ANALYSIS OF EPSTEIN-BARR VIRUS-ASSOCIATED POSTTRANSPLANTATION LYMPHOPROLIFERATIVE DISORDER AFTER LUNG TRANSPLANTATION

Background. Epstein-Barr virus (EBV)-associated posttransplantation ly mphoproliferative disorder (PTLD) is a serious complication of lung tr ansplantation, Besides immunosuppression the risk factors for PTLD dev elopment are largely unknown. Methods. The incidence of PTLD was ascer tained in a lung transplant population consisting of 45 patients. Nine patients (20%) experienced PTLD. The clinical, histologic, and human leukocyte antigen (HLA) data were collected on all patients. The incid ence of EBV infection in lymphoid tissue taken at the time of engraftm ent was studied by using EBV in situ hybridization. Results. All patie nts with PTLD had polymorphous lymphoproliferations, seven of which we re polymorphous B-cell hyperplasias and two of which were polymorphous B-cell lymphomas. EBV was identified in all lesions. All patients wit h polymorphous B-cell hyperplasias had clinically unsuspected disease, five of which were identified at autopsy. The two polymorphous B-cell lymphoma lesions were monoclonal and regressed with immunosuppression reduction. EBV in situ hybridization on donor or recipient lymph node s obtained at engraftment from the 45 transplant recipients showed no difference in the number of EBV positive cells in patients with and wi thout PTLD. Cyclosporine and azathioprine dosages and cyclosporine lev els were similar between patients with and without PTLD. PTLD was seen in patients with high cumulative doses of antilymphocyte globulin. An alysis of HLA status showed a predominance of HLA A2 and DR7 in the do nors of the patients with PTLD, whereas donor HLA B7 was more common i n patients without PTLD. Conclusions. Detailed studies are necessary t o further elucidate the risk factors for PTLD development in the lung transplant population.