminating proteins still remain in the eluate from the affinity column. The next step in the production process, virus filtration, is also an efficient step for the removal of residual impurities, mainly high molecular weight proteins, such as vitronectin and inter-alpha inhibitor proteins. In each production step, the active component, pd F IX and contaminating proteins are monitored by biochemical and immunochemical methods and by LC-MS/MS and their removal documented. Our methodology is very helpful for further process optimization, rapid identification of target proteins with relatively low abundance, and for the design of subsequent steps for their removal or purification.

Evaluation of expanded bed adsorption chromatography for extraction of prothrombin complex from Cohn Supernatant I

This study evaluated the feasibility of substituting expanded bed adsorption (EBA) chromatography for an existing chromatographic purification process for the isolation of prothrombin complex concentrate (PCC) from Cohn Supernatant I. The EBA chromatography (Streamline) resins were compared to the current DEAE-cellulose resin for the extraction of PCC from Cohn SNI. EBA chromatography resins efficiently bound PCC from Cohn SNI at a significantly higher flow rate of up to 300 cm/h compared to 30 cm/h for the current DEAE-cellulose process. Composition and yield of the recovered PCC reflected the elution conditions used. The results indicate that EBA chromatography could be used to efficiently produce PCC comparable to existing products.

Modern plasma fractionation

Protein products fractionated from human plasma are an essential class of therapeutics used, often as the only available option, in the prevention, management, and treatment of life-threatening conditions resulting from trauma, congenital deficiencies, immunologic disorders, or infections. Modern plasma product production technology remains largely based on the ethanol fractionation process, but much has evolved in the last few years to improve product purity, to enhance the recovery of immunoglobulin G, and to isolate new plasma proteins, such as α1-protease inhibitor, von Willebrand factor, and protein C. Because of the human origin of the starting material and the pooling of 10 000 to 50 000 donations required for industrial processing, the major risk associated to plasma products is the transmission of blood-borne infectious agents. A complete set of measures—and, most particularly, the use of dedicated viral inactivation and removal treatments—has been implemented throughout the production chain of fractionated plasma products over the last 20 years to ensure optimal safety, in particular, and not exclusively, against HIV, hepatitis B virus, and hepatitis C virus. In this review, we summarize the practices of the modern plasma fractionation industry from the collection of the raw plasma material to the industrial manufacture of fractionated products. We describe the quality requirements of plasma for fractionation and the various treatments applied for the inactivation and removal of blood-borne infectious agents and provide examples of methods used for the purification of the various classes of plasma protein therapies. We also highlight aspects of the good manufacturing practices and the regulatory environment that govern the whole chain of production. In a regulated and professional environment, fractionated plasma products manufactured by modern processes are certainly among the lowest-risk therapeutic biological products in use today.

Current strategies to prevent transmission of prions by human plasma derivatives

Protein products prepared from pooled human plasma are an essential class of therapeutics used mostly to control bleeding and/or immunological disorders. Because of the human origin of the starting material, there is a risk that these products may possibly transmit prions causing variant Creutzfeldt-Jakob disease (vCJD). No case of transmission of prions by plasma products has been observed. Case-by-case measures implemented in various countries, and several technical factors may contribute, to various degrees, to the prevention of the risk of transmission of prions by plasma products. Those measures include (a) the epidemiological surveillance of population in countries with cases of vCJD and/or bovine spongiform encephalopathies (BSE), (b) the deferral of blood donors who traveled or resided, for specific periods of time, to countries with BSE, or who received transfusion or tissue transplant, (c) the removal of leucocytes in plasma used for fractionation, and, last but not least, (d) the removal of the prion agents during the complex industrial fractionation process used to prepare plasma products. Numerous experimental infectivity studies, involving the spiking of brain-derived infectious materials, have demonstrated that several fractionation steps, in particular ethanol fractionation, depth filtration, and chromatography, can remove several logs of prions. Removal is explained by the distinct hydrophobic and aggregative properties of the prion proteins. In addition, nanofiltration using multi-layer membranes of 75 nm or smaller, which is commonly used for removing viruses from coagulation factors and immunoglobulins products, can remove more than 3-5 logs of spiked prions, presumably by size-exclusion and trapping mechanisms. Therefore, the risk of transmission of vCJD by human plasma products appears remote, but caution should prevail since the biochemical nature of the infectious agent in human blood is still unknown.

