Solvent/Detergent-Treated Plasma Has Decreased Antitrypsin Activity and Absent Antiplasmin Activity

Thawed solvent/detergent-treated plasma demonstrates comparable clinical efficacy to thawed plasma

BACKGROUND

Thawed Plasma (TP), plasma thawed and refrigerated for up to 5 days, is a commonly transfused plasma product. This pilot study was conducted to determine whether Thawed Solvent/Detergent-treated Plasma stored refrigerated for up to 5-days post-thaw (T-S/D) was as efficacious as TP.

STUDY DESIGN AND METHODS

This single institution retrospective cohort analysis evaluated the efficacy of T-S/D in reversing coagulopathies in comparison to TP. Utilizing the institution's electronic medical records, transfusion data were collected in adult patients who received either TP or T-S/D. The primary outcome was the incidence of subsequent transfusions within 24 hours after first dose of either type of plasma. Secondary outcomes included the number of blood products transfused within 24 hours of first-dose plasma, correction of pre-transfusion coagulation laboratory values, volume transfused, and clinical outcomes.

RESULTS

TP was received by 301 patients and 137 received T-S/D during the first 32 months post-implementation of T-S/D. There was no difference in incidence of subsequent transfusions or number of blood products given. The median pre-INR of both the TP and T-S/D cohorts was 1.9, with a similar decrease in INR of 0.2 and 0.3 (p = 0.36), respectively, post plasma transfusion. There was no difference in correction of PT/aPTT, mortality, transfusion reactions, readmission rates, length of stay, or inpatient deep venous thrombosis. The median volume of T-S/D plasma transfused for the first dose was 126 mL less than TP (p = .0001).

CONCLUSION

T-S/D was as efficacious as TP for the treatment of coagulopathies and the reversal of coagulation laboratory values.

Miropin, a novel bacterial serpin from the periodontopathogen Tannerella forsythia, inhibits a broad range of proteases by using different peptide bonds within the reactive center loop

All prokaryotic genes encoding putative serpins identified to date are found in environmental and commensal microorganisms, and only very few prokaryotic serpins have been investigated from a mechanistic standpoint. Herein, we characterized a novel serpin (miropin) from the human pathogen Tannerella forsythia, a bacterium implicated in initiation and progression of human periodontitis. In contrast to other serpins, miropin efficiently inhibited a broad range of proteases (neutrophil and pancreatic elastases, cathepsin G, subtilisin, and trypsin) with a stoichiometry of inhibition of around 3 and second-order association rate constants that ranged from 2.7 × 10(4) (cathepsin G) to 7.1 × 10(5) m(-1)s(-1) (subtilisin). Inhibition was associated with the formation of complexes that were stable during SDS-PAGE. The unusually broad specificity of miropin for target proteases is achieved through different active sites within the reactive center loop upstream of the P1-P1' site, which was predicted from an alignment of the primary structure of miropin with those of well studied human and prokaryotic serpins. Thus, miropin is unique among inhibitory serpins, and it has apparently evolved the ability to inhibit a multitude of proteases at the expense of a high stoichiometry of inhibition and a low association rate constant. These characteristics suggest that miropin arose as an adaptation to the highly proteolytic environment of subgingival plaque, which is exposed continually to an array of host proteases in the inflammatory exudate. In such an environment, miropin may function as an important virulence factor by protecting bacterium from the destructive activity of neutrophil serine proteases. Alternatively, it may act as a housekeeping protein that regulates the activity of endogenous T. forsythia serine proteases.

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.

Impact of Triton X-100 on alpha 2-antiplasmin (SERPINF2) activity in solvent/detergent-treated plasma

