Hematopoietic stem cell transplantation in Griscelli syndrome type 2: a single-center report on 10 patients.

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative treatment for Griscelli syndrome type 2, an inherited immune disorder causing fatal hemophagocytic lymphohistiocytosis (HLH). Optimal therapeutic modalities are not yet well known. We retrospectively analyzed the outcome for 10 patients who underwent HSCT in a single center between 1996 and 2008. Seven patients (70%) were cured of the primary immune defect (mean follow-up, 5.2 years; range, 0.8-12.0 years), 4 of them without neurologic sequelae. In the 3 deceased patients, death occurred within 110 days of HSCT and was probably due to adverse reaction to HSCT in 2 patients and to HLH relapse in one patient. One patient received 2 transplants because of graft failure. Clinical events included veno-occlusive disease (n = 5), acute (n = 7) or chronic (n = 1) graft-versus-host disease II-III, and Epstein-Barr virus-induced lymphoproliferative disease (n = 2). Of the 7 patients with neurologic involvement before HSCT, 4 survived and 2 presented sequelae. Furthermore, 1 patient lacking neurologic involvement before HSCT developed long-term sequelae. These results demonstrate the efficacy of HSCT in curing the immune disorder but also show that neurologic HLH before HSCT is a major factor, given the neurologic sequelae after otherwise successful HSCT. Additional studies are required to improve treatment.