Trajectory clustering of longitudinal donor chimerism after pediatric hematopoietic stem cell transplantation for non-malignant disorders.
AI interpretation is pending for this paper.
Open original publication →What the AI sees
Not AI summarized yet.
Research significance
Pending deeper interpretation.
Source abstract
BACKGROUND AIMS: Graft failure remains a serious complication of allogeneic hematopoietic stem-cell transplantation (HSCT) for non-malignant disorders (NMD) in children. Donor chimerism is monitored serially to assess engraftment and reflects a continuous biological process, yet its trajectory remains uncharacterized. We applied unsupervised trajectory clustering across NMD diagnoses to define distinct engraftment patterns. METHODS: In this study, we analyzed 566 serial whole-blood donor chimerism measurements, assessed by short tandem repeat PCR, from 41 transplants. Each transplant's chimerism trajectory was interpolated onto a common time grid, and trajectories were grouped by shape using Ward's hierarchical clustering; phenotypes were then characterized by donor chimerism at day +100 and by the rate of chimerism change (slope, % per month) over defined early windows. RESULTS: Hierarchical clustering of interpolated trajectories identified three phenotypes: stable full donor chimerism (n = 28, 70%), persistent mixed chimerism (n = 6, 15%), and progressive graft loss (n = 6, 15%), aligning with conditioning intensity and underlying diagnosis. The stable full donor phenotype was characterized by day +100 chimerism (median 100%) and a flat early slope (median 0%/month over day +30 to +60) separating it from the two non-full donor phenotypes by day +60. These two were indistinguishable at day +100 and by the early slope, but separated on the day +60 to +100 slope, where progressive graft loss declined more steeply (median -34 versus -2%/month). CONCLUSION: These findings describe the phenotypes and the sequence of their separability, supporting earlier identification of patients progressing toward graft loss.