Low incidence of hyperfibrinolysis and thromboembolism in 195 primary liver transplantations transfused with solvent/detergent-treated plasma.

BACKGROUND: Liver transplantation regularly requires transfusion of red blood cells (RBCs), plasma, and platelets. Compared to fresh frozen plasma (FFP) from single blood donors, solvent/detergent-treated plasma (SD-plasma) pooled from several hundred blood donors has advantages with respect to pathogen reduction, standardized content of plasma proteins, and significantly reduced risk of transfusion related lung injury and allergic/immunologic adverse reactions. However, SD-plasma has been suspected to increase the incidence of hyperfibrinolysis and thromboembolic events. STUDY DESIGN AND METHODS: We investigated the transfusion practices, hyperfibrinolysis parameters, and thrombosis outcomes in 195 consecutive adult primary liver transplants in our center using SD-plasma (Octaplas) as the exclusive source of plasma. RESULTS: Perioperatively, median (interquartile range) 4 (1 to 9) RBC-units, 10 (4 to 18) plasma-bags, and 0 (0 to 2) platelet-units were transfused. Hyperfibrinolysis defined as LY30 ≤ 7.5% was detected in 12/138 thrombelastography-monitored patients (9%). These patients received significantly more RBCs, plasma, and platelets than did patients without hyperfibrinolysis. Thrombotic graft complications were observed in three patients (2%). Pulmonary embolism was not observed in any patient. CONCLUSION: SD-plasma is a safe plasma product for liver transplant recipients, and the incidences of hyperfibrinolysis and thromboembolic events are not significantly different from those seen in centers using FFP.

The Use of Solvent/Detergent Treatment in Pathogen Reduction of Plasma.

The solvent/detergent (SD) process used for plasma can safely inactivate all lipid-enveloped viruses. The introduction of a specific prion-binding ligand gel in combination with SD treatment, time-reduced from 4 to 1-1.5 h, still ensures efficient virus kill, reduces abnormal prion protein by >5 log steps, and preserves levels of plasmin inhibitor at close to the reference range. Infections with known non-enveloped viruses such as HAV or parvovirus B19 are prevented by ensuring low virus loads in the starting plasma units, dilution through pooling of single plasma units, and neutralization of immune antibodies already present in the initial plasma pools. The major advantages of SD plasma over fresh frozen plasma and the other pathogen-inactivated plasmas are its extreme safety with respect to transfusion-related acute lung injury and the significantly lower likelihood of provoking allergic reactions. Both advantages are best interpreted as results of the dilution effect of pooling. No fewer than 18 clinical studies covering all indications for plasma, and extensive clinical experience have shown that reduced levels of coagulation factors and inhibitors as a result of SD treatment do not impair significantly the clinical efficacy or tolerance of plasma. Properly standardized clotting factor and inhibitor potencies and low batch-to-batch variations when compared with single-donor plasma units makes SD plasma more suitable for standardized treatment.

Indications for use and cost-effectiveness of pathogen-reduced ABO-universal plasma.

PURPOSE OF REVIEW: Donor selection and viral screening methods combined with pathogen reduction have increased the safety of pooled plasma to a level which makes reintroduction of ABO-universal plasma an important option. RECENT FINDINGS: Solvent detergent-treated pooled plasma has proved to be well suited for the production of pathogen-reduced ABO-universal plasma. One such product, Bioplasma FDP, was licensed in South Africa in 1994 and has since 1996 been in successful clinical use. A clinical study with this product and two studies with the European product, Uniplas, have confirmed the efficacy and safety of pathogen-reduced ABO-universal plasma. SUMMARY: Pooling of plasma enables the production of ABO-universal plasma. Pathogen reduction with solvent detergent eliminates lipid-enveloped viruses, whereas neutralizing antibodies in the plasma pool and nucleic acid amplification testing ensures the safety for recognized nonlipid-enveloped viruses. Pooling also eliminates transfusion-associated acute lung injury (the leading cause of plasma transfusion-related death), reduces immunologic/allergic adverse events by 60-80% and standardizes plasma protein content. Thus, in addition to ABO compatibility, pathogen-reduced ABO-universal plasma has important supplementary benefits that improve the product's cost-effectiveness.

Pathogen reduction of blood components.

