title: Indirect antiglobulin test-crossmatch using low-ionic-strength saline-albumin enhancement medium and reduced incubation time: effectiveness in the detection of most clinically significant antibodies and impact on blood utilization.
abstract: Indirect antiglobulin test-crossmatch (IAT-XM) using enhancement media such as low-ionic-strength saline (LISS) and polyethylene glycol (PEG) usually requires 15 minutes of incubation. These methods are necessary when testing samples from blood recipients who have a higher risk of alloimmunization. In emergency situations, IAT-XM can be time-consuming and can influence presurgery routine, resulting in more red blood cell (RBC) units being tested and stored to avoid the transfusion of uncrossmatched ones. The objective of this study was to evaluate the performance of a LISS-albumin enhancer to intensify antigen-antibody reaction after 5 minutes of 37oC incubation and compare this performance with that of other enhancers, gel, and conventional tube testing. Second, the study evaluated the impact of this method's implementation in the C:T ratio (crossmatched to transfused RBC units) of a transfusion laboratory. Ninety serum samples containing alloantibodies of potential clinical significance were tested against phenotyped RBCs using four different methods: (1) tube with LISS-albumin enhancer (5 minutes of incubation), (2) tube with LISS-albumin and PEG (15 minutes of incubation), (3) gel, and (4) conventional tube method (60 minutes of incubation). In parallel, the study compared the C:T ratio of a tertiary-hospital transfusion laboratory in two different periods: 3 months before and 3 months after the implementation of the 5-minute IAT-XM protocol. The use of LISS-albumin with 5 minutes of incubation exhibited the same performance as LISS-albumin, PEG, and gel with 15 minutes of incubation. Conventional tube method results were equally comparable, but reactions were significantly less intense, except for anti-c (p = 0.406). Accuracy was 100 percent for all selected methods. After the implementation of the 5-minute IAT-XM protocol, the C:T ratio fell from 2.74 to 1.29 (p < 0.001). IAT-XM can have its incubation time reduced to 5 minutes with the use of LISS-albumin enhancement. We suggest this strategy should be used to quickly prepare RBC units for surgical patients, keeping transfusion safety without compromising blood supplies.
authors.affiliation: MD, PhD, student (corresponding author), Chief of Immunohematology Division.
authors.forename: C L
authors.initials: CL
authors.lastname: Dinardo
authors.affiliation: MSc student, Chief of Immunohematology Quality Control Department.
authors.forename: S L
authors.initials: SL
authors.lastname: Bonifácio
authors.affiliation: MD, PhD, Director of Fundação Pró-Sangue/Hemocentro de São Paulo, Avenida Dr. Enéas de Carvalho Aguiar, 155-1st floor, Cerqueira César, São Paulo-SP, Brazil 05403-000.
authors.forename: A
authors.initials: A
authors.lastname: Mendrone
mesh_terms: D000418:Albumins / Q000737:chemistry; D001788:Blood Grouping and Crossmatching / Q000379:methods*; D001803:Blood Transfusion; D003298:Coombs Test / Q000379:methods*; D006801:Humans; D007518:Isoantibodies / Q000032:analysis / Q000097:blood*; D009994:Osmolar Concentration; D015203:Reproducibility of Results; D012965:Sodium Chloride / Q000737:chemistry
chemical_list: D000418:Albumins; D007518:Isoantibodies; D012965:Sodium Chloride