What is the typical finding of the direct antiglobulin test in a delayed hemolytic transfusion reaction?

In a delayed hemolytic transfusion reaction, the typical finding of the direct antiglobulin test can indeed present as mixed-field positive. This occurs because the immune response takes time to develop, and in these cases, the recipient's immune system may produce antibodies against specific red blood cell antigens after previously transfused blood, leading to destruction of the donor red blood cells while leaving the recipient's red blood cells unaffected.

The mixed-field positivity arises when there is a coexistence of both antibody-coated and non-antibody-coated red blood cells in the same sample, which is indicative of this reaction. This finding is typical of delayed reactions, where the antibody response can lead to a weaker and slower hemolytic process, as opposed to a stronger response seen in acute hemolytic reactions, where one would expect a more consistently positive result without the mixed-field appearance.

Analyzing the other options: A negative result would not reflect the immune response characteristic of a delayed transfusion reaction. A positivity due to complement would suggest a different type of immune mechanism, typically associated with certain types of hemolytic reactions, rather than the antibody-mediated response seen in delayed hemolytic reactions. A negative result when the antibody screen is negative does not accurately depict the