[Clinical analysis of sirolimus as an alternative GVHD prophylaxis for patients with kidney injury undergoing allo-HSCT]

Objective: To explore the feasibility of sirolimus as an alternative graft versus host disease (GVHD) prophylaxis in patients with kidney injury after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods: Retrospective case series study. Medical records of 11 patients in Peking University People's Hospital from 1 August 2008 to 31 October 2022, who received sirolimus instead of cyclosporine to prevent GVHD, due to renal insufficiency after allo-HSCT, were analyzed retrospectively. Incidence of GVHD, infection, and transplant-associated thrombotic microangiopathy (TA-TMA), as well as renal function, were evaluated. Results: Among the 11 patients who received sirolimus, 6 were treated with haploidentical donor HSCT, and 5 were treated using matched sibling donor HSCT. The median (range) time of sirolimus administration was 30 (7-167) days after allo-HSCT, and the median (range) sirolimus course duration was 52 (9-120) days. During sirolimus treatment, 1 case did not undergo combined treatment with other prophylactic drugs, 3 cases received combined mycophenolate mofetil (MMF), and 1 case underwent combined CD25 monoclonal antibody treatment, while 6 cases had combined therapy with both MMF and CD25 monoclonal antibody. Of the 11 patients, 2 developed Grade Ⅲ acute GVHD, 1 developed severe pneumonia and died, and 1 developed TA-TMA, while nine patients had normal or improved renal function. Median (range) follow-up time was 130 (54-819) days. Non-relapse mortality was observed in 1 patient. Relapse mortality was also observed in 1 patient. Conclusion: Sirolimus-based alternative GVHD prophylaxis is a potentially viable option for patients undergoing allo-HSCT who cannot tolerate cyclosporine, but its efficacy and safety require further optimization and verification in prospective studies.