Comparison of the Hemostatic Efficacy of Pathogen-Reduced Platelets vs Untreated Platelets in Patients With Thrombocytopenia and Malignant Hematologic Diseases: A Randomized Clinical Trial

IMPORTANCE

Pathogen reduction of platelet concentrates may reduce transfusion-transmitted infections but is associated with qualitative impairment, which could have clinical significance with regard to platelet hemostatic capacity.

OBJECTIVE

To compare the effectiveness of platelets in additive solution treated with amotosalen-UV-A vs untreated platelets in plasma or in additive solution in patients with thrombocytopenia and hematologic malignancies.

DESIGN, SETTING, AND PARTICIPANTS

The Evaluation of the Efficacy of Platelets Treated With Pathogen Reduction Process (EFFIPAP) study was a randomized, noninferiority, 3-arm clinical trial performed from May 16, 2013, through January 21, 2016, at 13 French tertiary university hospitals. Clinical signs of bleeding were assessed daily until the end of aplasia, transfer to another department, need for a specific platelet product, or 30 days after enrollment. Consecutive adult patients with bone marrow aplasia, expected hospital stay of more than 10 days, and expected need of platelet transfusions were included.

INTERVENTIONS

At least 1 transfusion of platelets in additive solution with amotosalen-UV-A treatment, in plasma, or in additive solution.

MAIN OUTCOMES AND MEASURES

The proportion of patients with grade 2 or higher bleeding as defined by World Health Organization criteria.

RESULTS

Among 790 evaluable patients (mean [SD] age, 55 [13.4] years; 458 men [58.0%]), the primary end point was observed in 126 receiving pathogen-reduced platelets in additive solution (47.9%; 95% CI, 41.9%-54.0%), 114 receiving platelets in plasma (43.5%; 95% CI, 37.5%-49.5%), and 120 receiving platelets in additive solution (45.3%; 95% CI, 39.3%-51.3%). With a per-protocol population with a prespecified margin of 12.5%, noninferiority was not achieved when pathogen-reduced platelets in additive solution were compared with platelets in plasma (4.4%; 95% CI, -4.1% to 12.9%) but was achieved when the pathogen-reduced platelets were compared with platelets in additive solution (2.6%; 95% CI, -5.9% to 11.1%). The proportion of patients with grade 3 or 4 bleeding was not different among treatment arms.

CONCLUSIONS AND RELEVANCE

Although the hemostatic efficacy of pathogen-reduced platelets in thrombopenic patients with hematologic malignancies was noninferior to platelets in additive solution, such noninferiority was not achieved when comparing pathogen-reduced platelets with platelets in plasma.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01789762.

A prospective, active haemovigilance study with combined cohort analysis of 19,175 transfusions of platelet components prepared with amotosalen-UVA photochemical treatment

BACKGROUND AND OBJECTIVES

A photochemical treatment process (PCT) utilizing amotosalen and UVA light (INTERCEPT(™) Blood System) has been developed for inactivation of viruses, bacteria, parasites and leucocytes that can contaminate blood components intended for transfusion. The objective of this study was to further characterize the safety profile of INTERCEPT-treated platelet components (PCT-PLT) administered across a broad patient population.

MATERIALS AND METHODS

This open-label, observational haemovigilance programme of PCT-PLT transfusions was conducted in 21 centres in 11 countries. All transfusions were monitored for adverse events within 24 h post-transfusion and for serious adverse events (SAEs) up to 7 days post-transfusion. All adverse events were assessed for severity (Grade 0-4), and causal relationship to PCT-PLT transfusion.

RESULTS

Over the course of 7 years in the study centres, 4067 patients received 19,175 PCT-PLT transfusions. Adverse events were infrequent, and most were of Grade 1 severity. On a per-transfusion basis, 123 (0.6%) were classified an acute transfusion reaction (ATR) defined as an adverse event related to the transfusion. Among these ATRs, the most common were chills (77, 0.4%) and urticaria (41, 0.2%). Fourteen SAEs were reported, of which 2 were attributed to platelet transfusion (<0.1%). No case of transfusion-related acute lung injury, transfusion-associated graft-versus-host disease, transfusion-transmitted infection or death was attributed to the transfusion of PCT-PLT.