Large-pool solvent/detergent (SD) plasma for transfusion exhibits reduced alpha 2-antiplasmin (alpha2-AP; SERPINF2) functional activity. The reason for the loss of alpha2-AP has not been described and could be due to the SD incubation itself and/or to the processing steps implemented to remove the solvent and the detergent. We have studied alpha2-AP activity during six down-scale preparations of plasma virally-inactivated by 1% (v/v) TnBP combined with two different non-ionic detergents, either 1% Triton X-100 or 1% Triton X-45, at 31 degrees C for 4h. The SD-treated plasmas were then extracted with 7.5% (v/v) soybean oil, centrifuged at 3800 x g for 30 min, and subjected to hydrophobic interaction chromatography (HIC) to remove the SD agents. Control runs without TnBP and Triton were performed to evidence possible impacts of each process step on alpha2-AP activity. TnBP, Triton X-100, and Triton X-45 were measured at all stages of the processes to evaluate potential interferences with the alpha2-AP assay. Alpha 2-AP activity was about 10% that of starting plasma after 1% TnBP-1% Triton X-100 incubation and about 50% after oil extractions, centrifugation, and HIC. By contrast about 73% of the antiplasmin activity was found after the incubation with 1% TnBP and 1% Triton X-45, 88% after removal of the SD agents by oil extractions, 90% after centrifugation and 92% after HIC. The control runs performed without SD agents showed that the process steps did not affect the alpha2-AP activity. In conclusion, the agent altering alpha2-AP activity in SD-plasma is Triton X-100. The choice of detergents for the SD viral inactivation of therapeutic plasma fractions used in patients at risk of fibrinolysis should consider the impact on alpha2-AP activity.

Haemostatic properties of human plasma subjected to a sterilizing dose of gamma irradiation in the presence of ascorbate

The objective was to study the effects of gamma irradiation, in the presence of sodium ascorbate, on coagulation/fibrinolytic activity of fresh frozen plasma to be applied to inactivate the transfusion-transmitted viruses in plasma-derived products. Plasma was irradiated (50 kGy total dose, on dry ice) using a 60Co source. The plasma proteins were analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and western blot and the following parameters estimated: prothrombin time, functional fibrinogen concentration, thrombin-induced fibrinogen polymerization, plasminogen activity, and tissue-type plasminogen activator-induced conversion of plasminogen to plasmin. In irradiated plasma a moderate fragmentation of the most labile plasma proteins was found. The prothrombin time was prolonged (1.5-fold), functional fibrinogen was significantly reduced (60%), fibrinogen polymerization was impaired, plasminogen was predominantly maintained (90%) and tissue-type plasminogen activator-induced conversion of plasminogen to plasmin was unchanged. Ascorbate (25 mmol/l) raised the level of functional fibrinogen in irradiated plasma (to 50%; P=0.0245) and slightly accelerated its polymerization. The small protective effect of ascorbate might be due to inhibition of the radiation-induced fibrinogen oxidation and/or fragmentation but addition of other antioxidants/stabilizers would be crucial when a high irradiation dose, an effective treatment for inactivation of the most resistant viruses, is applied.

A process for solvent/detergent treatment of plasma for transfusion at blood centers that use a disposable-bag system

BACKGROUND

Solvent/detergent (S/D) inactivates enveloped viruses in plasma. The current technology requires a plasma fractionation facility and is applied to large plasma pools, which increases the cost and risks of exposure to S/D-resistant pathogens and lowers the content of protein S and alpha2-antiplasmin. Two S/D treatment procedures for single donations or minipools of plasma have been developed with a single-use bag system.

STUDY DESIGN AND METHODS

Frozen plasma samples were thawed and treated in disposable bags with either 2 percent tri(n-butyl)phosphate (TnBP) at 37 degrees C or 1 percent TnBP and 1 percent Triton X-45 at 31 degrees C for 4 hours. Plasma samples were extracted three times with 7.5 percent sterile castor oil to remove TnBP and Triton X-45. The TnBP-treated plasma samples were further subjected to a clarifying centrifugation (3800 x g, 30 min). Final plasma samples were dispensed into individual bags and frozen at -30 degrees C. Plasma quality was assessed at each step of the procedures.

RESULTS

Both processes yielded greater than 90 percent mean recovery of coagulation factors (clottable fibrinogen, von Willebrand factor, and factors VIII, V, VII, IX, X, and XI), anticoagulants (protein C, protein S), protease inhibitors (antithrombin, alpha2-antiplasmin), total protein, albumin, and immunoglobulins. Global coagulation tests of the treated plasma samples were normal. Final TnBP and Triton X-45 content was less than 10 and 50 ppm, respectively.

CONCLUSION

S/D treatment of plasma can be performed in a closed-bag system under conditions that maintain plasma protein quality. The technology is simple, presents advantages over the industrial large-scale S/D plasma process, and could be performed in blood centers.

