The role of HLA mismatch, splenectomy and recipient Epstein-Barr virus seronegativity as risk factors in post-transplant lymphoproliferative disorder following allogeneic hematopoietic stem cell transplantation

Department of Laboratory Medicine, Division of Clinical Immunology F79, Karolinska Institutet, Karolinska University Hospital Huddinge, SE-141 86 Stockholm, Sweden. mikael.sundin@ki.se BACKGROUND AND OBJECTIVES: Post-transplant lymphoproliferative disorder (PTLD) following allogeneic hematopioetic stem cell transplantation (HSCT) is a fulminant disease with high mortality. The objective of this study was to determine risk factors in PTLD following HSCT in order to identify high-risk patients for surveillance, prophylaxis and treatment. DESIGN AND METHODS: Five hundred and fifty-three HSCT patients transplanted at Karolinska University Hospital in Huddinge between 1996 and 2004 were investigated retrospectively and 14 cases of PTLD were identified. Diseased patients were evaluated concerning transplantation procedure, PTLD diagnosis, treatment and outcome. Factors significant in univariate analysis were included in logistic regression multivariate analysis. RESULTS: The incidence of PTLD was 2.5% and the median onset of PTLD was 78 days post-transplantation. Only two PTLD patients survived. The most common therapy was anti-B-lymphocyte antibodies. Statistical analysis showed HLA mismatch (p