[Identification of alloantibodies and their associations: balance sheet of a year at the Auvergne-Loire French Blood Establishment].

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.