Microphotopheresis for the Treatment of Graft-Versus-Host Disease in Pediatric Patients.

Introduction: Extracorporeal photopheresis (ECP) is an attractive treatment for graft-versus-host disease (GVHD) following allogeneic hematopoietic stem cell transplantation due to the lack of systemic immunosuppression. Modifications of ECP without leukapheresis are being actively studied in clinical practice around the world. A low-volume method of extracorporeal photochemotherapy-micro-ECP-has been developed at the Rogachev Federal Scientific and Clinical Centre of Pediatric Hematology, Oncology and Immunology. We present the results of using micro-ECP to treat acute and chronic GVHD.

Patients and methods: We analyzed the treatment outcomes of 9 cases of acute GVHD and 15 cases of chronic GVHD using micro-ECP for the period from April 2021 to March 2024. The cellular product was obtained by collecting 20-30 mL of whole blood followed by photochemical treatment. The processed autologous cell product was administered to the patient.

Results: The overall response rate in patients diagnosed with acute GVHD was 44%, while the organ-specific response rate was 56% for skin and 40% for gastrointestinal. The steroid-sparing effect for acute GVHD was 89%. In the treatment of chronic GVHD, the overall response rate was 73.3%. The organ-specific response rate was 71% for skin, 67% for gastrointestinal, 67% for lung, 100% for eyes, and 100% for liver chronic GVHD. The steroid-sparing effect for chronic GVHD was 63%.

Conclusion: In the treatment of acute and chronic GVHD, micro-ECP has demonstrated promising efficacy. Although the method remains experimental, it is already apparent that micro-ECP constitutes an attractive alternative to standard ECP when leukapheresis is not a viable option.