[Use of platelet concentrates: a regional experience]. / Utilisation des concentrés plaquettaires : expérience d'une région.

PURPOSE OF THE STUDY: The Établissement français du sang (EFS) distributes two types of platelet concentrates: using a single donor in aphaeresis platelet concentrate (SDAP), versus pooled platelet concentrates (PPC). A retrospective study performed by the Blood Derivatives Group at Observatory for Drugs, Medical Devices and Therapeutic Innovations (OMEDIT), in collaboration with EFS and haemovigilance correspondents from eight regional health care establishments, has analyzed platelet concentrates prescriptions and the position of the prescribers concerning PPC supply. MATERIAL AND METHODS: Between the 2nd and 6th June 2008, 151 platelet concentrates were supplied by ESF. Data were collected for 144 platelet concentrates and in 83 transfused patients with an average age of 50years. During this study, 33 PPC (23%) and 111 SDAP (77%) were supplied. RESULTS: With regards to the 111 SDAP, the supply of PPC was refused in 47 cases (42%), accepted in 18 cases (16%) and unknown for 46 cases (42%). A total of 51 PPC could be supplied during this period, which represented 35% of platelet concentrates prescriptions. The rate of platelets before transfusion was known for 121 platelet concentrates, the median was 32G·L(-1) for SDAP and 44G·L(-1) for PPC. CONCLUSION: More frequent PPC use, with comparable therapeutic efficacy, could be interesting in a context of increasing platelet concentrates consumption in health care establishments. Moreover, prescribers did not seem to be against the idea. An information pamphlet on platelet concentrates was drafted and distributed to prescribers in order to promote the prescription of PPC. A second assessment is planned to measure the impact of this communication.

[The contribution of persuasion social psychology to the retention of donors: models to elaborate mailing to the donors]. / La psychologie sociale de la persuasion au service de la fidélisation des donneurs: modèles de conception de messages d'invitation au don.

The supply of blood cell products required from the National French Blood Institute (Établissement français du sang [EFS]) relies upon regular blood donors. Contact with donors, tailored to individuals as much as possible, helps them to donate on a regular basis. To communicate as efficiently as possible, the content of the mailings has to be adapted to individuals, each according to his/her motivation and the way he or she perceives and processes the information. Within the context of a research program conducted with the Psychology Department of the University of Caen Basse-Normandie, persuasive theoretical models from social psychology have been tested. These models allow adapting messages according to various combinations of types of information processing, motivations and content of the messages. Different types of mailing invitations have been sent to 1987 donors from the Normandy database, requesting them to donate blood. Every experimental letter worked better than the standard EFS letter (which was used as the "control" letter) in terms of effective blood donation after reception of the letter. Some of the letters are more efficient in motivating donors than others. When the systematic type of processing (deep and thorough processing) is activated it appears important to supply elaborate content. On the contrary, when a heuristic type of processing (fast and superficial) is activated, adaptation of the content is less essential. Last but not least, the nearness of the last blood donation plays a key role.

[The contribution of persuasion social psychology to the retention of donors: the impact of labelling the previous donation]. / La psychologie sociale de la persuasion au service de la fidélisation des donneurs: l'importance de donner du sens au dernier don.

The supply of blood cell products requires from the National French Blood Institute (Établissement Français du Sang - EFS) to rely upon regular blood donors. Contact with donors, tailored to individuals as much as possible, helps them to donate on a regular basis. Within the context of a research program conducted with the Psychology Department of the Université de Caen Basse-Normandie, persuasive theoretical models from social psychology have been tested. These models allow adapting messages according to the motivation of donors. The content is centred on the previous donation, differently labelled according to two types of labelling: functional labelling and social labelling. Functional labelling points out the efficiency of what "has been done" (the previous blood donation), whereas social labelling emphasizes the social value of the individual. Different types of mailing invitations have been sent to 1917 donors from the Normandy database, invited to three different blood collections. Every experimental letter worked better than the standard EFS letter (which was used as the "control" letter) in terms of effective blood donation after reception of the letter. Some of the letters are more efficient in motivating donors than other ones. The letters labelling the previous blood donation as functional (efficiency of the donation) appeared more efficient than those with social label (social value) in whichever motivation induced.