Chromatographic purification and properties of a therapeutic human protein C concentrate

Protein C deficiency (inherited and acquired) has a relatively high incidence rate in the general population worldwide. For many years, protein C deficient patients have been treated with fresh frozen plasma, prothrombin complex concentrates, heparin or oral anticoagulants, which all have clinical drawbacks. We report the production process of a highly purified human protein C concentrate from 1500 l of cryo-poor plasma by a four-step chromatographic procedure. After DEAE-Sephadex adsorption, protein C was separated from clotting factors II, VII and IX by DEAE-Sepharose FF and further purified, using a new strategy, by an on-line chromatographic system combining DMAE-Fractogel and heparin-Sepharose CL-6B. In addition, the product was treated against viral risks by solvent-detergent and nanofiltration on 15-nm membranes. The protein C concentrate was essentially free of other vitamin K-dependent proteins. Proteolytic activity was undetectable. Neither activated protein C, prekallikrein activator, nor activated vitamin K-dependent clotting factors were found resulting in good stability of the protein C activity. In vitro and in vivo animal tests did not reveal any sign of potential thrombogenicity. The final freeze-dried product had a mean protein C concentration of 58 IU/ml and a mean specific activity of 215 IU/mg protein, corresponding to over 12000-fold purification from plasma. Therefore, this concentrate appears to be of potential benefit for the treatment of protein C deficiency.

Preparation of vitamin K-dependent proteins, such as clotting factors II, VII, IX and X and clotting inhibitor protein C

A review is given of preparative methods for the isolation of the vitamin K-dependent clotting factors II, VII, IX, X and clotting inhibitor protein C, all derived from human plasma. Factor II, activated factor VII and activated protein C are also obtained from recombinant animal cells. The methods for their purification are described. The problem of difference in posttranslational modifications between plasma derived and recombinant protein is discussed with regard to therapeutic proteins.

Continuous purification of a clotting factor IX concentrate and continuous regeneration by preparative annular chromatography

Preparative continuous annular chromatography, a method to separate proteins in a truly continuous manner, was investigated in an industrial environment. Plasma-derived clotting factor IX concentrate was used as model protein. Separation of vitronectin, a common impurity in commercial available factor IX concentrates, from factor IX was studied and compared to conventional packed bed chromatography in batch mode. As sorbent, Toyopearl DEAE 650M was used. Regeneration was performed simultaneously with the purification of factor IX in continuous mode. All required parameters applied for preparative annular chromatography such as feed flow-rate and elution flow-rate were first estimated from experiments on conventional batch columns. Then preparative annular chromatography and conventional packed beds were compared regarding enrichment, purity and productivity. Three different process scenarios, the optimal batch process,the preparative annular chromatography process and the batch process equivalent to the preparative annular chromatography process were investigated. The productivity of the optimal batch process was higher than that of the preparative annular chromatography and batch process equivalent to the preparative annular chromatography process. Therefore the throughput could not be increased by the use of the continuous chromatographic system.

Affinity chromatography in the industrial purification of plasma proteins for therapeutic use

Affinity chromatography is a powerful technique for the purification of many proteins in human plasma. Applications cover the isolation of proteins for research purposes but also, to a large extent, for the production of therapeutic products. In industrial plasma fractionation, affinity chromatography has been found to be particularly advantageous for fine and rapid capture of plasma proteins from industrial plasma fractions pre-purified by ethanol fractionation or by ion-exchange chromatography. To date, affinity chromatography is being used in the production of various licensed therapeutic plasma products, such as the concentrates of Factor VIII, Factor IX, von Willebrand Factor, Protein C, Antithrombin III, and Factor XI. Most commonly used ligands are heparin, gelatin, murine antibodies, and, to a lesser extent, Cu(2+). Possible development of the use of affinity chromatography in industrial plasma fractionation should be associated to the current development of phage display and combinatorial chemistry. Both approaches may lead to the development of tailor-made synthetic ligands that would allow implementation of protein capture technology, providing improved productivity and yield for plasma products.