Are quality differences responsible for different adverse reactions reported for SD-plasma from USA and Europe?

Thromboembolic adverse reactions reported after transfusion of SD-plasma in the United States (US) prompted us to perform a comparative study with SD-plasma from the US and the European (EU) market. In SD-plasma from US, residual tri-N-butyl phosphate was found, and citrate concentrations were lower than in EU-plasma. Except for substantial losses of FV, FVIII and antiplasmin found for all SD-plasmas, clotting factor activities were mainly retained. However, for SD-plasma from US, markedly elevated concentrations of lipoprotein (a) [Lp(a)], fibrin monomer and a particularly high degree of complement activation (C3a des-Arg) were observed. Furthermore, pronounced differences were found for protein S. Although SD-plasma pools from US contained nearly normal concentrations of free and bound protein S antigen, protein S activities were almost completely absent. In contrast to this, SD-plasma from EU showed a moderate loss of both protein S activity and free antigen. Antitrypsin inhibitor activities were much more diminished in SD-plasma from US than from EU. In view of a possible thrombogenicity of SD-plasma from US, the loss of protein S and elevated Lp(a) concentrations could be of significance. The very high levels of C3a des-Arg in US plasma could possibly have an additional effect, through priming platelet activation after transfusion.

Recent advances in blood-related proteomics

Blood is divided in two compartments, namely, plasma and cells. The latter contain red blood cells, leukocytes, and platelets. From a descriptive medical discipline, hematology has evolved towards a pioneering discipline where molecular biology has permitted the development of prognostic and diagnostic indicators for disease. The recent advance in MS and protein separation now allows similar progress in the analysis of proteins. Proteomics offers great promise for the study of proteins in plasma/serum, indeed a number of proteomics databases for plasma/serum have been established. This is a very complex body fluid containing lipids, carbohydrates, amino acids, vitamins, nucleic acids, hormones, and proteins. About 1500 different proteins have recently been identified, and a number of potential new markers of diseases have been characterized. Here, examples of the enormous promise of plasma/serum proteomic analysis for diagnostic/prognostic markers and information on disease mechanism are given. Within the blood are also a large number of different blood cell types that potentially hold similar information. Proteomics of red blood cells, until now, has not improved our knowledge of these cells, in contrast to the major progresses achieved while studying platelets and leukocytes. In the future, proteomics will change several aspects of hematology.

Fresh frozen plasma prepared with amotosalen HCl (S-59) photochemical pathogen inactivation: transfusion of patients with congenital coagulation factor deficiencies

BACKGROUND

Photochemical treatment (PCT) with amotosalen HCl (S-59) was developed to inactivate pathogens and white blood cells in plasma (PCT-FFP) used for transfusion support.

STUDY DESIGN AND METHODS

An open-label, multicenter trial was conducted in patients with congenital coagulation factor deficiencies (factors [F]I, FII, FV, FVII, FX, FXI, and FXIII and protein C) to measure the kinetics of specific coagulation factors, hemostatic efficacy, and safety of PCT-FFP. Posttransfusion prothrombin time (PT), partial thromboplastin time (PTT), and clinical hemostasis were evaluated before and after PCT-FFP transfusions.

RESULTS

Thirty-four patients received 107 transfusions of PCT-FFP for kinetic studies or therapeutic indications (mean dose, 12.8 +/- 8.5 mL/kg). Incremental factor recoveries ranged from 0.9 to 2.4 IU per dL per IU per kg (FII, FV, FVII, FX, FXI, and protein C). Mean pretransfusion PT (20.7 +/- 22.2 sec) corrected after PCT-FFP (13.8 +/- 2.4 sec, p < 0.001). Mean pretransfusion PTT (51.2 +/- 29.3 sec) corrected after PCT-FFP (32.0 +/- 5.1 sec, p < 0.001). Thirteen patients required 77 transfusions for therapeutic indications. PCT-FFP provided effective hemostasis and was well tolerated.

CONCLUSIONS

Replacement coagulation factors in PCT-FFP exhibited kinetics and therapeutic efficacy consistent with conventional FFP.

Emergency treatment of acute attacks in hereditary angioedema due to C1 inhibitor deficiency: what is the evidence?

