O232: Enzymatic blood group conversion prevents complement activation in an ABO-incompatible model of human kidney transplantation
Bibliographic record
Abstract
Abstract Introduction Recently, enzymatic blood group conversion has been used to convert human kidneys from blood group A to universal blood group O using bacterial enzymes from Flavonifractor plautii. However, little is known about the functional consequences of antigen removal when a treated kidney is transplanted in an ABO-incompatible (ABOi) recipient. Here, we investigated classical complement activation during ABOi conditions in enzyme treated (ABOe) vs control human type A kidneys. Method Three biological pairs of type A human kidneys rejected for transplantation and offered for research were used in this study. One kidney per pair was treated with 1mg/L of FpGalNAc deacetylase and FpGalactosaminidase during 6hrs of hypothermic machine perfusion while the contralateral kidney was perfused without enzymes. Both kidneys were subsequently perfused for 4hrs in ABOi conditions using normothermic machine perfusion (10% AB serum; mouse anti-A IgM titre 1:128; type O red blood cells). Tissue-bound components of classical complement activation were assessed in pre- and post-perfusion biopsies. Results Following ABOi perfusion, control kidneys showed peritubular deposition of the classical complement component C1qA and further complement activation components C4d and C5b-9. The staining directly co-localised with regions of anti-A staining. In ABOe kidneys, no anti-A staining was observed, with no C1qA, C4d, or C5b-9 staining found in post-perfusion biopsies. Conclusions We have shown for the first time that ABOe kidneys do not activate the classical complement pathway in ABOi conditions. This work shows the potential of the enzymatic blood group conversion to evade hyperacute antibody-mediated rejection during renal transplantation.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| 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 | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".