Characterization of clotting factor IX in plasma-derived preparations by electrophoretic techniques

Clotting factor IX preparations from human plasma (pdFIX) have been characterized using electrophoretic methods like sodium dodecyl sulfate-polyacrylamide gel electrophoresis, isoelectric focusing and two-dimensional polyacrylamide gel electrophoresis. Factor IX prior to and after activation with factor XIa was separated by one- and two-dimensional polyacrylamide gel electrophoresis and on isoelectric focusing gels. The main differences between the band patterns of the two pdFIX preparations are due to their purity. Vitronectin was identified by immunological techniques as major accompanying plasma protein, separated from factor IX and characterized by isoelectric focusing and two-dimensional polyacrylamide gel electrophoresis.

Purification of factor X by hydrophobic interaction chromatography

Human factor X has been purified to homogeneity by hydrophobic interaction chromatography on phenyl-sepharose. The coagulation protein did not interact with the resin in the presence of 2-3 M NaCl whereas contaminants were retained. This single purification step, in conjunction with classical purification strategies, is a powerful tool in generating high purity factor X and is based on resins which are readily available.

Separation of human vitamin K-dependent coagulation proteins using hydrophobic interaction chromatography

A rapid and simple method was developed to separate human vitamin K-dependent plasma proteins from each other, yielding virtually homogeneous pools. The purification technique is based on the single use of hydrophobic interaction chromatography, starting from prothrombin concentrate (PC or DEFIX, also termed factor IX concentrate) as initial material. Phenyl-sepharose HP demonstrated optimal separation by comparing several hydrophobic resins as well as resins used in standard procedures like immobilised heparin and Cibacron blue. Under ideal conditions, factor X could be separated in a single step as well as prothrombin. Factor IX co-eluted with other minor proteins. Focus was given only on these three proteins due to their relative abundance. Complete separation of all proteins present in the starting material was achieved by MonoQ anion-exchange chromatography following the phenyl-sepharose run. The resulting purified material could be demonstrated to be of equal or higher purity than using described methods. This strategy employing hydrophobic interaction chromatography for blood macromolecules could be of immense value for purifying the human vitamin K-dependent proteins and represents a considerable simplification over other purification schemes. It not only involves minimal sample handling but also can be readily up-scaled and is a cost-efficient alternative.

Production of highly purified clotting factor IX by a combination of different chromatographic methods

A highly enriched preparation of human clotting factor IX was produced by a combination of adsorption chromatography, hydrophobic interaction chromatography and heparin affinity chromatography. The introduction of adsorption chromatography with a hydroxyaminopropyl support allows the capture step to be carried out directly from the cryoprecipitate-depleted plasma with a chromatographic column in flow-through mode. This replaces the batch procedure used until now. The other two chromatographic steps are designed in such a way that the eluate from the preceding step can be directly applied, without any intermediate treatment of the sample. This cuts the period of time required for the process by almost 50%, and increases the yield considerably. The isolated factor IX contains practically no contaminants and has a specific activity over 200 IU/mg of protein.

Application of bioaffinity technology in therapeutic extracorporeal plasmapheresis and large-scale fractionation of human plasma

This paper describes the increasingly unique and powerful role that affinity chromatography is occupying both as a tool for the treatment of extracorporeal plasma exchange (to discard biological compounds with noxious metabolic or immunologic effects in patients) and as a purification tool in the production of therapeutic plasma protein derivatives. Management of both applications requires careful monitoring of the parameters applied to the plasma material, to avoid immunological stimulation or activation of the coagulation cascade. Examples of direct current applications of affinity ligands in therapeutic removal and industrial production of plasma compounds are presented.

Size-exclusion chromatography of plasma proteins with high molecular masses

Two different hydrophilic materials with large pores, Superose 6 and Fractogel EMD BioSec (S), which are designed for size-exclusion chromatography (SEC) of plasma proteins with high molecular masses, are tested for their performance on a preparative scale. The model mixtures are preparations of the clotting factors VIII (FVIII) and IX (FIX). A combination of a Fractogel EMD BioSec (S) column and a Superose 6 column has proved to be particularly effective for separations in a wide molecular size range, from several millions down to about 20,000. Superose 6 showed good results on a small scale as well as on a large scale, even in the molecular mass range over 1,000,000. However, recovery of FVIII clotting activity was less than 70% with this material and therefore not satisfactory. Fractogel did not perform well in terms of separation on a small scale. However, in the case of biopolymers with high molecular masses, separation was improved by using larger columns. With Fractogel, recovery of activity of the two clotting factors FVIII and FIX was satisfactory, above 80%. On a large scale, the active fraction in the clotting factor concentrate was successfully separated from the non-active fraction with either size exclusion (SE) material. In the preparation under investigation, the clotting factor VIII is found in a complex with the von Willebrand factor (vWF). The FVIII-vWF complex has a molecular mass of several millions. It dissociates in the presence of high concentrations of Ca2+ ions. Under such conditions FVIII and vWF were successfully separated with both SEC columns.

