Session: 401. Basic Science and Clinical Practice in Blood Transfusion: Poster I
Hematology Disease Topics & Pathways:
Adult, Biological Processes, Technology and Procedures, Study Population, erythropoiesis, Clinically relevant, Quality Improvement , serologic tests
Methods: The transfusion records of all major-side or bidirectionally ABO-incompatible stem cell transplants performed at an academic cancer hospital between May 2009 and July 2018 were reviewed. Patients without detectable anti-donor isoagglutinins at time of transplant were excluded. Isoagglutinin clearance was defined as non-reactivity of patient plasma against donor-type reverse grouping cells occurring during the post-transplant period; relapse was defined as a 2+ or stronger reaction after one or more non-reactive results
Results: A total of 280 patients were included in analysis, of which 44 were native group A, 42 group B and 194 group O. Average age was 52 (±13) years and 130 (46%) were female. Compatibility samples were sent to the UHN blood bank during the post-transplant period for a median of 156 days (IQR 74-370 days). During this time period, donor-targeting/host-derived isoagglutinin clearance was documented in 192 (69%) patients at a median of 48 days (IQR 23-116.5) post-transplant. Of these, 52 (30%) experienced a subsequent return of reactivity at a median 98 days post-transplant (IQR 54-216). Amongst the 128 patients with at least 28 days of post-transplant monitoring and no return of previously cleared isoagglutinins, the median time to clearance was 60 days (IQR 26.5 – 127.5 days). There was no statistically significant difference in time to isoagglutinin clearance between those with and without a subsequent return of reactivity, and time to durable clearance did not correlate with patient age, sex or native ABO group.
Conclusions: Amongst patients undergoing major-side or bidirectionally ABO incompatible stem cell transplants, the majority will have cleared their donor-specific isoagglutinins within 120 days of stem cell infusion, although this does not guarantee against later return of reactivity. Thus, the persistence of donor-specific isoagglutinins beyond 120 days post-transplant, or the subsequent return of previously cleared isoagglutinins, may be considered abnormal results which warrant notification of the clinical team by the hospital transfusion service.
Disclosures: No relevant conflicts of interest to declare.
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