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?

Maintaining plasma quality and safety in the state of ongoing epidemic - The role of pathogen reduction

In the field of transfusion medicine, many pathogen reduction techniques (PRTs) are currently available, including those based on photochemical (PI) and photodynamic inactivation (PDI). This is particularly important in the face of emerging viral pathogens that may pose a threat to blood recipients, as in the case of the COVID-19 pandemic. However, PRTs have some limitations, primarily related to their adverse effects on coagulation factors, which should be considered before their intended use. A comprehensive search of PubMed, Wiley Online Library and Science Direct databases was conducted to identify original papers. As a result, ten studies evaluating fresh plasma and frozen-thawed plasma treated with different PI/ PDI methods and evaluating concentrations of coagulation factors and natural anticoagulants both before and after photochemical treatment were included in the review. The use of PI and PDI is associated with a significant decrease in the activity of all analysed coagulation factors, while the recovery of natural anticoagulants remains at a satisfactory level, variable for individual inactivation methods. In addition, the published evidence reviewed above does not unequivocally favour the implementation of PI/PDI either before freezing or after thawing as plasma products obtained with these two approaches seem to satisfy the existing quality criteria. Based on current evidence, if implemented responsibly and in accordance with the current guidelines, both PI and PDI can ensure satisfactory plasma quality and improve its safety.

Methylene blue-treated plasma, versus quarantine fresh frozen plasma, for acute thrombotic thrombocytopenic purpura treatment: Comparison between centres and critical review on longitudinal data

Introduction

Therapeutic plasma exchange (TPE) is the first-line treatment for acute thrombotic thrombocytopenic purpura (TTP). Methylene blue-plasma (MBP) has been used for over 20 years, but its efficacy in this setting remains controversial.

Patients and methods: this is a comparative analysis of the experience of two Centres, with different plasma products, to evaluate their efficacy in TTP. One centre used quarantine plasma (QP), and MBP the other. We performed a retrospective longitudinal study, analysing the clinical files of TTP patients of a 13-year data evaluation period. Duration of treatment and transfusion parameters, medical record, laboratory testing, concomitant medication, and survival rate, were assessed for every episode.

Results

During the study period, 12 (55.5 %) and 10 (45.5 %) new cases were treated with QP and MBP, respectively. There were no significant differences between the mean numbers of TPE processes, days elapsed from diagnosis to TPE, and plasma volume transfused. The QP TPE episodes of treatment were significantly associated with an increased time to recovery compared with MBP episodes of treatment (p = 0.004).

Conclusion

MBP was as effective as QP in the treatment of TTP patients. Since recovery was more favourable when MBP was used, we consider MBP remains a suitable alternative to treat TTP patients.

Solvent detergent treated pooled plasma and reduction of allergic transfusion reactions

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP) patients have increased risk for allergic transfusion reactions (ATR) due to the number of plasma products they require. This study evaluated the efficacy of solvent detergent treated plasma (S/D treated plasma) to reduce ATRs.

STUDY DESIGN AND METHODS

All TTP patients who presented from April 2014 to February 2015 and experienced a moderate-severe ATR to untreated plasma with TPE were switched to S/D treated plasma (Octaplas) for their remaining procedures and included in the study. Patient records were retrospectively reviewed.

RESULTS

The overall ATR rate per procedure decreased from 35.0% (95% CI = 15.4%-59.2%) with untreated plasma to 1.4% ([1/73] 95% CI = 0.0%-7.4%) with S/D treated plasma. The moderate-severe ATR rate decreased from 20.0% ([4/20] 95% CI = 5.7%-43.7%) with untreated plasma to 0.0% ([0/73] 95% CI = 0.0%-4.9%) with S/D treated plasma. The overall ATR rate per plasma unit decreased from 2.6% (95%CI = 1.0%-5.1%) with untreated plasma to 0.1% (95% CI = 0.0%-0.4%) with S/D treated plasma. No patients experienced VTE while receiving untreated plasma. Four patients experienced VTE events while receiving S/D treated plasma. All patients who experienced a VTE had additional risk factors for VTE.

CONCLUSION

S/D plasma has promise as an effective product to reduce the risk of ATRs in TTP patients. Given the high risk of ATR in TTP patients, consideration of S/D plasma instead of untreated plasma for TPE in these patients may be warranted, especially for patients with a history of moderate to severe ATR. More extensive studies are needed to confirm these findings.

