Red cell compatibility testing

Abstract

The term compatibility is used for the entire range of pretransfusion testing, including recipient identification, sample collection and handling, the selection of appropriate blood units, and the crossmatch. Crossmatching has come a long way from a simple slide or tile method by James Ewing in the early 19th century to the current automated technologies, including solid phase or no touch, to the virtual crossmatch by electronic methods. Each of them has its advantages and limitations. The center adopting them should weigh each of them as per requirement, type of patient catered to, logistics, and affordability to choose the most appropriate method for their facility. Genotyping by molecular methods, including sequencing, has paved the way for mass phenotyping and making provisions for the supply of phenotype-matched blood for relevant patients. Some modifications in the strategies need to be adopted while performing these tests in special populations like neonates with autoimmune conditions and patients requiring massive transfusion. The urgency of the requirement for blood transfusion and the time available for performing these tests also needs to be considered.