Dominique Legrand

HLA-DRB1 alleles and Jka immunization

BACKGROUND: In transfusion medicine, anti‐Jka has been implicated in hemolytic transfusion reactions. Development of anti‐Jka after transfusion does not always occur after Jk(a–) patients receive at least 1 unit of Jk(a+) blood unit. This study was designed to identify HLA‐DRB1 alleles associated with predisposition to Jka immunization after blood transfusion or pregnancy.

Analysis of ABO discrepancies occurring in 35 French hospitals.

BACKGROUND:  The risk of immunohemolytic reaction owing to ABO‐mismatched mistransfusion is 100 to 1000 times higher than the risk of viral infection. Like analysis of incident reports, evaluation of near‐miss events can provide useful insight into hazardous situations for mis‐matched blood transfusion. The aim of this prospective study was to assess the incidence and root causes of all ABO discrepancies, detected by a central hematology laboratory, in blood samples referred from 35 district hospitals.

HLA-DRB1 polymorphism is associated with Kell immunisation

K immunisation is observed in some polytransfused patients and pregnant women but does not occur in all cases of K incompatibility. This study analysed the role of genetic background in this selective response to K antigen by investigating HLA‐DRB1 alleles associated with K immunisation in a southern European population. HLA‐DRB1 genotyping was performed by polymerase chain reaction sequence‐specific oligonucleotide/sequence‐specific primer procedures in 54 K immunised patients and 200 healthy controls. The frequency of HLA‐DRB1*11 was significantly higher in K immunised patients than healthy controls: 31 of 54 (57%) vs. 56 of 200 (28%) (Pc < 0·001). In the remaining K immunised HLA‐DRB1*11‐negative patients, the frequency of HLA‐DRB1*13 was increased: 14 of 23 (61%) vs. 49 of 144 in healthy controls (34%) (P < 0·02). The combined frequency of the two HLA‐DRB1 alleles (HLA‐DRB1*11 and HLA‐DRB1*13) was 83% in K immunised patients when compared with 52% in healthy controls (Pc < 0·001). K and k differ by a single amino acid T193 (M). The DRB1*11 and DRB1*13 alleles share a HLA‐DRB1 gene sequence containing S in position 13, D in 70 and A in 74, and coding for the P4 pocket within the HLA‐DR binding groove. This feature of the HLA‐DRB1 gene could be involved in the K peptide presentation through a polymorphism ligand specific for the T193 (M) of K. In conclusion, this study demonstrated a high frequency of HLA‐DRB1*11 or HLA‐DRB1*13 alleles in K immunised patients, which could be due to specific K peptide presentation by HLA‐DR molecules.

Prevention of syncopal-type reactions after whole blood donation: a cluster-randomized trial assessing hydration and muscle tension exercise.

The prevention of presyncopal and syncopal reactions to whole blood donation is important for both the donors safety and their retention as blood donors. The best strategy to achieve this remains debated.

Blood products use in France: a nationwide cross‐sectional survey

Blood products use has increased in France between 2000 and 2011. To understand the reasons for this increase, data about transfused patients and transfusion practices needed to be updated.

Organisation de l'hémovigilance et de la sécurité transfusionnelle à l' assistance publique hôpitaux de Marseille (AP-HM): partenariat AP-HM - établissement français du sang Alpes-Méditerranée (EFS AM)

The Marseille public hospital system (APHM) has expressed its willingness to pool its services of immunohematology and delivery of labile blood products with those of the French blood institute Alps Mediterranean division (EFS AM). An agreement setting out the terms of this partnership was signed between the two parties. The users of the APHM and EFS AM blood watch wished to preserve the channels of distribution. Implementation of this reorganization has focused on ensuring transfusional safety, reinforcing harmonization of APHM practices, and finding ways to reduce costs. Despite joint information campaigns (to medical and paramedical personnel) carried out by the APHM and EFS AM blood watch, problems have arisen during start-up and adjustments have been necessary on both sides. The success of this project hinges on the involvement of the EFS AM in our transfusional practices, deployment of a system for diffusion of information, and consolidation of physical and human resources at the level of the APHM blood watch.

La sécurité immuno-hématologique des receveurs

L’accident de type immuno-hemolytique, qu’il soit immediat ou retarde, demeure l’un des risques majeurs des transfusions sanguines. Celui-ci peut s’averer plus eleve en hematologie compte tenu de la survenue d’une allo-immunisation plus frequente et plus complexe chez ce type de malades. Sa prevention et son diagnostic reposent sur la mise en œuvre de regles dont certaines sont definies par voie reglementaire. Toutefois, la persistance dans ce processus d’operations purement « manuelles » necessite encore un renforcement securitaire des etapes considerees comme critiques.