Health Technology Assessment of pathogen reduction technologies applied to plasma for clinical use

Although existing clinical evidence shows that the transfusion of blood components is becoming increasingly safe, the risk of transmission of known and unknown pathogens, new pathogens or re-emerging pathogens still persists. Pathogen reduction technologies may offer a new approach to increase blood safety. The study is the output of collaboration between the Italian National Blood Centre and the Post-Graduate School of Health Economics and Management, Catholic University of the Sacred Heart, Rome, Italy. A large, multidisciplinary team was created and divided into six groups, each of which addressed one or more HTA domains.Plasma treated with amotosalen + UV light, riboflavin + UV light, methylene blue or a solvent/detergent process was compared to fresh-frozen plasma with regards to current use, technical features, effectiveness, safety, economic and organisational impact, and ethical, social and legal implications. The available evidence is not sufficient to state which of the techniques compared is superior in terms of efficacy, safety and cost-effectiveness. Evidence on efficacy is only available for the solvent/detergent method, which proved to be non-inferior to untreated fresh-frozen plasma in the treatment of a wide range of congenital and acquired bleeding disorders. With regards to safety, the solvent/detergent technique apparently has the most favourable risk-benefit profile. Further research is needed to provide a comprehensive overview of the cost-effectiveness profile of the different pathogen-reduction techniques. The wide heterogeneity of results and the lack of comparative evidence are reasons why more comparative studies need to be performed.

Thrombocytopenia in Critical Care Patients

Thrombocytopenia is a common laboratory finding in the intensive care unit (ICU) patient. Because the causes can range from laboratory artifact to life-threatening processes such as thrombotic thrombocytopenic purpura (TTP), identifying the cause of thrombocytopenia is important. In the evaluation of the thrombocytopenia patient, one should incorporate all clinical clues such as why the patient is in the hospital, medications the patient is on, and other abnormal laboratory findings. One should ensure that the patient does not suffer from heparin-induced thrombocytopenia (HIT) or one of the thrombotic microangiopathies (TMs). HIT can present in any patient on heparin and requires specific testing and antithrombotic therapy. TMs cover a spectrum of disease ranging from TTP to pregnancy complications and can have a variety of presentations. Management of disseminated intravascular coagulation depends on the patient’s condition and complication. Other causes of ICU thrombocytopenia include sepsis, medication side effects, post-transfusion purpura, catastrophic anti phospholipid antibody disease, and immune thrombocytopenia.

Comparative biochemical studies of fresh frozen plasma and pooled solvent/detergent-treated plasma (octaplasLG® ) with focus on protein S and its impact in different thrombin generation assay set-ups

BACKGROUND AND OBJECTIVES

The solvent/detergent treatment enables effective and robust inactivation of all lipid-enveloped viruses, but also inactivates partly sensitive plasma proteins such as protein S. The aim of this study was to investigate the thrombin generation capacity of octaplasLG^® , in particular focusing on the function of protein S in thrombin generation assay and the impact of assay settings.

MATERIALS AND METHODS

Sixteen octaplasLG^® batches and 32 units of single donor fresh frozen plasma (FFP) were investigated. For protein S, both functional activity and free antigen levels were measured. Thrombin generation assay was performed using two fluorogenic tests with different triggers. Finally, rotational thromboelastometry was performed.

RESULTS

Mean protein S levels were lower in octaplasLG^® , but a wider range of values was found for FFP. Clotting parameters and thrombin generation capacities overlapped between the two plasma groups as demonstrated using both thrombin generation assays and different triggers. Spiking studies with protein S-depleted plasma, human purified protein S or antibodies against protein S confirmed a correlation between protein S and thrombin generation capacity under specific assay conditions, especially in an assay with low tissue factor concentration.

CONCLUSION

Correlation between protein S and thrombin generation capacity was demonstrated in the TGA. Due to higher variability in protein S content in the FFP group, overlapping haemostatic potentials of the two plasma groups were found.

Solvent/detergent plasma: pharmaceutical characteristics and clinical experience

The solvent/detergent treatment is an established virus inactivation technology that has been industrially applied for manufacturing plasma derived medicinal products for almost 30 years. Solvent/detergent plasma is a pharmaceutical product with standardised content of clotting factors, devoid of antibodies implicated in transfusion-related acute lung injury pathogenesis, and with a very high level of decontamination from transfusion-transmissible infectious agents. Many clinical studies have confirmed its safety and efficacy in the setting of congenital as well as acquired bleeding disorders. This narrative review will focus on the pharmaceutical characteristics of solvent/detergent plasma and the clinical experience with this blood product.