Hereditary angioedema (HAE) is caused by a deficiency in C1 esterase-inhibitor (C1-INH) and is characterised by skin swelling, abdominal pain and episodes of upper respiratory tract obstruction. Oedema of the larynx can result in rapid asphyxiation and requires emergency treatment. Three treatment options for emergency treatment of HAE are reviewed: fresh frozen plasma, solvent/detergent-treated plasma and C1-INH concentrate. It is concluded that while all three treatment options are theoretically effective in the emergency treatment of HAE, C1-INH is the treatment of choice.

Protecting the blood supply from emerging pathogens: the role of pathogen inactivation

Although the risk of infection by blood transfusion is relatively low, breakthrough infections still occur, Transfusion-related fatalities caused by infections continue to be reported, and blood is not tested for many potentially dangerous pathogens. The current paradigm for increasing the safety of the blood supply is the development and implementation of laboratory screening methods and restrictive donor criteria. When considering the large number of known pathogens and the fact that pathogens continue to emerge, it is clear that the utility of new tests and donor restrictions will continue to be a challenge when considering the cost of developing and implementing new screening assays, the loss of potential donors, and the risk of testing errors. Despite improving the safety of blood components, testing remains a reactive approach to blood safety. The contaminating organisms must be identified before sensitive tests can be developed. In contrast, pathogen inactivation is a proactive strategy designed to inactivate a pathogen before it enters the blood supply. Almost all pathogen inactivation technologies target nucleic acids, allowing for the inactivation of a variety of nucleic acid-containing pathogens within plasma, platelets, or red blood cells thus providing the potential to reduce transfusion-transmitted diseases. However, widespread use of a pathogen inactivation technology can only be realized when proven safe and efficacious and not cost-prohibitive.

Solvent/detergent-treated plasma: composition, efficacy, and safety

PURPOSE OF REVIEW

Recent reports on adverse events associated with solvent/detergent-treated plasma have raised concerns about the efficacy and safety of this type of therapeutic plasma. Comparisons of various brands of solvent/detergent-treated plasma have revealed substantial differences in their composition.

RECENT FINDINGS

Retrospective analyses and case reports suggest an association between the low protein S activity levels found in solvent/detergent-treated plasma and venous thromboembolism when solvent/detergent-treated plasma is given for thrombotic thrombocytopenic purpura or transfused massively during liver transplantation surgery. Augmented bleeding caused by hyperfibrinolysis, possibly caused by the low plasmin inhibitor (also termed alpha2-antiplasmin) activity of solvent/detergent-treated plasma, has also been a matter of concern. The efficacy and safety of various types of solvent/detergent-treated plasma have been studied intensively for all indications for therapeutic plasma by at least five prospective trials, four observational studies, and post-licensure monitoring. A review of the literature shows that the clinical significance of transient protein S and plasmin inhibitor deficiency has been considerably overstated, even when such deficiency might be aggravated by the administration of large amounts of solvent/detergent-treated plasma. However, different brands of solvent/detergent-treated plasma differ substantially with respect to their composition and hemostatic balance. It cannot be completely excluded that the very low citrate and protein S concentrations versus higher clotting factor concentrations found in a given brand of solvent/detergent-treated plasma could contribute to coagulation activation in the settings of thrombotic thrombocytopenic purpura and liver transplantation.

SUMMARY

Future research should seek to optimize the composition of solvent/detergent-treated plasma. Prospective trials and prospective hemovigilance studies are required to determine the rate of adverse events occurring after treatment with solvent/detergent-treated plasma and other types of therapeutic plasma.

Plasma quality after whole-blood filtration depends on storage temperature and filter type

The study evaluated the quality of plasma obtained after whole-blood filtration with four different polyester filters and one polyurethane filter. The activities of coagulation factors and proteinase inhibitors were not or only negligibly affected by filtration, in all experiments. Filtration did not increase markers of clotting and fibrinolysis. Only a strong neutrophil and complement activation was observed, which depended on the type of filter and whole-blood storage conditions. However, as neutrophil elastase-specific degradation products did not increase and the complement-derived anaphylatoxin C3a was found in its inactivated form, C3a-desArg, these filtration-dependent changes apparently have little impact on the therapeutic quality of whole-blood-filtered fresh frozen plasma for transfusion.

