Haploidentical Hematopoietic Stem Cell Transplantation for Paediatric Patients with X-linked Lymphoproliferative Syndrome.

The aim of this study was to investigate the prognostic factors of haploid hematopoietic stem cell transplantation in the treatment of X-linked lymphoproliferative syndrome. Seven children with X-linked lymphoproliferative syndrome diagnosed by XIAP gene analysis were enrolled. The conditioning regimens were tolerated in all seven patients, and the median time of neutrophil engraftment was 10 days (8-13 days), and that of platelet engraftment was 21 days (14-24 days). STR-PCR analysis on the peripheral blood cells showed complete donor origins. Four cases developed Grade I acute graft versus host disease (aGVHD), one developed Grade III aGVHD (intestinal tract), and two cases had limited chronic GVHD. Four cases had cytomegalovirus (CMV) reactivation, and two cases had Epstein-Barr virus (EBV) reactivation. One case was diagnosed as pneumocystosis, and thrombotic microangiopathy (TMA) occurred in three cases. During the follow-up period (median time of 42 months), one patient died of TMA and six patients survived. Statistical analysis showed that the status of disease remission and the positive result of virus in blood before transplantation were independent prognostic factors. Haplo-HSCT might be a curative option for children with refractory X-linked lymphoproliferative syndrome. Low-intensity conditioning regimens may reduce transplant-related mortality and improve overall survival.