Split Blood Products

The last 20 years have seen many advances in transfusion therapy and safety. Blood products are biological products engendering complex interactions with the immune system. Prestorage leukoreduction results in a reduced risk of febrile reactions, CMV transmission, and immune modulation, proving to be safer for patients than non-leuko reduced products.

Simple patient identification issues and clerical error continue to be the primary causes of ABO-incompatible transfusions. Rigorous donor screening as well as serologic and nucleic acid testing for transfusion transmitted infection have brought the blood supply to a very safe level, although transmission of these agents continues to be a problem in underdeveloped countries. Emerging infectious diseases, beyond current laboratory detection capabilities, combined with global travel, pose unknown imminent risks everywhere. We also briefly discuss the current risks of transfusion-transmitted infections.

We review currently available hemostatic blood products, their compositions, and their clinical indications; we mention product modifications currently in development; and we touch upon the hemostatic properties and drawbacks of whole blood, which is currently gaining popularity as an alternative to split blood products. We conclude with an in-depth overview of the risks associated with transfusion, including incompatibility, hemolytic transfusion reactions, transfusion-associated circulatory overload (TACO), and transfusion-related acute lung injury (TRALI).

Macrovascular thrombosis in critically ill patients with thrombotic micro-angiopathies

The purpose of this study is to assess the incidence and describe the clinical and pathological features of macrovascular thrombosis during the course of thrombotic micro-angiopathy (TMA) in a 6 year retrospective study of all adults with TMA, admitted to a teaching-hospital ICU. Of the 55 patients identified, all had anaemia and thrombocytopenia and 45 (82 %) had renal or neurological impairment. All patients received plasmapheresis, steroids, and strict blood pressure control. Macrovascular venous or arterial thromboses were diagnosed in 28 (51 %) patients; among them, 7 had cerebral artery thrombosis and 21 (including 13 with central venous catheters) had deep vein thrombosis. Median time from plasmapheresis initiation to thrombosis was 7 (4-10) days. Clinical findings were suggestive of deep venous thrombosis in 7 of the 21 patients (33 %) and only one of the 7 patients with stroke had corresponding clinical signs. By multivariate analysis, factors independently associated with macrovascular thrombosis were undetectable ADAMTS13 activity (odds ratio 7.33, 95 % confidence interval 1.3-41.3), cardiac involvement with TMA (odds ratio, 3.46; 95 % confidence interval, 1.1-13.9) and TMA flare (odds ratio 9.03; 95 % confidence interval 1.03-79.4). In conclusion, half of the patients with TMA experience macrovascular thrombosis. Patients with TTP-related ADAMTS13 deficiency and those with cardiac manifestations of TMA are at higher risk for arterial or deep venous thrombosis.

Advances in military, field, and austere transfusion medicine in the last decade

Two decades of war in south-west Asia has demonstrated the essential role of primary resuscitation with blood products in the care of critically injured soldiers. This idea has been widely adopted and is being critically tested in civilian trauma centers. The need for red cells, plasma and platelets to be immediately available in remote locations creates a logistic burden that will best be eased by innovative new blood products such as longer-stored liquid RBCs, freeze-dried plasma, small-volume frozen platelets, and coagulation factor concentrates such as fibrinogen concentrates and prothrombin complex concentrates. Such products have long shelf-lives, low logistic burdens of weight, fragility, or needs for processing prior to use. Developing and fielding a full family of such products will improve field medical care and make products available in the evacuation chain. It also will allow treatment in other austere environments such as the hundreds of small hospitals in the US which serve as Levels 3 and 4 trauma centers but do not currently have thawed plasma or platelets available. Such small trauma centers currently care for half of all the trauma patients in the country. Proving the new generation of blood products work, will help assure their widest availability in emergencies.

Pharmacologic reversal of warfarin-associated coagulopathy in geriatric patients with hip fractures: a retrospective study of thromboembolic events, postoperative complications, and time to surgery

PURPOSE

Patients with acute hip fractures who are on maintenance warfarin for anticoagulation present a significant challenge and their management remains controversial. The purpose of this study was to assess thromboembolic and systemic complications associated with pharmacological reversal of warfarin-associated coagulopathy in a population of geriatric patients with hip fractures.