Coagulation factor content of solvent/detergent plasma compared with fresh frozen plasma

Solvent/detergent (S/D) plasma is being increasingly widely used in clinical practice, as it carries significantly lower risk of lipid-enveloped viral transmission than standard fresh frozen plasma (FFP). However, previous reports have suggested that S/D processing might influence the coagulation factor content of plasma. We have investigated this question by measuring procoagulant factors (fibrinogen, factor V and factor VIII), anticoagulant factors (protein C and protein S) and routine coagulation screening tests (prothrombin time and activated partial thromboplastin time) in 48 single-donor units of FFP, and in 16 units of S/D plasma (Octaplas). All routine coagulation screening tests, factor VII and protein C levels were within the normal reference range for both S/D plasma and FFP. However, we found significant reductions in factor V (31%), factor VIII (28%) and protein S (50%) in S/D plasma. The observed quantitative differences in coagulation factor levels may be further exacerbated by the lower volume of solvent detergent plasma units (200 ml) compared with units of standard fresh frozen plasma (250 ml). These findings are of potential clinical significance, particularly in those patients with liver disease, constitutional factor V deficiency and congenital or acquired protein S deficiency.

The Norwegian Plasma Fractionation Project--a 12 year clinical and economic success story

The establishment of the Norwegian Fractionation Project (Project) was of major importance in preserving national self-sufficiency when plasma, cryoprecipitate and small batch factor IX-concentrates were replaced by virus inactivated products in the last part of the 1980s. Fractionation was performed abroad by contract with Octapharma after tenders on the European market. All Norwegian blood banks (>50) participated in the Project. Total yearly production was 50-60 tons of mainly recovered plasma. From 1993 solvent detergent (SD) treated plasma has replaced other plasma for transfusion. The blood banks paid for the fractionation and/or viral inactivation process, while the plasma remained the property of the blood banks and the final products were returned to the blood banks. The Project sold surplus products to other Norwegian blood banks and the majority of the coagulation factor concentrates to The Institute of Haemophilia and Rikshospitalet University Hospital. Both plasma and blood bank quality was improved by the Project. Clinical experience with the products has been satisfactory and self-sufficiency has been achieved for all major plasma proteins and SD plasma, but a surplus exceeding 3 years consumption of albumin has accumulated due to decreasing clinical use.The Project has secured high yields of the fractionated products and the net income from the produced products is NOK 1115 (140 Euros or US dollars) per litre plasma. An increasing surplus of albumin and the possibility of significant sales abroad of currently not fractionated IVIgG, could lead to a reorganisation of the Project from that of a co-ordinator to a national plasma handling unit. This unit could buy the plasma from the blood banks and have the plasma fractionated by contract after tender, before selling the products back for cost recovery. The small blood banks could produce plasma for products for the Norwegian market, while surplus products from the larger blood banks which are certified for delivery of plasma for fractionation of products to be consumed in the European Community, could be sold on the international market.

Manufacture and composition of fresh frozen plasma and virus-inactivated therapeutic plasma preparations: correlation between composition and therapeutic efficacy

The clinical efficacy of the therapeutic plasma used in the treatment of congenital and acquired severe coagulopathy depends on the potency of clotting factor and inhibitor activities. The composition of plasma strongly depends on the conditions under which it is produced. A low citrate anticoagulant-to-blood ratio, short intervals between donation and plasma separation and rapid freezing markedly improve the preservation of unstable coagulation factors. The influence of different leukocyte reduction filters on plasma quality still requires clarification. Recent trials on long-term storage conditions suggest that keeping plasma at -30 degrees C or colder over a period of 24-36 months prevents substantial decrease in clotting factor activities including factor VIII (FVIII). Three types of therapeutic plasma are currently available. Quarantine-stored fresh frozen plasma (FFP) contains physiological activities of therapeutically relevant plasma proteins, but carries a risk of transmitting blood-borne viruses that cannot be detected by human immunodeficiency virus (HIV) and hepatitis B and C screening. In contrast, solvent/detergent-treated plasma (SDP) and methylene blue/light-treated plasma (MBP) is virtually free of HIV and hepatitis C virus (HCV) subtypes. Virus inactivation procedures can have the consequence of reducing several clotting factors and inhibitors in SDP and MBP to varying degrees. However, pooling of plasma units before solvent/detergent (SD) treatment results in well-standardized protein levels of SDP. At least five prospective trials and four observational studies covering different clinical settings suggest that SDP and FFP do not substantially differ in their clinical efficacy or in their tolerance. By way of contrast, there is a lack of data about the clinical efficacy and tolerance of MBP compared to FFP.

