A young woman comes for a checkup with the hematologist for her beta-thalassemia. She is feeling a little worse than usual and is in pain. Since she is going on vacation soon and wants to enjoy it, she would very much like a blood transfusion to boost her hemoglobin a bit.

A blood transfusion is not without risks, so the hematologist initially advises against a transfusion. After much discussion, they do reach an agreement. She is given a 1 unit trial transfusion to see how she tolerates it. Her laboratory results before and after this transfusion are below.

Her low hemoglobin, low MCV, elevated LDH and bilirubin fit well with the continuous low-grade hemolysis in beta-thalassemia.

The transfusion is well tolerated and the hemoglobin shows a nice increase. She is given an appointment to receive two more units later. This transfusion also goes off without a hitch. A few days later, she comes to the outpatient clinic for a check-up. She looks very pale, has a fever, suffers from shortness of breath and is lightheaded when she gets up from her chair. Her blood results are as follows:

From the increased LDH and bilirubin and decreased hemoglobin compared to several days earlier, it is concluded that there is increased erythrocyte breakdown.

A hemoglobin concentration significantly lower after transfusion than before (6.3 to 4.7) indicates breakdown of both transfused and native erythrocytes. One speaks of "hyperhemolysis" in this case.

The direct antiglobulin test is weakly positive for complement. However, no antibodies can be identified with the available techniques in this patient, so no clear cause of complement activation or hemolysis is found.

She is admitted and treated with prednisone and darbepoetin (epo). During her admission, HLA antibodies are detected in the laboratory, possibly related to the transfusion reaction. Her hemoglobin initially continues to drop, but slowly rises again as treatment kicks in. She is discharged and goes on vacation a short time later.