Successful First-Line Haploidentical Hematopoietic Stem Cell Transplantation in an Elderly Patient With Severe Aplastic Anemia and Complex Comorbidities: A Case Report.

Standard management guidelines generally recommend immunosuppressive therapy (IST) as first-line treatment for older patients with severe aplastic anemia (SAA), whereas the role of upfront haploidentical hematopoietic stem cell transplantation (haplo-HSCT) in this population remains uncertain, particularly in patients with complex comorbidities. We report a 62-year-old woman with SAA, a history of surgically resected stage IA lung adenocarcinoma, and previous left lower extremity deep vein thrombosis treated with venous stent implantation and long-term aspirin therapy. Because no matched sibling or unrelated donor was available, and following individualized counseling regarding IST and transplantation, the patient underwent upfront haplo-HSCT combined with umbilical cord-derived mesenchymal stem cells after a conditioning regimen including fludarabine, busulfan, cyclophosphamide, antithymocyte globulin, and thiotepa. Neutrophil engraftment occurred on post-transplant day +12, and platelet independence was achieved on day +13. Donor chimerism reached 99.6% by day +14 and remained within the complete-chimerism range through the latest available assessment in January 2026. In late December 2025 and January 2026, the patient developed cytomegalovirus infection accompanied by transient trilineage cytopenia; after anti-CMV treatment with maribavir, the infection was controlled and peripheral blood counts subsequently recovered. At the most recent clinical follow-up on August 6, 2026, approximately 17 months after transplantation, no chronic graft-versus-host disease had developed, the previous lung adenocarcinoma remained in remission, and the thrombotic condition remained clinically stable. This case suggests that upfront haplo-HSCT combined with UC-MSCs may represent a feasible individualized treatment option for carefully selected older patients with SAA who lack matched donors, although broader conclusions require larger studies and longer follow-up.