Quality of therapeutic plasma-requirements for marketing authorization

Fresh frozen plasma (FFP) contains higher levels of intact coagulation factors and coagulation and fibrinolysis inhibitors than solvent/detergent-treated plasma (SD plasma), and also greater residual cell contamination. SD plasma is a particle-free plasma of uniform quality. SD treatment, however, has the specific result of reducing the activities of some inhibitors. Both plasma types carry a minimal residual risk of transmitting human immunodeficiency virus (HIV)-1/2, hepatitis virus B (HBV), and hepatitis virus C (HCV), but SDP is, in addition, also safe with respect to other lipid-enveloped viruses and perhaps with respect to hepatitis virus A (HAV), also due to its antibody (Ab) content. Future revisions of therapeutic plasma safety and quality standards should consider the following points:For FFP:reduce residual cell count in all FFP units to values below 5 x 10(6) leukocytes/l;screen donors for Parvovirus B19 genome and antibodies in order to establish a sufficiently large collection of genome-negative and antibody-positive donors whose FFP can be used for selected patients;For SDP:introduce pool testing for Parvovirus B19 genome; fix an upper limit for genome and a lower limit for antibody content;in addition to the standard quality control methods for therapeutic plasma, focus on assays to test for functionally intact proteinase inhibitors such as alpha(2)antiplasmin (alpha(2)AP) and alpha(1)proteinase inhibitor (alpha(1)PI) that are important for plasma indications. Commercially available kits may not be sufficient to show changes in inhibition kinetics. For both types:introduce an activation marker such as thrombin-antithrombin complex (TAT) as a random test to monitor activation processes during withdrawal, separation, manufacturing, and storage;abolish inappropriate parameters like Antithrombin III (AT III) and coagulation factor XI that are not relevant for changes in plasma quality;finally, support every effort towards establishing an efficient documentation and reporting system on efficacy and side effects of plasma transfusions. Effective reporting alone might help to reveal deficiencies of specific plasma quality and to overcome them through modifications to manufacturing processes and testing, or by defining its indications more precisely.

alpha(1)-Proteinase inhibitor mutants with specificity for plasma kallikrein and C1s but not C1

Coagulation and complement proteinases are activated in sepsis, and one approach to therapy is to develop proteinase inhibitors that will specifically inhibit these proteinases without inhibiting activated protein C, a proteinase that is beneficial to survival. In this study, we made mutants of the serpin alpha(1)-PI, designed to mimic the specificity of C1-inhibitor. The P3-P2-P1 residues of alpha1-PI were changed from IPM to LGR and PFR, sequences preferred by C1s and kallikrein, respectively. Inhibition of C1s, kallikrein, factor XIIa, and activated protein C was assessed by SDS-PAGE, and by determination of the k(app) and SI. alpha(1)-PI-LGR inhibited C1s with a rate of 7790 M(-1)s(-1), but only minimal inhibition of C1 in a hemolytic assay was observed. Kallikrein, factor XIIa, and activated protein C were inhibited with rates of 382,180 M(-1)s(-1), 10,400 M(-1)s(-1), and 3500 M(-1)s(-1), respectively. alpha(1)-PI-PFR was a poor inhibitor of C1s, factor XIIa, and activated protein C, but had enhanced reactivity with kallikrein. Changing the P4' residue of alpha(1)-PI-LGR Pro to Glu reduced the activity with C1s, consistent with the idea that C1s requires hydrophobic residues in this region of the serpin for optimal interaction. The data provide insight into the requirements for kallikrein and C1s inhibition necessary for designing inhibitors with appropriate properties for further investigation as therapeutic agents.

