Extravascular hemolytic transfusion reaction: Difference between revisions

Latest revision as of 01:43, 21 March 2026

Background

Delayed immune-mediated destruction of transfused RBCs by recipient antibodies (IgG)
Occurs 2-10 days after transfusion (delayed hemolytic transfusion reaction, DHTR)
Caused by anamnestic antibody response: recipient was previously sensitized (prior transfusion, pregnancy) but antibody titer fell below detection at time of crossmatch
Hemolysis occurs extravascularly in the spleen, liver, and bone marrow (reticuloendothelial system)
Most common clinically significant antibodies: Kidd (Jk), Rh, Duffy (Fy), Kell

Clinical Features

Often subclinical or mild
Unexplained drop in hemoglobin or failure of expected post-transfusion hemoglobin rise
Low-grade fever
Mild jaundice (indirect hyperbilirubinemia)
Dark urine (less common than in intravascular hemolysis)
Rarely progresses to clinically significant hemolysis

Differential Diagnosis

Transfusion Reaction Types

Evaluation

Positive direct antiglobulin test (DAT/Coombs)
Elevated indirect bilirubin, LDH
Decreased haptoglobin
Positive antibody screen with new alloantibody identified
Inadequate hemoglobin rise after transfusion
Reticulocytosis

Management

Rarely requires specific treatment — usually self-limited
Notify blood bank immediately for antibody identification
Future transfusions must be antigen-negative for the identified antibody
Supportive care; transfuse if clinically indicated (with antigen-negative units)
Monitor for rare progression to severe hemolysis

Disposition

May not require admission if hemodynamically stable and hemolysis is mild
Ensure blood bank notification and updated antibody record

References

Authors:

@@ Line 1: / Line 1: @@
 ==Background==
-*Occurs days to weeks after transfusion
+*Delayed immune-mediated destruction of transfused RBCs by recipient antibodies (IgG)
+*Occurs '''2-10 days''' after transfusion (delayed hemolytic transfusion reaction, DHTR)
+*Caused by anamnestic antibody response: recipient was previously sensitized (prior transfusion, pregnancy) but antibody titer fell below detection at time of crossmatch
+*Hemolysis occurs extravascularly in the spleen, liver, and bone marrow (reticuloendothelial system)
+*Most common clinically significant antibodies: Kidd (Jk), Rh, Duffy (Fy), Kell
 ==Clinical Features==
-*Hemolysis occurs in spleen, liver, and bone marrow
+*Often subclinical or mild
+*Unexplained drop in hemoglobin or failure of expected post-transfusion hemoglobin rise
+*Low-grade [[fever]]
+*Mild [[jaundice]] (indirect [[hyperbilirubinemia]])
+*Dark urine (less common than in [[intravascular hemolytic transfusion reaction|intravascular hemolysis]])
+*Rarely progresses to clinically significant hemolysis
 ==Differential Diagnosis==
@@ Line 9: / Line 18: @@
 ==Evaluation==
-*[[Hyperbilirubinemia]]
+*Positive direct antiglobulin test (DAT/Coombs)
-*Poor response to transfusion
+*Elevated indirect bilirubin, LDH
+*Decreased haptoglobin
+*Positive antibody screen with new alloantibody identified
+*Inadequate hemoglobin rise after transfusion
+*Reticulocytosis
 ==Management==
-*None necessary; rarely fatal
+*'''Rarely requires specific treatment''' — usually self-limited
+*Notify blood bank immediately for antibody identification
+*Future transfusions must be antigen-negative for the identified antibody
+*Supportive care; transfuse if clinically indicated (with antigen-negative units)
+*Monitor for rare progression to severe hemolysis
 ==Disposition==
+*May not require admission if hemodynamically stable and hemolysis is mild
+*Ensure blood bank notification and updated antibody record
 ==See Also==
 {{Transfusion reactions see also}}
-==External Links==
 ==References==