In the field of pediatric hematology, haploidentical hematopoietic stem cell transplantation (haplo-HSCT)—where parents or relatives with only 50% HLA compatibility serve as donors—has emerged as a "lifeline" for children lacking fully matched donors. Professor Sun Yuan, Director of the Hematology and Oncology Center at Beijing Jingdu Children’s Hospital, has pioneered this technology in China, elevating its safety and efficacy to international standards while establishing groundbreaking "Chinese protocols" that have reignited hope for countless families.
Traditional haplo-HSCT required high-intensity chemotherapy to eliminate the recipient’s immune system, often leading to severe infections, organ damage, or even death. Professor Sun’s team developed a stratified conditioning strategy tailored to pediatric physiology:
Low-risk patients: A fludarabine + cyclophosphamide backbone combined with low-dose total body irradiation (2–4 Gy) to eradicate malignant cells while protecting vital organs.
High-risk/relapsed patients: Introduction of cladribine to enhance anti-leukemic effects, alongside umbilical cord blood-derived mesenchymal stem cells to mitigate graft-versus-host disease (GVHD) risks.
This approach reduced transplantation-related mortality from 30% to below 8%, aligning with outcomes from leading global centers.
Professor Sun recognized GVHD prevention as critical to success. Her team pioneered TCRαβ+/CD45RA+ cell depletion technology, selectively removing GVHD-triggering T-cell subsets while preserving anti-tumor and anti-infection immunity:
Acute GVHD incidence dropped from 40–60% to 15%.
Chronic GVHD rates fell to 7%, far below the 20% reported in international studies.
Immune recovery accelerated, with T-cell counts reaching safe levels by postoperative day 50.
For children with chemotherapy-resistant acute lymphoblastic leukemia, Professor Sun’s team combined haplo-HSCT with sequential CAR-T therapy:
Donor stem cell infusion post-conditioning harnessed graft-versus-leukemia (GVL) effects to eliminate residual disease.
CD19 CAR-T cells administered three months post-transplant consolidated efficacy.
This strategy achieved a 58% 5-year disease-free survival rate, a 20% improvement over transplantation alone .
In hereditary immune disorders like XIAP-associated hemophagocytic lymphohistiocytosis (HLH), Professor Sun’s insights include:
Donor selection: Maternal donors yielded higher survival rates (82% vs. 65% for paternal donors), likely due to maternal microchimerism-induced immune tolerance.
Cord blood augmentation: Co-infusion of autologous cord blood elevated 5-year survival rates from 40% to 75% in XIAP-deficient patients .
Professor Sun spearheaded critical national guidelines:
The Clinical Guidelines for Pediatric Cord Blood Transplantation specify a minimum cord blood cell dose of 3.0×10⁷/kg for haplo-HSCT, with cyclosporine + short-course methotrexate as first-line GVHD prophylaxis.
Dynamic chimerism monitoring: Weekly assessment of donor-recipient cell ratios post-transplant reduced rejection risks by 60% through timely immunosuppressant adjustments.
As China’s pioneer in autologous cord blood transplantation, Professor Sun achieved historic milestones:
First autologous cord blood transplant for severe aplastic anemia (2009): The patient exhibited normal hematopoietic function at 10-year follow-up.
Neuroblastoma paradigm shift (2016): Autologous cord blood combined with chemotherapy improved 3-year survival in advanced cases from 20% to 65%.
Family cord blood banking validation: Sibling haplo-HSCT using cord blood reduced GVHD incidence to 18% and costs by 40%.
Professor Sun established a three-tiered treatment network across China:
High-risk screening: Neonatal genetic testing identifies potential transplant candidates.
Rapid referral: A 72-hour green channel connects regional hospitals to transplant centers.
Postoperative telemedicine: Remote monitoring of 12,000+ patients reduced complication detection time to 48 hours.
Professor Sun’s team is advancing three frontiers:
1. AI-driven donor selection: An HLA epitope-matching algorithm to reduce GVHD risk by 30%.
2. Gene-edited transplants: CRISPR-mediated knockout of GVHD-associated genes (e.g., CD40L) in donor cells while preserving anti-tumor function.
3. Metabolomics-guided care: Plasma metabolite analysis (e.g., kynurenine/tryptophan ratio) predicts infection risks and personalizes immunosuppression.
Over two decades, Professor Sun Yuan has transformed haplo-HSCT in China: her protocols elevated 5-year survival rates from <30% to 68% while cutting costs to one-third of Western expenses. Her 11 autologous cord blood cases achieved 100% long-term survival, cementing cord blood’s role as a "life-saving seed." As she declared at the International Cord Blood Congress: "Our goal is not just survival—it is enabling children to run, learn, and live fully." This ethos embodies the fusion of scientific rigor and humanitarian care.
(Note: All data cited are derived from publicly available medical literature and institutional reports. Treatment plans must be tailored to individual clinical evaluations.)
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