Major Abo Incompatible Bone Marrow Transplantation: Effect of Isohemagglutinin Reduction by Plasmapheresis
Bibliographic record
Abstract
The impact of donor-recipient ABO incompatibility on BMT outcome remains controversial. While some studies have found no impact, others have found an increased risk of GVHD and graft failure and an adverse effect on engraftment and OS. This variability may be partially explained by the lack of consensus on the management of ABO incompatibility. A common strategy is to deplete the product of red cells, although this adversely affects stem cell yield and there is no agreed upon volume that is safe to infuse. At the Ottawa Hospital (TOH), recipients of major ABO incompatible BMT undergo plasmapheresis using 5% albumin when the product hematocrit is > 10%. Acceptable titres are 1:4 for Anti-A and 1:8 for Anti-B. The graft is not manipulated. As manipulation of the marrow is the more common strategy in North America, the goal of our study is to review the efficacy and safety of this approach in ABO incompatible BMT. We conducted a retrospective review of all major ABO incompatible BMT at TOH over a 10-year period from Jan. 1, 2000 to Dec. 31, 2010. The primary outcome was time to engraftment. Secondary outcomes included number of plasmaphereses, transfusion requirements, clinically significant hemolysis and OS. 26 pts underwent BMT using a major ABO incompatible donor. 20 pts were male and the median age was 41(11 – 61) years. Indications for BMT were AML(n = 11), ALL(n = 6), NHL(n = 3), CML(n = 2) and others(n = 4). 19 pts had matched sibling donors and 7 had unrelated donors - 2 of whom were mismatched at 1 antigen. 20 pts underwent myeloablative and 6 underwent reduced-intensity conditioning. The median number of plasmaphereses was 1(0 – 4). The median time to neutrophil engraftment for this cohort was 26(17 – 38) days. This was not significantly different than 110 pts undergoing BMT without major ABO incompatibility at TOH during the same period (21 days; 10 – 60; p = 0.7). Median platelet engraftment (platelet count > 20 x 109/L) occurred at day 23.5(18 – not reached) in this cohort and day 21.5(12 – not reached) in the larger cohort (p = 0.5). The median number of red cell and platelet transfusions were 6(2 – 47) and 24(4 – 140), respectively. No acute hemolytic transfusion reactions were observed. OS at a maximum of 11 years is 52.8% for pts undergoing major ABO incompatible BMT vs. 42.7% for the larger cohort. As an alternative to RBC depletion, recipient plasmapheresis is a safe and effective method of managing donor-recipient major ABO incompatibility prior to BMT.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 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".