Direct antiglobulin test positive blood donors and blood transfusion safety

Direct antiglobulin test (DAT), also known as Coomb's test, is a method used in blood immunology to detect whether the surface of red blood cells is sensitized by immunoglobulin or complement. It is mainly used in the diagnosis of autoimmune hemolytic anemia (AIHA), neonatal hemolytic anemia, hemolytic transfusion reaction and blood matching during blood transfusion. DAT positive has always been the focus of researchers, because it has an important impact on the efficacy of blood transfusion. In recent years, there has been extensive research on the identification of DAT positivity types and the distribution characteristics of diseases in clinical patients, and the study on hemolytic disease of the newborn has also been popular. However, the transfusion safety of DAT-positive blood donors has been a hot topic in the field of blood transfusion for many years. Moreover, there is no clear requirement from the state on the handling of DAT-positive blood and whether DAT-positive blood donors should be deferred from donation. Therefore, this article reviews the serological studies on DAT immunotyping and IgG subtype typing of voluntary blood donors, as well as the impact of DAT-positive blood on blood transfusion safety, in order to provide references for the blood issuance strategy of DAT-positive blood and whether DAT-positive blood donors should be deferred.