CONCLUSION

This longitudinal haemovigilance safety programme to monitor PCT-PLT transfusions demonstrated a low rate of ATRs, and a safety profile consistent with that previously reported for conventional platelet components.

Impact of leucocyte depletion and prion reduction filters on TSE blood borne transmission

The identification in the UK of 4 v-CJD infected patients thought to be due to the use of transfused Red Blood Cell units prepared from blood of donors incubating v-CJD raised major concerns in transfusion medicine. The demonstration of leucocyte associated infectivity using various animal models of TSE infection led to the implementation of systematic leuco-depletion (LD) of Red Blood cells concentrates (RBCs) in a number of countries. In the same models, plasma also demonstrated a significant level of infectivity which raised questions on the impact of LD on the v-CJD transmission risk. The recent development of filters combining LD and the capture of non-leucocyte associated prion infectivity meant a comparison of the benefits of LD alone versus LD/prion-reduction filters (LD/PR) on blood-borne TSE transmission could be made. Due to the similarity of blood/plasma volumes to human transfusion medicine an experimental TSE sheep model was used to characterize the abilities of whole blood, RBCs, plasma and buffy-coat to transmit the disease through the transfusion route. The impact of a standard RBCs LD filter and of two different RBCs LD/PR prototype filters on the disease transmission was then measured. Homologous recipients transfused with whole-blood, buffy-coat and RBCs developed the disease with 100% efficiency. Conversely, plasma, when intravenously administered resulted in an inconstant infection of the recipients and no disease transmission was observed in sheep that received cryo-precipitated fraction or supernatant obtained from infectious plasma. Despite their high efficacy, LD and LD/PR filtration of the Red Blood Cells concentrate did not provide absolute protection from infection. These results support the view that leuco-depletion strongly mitigates the v-CJD blood borne transmission risk and provide information about the relative benefits of prion reduction filters.

[Automation in the preparation of labile blood products]

The preparation of labile blood products in a blood bank is in permanent technological progress. Many operations, such as blood centrifugation, components separation, etc. are now performed by automated devices. A new generation of equipments is able to prepare blood products by reducing the number of manual operations. Therefore, buffy-coat platelet concentrate preparation and whole blood preparation can be prepared by these automated systems. Consequently, this directly impacts working conditions of employees, quality of blood products and process management.

[Evolution of techniques for preparation of labile blood products (LBP): pathogen inactivation in LBP]

The techniques for inactivation of pathogens in labile blood products (LBP) would appear to be the new strategy which will permit us to increase transfusion safety in the face of the risks of transmission of pathogenic agents by LBP. Various methods are in the course of development or already validated and used in France. The latter only apply however to plasma or platelet concentrates. The mechanisms of action and the efficacy of inactivation and attenuation of pathogenic agents vary with the different techniques. Each of these constitutes a preparative procedure composed of unit steps which have to be fully mastered in order to ensure the quality and transfusion efficacy of the treated product.

Introduction en pratique transfusionnelle des concentrés de plaquettes en solution de conservation

Platelet additive solutions (PAS) have been developed since the years 1980. However, decisive improvements have been made in the last five years, leading nowadays to several PAS available for transfusion practice. Few compounds are present in PAS, with the intention of controlling platelet metabolic alterations and activation that occur during storage: acetate, which is a substrate for the tricarboxylic acid cycle, enables to maintain oxidative metabolism, is present in all PAS; a buffer effect is required to prevent the progressive pH fall during storage, and is obtained either with sodium phosphate or gluconate; platelet activation is controlled by citrate, and in the latest PAS, by magnesium and potassium. It is important to note that whatever the PAS used, it is mandatory to maintain a final concentration of 20-40% of plasma, mainly in order to ensure glucose availability. The use of PAS leads to a more rationalized blood processing, as it provides an additional volume of plasma available for plasma fractionation, it contributes to standardization of blood components, and it is part of at least one pathogen reduction process. The expected benefit for patient is the reduction of adverse reactions related to plasma. There is already evidence that the incidence of allergic adverse reactions is reduced. In the case of other less frequent adverse reactions such as transfusion related acute lung injury (TRALI) or haemolytic reaction due to minor ABO incompatibility, only a long-term follow-up through haemovigilance organization will be informative.

