Bengisu MENENTOĞLU, Selen Duygu ARIK, Salih GÜLER, Deniz TUĞCU, Zeynep KARAKAS, Nuray Aktay AYAZ
The Turkish Journal of Pediatrics - 2026;68(3):539-546
Background. Autoimmune manifestations are increasingly recognized as late complications following hematopoietic stem cell transplantation (HSCT), particularly in association with chronic graft-versus-host disease (cGvHD). However, the occurrence of systemic lupus erythematosus (SLE)-like features remains extremely rare, especially in pediatric patients. Understanding the mechanisms underlying such manifestations, including the role of mixed chimerism, is important for early recognition and management. Case Presentation. We report the case of a girl with thalassemia major who underwent HSCT from a fully matched unrelated donor at the age of six years. Her early post-transplant course was complicated by gastrointestinal cGvHD, followed by autoimmune hemolytic anemia and arthritis, which responded to corticosteroids and methotrexate. Four years post-HSCT, she developed a lupus-like syndrome characterized by malar rash, serositis, cytopenias, arthritis, high-titer antinuclear antibodies (ANA), elevated anti-double-stranded DNA (anti-dsDNA) antibodies, and low complement levels, fulfilling the American College of Rheumatology classification criteria for SLE. At the time of symptom onset, mixed chimerism was documented, with a notable proportion of recipient-derived lymphocytes. Treatment with mycophenolate mofetil and hydroxychloroquine led to rapid clinical and laboratory improvement. Conclusion. This case illustrates the evolving nature of post-transplant immune dysregulation and suggests that declining donor chimerism may contribute to the reactivation of autoreactive lymphocytes, leading to atypical autoimmune manifestations. In pediatric patients presenting with unusual post-transplant symptoms, careful clinical assessment and immune monitoring may aid in timely diagnosis. Individualized immunosuppressive therapy can facilitate symptom control and support favorable long-term outcomes.