Thanks to many blood safety interventions introduced in developed countries the risk of transfusion transmitted infections has become exceedingly small in these countries. However, emerging pathogens still represent a serious challenge, as demonstrated by West Nile virus in the US and more recently by Chikungunya virus in the Indian Ocean. In addition bacterial contamination, particularly in platelets, and protozoa transmitted by blood components still represent sizeable risks in developed countries. In developing countries the risk of all transfusion transmitted infections is still high due to insufficient funding and organisation of the health service. Pathogen reduction of pooled plasma products has virtually eliminated the risk of transfusion transmitted infections, without compromising the quality of the products significantly. Pathogen reduction of blood components has been much more challenging. Solvent detergent treatment which has been so successfully applied for plasma products dissolves cell membranes, and can, therefore, only be applied for plasma and not for cellular blood components. Targeting of nucleic acids has been another method for pathogen inactivation of plasma and the only approach possible for cellular blood products. As documented in more than 15 year's track record, solvent detergent treatment of pooled plasma can yield high quality plasma. The increased risk for contamination by unknown viruses due to pooling is out weighed by elimination of TRALI, significant reduction in allergic reactions and standardisation of the product. Recently, a promising method for solvent detergent treatment of single donor plasma units has been published. Methylene blue light treatment of single donor plasma units has a similar long track record as pooled solvent detergent treated plasma; but the method is less well documented and affects coagulation factor activity more. Psoralen light treated plasma has only recently been introduced (CE marked in Europe, but not licensed by the FDA), while the method of Riboflavin light treatment of plasma still is under development. In addition to pathogen reduction the methods, however, result in some reduction of coagulation factor activity. For platelets only Psoralen and Riboflavin light treatment have been implemented. Both are CE marked products in Europe but only approved for clinical trials in the USA. The methods affect platelet activity, but result in clinically acceptable platelets with only slightly reduced CCI and increased demand for platelet transfusions. Pathogen reduction of red blood cells with FRALE (S-303) or INACTINE (PEN110) has so far resulted in the formation of antibodies against neo-epitopes on red blood cells. A promising method for Riboflavin treatment of red blood cells is under development. This manuscript reviews the current experience and discusses future trends.

The six questions of pathogen reduction technology: an overview of current opinions.

The current measures to ensure blood safety include: donor selection, conventional serology testing for infectious markers by ELISA and NAT, leukoreduction, UV/Gamma irradiation and pathogen reduction technologies (PRT). These measures offer some conceptual assurance on continual improvement in blood safety, but with respect to PRT, there are at least six unresolved questions [6 Qs] that still need to be addressed to make them universally acceptable. The current status of PRT for plasma, platelets and red blood cells is explored through comparative analyses, in tabulated format, to help in answering the questions posed by the authors of this overview.

Current opinions on safer red cell transfusion practice and the appropriate use of alternative strategies.

This report summarizes the need for changes in certain areas of transfusion practice that may have some beneficial effect in improving transfusion safety and reducing the ever increasing demand for the use of red blood cells. These dual objectives can be achieved through a continuous educational and quality awareness program, encouraging the use of other available alternatives, including implementation of transfusion triggers reducing hemoglobin values, increased application of peri-operative/post-operative blood salvage, introduction of improved additive solutions and apheresis double dose RBC with a standardized hemoglobin content per unit; and changes in the clinical/laboratory practices, in particular when preparing patients for surgery. It is only through continuous education integration of better diagnosis/development/research and clinical practices in targeted patients that one can anticipate making a true contribution to the plodding and controversial issue of predicting transfusion safety and the cost benefit value of alternative strategies for transfusion. The current opinions on "safer transfusion" through the use of currently available alternatives are highlighted with the goal of promoting the use of transfusion alternatives in everyday clinical practice.

Universal pathogen-reduced plasma in elective open-heart surgery and liver resection.

ABO-incompatible transfusions and transfusion-related lung injury are today the leading transfusion-related causes of death in the developed world. Since anti-A and anti-B antibodies in plasma can give rise to serious, even fatal, transfusion reactions, ABO-identical/compatible plasma is indicated, but presents a logistical challenge and a risk for transfusion of incorrect plasma. In an effort to circumvent these problems, an ABO-independent universally applicable, pathogen-reduced plasma, Uniplas, has been developed and proven safe and efficacious for use in adults through prospective, randomized, controlled open-heart surgery studies and in prospective, parallel group, controlled liver resection studies. The results of these trials are presented and discussed in relation to solvent/detergent (SD) treated plasma, in general. The cost effectiveness of pathogen-reduced plasma is low because of the very low risk for transfusion transmitted viral infections in the developed world (US 2 to 9 million dollars per quality-adjusted life year). However, taking into account the combined safety of Uniplas with regard to transfusion-related lung injury, pathogen reduction and independence of ABO blood groups, the cost per gained life year is reduced to US 40,000 dollars to 100,000 dollars.

Microchimerism in immune competent patients related to the leukocyte content of transfused red blood cell concentrates.

BACKGROUND: Microchimerism may play a part in transfusion complications. The aim of this study was to examine whether establishment of post-transfusion microchimerism was related to leukocyte content. METHODS: Twenty non-pregnant female patients, without known malignant or immunological diseases, mean age 68 years, receiving 2-4 units of red blood cell concentrates during elective surgery, were included. One or two of the units were from male donors. Ten patients received buffy-coat depleted red blood cell concentrates, leukocyte count 108-109 per unit, and 10 patients received red blood cells leukoreduced by prestorage leukocyte filtration, with a leukocyte count of <106 per unit. EDTA samples were collected in vacuum tubes before and after 1 week and 6 months after transfusion. The tubes were frozen and stored at -400 degrees C. Genomic DNA was isolated and PCR performed using four primer sets amplifying markers on the Y-chromosome. RESULTS: Microchimerism was detected in a total of eight out of the 20 patients. In three patients microchimerism was detected only before transfusion. These patients had given birth to one or two boys each, and had no history of previous transfusion. Two patients receiving buffy-coat depleted red blood cell concentrates and two patients receiving leukoreduced red blood cell concentrates had detectable microchimerism 1 week after transfusion. The age of the transfused red blood cell concentrates was 6, 24, 8 and 7 days, respectively. One patient receiving leukoreduced red blood cell concentrates had detectable microchimerism after 6 months. The age of this concentrate was 22 days. DISCUSSION: This study demonstrates that microchimerism after transfusion does not seem to be dose dependent, and can be induced even by a >3 week old leukoreduced red blood cell concentrate with a very low leukocyte content.

