Outcomes Following Hematopoietic Cell Transplant in CD3δ SCID Patients in Canada
Bibliographic record
Abstract
Introduction In the Low German Mennonite (LGM) population, CD3δ severe combined immunodeficiency (SCID) is the result of a homozygous c.202C>T; p.Arg68Ter pathogenic variant. The block in T cell development causes infant mortality without allogeneic hematopoietic cell transplantation (HCT). We evaluated outcomes following HCT in Canadian LGM infants from 2011-2023. Methods Data were collected and analyzed using descriptive statistics for 11 patients treated in Alberta and Manitoba in collaboration with the Primary Immune Deficiency Treatment Consortium. Results Trigger for diagnosis was newborn screening (NBS) in 4, family history in 1, infections prior to the implementation of NBS in 6. HCT donor and conditioning were as follows: matched related donor (MRD) (1): no conditioning; MRD (3), matched unrelated donor (2), and 9/10 mismatched unrelated donor (1): reduced intensity conditioning (RIC) alemtuzumab, treosulfan, and fludarabine; haploidentical TCRαβ/B cell deplete (3): myeloablative antithymocyte globulin, rituximab, treosulfan, and fludarabine; haploidentical with posttransplant cyclophosphamide (1): RIC with fludarabine and cyclophosphamide. Overall survival was 100%, with median follow-up of 3 years. Three patients developed grade I–II acute graft-versus-host disease (GVHD) and 2 chronic GVHD. By 12 months post-HCT, 7 patients achieved CD4 >500 × 106 cells/L. All but 1 patient had normal B cell numbers. Immunoglobulin was stopped by one year in all patients; one developed hypogammaglobulinemia 5 years post-HCT and restarted. All achieved full T cell chimerism (>95%); 4 had full chimerism in all cell lines. Myeloid and B cell chimerisms were <5% in 3 and mixed (5-95%) in 4. Conclusion Despite excellent survival, we observed incomplete T cell immune reconstitution, poor chimerism in myeloid and B cell lines, and GVHD. Further research is required to identify the optimal HCT approach and clinical significance of mixed chimerisms. Outcome data comprises the historical control for an upcoming clinical trial on base editing gene therapy for CD3δ SCID.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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".