Delayed hemolytic transfusion reaction

A delayed hemolytic transfusion reaction (DHTR) is a type of transfusion reaction. According to the Centers for Disease Control's (CDC) National Healthcare Safety Network's (NHSN) Hemovigilance Module, it is defined as:
Mechanism.
If a person without a Kidd blood antigen (for example a Jka-Jkb+ patient) receives a Kidd antigen (Jka-antigen for example) in a red blood cell transfusion and forms an alloantibody (anti-Jka); upon subsequent transfusion with Jka-antigen positive red blood cells, the patient may have a delayed hemolytic transfusion reaction as their anti-Jka antibody hemolyzes the transfused Jka-antigen positive red blood cells. Other common blood groups with this reaction are Duffy, Rhesus and Kell.
Diagnosis.
PROBABLE DIAGNOSIS
Epidemiology.
Delayed blood transfusion reaction occurs more frequently (1 in 20,569 blood components transfused in the USA in 2011) when compared to acute haemolytic transfusion reaction.