What is the “screen” in type and screen?

By William Aird

Screening for complement-activating alloantibodies in a patient who will receive a blood transfusion, using commercially available group O RBCs that express all antigens as required by the FDA.

Per the AABB:

Pretransfusion compatibility testing begins with the type and screen procedure. The recipient’s ABO group and Rh type are determined first; then a screening procedure is used to detect any unexpected non-ABO blood group antibodies that may be present. If the screening test reveals the presence of an antibody, the specificity of that antibody is determined by an antibody identification panel. Once the specificity of the antibody has been identified, donor units of the appropriate ABO group and Rh type are screened for the corresponding antigen. Units that are negative for that antigen are crossmatched with the recipient to ensure compatibility.

Antibody screening using an indirect antiglobulin test. Commercially available group O RBCs for antibody screening may be performed by 2 reagent single donor RBCs or 3 reagent single-donor RBCs. if antibody screen is positive, serum or plasma samples are tested against a panel of group O RBCs (typically 8-14 samples) with known antigenic composition to identify alloantibody specificity.