METHODS

This retrospective cohort study identified patients with operative hip fractures on oral warfarin therapy who had an international normalized ratio (INR) >1.50 on admission (N = 93) approximately over a 13-year span. The control group consisted of patients whose warfarin was held upon admission without further intervention preoperatively (n = 23). The treatment group consisted of patients who underwent pharmacologic reversal of elevated INR with vitamin K and/or fresh frozen plasma (FFP) in addition to holding warfarin (n = 70). Primary outcomes included thromboembolic and other complications as well as mortality within 3 months of presentation. Time to surgery was a secondary outcome.

RESULTS

The 3-month mortality rate was 4% in the pharmacological intervention group and 17% in the watch-and-wait group; this difference trended toward statistical significance (P = .06). There were no significant differences in the likelihoods of other thromboembolic or nonthromboembolic complications between groups. While the difference in mean time to surgery was not significantly different overall between groups, this difference was significant in a subgroup of patients with higher baseline INRs (n = 46, INR >2.17), with a mean difference of 4.0 fewer days until surgery in the pharmacological intervention group (P < .01).

CONCLUSIONS

Pharmacological reversal of warfarin-associated coagulopathy with a combination of vitamin K and FFP appears to be a safe way to optimize patients for operative fixation of hip fractures and is associated with a shorter delay to surgery in patients with more elevated INRs preoperatively.

LEVEL OF EVIDENCE

retrospective cohort study (level III).

Evaluation of the hemostatic potential including thrombin generation of three different therapeutic pathogen-reduced plasmas

BACKGROUND AND OBJECTIVES

Several pathogen inactivation methods currently applied to therapeutic plasma may result in products with different hemostatic properties. This study aims at evaluating and comparing the hemostatic potential of different therapeutic plasma preparations currently available in France.

MATERIALS AND METHODS

We studied three types of pathogen-reduced plasma for transfusion (MB/light, Amotosalen/UVA, industrial S/D plasma). Quarantine, non-pathogen-reduced plasma, was used as a control. This study compared more specifically the content in FVIII, fibrinogen (clottable and antigen assays) and ADAMTS-13 and evaluated the intrinsic hemostatic properties using a thrombin generation test [Calibrated Automated Thrombogram (CAT)] at high and low concentrations of tissue factor to assess the maximum quantity of thrombin generated or the contribution of FVIII and FIX in the amplification phase of thrombin generation, respectively.

RESULTS

The median FVIII concentration was >70 IU/dl for each preparation. Endogenous thrombin potential values were significantly different among the methods of plasma preparation (P<0·001) but were all in the range of the values measured in donors' plasma. Control by the thrombomodulin-activated protein C system was preserved in all preparations (>50% inhibition of endogenous thrombin potential). Fibrinogen concentrations were all within normal range but fibrinogen levels were lower in the plasmas treated with photochemical methods. ADAMTS-13 levels were preserved.

CONCLUSION

The hemostatic potential appears well preserved in all therapeutic plasmas tested but there are some differences between preparations, the clinical relevance of which remains to be elucidated.

A comparison of methods of pathogen inactivation of FFP

INTRODUCTION

Current methods for pathogen inactivation of plasma involve four major processes using solvent-detergent (SD), methylene blue (MB), amotosalen and riboflavin as additives. Three of these methods involve the use of visible or ultraviolet light.

METHODS

A comparison of the four methods was made using publications in Medline, Pubmed, Embase and Biosis to obtain data on the logistics of use, the quality of the plasma proteins and the effectiveness of pathogen inactivation.

RESULTS

Three of the methods, MB, amotosalen and riboflavin, are designed for use in a blood bank; the SD method is generally applied at a centralized manufacturing centre and involves large plasma pools. All methods result in a reduction in protein values with the per cent retention of FVIII activity in the range of 67-78% and fibrinogen of 65-84%. Protein S and alpha(2)-antiplasmin are lower following solvent-detergent treatment. Alterations in fibrinogen structure have been reported with methylene blue.

DISCUSSION

Three of the methods are designed for small volume use in a blood bank. All four methods have some effect on the coagulant proteins; however, the final concentrations are within regulated limits. While there is variability in the effectiveness against pathogens, direct comparison is difficult because of the methodologies used. Nonetheless, all are effective in inactivating HIV and other lipid-enveloped pathogens. Clinical studies on the effectiveness of these products are surprisingly sparse, and no randomized clinical trials have yet been performed with amotosalen or riboflavin plasmas.

