Delayed Hemolytic Transfusion Reaction (DHTR), anti-M

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Record number: 
Adverse Occurrence type: 
MPHO Type: 
Time to detection: 
12 days
Alerting signals, symptoms, evidence of occurrence: 
Twelve days after 5 units of red blood cells, without signs of rebleeding, her hematocrit was 17 percent, and her spleen, not felt at the time of admission, was palpable 8 cm below the left costal margin. Other laboratory data included reticulocytes 16.7 percent, total bilirubin 1.8 mg per dl, direct reacting bilirubin 0.4 mg per dl, lactic dehydrogenase 539 IU per 1, haptoglobin I5 mg per dl. A suspected DHTR was investigated.
Demonstration of imputability or root cause: 
An indirect antiglobulin test (IAT), previously negative, became 3+positive. The patient's serum contained an anti-M. Measurements of erythrocyte survival using 51Cr-labeled donor M+ and M- red cells and in vitro studies of monocyte-macrophage phagocytosis of sensitized reagent red cells implicate anti-M in the pathogenesis of hemolysis.
Imputability grade: 
2 Probable
Groups audience: 
Reference attachment: 
Suggest references: 
Alperin JB, Riglin H, Branch DR, Gallagher MT, Petz LD. (1983). Anti-M causing delayed hemolytic transfusion reaction. Transfusion 23:322-4.
Expert comments for publication: 
The antibodies of the MNS system to glycophorin B, anti-S, -s, and -U can all cause immediate and delayed hemolytic transfusion reactions, and anti-U is a particularly dangerous antibody. Anti-M and -N, on the other hand, rarely cause hemolytic transfusion reactions.