delayed haemolysis of red blood cells
Last reviewed 01/2018
Uncommonly, serological reaction to transfusion may be delayed for 1 - 2 weeks.
Invariably, the reaction is a secondary antibody response in previously sensitised recipients, the level of antibodies in their serum at the time of transfusion being below the limit of detection of the laboratory.
The antibodies involved often include JK-a (Kidd), K (Kell), and Fy-a (duffy). The delay represents the time needed to mount a detectable antibody response.