Proceedings of a Consensus Conference: pathogen inactivation-making decisions about new technologies

Significant progress has been made in reducing the risk of pathogen transmission to transfusion recipients. Nonetheless, there remains a continuing risk of transmission of viruses, bacteria, protozoa, and prions to recipients. These include many of the viruses for which specific screening tests exist as well as pathogens for which testing is currently not being done, including various species of bacteria, babesiosis, variant Creutzfeld-Jacob disease, hepatitis A virus, human herpes virus 8, chikungunya virus, Chagas disease, and malaria. Pathogen inactivation (PI) technologies potentially provide an additional way to protect the blood supply from emerging agents and also provide additional protection against both known and as-yet-unidentified agents. However, the impact of PI on product quality and recipient safety remains to be determined. The purpose of this consensus conference was to bring together international experts in an effort to consider the following issues with respect to PI: implementation criteria; licensing requirements; blood service and clinical issues; risk management issues; cost-benefit impact; and research requirements. These proceedings are provided to make available to the transfusion medicine community the considerable amount of important information presented at this consensus conference.

Cryosupernatant and solvent detergent fresh-frozen plasma (Octaplas) usage at a single centre in acute thrombotic thrombocytopenic purpura

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP) is an acute, life-threatening disorder and plasma exchange (PEX) remains the mainstay of treatment.

METHODS

We reviewed 50 acute TTP episodes to establish the efficacy and safety of cryosupernatant (CPP) and Octaplas.

RESULTS

Twelve episodes used CPP only and 15 episodes started with CPP and changed to Octaplas. Once Octaplas had been used, it was continued on further admissions. Cryosupernatant was used exclusively in 24% and Octaplas exclusively in 42% of all episodes. The number of citrate reactions and allergic (plasma) reactions were halved in those receiving only Octaplas compared with cryosupernatant. There were 22 line infections and in approximately 70% of cases the infection was associated with a reduction in platelet count. In all 50 episodes, the only documented thrombosis was a superficial non-central vein. In episodes receiving only cryosupernatant or Octaplas, there was no significant difference in the median number of PEX to remission, 7.0 (interquartile range, IQR 5-8.8) and 8.0 (IQR 6.5-22), respectively. Baseline viral screen in all episodes was negative after discharge following an acute episode.

CONCLUSION

There was no difference in number of PEX to remission with cryosupernatant and solvent/detergent fresh-frozen plasma (Octaplas). However, allergic/urticarial and citrate reactions were more common with cryosupernatant. There was no documented viral transmission with either product.

Coagulation function in fresh-frozen plasma prepared with two photochemical treatment methods: methylene blue and amotosalen

BACKGROUND

Pathogen inactivation of plasma intended for transfusion is now the standard of care in Belgium. Two methods for treatment of single plasma units are available: amotosalen plus ultraviolet A light and methylene blue plus visible light. This study compared the quality and stability of plasma treated with these two methods.

STUDY DESIGN AND METHODS

Plasma units made from a pool of two ABO-matched fresh apheresis units were photochemically treated with either amotosalen (PCT-FFP) or methylene blue (MB-FFP). A total of 12 paired samples were evaluated. Plasma coagulation function was assessed at three time points: immediately after treatment, after 30 days of frozen storage, and an additional 24 hours at 4 degrees C after thawing. Comparison between PCT-FFP and MB-FFP was assessed with the paired t test and a p value of less than 0.05 indicated statistical significance.

RESULTS

Based on statistical analysis, mean levels of factor (F)II, FXII, FXIII, von Willebrand antigen, ADAMTS-13, D-dimers, and protein C were equivalent between PCT-FFP and MB-FFP for all three time points. PCT-FFP exhibited shorter mean prothrombin time, activated partial thromboplastin time (two time points), and thrombin time and higher mean levels of fibrinogen, FXI, and protein S than MB-FFP. Retention of FV, FVII, FVIII, FX, or von Willebrand factor:ristocetin cofactor in PCT-FFP was either equivalent to or higher than MB-FFP. MB-FFP contained higher mean levels of plasminogen, antithrombin, and plasmin inhibitor than PCT-FFP. Retention of F IX in MB-FFP was higher than PCT-FFP only after the 4 degrees C storage after thawing.

CONCLUSION

There is adequate preservation of therapeutic coagulation factor activities in both PCT-FFP and MB-FFP. The overall coagulation factor levels and stability of PCT-FFP were better preserved than MB-FFP.

