12.12: Donations found to have a positive direct antiglobulin test

Direct antiglobulin test (DAT) positive donations may be identified incidentally by testing laboratories when:

• the autologous/reference control is positive in ABO/RhD blood grouping
• the antibody screen is positive
• anomalies are identified in extended phenotyping tests.

Non-red cell components may be prepared and issued from DAT positive red cell donations. Red cell units may be prepared and issued from DAT positive red cell donations provided that:

• the ABO and RhD groups are confirmed
• red cell antibodies have been excluded as per the mandatory antibody screening (see Table 12.1)

Donors who have been found incidentally to have a positive DAT at donation testing may remain as blood donors provided they continue to pass the health screening questionnaire and have a normal haemoglobin.