Prevention of Delayed Hemolytic Transfusion Reactions (DHTR)

Preventing DHTR may be impossible if the patient's antibody is too weak to be detected by routine antibody detection methods. However there are many standard procedures and protocols that transfusion services can use to minimize this complication. Some examples include:

• Performing a history check to identify patients that have existing antibodies that may have weakened over time.
   
• Using sensitive antibody detection methods.
   
• Using antibody screen cells from donors who between them are homozygous for all of the common antigens that are expressed more strongly on homozygous RBCs (i.e., show a "dosage effect"). Such blood groups include Rh (C,E,c,e), Kidd (Jka, Jkb), Duffy (Fya, Fyb), MNSs.
   
• For patients who have been transfused or pregnant in the last three months, using crossmatch specimens that are no older than three days (where the date of collection is day one).
   
• For patients who have clinically significant antibodies, antigen phenotyping donors using commercial antisera, followed by serologic crossmatching of antigen-negative donors using an antiglobulin test or equivalent method, even when the antibody (antibodies) are not currently detectable.
   
• For patients with known clinically significant antibodies, assuring, on each pre-transfusion sample tested, that the evaluation for the presence of additional (new) clinically significant antibodies has been correctly performed (i.e., that appropriately phenotype tested RBCs have been selected to investigate this possibility).
   
• For patients with clinically significant antibodies, issuing, via the patient's physician, antibody cards that specify the antibodies present. Patients can carry these cards and alert medical staff as appropriate.