Automatic Marsh method for detection and identification of erythrocyte antibodies in patients and blood donors

Using a Technicon autoanalyzer method of Marsh 752 sera of patients, Rh-negative subjects in the initial stage of immunization with Rh-positive blood, and healthy blood donors were investigated. In 56 sera (8.7%) positive reactions with standard erythrocytes were found. In 21 of these cases (36%) specificity of antibodies was established. They were mostly alloantibodies or autoantibodies against Rh antigens. In 1 case anti-Ika alloantibody and in 1 case anti-K autoantibody were demonstrated. Antibodies with undetermined specificity belonged to the so called "analyzer antibodies", which are detected only by the automatic methods, and probably have no clinical importance. The possibility of recording by the autoanalyzer of subthreshold levels of alloantibodies undetected by other methods may be of great practical importance of patients receiving multiple transfusions of blood and for immunized blood donors.