RESUMEN
BACKGROUND: Partial Rh antigens have been widely described in black individuals. Carriers are prone to immunization when exposed to the normal antigens. In sickle cell disease (SCD), patient alloimmunization is a major cause of transfusion failure. The potential of individuals with partial C antigen to make anti-C has not been investigated. We sought partial C status and anti-C production in a cohort of SCD patients with the C+ phenotype, to determine whether exposure to normal C antigen should be avoided. STUDY DESIGN AND METHODS: We constituted a cohort of 177 randomly selected SCD patients expressing C antigen. We screened for (C)ce(s) and R(N) haplotypes, presumably associated with partial C antigen in Afro-Caribbeans, and we recorded the number of transfused C+ red blood cell (RBC) units, immunization status, and extended phenotype. RESULTS: Forty-nine patients carried abnormal C antigen, deduced from the presence of (C)ce(s) and/or R(N), not compensated by a normal RHC allele in trans. Among patients with partial C phenotype exposed repeatedly to C+ RBCs, 30% produced anti-C. Two patients experienced hemolysis. In our hospital, with 22% of SCD patients expressing C, prevention of anti-C immunization for all individuals with partial C antigen would require a 7% increase in the use of C- RBC units. These RBCs are already in short supply for SCD patients who are C-. CONCLUSION: This study demonstrates the need to detect partial C within C+ SCD patients and to prevent immunization. A larger number of Afro-Caribbeans donors is needed to provide these patients with C- RBCs.
Asunto(s)
Anemia de Células Falciformes/inmunología , Isoanticuerpos/sangre , Sistema del Grupo Sanguíneo Rh-Hr/inmunología , Reacción a la Transfusión , África/etnología , Anemia de Células Falciformes/etnología , Anemia de Células Falciformes/genética , Incompatibilidad de Grupos Sanguíneos/inmunología , Francia , Haplotipos , Humanos , Estudios Retrospectivos , Sistema del Grupo Sanguíneo Rh-Hr/genética , Indias Occidentales/etnologíaRESUMEN
In this report the role of crossmatching in pre-transfusion tests is France considered. The serological techniques and a comparison of immunohematological data of the patients and the blood banks available using computerization are also discussed.
No relato é apresentado o papel de prova cruzada nos testes pré-transfusionais. Discute-se as técnicas sorológicas e dados imunohematológicos dos pacientes e das unidades de sangue disponíveis através de comparação computadorizada.
Asunto(s)
Tipificación y Pruebas Cruzadas Sanguíneas , Transfusión SanguíneaRESUMEN
The Rh system was first described 60 years ago, and is the most important in transfusion medicine with more than 50 antigens described. In this report, advances obtained with knowledge of the system of blood grouping are presented.
O sistema Rh foi descrito há mais de 60 anos, sendo o mais importante em medicina transfusional com aproximadamente 50 antigenos descritos. No relato são apresentados os avanços obtidos no conhecimento do sistema de grupo sanguíneo.
Asunto(s)
Sistema del Grupo Sanguíneo ABORESUMEN
Methods to assist in the detection of low affinity antibodies and the clinical importance of these methods are discussed in this work.
Apresentamos no relato métodos que auxiliam na detecção de anticorpos de baixa afinidade e a importância clínica dos mesmos.