Human pre-alpha-inhibitor: isolation from a by-product of industrial scale plasma fractionation and structural analysis of its H3 heavy chain

Pre-alpha-inhibitor (P alpha I) is a serine proteinase inhibitor from human plasma. It comprises bikunin (BK) responsible for antiprotease activity, covalently linked to a heavy chain H3. Here we describe its isolation from a side fraction of an industrial preparation of plasma clotting factors. By using a highly specific polyclonal antiserum prepared from rabbit immunized with a H3P polypeptide obtained in a bacterial expression system, we were able to identify the fractions containing P alpha I. Then, taking advantage of the differential affinity of the members of the inter-alpha-inhibitor family (I alpha I) for heparin-Sepharose and blue-Sepharose, we isolated P alpha I. Its specific antitryptic activity was 580 IU/g, higher than that of I alpha I: 420 IU/g. Its M(r), determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis, with or without prior reduction, was 130,000. Its peptide chains were identified by N-terminal sequencing. The H3 heavy chain was isolated from P alpha I by alkaline dissociation and anion-exchange chromatography. Its electrophoretic mobility was compared to that of the HI and H2 heavy chains of I alpha I. In reducing conditions, it was quite similar to that of H2 (M(r) 85,000) but clearly different from that of H1 (M[r] 78,000). Thus, the so-determined apparent M(r) of H3 was overestimated since its molecular mass determined by MALDI-TOF was 74,100. This result agrees with the proposed structure for H3. Indeed, by carbohydrate analysis and PNGase F digestion, we demonstrate that the two potential N-glycosylation sites present in the core-protein (theoretical mass: 69,454) are really occupied by two N-glycans, probably of biantennary type.

The choice of plasma-derived clotting factor concentrates

The gloomy picture caused by the AIDS epidemic is now partially lightened by spectacular improvements in therapy. One important step forward toward elimination of the risk of transfusion of blood-borne infections by plasma products was the development of virucidal methods and their application to clotting factor concentrates. Another important advance was the production of ultrapure factor VIII concentrates by immuno-affinity chromatographic techniques. Not only are these concentrates at least as safe as less-pure concentrates in terms of transmission of blood-borne viral infections, but there is also a hint that the deteriorating immune system of HIV-positive haemophiliacs may be stabilized by these highly purified concentrates. Factor VIII produced by recombinant DNA technology is licensed for treatment of haemophilia A. Hopefully, it will be free of the risk of transmitting infections and will be available in sufficiently large amounts to meet the needs of haemophiliacs worldwide. The availability of concentrates containing only factor IX is another substantial step forward in the treatment of haemophilia B, while we wait for the cure of this disease through gene-transfer therapy.

Chromatography in plasma fractionation: benefits and future trends

Industrial-scale chromatographic fractionation and purification methods have been used increasingly in the last few years for plasma fractionation. This has resulted in the development of a new generation of therapeutic plasma derivatives, especially coagulation factors, protease inhibitors and anticoagulants. Implementation and combination of ion-exchange, affinity and size-exclusion chromatography have allowed the development of new therapeutic products with improved purity and safety for treating congenital or acquired plasma protein deficiencies in patients. More recently, the benefit of chromatographic purification of plasma proteins in the removal of plasma-borne viruses has been revealed. Development of packing materials with improved characteristics for industrial applications, including higher capacity and rigidity, should further promote the use of chromatography as an essential plasma fractionation tool and confine more and more the traditional ethanol precipitation methods to the final processing stages used to recover albumin.

