Fludarabine‐based reduced‐intensity conditioning regimen for hematopoietic stem cell transplantation in primary hemophagocytic lymphohistiocytosis

Objective Primary hemophagocytic lymphohistiocytosis ( HLH ) is a life‐threatening condition that clinically characterized by fever, hepatosplenomegaly, and cytopenia. Hematopoietic stem cell transplantation ( HSCT ) is the only curative treatment option for patients diagnosed with primary HLH . Methods In this prospective study, we analyzed the outcome of 10 pediatric patients with primary HLH who had received HSCT , using reduced‐intensity conditioning ( RIC ) regimen from 2007 to 2012. The median age at transplantation was 22.6 months (range: 6–60). All of the patients received the same RIC regimen based on the use of fludarabine in combination with melphalan and horse antithymocyte globulin ( ATG ). Cyclosporine and methylprednisolone were used as graft‐vs.‐host disease ( G v HD ) prophylaxis. Results Hematopoietic engraftment occurred in all patients. At the present time, 8 patients with a median follow‐up of 39 months are still alive and all of them are disease free. Acute and chronic Gv HD developed in 6 and 2 patients, retrospectively. Two patients died of sepsis and chronic Gv HD during the study. Conclusion Because of pretransplant infections caused by underlying immunodeficiency in patients with primary HLH , the use of less toxic regimen with RIC seems to be highly effective in this regard. Recipients of RIC transplant, with either full or mixed chimerism, had a long‐term survival rate with no manifestation of primary HLH symptoms.