Quality assessment of seven types of fresh-frozen plasma leucoreduced by specific plasma filtration.

BACKGROUND AND OBJECTIVES: A study was undertaken to determine plasma quality after specific filtration. MATERIALS AND METHODS: Seven types of plasma were tested, after filtration of plasma from filtered or non-filtered whole blood. Leucocyte counting was carried out after a 30-fold concentration of the sample. Twenty-nine parameters (including coagulation testing, proteins, coagulation factors and activation markers) were measured before and after filtration, and after 6 months of storage. RESULTS: After specific plasma filtration, the average residual leucocyte counts were less than 2250/l. In spite of small statistically significant changes in proteins, coagulation factors and complement activation, this study showed that plasma filtration did not alter plasma quality. After 6 months of storage at -30 degrees C, factor VIII recovery varied between 91 and 109%. Haemostasis parameters and activation markers remained within the normal range. CONCLUSIONS: Specific plasma filtration reduced the leucocyte number to < 104 leucocytes/l. The quality of plasma was not altered by the additional step of specific plasma filtration.

[Indications for labile blood products]. / Indications des produits sanguins labiles.

The aim of blood transfusion therapy is to supply specific labile products to patients in quality and in quantity. Different basic blood products are available: red blood cell concentrates, platelets concentrates and fresh frozen plasma, and according to their biological parameters, some of them can be selected and secondly adapted. Therefore, because some blood products are very rare and expensive, it is not possible to systematically use blood products having all the specifications. Also, it is necessary for clinicians to know blood product indications in order to avoid inadapted and abusive prescriptions inducing blood product unavailability damaging for other patients. The benefice risk ratio must be continuously measured, because these human products have some adverse effects: specially immunologic reactions and transfusion transmitted diseases. The systematic cell blood product leukoreduction since April 1st 1998 in France, allowed us to decrease these risks and to obtain a good tolerance. The hypothetical prion blood product transmission must be taken into consideration by plasma leukoreduction and limiting the blood product transfused number, in the respect of each specific clinical situation.

[Immuno-hemolytic transfusion reactions. III. Report of 61 cases]. / Les accidents immuno-hémolytiques transfusionnels. III. Etude de 61 cas.

Blood transfusion is mainly bound to immunological and infectious risks. The immunological risk originates from an incompatibility between the blood of the donor and that of the recipient; this risk remains insufficiently assessed. A multicentre study has been carried out by the French Blood Transfusion Society and the National Institute for Blood Transfusion. Sixty-one accidents due to an erythrocyte incompatibility were found: 26 cases with ABO incompatibility, and 35 cases with alloantibodies of other blood group systems. For the former category of accidents, the most frequent cause was due to a failure in the realization of the bedside ABO check. For the latter, the main problem was the achievement and the interpretation of antibody screening. The long term follow-up shows no chronic after-effects of immunological accidents. For each accident, errors have been identified and analysed. It was proven that they all originate from health care establishments.

Expression of a subclass of human blood group A antigenicity in A+ rabbit jejunum: specific glycosylation of the glycocalyx and a 140 K brush border glycoprotein.

A monoclonal antibody (14 A4) raised against human A erythrocytes has been produced. It specifically reacts with a subclass of human blood group A determinants. Whereas all the major secreted and membrane-bound glycoproteins of A+ rabbit jejunum epithelium bear human blood group A-like determinants recognized by anti-A polyclonal serum or a monoclonal antibody with broad specificity (Cl 3.3), expression of the A-subclass recognized by 14 A4 is very restricted. The contents of secretory granules of Paneth cells but not the mucins of goblet cells were labeled by 14 A4. In the enterocytes, glycans recognized by 14 A4 were present in the glycocalyx, on an early expressed 140 K glycoprotein of brush border membranes and also on a glycoconjugate of the basolateral membrane of immature crypt cells. In the jejunal brush border membrane of blood group A secretor humans, only one glycoprotein of molecular weight 140 K bears the A-subclass recognized by 14 A4.