Combined factor IX and protein C deficiency in a child: thrombogenic effects of two factor IX concentrates

We have recently described an unusual situation which involved a combination of a factor IX and a protein C deficiency in a young child who presented, according to the bleeding tendency, as a hemophilia B patient. In this particular hemophiliac, baseline prothrombin fragment F1 + 2 levels were unexpectedly elevated and increased after an injection of a very high purity factor IX concentrate. This observation raised a question regarding the substitution schedule in the case of repeated injections of factor IX, since the thrombotic tendency has been a major concern with some factor IX concentrates. We monitored factor IX, prothrombin fragment F1 + 2, and D-dimer plasma levels before and during the 6 hr following the injection of an immunopurified factor IX concentrate. The results showed an increase in the F1 + 2 levels after the factor IX injection, but an increase lower than previously observed with an ion-exchange chromatography-purified concentrate. Furthermore, the F1 + 2 level returned to baseline value 6 hr after administration. This factor IX concentrate seems to be best for use in the patient where repeated injections are involved (as employed during surgery). Moreover, the data point out the advantage of a monoclonal antibody-purified factor IX concentrate over less purified concentrates in a specific situation, with regard to the thrombogenic risk.

The practical management of haemophilia

Haemophilia is a rare and complex disorder and its successful management will depend upon the establishment of a network of 'comprehensive care' including the services of haematologists, orthopaedic surgeons, rheumatologists, dental surgeons, physiotherapists, specialised nurses and counsellors. One of the major lessons to be learned from the HIV epidemic in haemophilia is that it is critical to strive to obtain the safest and purest forms of blood products for these patients. The advent of clinically available recombinant factor VIII is expected soon; in the meantime there is a move towards treating all patients with high purity products.

Myocardial infarction after FEIBA therapy in a hemophilia-B patient with a factor IX inhibitor

A case of myocardial infarction (MI) in a hemophilia B patient with a factor IX (FIX) inhibitor (6 BU) is described. MI occurred after two infusions of FEIBA concentrate. Unexpectedly, these infusions resulted in a neutralization of the inhibitor and a consistent plasma FIX activity which may have increased the thrombotic risks. Four days later, a psoas hematoma was suspected. At that time the inhibitor remained undetectable, allowing a therapy with purified FIX concentrates. No recurrence of thrombotic complication was observed. This is an additional illustration of the thrombotic risks associated with the use of activated prothrombin complex concentrates, especially in patients having pre-existing risk factors for thrombosis. The management of bleeding episodes in hemophilia B patients with inhibitor represents an especially difficult challenge.

Safety aspects in the manufacturing of plasma-derived coagulation factor concentrates

Plasma-derived coagulation factor concentrates, prepared using traditional manufacturing processes, have transmitted viral diseases, especially AIDS, hepatitis B and hepatitis C to patients. To date, more extensive selection of blood donors, improved screening procedures of each plasma donation for direct and indirect viral markers, and newly developed virucidal procedures, especially pasteurization and solvent-detergent, together with extraction technologies of plasma proteins based on high-resolution chromatographic separations, have diminished considerably the risks of transmitting these pathogenic agents. To ensure safety, each production process must be carefully validated, following a rigorous scientific approach to assess its ability to inactivate or eliminate viruses. In addition, Good Manufacturing Practices must avoid any variation from these validated viral inactivation processes and must eliminate risks of potential downstream contamination of purified plasma fractions following viral inactivation or elimination steps. Other side-effects associated with conventional low-purity preparations, such as acute haemolytic anemia due to contamination by isohaemagglutinins, or immunosuppression possibly due to an overload in fibrinogen and immunoglobulins, have not been reported following infusion of highly purified coagulation factor concentrates. Present state-of-the-art virus inactivation and protein-purification technologies have significantly improved the safety of plasma coagulation factor concentrates.

Human plasma fractionation and the impact of new technologies on the use and quality of plasma-derived products

Recent years brought several important changes in the domain of human plasma derived products. High purity and effective anti-viral treatment became a reality. This radically improved the quality of patient treatment. At the same time recent discoveries in molecular biology paved the way for the production of several crucial plasma components by recombinant technology. In the light of these developments the future possibilities for different plasma components production is widely discussed and the eventual benefit of more expensive technologies is being evaluated. This paper, analyzes and presents methods applied by different producers to obtain plasma derived components preparations. The impact of these technologies, the quality of the products and the future of the plasma industry is being discussed.