Cure of X-linked lymphoproliferative disease (XLP) with allogeneic hematopoietic stem cell transplantation (HSCT): Report from the XLP registry

Seven male patients in the David T Purtilo International X-Linked Lymphoproliferative Disease (XLP) Registry have undergone allogeneic hematopoietic stem cell transplantation (HSCT), All patients received HSCT from HLA-identical donors: sibling BM, five; unrelated BM, one; and sibling umbilical cord blood, one, Ages at time of HSCT ranged from 5 to 30 years, Pre-HSCT clinical course varied, but four boys had a significant history of chronic and/or serious infections, Conditioning regimens varied: TBI containing regimens, four, chemotherapy only, three, All patients engrafted, Six developed grade I-II acute GVHD but no chronic GVHD, Four are alive and well with normal immune function greater than 3 years following HSCT, Three died within 100 days: disseminated adenovirus, one; polymicrobial. sepsis, one; and multiple organ system failure and bleeding diathesis, one, No EBV-associated post-transplant complications were observed, even though all donors except the umbilical cord blood were EBV-seropositive. Unsuccessful HSCT was associated with age at HSCT (>15 years), TBI-containing regimen and significant history for pre-HSCT infections, These results provide evidence that HSCT performed during childhood with HLA-identical sibling donors, regardless of EBV serostatus, offers the only curative therapy for XLP.