ABO blood group system consists of A, B, and H (ABH) antigens. Group O individuals express the precursor H antigen but lack A and B antigens. Individuals form antibodies (anti-A and anti-B) to the antigens they lack. These antibodies are…
DNA-based testing for blood group antigens has become commonplace in number of clinical situations. These include typing for minor antigens in multiple transfused immunized patients to determine risk for production of additional blood group antibodies, patients with positive direct antiglobulin…
Direct antiglobulin test (DAT [e.g., Coombs’]) detects in vivo sensitization of RBCs with immunoglobulins and/or complement. DAT is useful in investigation of acute and delayed hemolytic transfusion reaction (AHTR and DHTR), hemolytic disease of the fetus and newborn (HDFN), autoimmune hemolytic…
Antibodies to RBC antigens except anti-A and anti-B are called unexpected antibodies. Unexpected RBC antibodies may be alloantibodies reacting against foreign antigens or autoantibodies reacting against self-antigens. Depending on the patient population, 1%–35% of patients have unexpected alloantibodies. Once an…
Pretransfusion testing is performed to select compatible blood components for transfusion, thereby preventing harm to recipient and maximizing posttransfusion survival. AABB Standards require the following: 1. Positive patient identification and their corresponding blood specimen; 2. ABO group and D typing…
According to the AABB Standards (Standard 1.0), the transfusion service (TS) must have a clearly defined structure and documentation of individuals responsible for key functions, including executive management. TS must have a medical director who is responsible for medical and…
Bacterial contamination of blood components may result in septic transfusion reactions ( Chapter 67 ), which can be fatal. Platelet products, particularly those on day 4 or 5 of storage, are most commonly associated with these reactions because they are…
Testing blood donors for syphilis, human T-cell lymphotropic virus (HTLV), and Trypanosoma cruzi infection is mandated by the FDA and AABB Standards. Syphilis was the first transfusion-transmitted disease for which the blood supply was screened in the United States. HTLV…
Babesia microti is the leading red blood cell (RBC) transfusion-transmitted pathogen reported to the FDA. Babesiosis most commonly occurs after a tick bite but can be transfusion-transmitted and vertically transmitted. Owing to the increasing incidence of babesiosis and transfusion-transmitted babesiosis…
In 2016, the association between maternal Zika viral infection and microcephaly in babies was recognized. Zika virus is spread through mosquitoes, sexual transmission, and potentially through transfusion. Owing to its associated morbidity, FDA recommended screening the blood supply by nucleic…