[A clinical study of lymphoproliferative disorders following allogeneic hematopoietic stem cell transplantation]

To study the risk factors and clinical characteristics of post transplantation lymphoproliferative disorders (PTLD) after hematopoietic stem cell transplantation (HSCT).

Between August 2002 and October 2006, 585 patients underwent allogeneic HSCT (327 related matched donor, 208 mismatched family donor, 44 unrelated volunteer donor, 6 unrelated cord blood) at the Institute of Hematology in Peking University. PTLD was diagnosed on the basis of finding diffuse hyperplasia characterized by invasion of other organ structure with disorganization of the nodal structure in lymph nodes. If pathological investigation was not possible, PTLD was diagnosed by the presence of fever, lymph node enlargement and/or EBV viral load, which could not be explained by other causes. The incidence of PTLD was compared among different groups with chi2 test. Statistics was completed with PC by SPSS 13.0 Microsoft.

The incidence of PTLD was 0.3% (1/327) in HLA matched related HSCT patients, 3.4% (7/208) in haploidentical HSCT patients and 2.3% in unrelated HSCT patients. The incidence of PTLD was higher in mismatched or unrelated HSCT group than that in conventional HSCT patients (7/208, 1/44,vs 0/323, P = 0.036). The incidence of PTLD is higher in patients with conditioning regimen including antithymocyte globulin (ATG) than that in patients without (9/262 vs 0/323, P = 0.005) (PTLD occurred in one patient who received reduced-intensity conditioning including ATG, but no PTLD occurred in conventional HSCT). 9 patients developed PTLD. 4 patients were diagnosed with pathology, the remaining 5 with clinical data. Onset of PTLD occurred at a median day of 43 (range 32450). 2 of them it occurred 6 months after HSCT and presented, with local mass and enlarged mediastinum. The morphology of biopsy appeared as small B-lymphocytic lymphoma; there was no response to chemotherapy and the patients died. In the remaining 7 patients it occurred an early stage after HSCT (day 32-78). 5 of them had a rapidly progressive course characterized by fever and lymphadenopathy, lung or liver or central nervous system involvement and died within weeks. One patient recovered by reducing immunosuppressive drug therapy combined with MP and one patient recovered by reducing immunosuppressive/antivirus therapy and donor lymphocyte infusion.

Post HSCT PTLD occurs characteristically as disseminated disease with a rapidly progressive and often fulminant course and had a high mortality. It is essential to keep a vigilant eye on it especially in high risk patients.