[Discovery of a chronic HVC infection without seroconversion in a blood donor in France during 28 months]

The HCV-RNA screening technique developed by the French Fractionation and Biotechnology Laboratory singled out in March 1998 a case of positive HCV-RNA viremia in a blood donor without any anti-HCV antibody. That donor was a 46-year-old woman who had made 54 donations of blood products from 1988 to 1997. She had no history of blood transfusion, no history of hepatitis and no life-style risk factor. Clinical examination was normal. Liver tests (serum alanine amino transferases, gamma glutamyl transpeptidase , alkaline phosphatase, bilirubin , prothrombin and albumin) were normal. Total blood count was normal. Lymphocyte count was normal as well as in vitro functional analysis of lymphocytes (stimulation with different antigens). All screening HCV Elisa tests and immunoblot System available on the French market were unable to detect anti-HCV antibodies. Quantification of serum HCV-RNA (Amplicor Monitor Roche) showed 294,000 copies/mL and HCV genotype 1b determination was performed using Innolipa assay. Further examination of the HCV genotype by direct sequencing of the PCR product showed a classical 1b genotype sequence. The hemovigilance inquiry identified 25 labile products distributed since 1988. Analyzing the records of the recipients that have so far been traced and identified revealed three periods: 1997 to 1995: three recipients were found to be positive for anti-HCV antibodies; two are now cured of hepatitis C. In one recipient, direct sequencing after specific PCR of the hypervariable region coding for the envelope domain showed 100% homology with the donor; 1993 to 1990: four recipients were identified and traced without contamination; in 1988: three of four blood product recipients were anti-HCV negative without HCV-RNA viremia. The forth carried anti-HCV antibodies and genotype 1b HCV-RNA but had a history of multiple surgery. Alter et al. [4] and Bush et al. [5] have previously suggested the possibility of a chronic, immunologically silent state of infection. The case described herein, is the first evidence for this hypothesis. Indeed, the donor has not yet seroconverted 28 months after viremia was discovered. This blood donor was identified by HCV-RNA screening of plasma products. The identification of the same sequence in a recipient of blood from this donor clearly establishes the transmission of the virus by transfusion. The prevalence of such cases of infectious silent chronic HCV carriers has to be determined and the mechanisms responsible for the absence of antibody production need to be clarified.

[Biomechanical study of the vasomotor system of the arterial smooth muscle after long-term cryopreservation of a human arterial graft at two different temperatures -80 and -150C]

We conducted two parallel studies on cryopreserved arterial homografts: a biomechanical study based on traction tests and a functional study coupled with a histology examination. Twenty-four arterial segments from 6 donors (2 iliac and 2 superficial femoral segments per donor) were cryopreserved at -150 degrees C and -80 degrees C. Cryopreservation lasted at least 6 months. Lengthening at rupture, the Young elasticity module, and rupture stress were calculated from the traction test. Results were significantly different depending on the preservation temperature. The functional properties of the cryopreserved arterial grafts were evaluated by studying the vasomotricity capacity of the vascular smooth muscle (VSM) and the endothelium. The expected results (direct contracture of VSM induced by PHE and endothelial dependent relaxation of VSM induced by ACH) were measured on fresh arteries. Cryopreserved arteries showed no response to physiological doses of PHE and ACH, whatever the preservation temperature. In one-third of the cases, a lower amplitude vasoconstriction was obtained using nonphysiological doses of PHE; there was no relaxation with ACH.

[Evaluation of the cost of autologous erythrocyte concentrates in a hospital]

This study evaluated the cost of autologous and homologous blood products. The cost effectiveness of the transfusion therapy was not evaluated. To compare the different products, the cost of one gram of transfused haemoglobin was calculated. Acute normovolaemic haemodilution is the most economical technique. Intraoperative autologous transfusion without washing is the most expensive. All blood products from the autologous techniques, except the latter, were less expensive than homologous red cells.

