[Identification of alloantibodies and their associations: balance sheet of a year at the Auvergne-Loire French Blood Establishment]. / Identification d'allo-anticorps et leurs associations : bilan d'une année à l'Établissement français du sang Auvergne-Loire.

OBJECTIVES: Some alloantibodies and their combinations can lead to delays or even an impasse in a transfusion, owing to the necessity of finding compatible red blood cell concentrates. The aim of this study was to determine the specificities of the most common alloantibodies, as well as the most common combinations of alloantibodies. METHODS AND MATERIALS: A retrospective study analysed erythrocyte alloantibodies identified in 2008 in the immunohematology laboratories at the Auvergne-Loire French Blood Establishment. The following data were studied: frequency, specificities of the alloantibodies, date of discovery, and patient age and sex. RESULTS: One thousand eight hundred and fifteen alloantibodies were identified in 1575 patients (median age: 63.5years, female/male ratio: 3.03). The most common alloantibodies were directed against the following antigens: RH3/E (18.7%), KEL1/K (17.3%), RH1/D (16.4%), MNS1/M (9.4%), FY1/Fya (6.9%), RH2/C (6.1%), KEL3/Kpa (4.7%), JK1/Jka (4.3%) and RH4/c (4.1%). In 13.1% of patients, at least two alloantibodies were identified. The pairs most frequently combined were anti-RH1/RH2, anti-RH3/RH4 and anti-RH3/KEL1. CONCLUSION: Specific associations of paired alloantibodies were identified. The main combinations provide indications on the choice of red cell concentrates in the inventory for a given patient. The data collected in our study show that when an antibody is identified, it is recommended for subsequent transfusion episodes to respect the phenotype RH 1-5 (D, C, E, c, e) and KEL1 (K) of the patient, and if possible antigens JK1 (Jka) and FY1 (Fya), and to a lesser extent MNS3 (S). Detailed knowledge of the immunological mechanisms leading to the formation of these alloantibodies and their combinations would allow better prevention of erythrocyte alloimmunization.

[Anti-RH1 (anti-D) alloimmunization after transfusion of platelet concentrates from RH :1 donors]. / Allo-immunisation anti-RH1 (anti-D) après transfusion de concentrés plaquettaires issus de donneurs RH :1.

Anti-erythrocyte alloimmunization may occur following the transfusion of platelet concentrates, in response to the presence of residual erythrocytes. Immunization against RH1 (D) antigen is the most frequent, but transfusion of RH1 compatible platelet concentrates is not always possible because of supply constraints. We report here three cases of anti-RH1 (anti-D) alloimmunization in RH :-1 patients after transfusion of platelet concentrates from RH :1 donors. Criteria for selection of platelet concentrates are numerous and difficult to achieve in practice. Respect of RH1 compatibility is not obligatory, but in case of transfusion of RH1 incompatible platelet concentrates, anti-RH1 immunoprophylaxis must be made for RH :-1 women of child-bearing age and without profound immunosuppression, as recommended by Afssaps (Agence française de sécurité sanitaire des produits de santé). These data point out the need to perform post-transfusional screening test for irregular erythrocyte antibodies as part of the transfusion of platelet concentrates.

[Identitovigilance and its impact on the results ensuring the transfusion security]. / Identitovigilance et son impact sur les résultats d'immuno-hématologie érythrocytaire assurant la sécurité transfusionnelle.

Errors on identity of patients during their registration may lead to non-compliance with a transfusion procedure, a non-issue adjusted blood and thus a transfusion risk. The main mistake is the misknowledge of an antibody, secondarily a loss of transfusion information and a redundancy of examinations. The creation of a working group "identitovigilance" helped sensitize the staff of health establishments and clinical chemistry laboratories. In this area of computerization of medical and transfusion records, shared folders and networking, identification of patients is a real issue of risk management hospital.