The effect of fibrinogen concentrate on thrombocytopenia

OBJECTIVES

The hypothesis that the administration of fibrinogen concentrate enables restoration of impaired clot formation and increased bleeding in severe thrombocytopenia was tested.

METHODS

Thirty pigs were anesthetized, instrumented for blood sampling (routine coagulation tests, modified thrombelastography ROTEM, hemodynamic monitoring and platelet apheresis to a target below 30 x 10(9) L(-1) after splenectomy. Thereafter 10 each of the animals randomly received two apheresis platelet concentrates, 250 mg kg(-1) fibrinogen concentrate or normal saline solution. A standardized liver injury was subsequently inflicted to induce uncontrolled hemorrhage.

RESULTS

Median (Q1, Q3) clot firmness increased significantly more in thrombocytopenic pigs after fibrinogen administration (42 mm (41, 43) to 60 mm (57, 63)) than following platelet transfusion (40 mm (37, 45) to 52 mm (48, 55), P = 0.0004) or placebo (45 mm (41, 48) to 45 mm (43, 46), P = 0.0002). Median blood loss velocity after liver injury was significantly less with fibrinogen (33 mL min(-1), P = 0.005) than with platelets (62 mL min(-1), P = 0.037) or saline (84 mL min(-1), P = 0.005), and median survival time after liver injury was 55 min in the fibrinogen, 26 min in the platelet (P = 0.035) and 19 min in the saline group (P = < 0.0001).

CONCLUSIONS

These data show for the first time that impaired clot formation during thrombocytopenia improves with administration of fibrinogen concentrate, which results in a slowdown of blood loss and prolonged survival.

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.

A randomized, controlled Phase III trial of therapeutic plasma exchange with fresh-frozen plasma (FFP) prepared with amotosalen and ultraviolet A light compared to untreated FFP in thrombotic thrombocytopenic purpura

BACKGROUND

Photochemical treatment of fresh-frozen plasma (FFP) with amotosalen and ultraviolet (UV) A light (PCT FFP) results in inactivation of a broad spectrum of pathogens while retaining coagulation factor activity, antithrombotic proteins, and von Willebrand factor-cleaving protease (VWF-CP) activity.

STUDY DESIGN AND METHODS

A randomized, controlled, double-blind Phase III trial was conducted with PCT FFP or control FFP for therapeutic plasma exchange (TPE) in patients with thrombotic thrombocytopenic purpura (TTP). Owing to the rarity of this diagnosis, the trial was not powered to demonstrate small differences between treatment groups. Patients were treated with study FFP for a maximum of 35 days until remission was achieved (for a maximum of 30 daily study TPEs with no remission) plus an additional 5 days after remission.

RESULTS

Among the 35 patients treated, the primary endpoint, remission within 30 days, was achieved by 14 of 17 (82%) PCT patients and 16 of 18 (89%) control patients (p = 0.658) The 90 percent confidence interval for treatment difference in remission rate for test - control was (-0.291 to 0.163). Time to remission, relapse rates, time to relapse, total volume and number of FFP units exchanged, and number of study TPEs were not significantly different between groups. Improvement in VWF-CP and inhibitors was similar for both groups. The overall safety profile of PCT FFP was similar to control FFP. No antibodies to amotosalen neoantigens were detected.

CONCLUSION

The comparable results between treatment groups observed from this small trial suggest that TPE with PCT FFP was safe and effective for treatment of TTP.

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.

Therapeutic apheresis: use of human serum albumin, fresh frozen plasma and cryosupernatant plasma in therapeutic plasma exchange

In therapeutic plasma exchange, patient plasma is removed and a colloid replacement solution is infused in its stead. A solution of 4-5% human serum albumin in saline is the recommended replacement solution in most instances, even though it leads to transient mild deficiencies of most plasma proteins. Albumin solutions are pasteurized to inactivate viruses, carry a very low risk of febrile and allergic reactions, and are convenient to store and administer. Fresh frozen plasma, which must be type specific and needs to be ordered in advance and thawed before use, carries a higher risk of reactions; however, it replaces all plasma constituents and is appropriate for patients with thrombotic thrombocytopenic purpura or a pre-existing coagulopathy. Neither cryosupernatant plasma, which is relatively depleted of the proteins in cryoprecipitate, nor pooled plasma that has been virally inactivated with organic solvents and detergents has been shown to be superior to fresh frozen plasma for any indication.