Effects of solvent/detergent-treated plasma and fresh-frozen plasma on haemostasis and fibrinolysis in complex coagulopathy following open-heart surgery

BACKGROUND AND OBJECTIVES

Solvent/detergent-treated plasma (SDP) contains markedly lower protein S (PS) and plasmin inhibitor (PI) activity than standard fresh-frozen plasma (FFP). It has also been reported that SDP contains no alpha(1)-antitrypsin. Despite the lack of clinical data, it is suspected that SDP may be less effective than FFP in the treatment of complex coagulopathies. We therefore conducted a prospective trial to study the impact of SDP and FFP on haemostasis and fibrinolysis in complex coagulopathy after open-heart surgery.

MATERIALS AND METHODS

Patients received either 600 ml of SDP (n = 36) or 600 ml of FFP (n = 31) at an infusion rate of 30 ml/min. The following parameters were measured before treatment and 60 min after termination of plasma infusion: prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, factor VIII, antithrombin, protein C (PC), free PS and PS activity, prothrombin fragments F1+2 (F1+2), D-dimers (DD), fibrinogen degradation products (FDP), plasmin-plasmin inhibitor complexes (PPI), plasminogen, PI and alpha(1)-antitrypsin.

RESULTS

The rise in fibrinogen, factor VIII, antithrombin, PC, free PS, alpha(1)-antitrypsin and plasminogen, and the decrease in PT and APTT, did not significantly differ between the two study arms. However, PS activity did not increase after SDP infusion but did show a significant elevation after infusion with FFP. PI declined significantly after SDP and remained uninfluenced by FFP. Neither SDP nor FFP had any significant influence on F1+2, DD or FDP. However, a significant decrease in PPI levels caused by both types of plasma indicated a reduction in hyperfibrinolysis. Clinical haemostasis evaluation revealed no significant difference between the two treatment regimens. No adverse reactions were observed.

CONCLUSION

With the exception of PS and PI, SDP and FFP improved haemostasis and fibrinolysis to a similar degree. The clinical significance of these findings has to be determined in patients with severe acquired PS and PI deficiency requiring plasma transfusions.

Inactivation of infectious pathogens in labile blood components: meeting the challenge

Substantial improvement in the safety of blood transfusion has been achieved through the addition of new tests, such as nucleic acid tests, yet residual risk associated with transfusion of blood components persists. Transfusion of blood components has been implicated in the transmission of viruses, bacteria, and protozoa. While it is commonly recognized that hepatitis B virus (HBV), hepatitis C virus (HCV), cytomegalovirus (CMV), and the retroviruses, such as human immunodeficiency virus (HIV) and the human lymphotrophic viruses (HTLV) can be transmitted through cellular components, other pathogens are emerging as potentially significant transfusion-associated infectious agents. For example, transmission of protozoan infections due to trypanosomes and babesia have been reported. In addition to viral and protozoal infectious agents, bacterial contamination of platelet and red cell concentrates continues to be reported; and may be an under-reported transfusion complication. More importantly, new infectious agents may periodically enter the donor population before they can be definitively identified and tested for to maintain consistent safety of the blood supply. The paradigm for this possibility is the HIV pandemic, which erupted in 1979. During the past decade a number of methods to inactivate infectious pathogens in labile blood components have been developed and have entered the advanced clinical trial phase.

Study of three patients with thrombotic thrombocytopenic purpura exchanged with solvent/detergent-treated plasma: is its decreased protein S activity clinically related to their development of deep venous thromboses?

Solvent/detergent treated plasma (S/DP) has reduced protein S activity (about 0.5 units/mL) as compared with fresh frozen plasma (FFP). When used as replacement fluid for repetitive therapeutic plasma exchange (PEX), e.g., in patients with thrombotic thrombocytopenic purpura (TTP), S/DP could lead to lowered protein S levels and, possibly, risk of hypercoagulable complications. We describe three patients with TTP who had low functional protein S (FPS) levels during PEX for TTP. Each developed one or more deep vein thromboses (DVTs) while receiving 100% S/DP or 50% S/DP and 50% cryosupernatant plasma (CSP) as replacement fluid. FPS levels rose when 100% CSP was substituted for S/DP. Our observations suggest that use of S/DP alone or in 50% combination with CSP as replacement fluid in PEX for TTP may lead to difficulty in maintaining safe FPS levels. Determination of risk of resulting clinically significant thrombotic events requires further study.