Donor-Specific Isoagglutinin Clearance in ABO Mismatched Stem Cell Transplant Recipients: How Long Should It Normally Take?
Bibliographic record
Abstract
Abstract Introduction: In patients undergoing ABO-incompatible stem cell transplants, recipient isoagglutinins with specificity for donor antigens are expected to slowly become undetectable during the post-transplant period, presumably secondary to the loss of recipient plasma cells via either conditioning chemotherapy or graft-versus-host-disease. Conversely, the persistence or return of these anti-donor isoagglutinins may induce hemolytic anemia or pure red cell aplasia, and may even signify disease relapse. In order to define the expected time to clearance of these donor isoagglutinins at our institution, a retrospective study was performed 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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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".