Universal fresh frozen plasma (Uniplas): a safe product in open-heart surgery.

OBJECTIVE: To test the tolerability and safety of the universal plasma Uniplas [solvent/detergent (SD)-treated plasma], infused regardless of the patient's blood group. DESIGN: Prospective, parallel group, controlled and observer-blinded study, randomized with respect to patients requiring plasma transfusion. SETTING: Cardiothoracic operating room and ICU in a university hospital. PATIENTS: Eighty-four patients undergoing open-heart surgery comparing three parallel treatment groups and one control group. INTERVENTIONS: The Uniplas treatment group was subdivided into patients with blood group A, B or AB, and group O. The treatment group receiving Octaplas of type AB, was not subdivided. Patients who did not require any plasma transfusion served as control. MEASUREMENTS: Complement activation (C3bc, TCC), direct antiglobulin test (DAT) and other immunohaematological tests, tests for haemolysis, and relevant clinical observations during treatment phase. Blood samples were collected again after 6 months for evaluation of viral safety. RESULTS: Of the 84 patients, 29 served as control group. Uniplas was transfused in 36 of the patients (1-23 units). Octaplas was transfused in 19 patients (1-11 units). During the study no clinical adverse events related to plasma transfusion were observed. The degree of complement activation C3bc and TCC, a recommended test for biocompatibility, did not show any increased activation after Uniplas or Octaplas transfusion. No haemolytic reactions, positive DAT-tests or viral transmissions were observed after Uniplas transfusion. CONCLUSION: In open-heart surgery, Uniplas, which can be transfused regardless of a patient's blood group, was well-tolerated and gave no adverse drug reactions.

Donor lymphocytes transferred with the graft to kidney recipients. Potential for establishing microchimerism.

After solid organ transplantation donor lymphocytes have been shown to survive and multiply in the organ recipient for a prolonged period. It is not clear whether this chimerism detected is the result of immunosuppression or the cause of allograft acceptance. The number of cells transferred, as well as the type of cells, and the degree of activation are likely to be of importance for the establishment of microchimerism. The cells that are flushed out of the vascular tree may be of particular importance since when an antigen primarily bypasses or secondarily avoids organised lymphoid collections, the immune system in the recipient may remain or become "indifferent" to its presence. In the present study we examined the amount of residual donor blood cells that we could flush out from the vascular tree of living donor kidneys and cadaveric donor kidneys immediately prior to transplantation, with special emphasis on T and B lymphocytes. Our study shows that perfusion of donor kidneys just prior to transplantation releases from 0.1 to 1.8x10(6) B-lymphocytes, with an average of 0.7x10(6) and from 0.5x10(6) to 2.6x10(6) T-lymphocytes, with an average of 1.8x10(6), for CD kidneys, and somewhat less for LD kidneys. These cells would otherwise have been flushed out into the organ recipient's circulation, where they might play a role in the establishment of microchimerism.

Practical guidelines for the clinical use of plasma.

Despite differences in the composition of fresh frozen plasma (FFP) and solvent/detergent-treated plasma, prospective controlled clinical trials have not revealed any significant difference in clinical efficacy and tolerance between the two types of plasma. Evidence of the clinical efficacy of plasma is mainly based on expert opinion, case reports, and on controlled and uncontrolled observational studies. The application of plasma without laboratory analysis to verify the coagulopathy is normally not justified. With the exception of emergency situations when timely clotting assay results are not available, the administration of plasma in coagulopathy must be verified both clinically and by laboratory analysis before plasma is administered. The rapid infusion of at least 10 ml plasma/kg of body weight is required to increase the respective plasma protein levels significantly. Based on the present state of knowledge, plasma is indicated for complex coagulopathy associated with manifest or imminent bleeding in massive transfusion, disseminated intravascular coagulation, and liver disease. Therapeutic plasma exchange with 40 ml plasma/kg of body weight is the treatment of first choice in acute thrombotic-thrombocytopenic purpura-adult hemolytic uremic syndrome (TTP-HUS). A rare indication is the treatment or prevention of bleeding in congenital factor V or factor XI deficiency, plasma exchange in neonates with severe hemolysis or hyperbilirubinemia, and filling of the oxygenator in extracorporeal membrane oxygenation (ECMO) in neonates. Prothrombin complex concentrates should be preferred to plasma for the reversal of oral anticoagulation in emergency situations, since controlled studies have shown a minor efficacy of plasma. Side effects resulting from the administration of plasma are rare but have to be considered.