[Rheologic and cytologic study of autologous blood collected with Cell Saver 4 during cesarean]

Intra-operative autologous transfusion has been frequently used in vascular and traumatic surgery for about ten years. The technique would be justified in other procedures when intra-operative bleeding is significant and the quality of retrieved blood is satisfactory. We have studied the potential use of intra-operative autologous transfusion during caesarean section of 15 parturients. The quality of autologous blood (at different stages of the procedure) was assessed after being recovered and washed by "Cell Saver 4" (Haemonetics). Blood quality was assessed through 1) measuring the following: erythrocyte deformability with Erythrometer and Hemorheometer; blood and plasma viscosities; ATP, 2.3 DPG and plasma hemoglobin rates; and RBC morphology through SEM; 2) bacterial detection and identification; 3) detection of foetal cells which could create immunological disturbances if reinjected into the mother. The results showed: 1) little variation in RBC deformability properties with ATP and 2.3 DPG rates which, apart from a slight decrease, remained within the normal range; 2) a 20 fold increase in plasma hemoglobin persisting, despite successive washes, in 80% of cases; 3) positive Staphylococcus epidermidis hemoculture clinically irrelevant in the reinjectable bag in 90% of cases; 4) close to 1% foetal cells in the reinjectable bag in 20% of cases; 5) 8% abnormal cells as seen on SEM (Stage I echinocytes) and a slight swelling of the RBCs, which could account for their fragility. These preliminary results show that intraoperative autologous transfusion could be used in obstetrical surgery, provided that certain precautions are taken to minimize the aforesaid drawbacks.

Prevention of HLA immunization with leukocyte-poor packed red cells and platelet concentrates obtained by filtration

HLA immunization is a common complication of transfusion therapy in 30% to 60% of oncohematologic patients. Evidence shows that leukocytes present in cellular blood products are the main component involved in the occurrence of HLA immunization, and several studies showed that leukocyte-poor blood products are less able to induce it. However, leukocyte-poor platelet concentrates obtained by conventional techniques, ie, centrifugation, frequently have a high level of remaining leukocytes. Cotton wool filter Imugard IG 500 can be used to obtain leukocyte-poor cellular blood products. The technique is easy to perform, even in an emergency, and can be used with either packed RBCs or platelet concentrates. Means of 97%, 92%, and 76% elimination of leukocytes are obtained for packed RBCs, pooled standard platelet concentrates, and single-donor platelet concentrates, respectively. Patients were randomized to receive either standard (control group) or filtered (leukocyte-poor group) blood products. Of 112 randomized patients, 69 were evaluable, 35 in the control group and 34 in the leukocyte-poor group. Both groups are comparable according to age, diagnosis, sex ratio, previous transfusions, and pregnancies. There is a significant difference in regard to the HLA immunization rate (31.4% in the control v 11.7% in the leukocyte-poor group, P less than .05) and frequency of refractoriness to platelet transfusions (46.6% v 11.7%, P less than .05). We conclude that this filtration technique can be an efficient means to reduce the HLA immunization rate in polytransfused oncohematologic patients.

A new method for monitoring the sterility of blood donation

Sterility of blood products is a cardinal contributor to patient safety. Bacteriologic controls of stable products comply with strict regulations, but legislation imposes only limited constraints in the case of perishable products, such as packed red cells (RBCs) or fresh-frozen plasma (FFP). Therefore, it is essential to monitor the sterility of aseptic donations from uninfected donors. Such bacteriologic monitoring can now be carried out through a tertiary bag (containing a soybean casein culture medium) connected to the classical double-pack system. This system does not jeopardize the sterility of the whole system, as the connection is tightly stoppered by a membrane. After the blood drawing, this tertiary bag is filled with 5 ml of blood, and separated from the rest of the system. It is then incubated for 3 days at 30 degrees C and for 14 days at 22 degrees C, to test for eventual bacteriologic or fungal contamination. In order to check the feasibility of this technique, we studied 76 blood drawings in the control laboratory of the blood center, and the results confirm the value of this system.